So, welcome to the fifth lecture on cryogenic engineering under this NPTEL program. Just taking a view of what we have done in the earlier lectures, we had introduction to cryogenics as topic 1 and in the topic 2 what we had was the information regarding all the cryogens, the properties, temperature and entropy diagrams and we talked about various cryogens which are aragon, air, nitrogen, oxygen and then we went little bit in depth regarding hydrogen and we talked about ortho and para-hydrogen and its conversion and also we talked about helium. We talked about helium isotopes which is helium 3 and helium 4, also we talk about normal helium 1 which is helium at 4.2 k helium liquid and we talked about helium as super fluid which is helium 2. In this lecture, we will talk about material properties at low temperature. Ultimately all these cryogens are kept in some cryo containers which are made up of some material, metal and sometimes non-metal and therefore, it is very important to understand how these materials behave at low temperature wherein we will study the structure of matter. Also we will study stress strain relationship for this material and in this particular lecture, we will talk about mechanical properties of metals and plastics at low temperature. Where we studying all these things? We want to study this because the properties of material change when cooled to cryogenic temperatures and sometimes these changes are drastic. For example, we have seen a video earlier and we will see the experiment again. We can see from this experiment that rubber when it got quenched into liquid nitrogen, it turns hard and it broke like a brittle material which we just saw. We can also see sometimes in a another experiment which we have not done yet. We can see that the wires made of material like niobium titanium, it exhibits 0 resistance when subjected to liquid helium temperature that means, this wire becomes superconducting wire. It shows r is equal to 0, i square r is equal to 0 that is no joule heating. These are very important changes that happen in these materials and these examples therefore, show that the material becomes hard and brittle at low temperature. At the same time, the electrical resistance decreases as temperature decreases for certain materials. These two examples show that material property do change drastically. In addition to these two properties which were just shown to you as an example, we got several other properties like strength, ductility of material, thermal and electrical conductivity, specific heat capacity, thermal expansion. All these properties change at low temperature and therefore, the knowledge of this material property changes at low temperature is very important for proper design of a material which is going to subjected to low temperature and this is what we plan to do in this particular lecture. Before we study the property changes at low temperature, it is important to understand the structure of matter. Solids are composed of atoms which are bound together and arranged in regular arrays. We know this. Solids are broadly classified into two types metals and nonmetals and in cryogenics we use both metals as well as nonmetals. The nonmetals are further classified into plastics and classes. Any cryo container for example, or any cryogenic equipment, we can have metals, we can have plastics and we can have glasses also. Well, glasses make a very special case. Most of the places metals are used and plastics are also used sometimes to support this metal and therefore, I am keeping this lecture limited to discussion regarding metals and plastics and we will study the property variations of these materials at low temperature. So, from cryogenic perspective I will discuss metals and plastics only. As you know now we will come to metals. We know that metals have highly ordered structure. The atoms are arranged in symmetrical crystal lattices and the most common of these lattice structures are face centered cubic that is FCC material, body centered cubic that is BCC material and hexagonal close packed material that is HCP material. I think we have studied all these things in the material science, in the fundamentals of material science may be in the first year or second year of engineering. We will just revise those fundamentals and find out what exactly FCC, BCC or HCP mean. The face centered cubic structure has an one atom at each of the 8 corners and an atom at the center of each of the 6 faces. Here you can see an FCC structure where you have got 4 plus 4 8 atoms and atom at the center of each of the faces and there are 6 faces. So, 8 plus 6 makes 14 atoms for FCC structure. The BCC structure has an atom at each of the 8 corners and one atom at the center of the cube that means there are 8 corners plus one at the center which makes it 9 atoms in total for BCC material. As far as HCP material is concerned which is hexagonal close packed we have got hexagonal side now. We have got 2 hexagons one at the top one at the bottom and there is an atom at each of this corner and this makes 12 corners. So, we got atoms at 12 corners and an atom at the center of each of the 2 vertical hexagonal ends which are these 2 and then 3 atoms at the center of here. So, here we can see that we have got 3 atoms at the center of a prism which is formed by this triangular face. So, you got a 6 atoms on the top 6 atom at the bottom plus 2 at the faces over here and then 3 atoms at the center of the middle plane of this prism which joins the top hexagonal face and the bottom hexagonal face. All these make around 17 atom for HCP lattice structure. The above lattice structure decides the number of slip planes in the crystal and this slip plane is a very important concept. This slip plane will decide lot of properties for this material. The slip planes are the directions within the crystal in which the planes can slip or move easily one over the another. So, slip plane basically will decide in what direction the thing should move. The dislocation should move and this is what we are going to talk about. The real crystals do not have perfect lattice arrangement. The real crystal will have some kind of defect and dislocations and there exists always some dislocations like edge dislocations, screw dislocations, some imperfections like we got an additional atom called interstitial atom. We can have some atom absent which is called as vacancy etcetera and all the movement of this dislocation decides the properties of this material. The number of slip planes now the number of slip planes are governed by the lattice structure we talked about. The number of slip plane governs the movement of these dislocations and this governs the ductility and the impact strength of any material. Now this is all related the lattice structure. The atom structure in a lattice will determine how many slip planes are there and the number of slip planes will allow the dislocation to move in the structure. So, ultimately the lattice structure will decide whether a particular material allows the motion of dislocations or not. The FCC structure what we found was FCC structure has maximum number of slip planes while the BCC structure has the least. The SCP structure falls in between the above two lattices. What does this mean? It means that the FCC solids are more ductile as compared to the BCC and SCP. So, FCC we can call as a most ductile material followed by SCP followed by BCC based on the available slip planes in which direction the dislocations can move. With this background now we will try to study various properties of material which are mechanical properties, thermal properties, electrical properties, magnetic properties. So, there are several of these properties which we can study because this course is meant for mechanical engineers. I am going to talk about mechanical properties and thermal properties from mechanical engineering point of view. While there are several electrical properties, several magnetic properties which I think we will not bother about so much while I will cover these properties in terms of superconductivity. So, we will devote some more time to understand what are these mechanical properties, what are these thermal properties because that is what will govern the thermal design of any material, thermal design of any cryostat. At the same time thermal and mechanical design of any cryostat for example, or any cryogenic equipment. While I will not cover these properties in details the electrical magnetic properties, but I will instead talk about superconductivity in this case. The mechanical properties can be well understood once we understand the stress strain curve for any material where the stress is kept on the y axis while the strain is kept on the x axis. Now, when a ductile specimen is subjected to a tensile test, the stress strain relationship is shown as follows. So, you can see that in this case the stress is varying in relation with the strain and the variation is linear variation or we can see that the stress is directly proportional to strain in this case. Now, you could see that when the material is subjected to tensile loading the stress increase in a straight line up to the point called proportional limit or PL which is what I have written here. What is this PL? This PL is the limit in which the elongation of the specimen is directly proportional to the stress applied. So, we can say that during this period stress is directly proportional to strain. Most of you may have done all these things into details I am just trying to give you some fundamentals. So, that we can understand the variation of properties which we are going to discuss in the next slides. The slope of this line which is constant during this entire line is called as you know Young's modulus. So, stress upon strain is constant during this period. Now, if this elongating force is removed in this case the material will come back to its original shape and size and that is why we call that this particular behavior is nothing but elastic behavior of the material. Even if we remove the elongating force the material will come back to its original shape and size. However, if we apply the force beyond this particular strain or beyond this particular stress you can see lot of different things happen. We can see first at this point at point C that there is a tremendous increase in strain immediately by the application of very small stress and if we apply more stress or if we apply more force we can follow the behavior in this pattern and this is what a stress strain curve of any ductile material would be. What you can see from this is we can see the elastic region up to P L. We can see that the material yields during this space this is called yielding and the material shows plastic behavior at this point. Now, during this period if the stress or the elongating force is removed the material will not come to the original shape and size. You will find some deformation in the material.  The point C is called as the yield point and the stress is called as yield stress. The value of the stress at this particular point is called as yield stress while the point F we called as ultimate tensile stress. If we increase the stress beyond this value we find this kind of behavior and at this particular point G the there is a breakage point. In principle the force at point G will be actually more than that of point F but as you go beyond this point the area of cross section goes on decreasing and therefore the force upon area or the stress starts coming down. However, the engineering diagram will show that the G is more than F. Now, this is what we call as a typical stress strain curve for any material and what is important to note here are the two properties one is a yield stress and other one is a ultimate tensile stress. We will study the behavior of these two properties at low temperature. This is typical diagram for a ductile material and we can see now the brittle material also has a stress strain curve and it will also have its proportionate limit. So, if I want to compute if I want to draw a stress strain curve for a brittle material let us say this is a brittle material it will have its own proportion limit now during which time this behavior is elastic behavior. If I increase the stress beyond this value this is the behavior and G is a breakage point and the material will break. So, a stress strain curve of brittle material is as shown over here and stress when exceeds the p l value it will break at this point G. So, in summary we have got two stress strain curve one is showing the ductile material and one is showing the brittle material. We will study these two properties more that is a yield strength and ultimate tensile strength what happens to this property at lower temperature. The mechanical properties which we want to study in this particular course are the yield and ultimate strength of which we just talked about. We talk about the fatigue strength of a material. We talk about the impact strength of a material. We talk about the hardness and ductility of the material and we talk about elastic model of the material. So, all these five properties in fact six property they are basically the mechanical properties. In the next lecture maybe we talk about the thermal properties and the electrical property and the magnetic properties. Now, these are the five mechanical properties which we will discuss in this particular lecture for different materials. First we will come to yield and ultimate strength of the material. Just to redefine those property which we just saw what is the yield stress? It is a stress at which the strain of a material shows a rapid increase with an increase in stress value when subjected to simple tensile test. We found that suddenly the strain increased by giving a small stress at a particular location and that is called as yield point and the stress is called yield stress. Ultimate stress it is the maximum nominal stress attained by a test specimen during a simple tensile test. So, ultimate stress is also a very important property, a very characteristic property of any material and also yield stress also is a characteristic of a characteristic of a any material. Now, we will study what happens to this properties at low temperature. This particular figure gives the variation of yield strength at low temperature. You can see the y axis is giving the yield strength while the x axis gives the temperature variation in the reverse direction. That means, what I am saying here is a 300 Kelvin is a room temperature and then I am coming down towards 0 Kelvin or towards cryogenic temperature. What you can see? I have shown different curves here they are meant for different materials. For example, this curve is meant for 304 stainless steel SS 304. The second curve is 9 percent nickel steel. The third curve is carbon steel CT 1020 and then we have got an aluminum alloy. All these materials are shown in this legend in the order of decreasing strength value. So, you can see that in all these cases the strength as you come down lower in temperature the strength has increased most of the cases in all the cases almost while the stainless steel shows maximum strength as compared to other materials. So, we can conclude from heat the yield strength of various commonly used material increases with decreasing temperature. This is what we see from this particular curve. These materials are normally alloys of iron and aluminum etcetera. When we saw the curve it was for yield strength and now see the similar kind of a curve for ultimate strength. So, again in this particular map what you see is a ultimate strength plotted on a y axis and again temperature on the x axis and again you can see that as the temperature is lowered from room temperatures to 0 Kelvin the ultimate strength of the material have increased the way it was shown for yield strength. So, we can see that in both the cases the yield strength and the ultimate strength increase as the temperature is lowered. At the same time what we again can see from this that the stainless steel shows maximum ultimate strength in these four materials followed by 9 percent nickel followed by carbon steel followed by aluminum as shown in the order in given in this legend. So, again we can conclude similar to the yield strength the ultimate strength of the material also increases with decreasing temperature. This is a very important thing at the same time what it shows is the room temperature is actually the unsafe thing. If the material is safe at room temperature that means it is definitely safe in the cryogenic temperature. So, for any design your reverse design will be at room temperature because your ultimate strength or the yield strength is lowest at room temperature. So, the safest case if you want to see the failure mode it should happen at room temperature as far as the failure based on ultimate strength and yield strength is considered. We could also conclude from the two figures that stainless steel has the high strength and is mostly preferred material at cryogenic conditions. So, many applications what you see is having stainless steel as a material. I have just got a small specimen over here you can see a very thin walled tube which has got around 0.15 millimeter thickness and this is welded to a flange what is constituting one tube and if I close from this side if I got some welded structure at this point we have used this tube for pulse tube cooling and we have seen that this particular tube of thickness 0.15 millimeter can stand very high pressures and as high as 25 bar pressure of gas. It shows that such a small thickness of a material also can stand very high pressure and in most of the application therefore what we have used is stainless steel this is SS 304 what we use it stands very high pressure as high as 30 to 35 bar also one has to really calculate the hoop stress in this case and then calculate the dimensions of this, but a thickness of 0.15 to 0.2 millimeter or 0.3 millimeter can stand very high pressure. I just bought this specimen to show you that such a small thin walled tube can stand very high pressure SS 304 is the material which is being used for this particular purpose. Going back from having studied this ultimate strength behavior and yield strength behavior at low temperature let us start to understand why it happens like this ultimate and yield strength of the material largely depend on the movement of dislocations. We have earlier studied the movement of dislocations and its relation with the slip planes and its relation with the lattice structure. The movement of dislocation also depends on the internal energy or the lattice vibrations and at lower temperatures the internal energy of the atoms is very much low. As you know the internal energy is basically a function of temperature and if the temperature is low the internal energy of the atoms also is low. As a result the atoms of the material vibrate less vigorously with less thermal agitation. So at lower and lower temperature the vibrations the lattice vibration is very very minimum and therefore the material vibrate less vigorously with less thermal agitation. When these agitations are low when this agitation are low at low temperature the movement of dislocation is hampered. You can imagine that when the dislocation movement is ultimately it may be a long dislocation movement a very large dislocation movement at room temperature. However at lower and low temperature the motion has come down and this vibration if they are reduced it does not allow the dislocation to move. It will hamper the movement of the dislocation. When the movement of the dislocation is hampered what will you have to do? This dislocation movement now will require a very large stress to tear the dislocation from their equilibrium position. If we want to move this dislocation now when the thermal vibrations are very large or the lattice vibrations are very large we will require very large stress to tear these dislocations from their equilibrium position which means that the material will exhibit high yield and ultimate strength at low temperature. So the behavior of the material at low temperature in terms of increased yield strength and increased ultimate tensile strength at low temperature could be understood by this particular analysis that the lattice vibrations are very very low at low temperatures and this hampers the dislocation movement at low temperature. So till now we studied the yield strength and ultimate tensile strength variations at low temperature. In cryogenics we also have to study fatigue strength. What is fatigue strength? The material exhibit fatigue failure when they are subjected to fluctuating loads. Now this fluctuating loads could be for example I have got a small little sample over here and you can see that this is small bearing through which the piston goes and as you know the piston is going to have an oscillating motion or a fluctuating motion up and down and this is called as flexure bearing and this particular bearing goes up and down and therefore this will be subjected to fatigue failure. If at all it fails it will fail by fatigue. So I have to ensure that while designing this particular flexure bearing the stress achieved by this while in motion are less than a particular value or the particular fatigue strength of this particular material. This is very important that the bearing which is subjected to fluctuating load can stand the stresses generated during this motion. So these failures can happen even if the stress applied is much lower than the ultimate stress value. This is very important that the fatigue strength is actually much less than the ultimate strength of a material. So one has to really compute one has to really understand that the failure of this particular item will because of fatigue. The failure for example of this bearing is going to be because of fatigue and not because of tension or compression. The fatigue strength of a material is the stress at which the specimen fails after a certain number of cycles. This is what a definition of fatigue strength is that it is a stress at which the specimen fails after a certain number of cycle. So fatigue strength is normally defined in terms of cycles 10 to the power 6 cycle 10 to the power 8 cycles etc. Now let us see how the strength variation happens at low temperature. So here again you can see a curve on the y axis what we have plotted is fatigue strength at 10 to the power 6 cycle e to the power 6 cycles over here while on the x axis what we have plotted is temperature and this is my room temperature at 300 Kelvin and this is where you move towards the cryogenic temperature range as you have seen earlier in the yield strength and ultimate strength variation. Then you can see that as the temperature gets lower down the fatigue strength increases. So on all the three cases these are the materials which can stand fatigue strength. Again we have got a stainless steel, beryllium copper over here and carbon steel. In all these three cases what we see is at lower temperature the fatigue strength shows an increase over here. So again the worst case for these materials is at room temperature. So we can conclude again the fatigue strength increases as the temperature decreases. So as the temperature goes down towards cryogenic region the fatigue strength increases. The fatigue strength of a stainless steel is higher as shown over here. So again we can conclude that stainless steel is a preferred material if it is going to be subjected to fatigue loading. Now any fatigue failure begins with a micro crack. Again we will try to understand why does it happen the way it is. We have seen that the fatigue strength increases at lower temperature and any fatigue failure normally begins with a micro crack initiation. And at lower temperature after the initiation of a crack we require a large stress to stretch this crack. Why do we require large strength because the ultimate strength of the material has increased. So at lower temperature ultimate strength increases and therefore the crack stretching or the crack propagation. The crack initiation is okay but the crack propagation or crack stretching the stress required for this is going to be very large because of the increased ultimate strength of a material. And that is why like the ultimate strength the fatigue strength also increases at lower temperature or as the temperature decreases. Now in order to avoid fatigue failure when a specimen is subjected to fluctuating load the working stress is maintained below a certain value called endurance limit. So if I want to worry about a certain failure which I know that it is going to happen due to fatigue what I have to worry about is not the fatigue strength but I should worry about the endurance limit. If I keep the value of the stress generated below the endurance limit that means in principle this material should never fail. And therefore the endurance limit of a material is very important. The property we should know the endurance limit of particular material which is going to be subjected to fatigue loading and I should ensure that the stresses generated are less than this endurance limit. And flexure bearing which I showed to you is made out of beryllium copper alloy. So here you can see a beryllium copper alloy and this is what we call as flexure and this is what is used to manufacture the flexure bearing. The working stress is kept below the endurance limit to avoid fatigue failure. So I should know the endurance limit of the beryllium copper alloy and I should keep the stresses generated below the endurance limit of this particular material which will ensure that this particular material will never fail by fatigue. Now let us come and discuss regarding the impact strength and ductility of the material. These are very important characteristics. We have got various tests which we have studied in metallurgy or in material science that Charpi and Isoate tests are conducted in order to measure the resistance of a material to impact loading. So a certain material we know that it is going to be subjected to impact loading that is sudden loading we conduct these two tests Charpi and Isoate tests from where we understand how much that material is resistant to impact loading. Measure of resistance is basically nothing but the amount of energy absorbed. The energy absorbed when the material is fractured suddenly which means impact loading by a force and this is a measure of the impact strength. How much energy it can absorb after the fracture? If the material is fractured how much energy it can absorb will basically determine the impact strength of a material. More the energy it can absorb it has got more impact strength. In both these Charpi and Isoate tests the difference in the height attained by a hammer basically in these cases what you have is a hammer which comes down from a predetermined height. It hits the material and it fractures the material and this hammer goes beyond the material. So depending on the height which this hammer attains after the fracture is basically determine the impact of a material. So in both these tests the difference in the height attained by the hammer pendulum after the impact that basically it loses potential energy. This determines the impact strength of a material and this is nothing but the amount of energy the material can absorb after the fracture. Now this is a very different curve as compared to what you saw earlier. Here we have got a Charpi impact strength on a y axis and what you see on the x axis is a temperature again. So again we see from room temperature and come down to cryogenic temperature. Now here when we know that a particular material is going to be subjected to impact load we have to check that that the impact strength of a particular material is high enough alright. So you can see different curves here and in general for example you see that this is coming down, this is coming down, this is coming down. Well for this particular material which is stainless steel is almost horizontal that means there is not much variation in the strength value with the temperature. So in general what you can say from this the impact strength of the material decreases with the decrease in temperature or at most it remains constant for a particular material which is SS 304. While for all the material the impact strength has come down. So as the temperature gets reduced the impact strength of a material does get reduced. Now there is a very funny curve in this and this a particular curve I would like to highlight your attention and this material show some very specific characteristic. Few of the materials exhibit ductile to brittle transition or dbt at lower temperature. So you can see from this particular curve that this material can be called as ductile over in this region alright or it has high impact strength in this region while at this temperature around 100 Kelvin it suddenly came down the impact strength came down and came down to very low level and it is we can say that it is no more impact strength has drastically come down that means maybe this material was ductile at in this region during this temperature range and suddenly it has become brittle in this temperature range. It has undergone a dbt or a ductile to brittle transition in this temperature region that is what we call as while this does not happen for stainless steel it is happening for carbon steel ok. So carbon steel basically undergoes ductile to brittle transition at low temperature and the temperature at which this transition happens this dbt happens is called ductile to brittle transition temperature dbt and this dbt for carbon steel around 80 to 100 Kelvin. So carbon steel undergoes dbt at the temperatures around 80 to 100 Kelvin. This causes sudden decrease in the impacts of the material as I just said that this is having high impact strength over here while the impact strength drastically came down at this point. Similarly for 9 percent nickel the impact strength was very high here impact strength suddenly comes down at lower temperature while what you can see from here is the impact strength of stainless steel remains unchanged at lower temperature. This dbt variation the way it looks it is called as sometimes S transformation or S curve. So this decrease is as shown in this S curve many literatures refer this as also S transformation or S curve existence for this particular material. So this S transformation happens at 80 to 100 Kelvin in this particular material. Hence these materials cannot be used for cryogenic application. So for all those material which have got S transformation which have got dbt which has got dbt they cannot be used in cryogenic application because at lower temperatures they do not have any impact strength. Again we can find from the curve that stainless steel is the most preferred material from the impact strength point of view alright this is a very important finding from this curve. The impact strength of a material is largely governed by its lattice structure. At low temperature the material with body centered cubic lattice break easily that means BCC which have got minimum slip planes it breaks easily because the dislocations cannot move in this case. This is due to the reasons mentioned earlier on the slip planes and moment of dislocations. As a result the materials with BCC lattice are not preferred for low temperature application. The material with FCC or hexagonal lattice have more slip planes and these slip planes assist in plastic deformation. As we know that dislocation can easily travel through FCC material through SCP material and hence increase the impact strength of material even at lower temperature. As a result the material with FCC and SCP lattice are preferred for cryogenic application while the BCC material that the carbon steel are not preferred for cryogenic application because they become completely brittle at low temperature or the impact strength is very very low at low temperature. Now, let us see the next property which is ductility which is in a way related to the impact strength what we studied just now. A material which elongates more than 5 percent of the original length before failure is called as ductile material. This is the clear definition of a ductile material which material can be called ductile. When a specimen is subjected to simple tensile test ductility is given as a measure of percentage elongation of the length of the specimen at the failure or the percentage reduction in cross sectional area of the specimen at the failure. So, basically percentage elongation or percentage reduction in cross sectional area will determine whether a particular material is ductile at a given temperature or not. We will call percentage elongation to study the ductility of a particular material. Again this curve shows similar curve as we saw earlier that is the impact strength and this gives percentage elongation before failure versus temperature on the x axis. As you can see as the temperature gets reduced the percentage elongation decreases. So, this is for stainless steel, this is for nickel, this is for carbon steel and this is for aluminum. In all the cases what you see is at the temperature gets lower the percentage elongation gets lower down. So, again you have got a S transformation for carbon steel meaning which that it is it cannot be used at low temperature while the stainless steel, nickel steel and aluminum can definitely be used although the ductility is lower at lower temperature as compared to the room temperature. In general therefore, we can say the ductility of the material decreases with decrease in temperature. The materials which undergo DBT are not preferred due to decrease in ductility that means material like carbon steel cannot be used at lower temperature because they are no more ductile at lower temperature. For stainless steel the percentage elongation is around 30 percent at this point you can see at 0 Kelvin what we have is our 30 percentage elongation at 0 Kelvin meaning that it is fairly ductile for cryogenic applications. In summary what we can see here is a different material the embrittlement at low temperature for different material and under ductile what you see is a FCC and HCP can be used while in brittle material also there is some HCP material and all the BCC material. So, under ductile material we can use most of the FCC material which is copper, nickel, copper, nickel alloys, aluminum and alloys and austenitic stainless steel. The HCP material which we can use as a ductile material is titanium. So, all these materials can definitely be used for cryogenic temperature provided it satisfied other requirement like ultimate strength and yield strength etcetera depending on the failure mode for those particular materials. While these are all material which are brittle which remain brittle at lower temperature and therefore, they cannot be used unless specifically required and specifically evaluated at lower temperature, but mostly these materials will not be used for cryogenic applications. The next property is hardness of material. The hardness is the measure of the depth of standard indentation made on the surface of the specimen by a standard indenter. Most of you have studied this that you got a standard indenter and you see the depth of this indentation. The common hardness tests include brinal test, wicker test and rock weld test. So, you got a brinal test number BHN and VHN etcetera to determine or to measure the hardness number of a particular material. Hardness is directly proportional to the ultimate stress of a material and therefore, we know that the ultimate stress of a material increases at lower temperature meaning which we can conclude that the same trend will be holding good for hardness also that means, the hardness increases as the temperature decreases alright. So, we can conclude from here that the hardness of a material increases at lower temperature. The next property is elastic moduli. The three commonly used elastic moduli are Young's modulus, Shear modulus and bulk modulus. Let us not go into the definition of all these models, but we have studied the Young's modulus for tensile stress as I shown in the earlier curves. With the decrease in temperature, the disturbing vibrations and thermal agitation of the molecules decrease. This is what we studied because they all depend on the temperature of a material. At lower temperature, the vibrations and thermal agitation of the material will be less. This will increase the interatomic forces and verify reducing the strain at low temperature. What we mean to say that at lower temperature the interatomic forces will be higher and therefore, strain induced will be low at lower temperature. So, if I want to understand that thing, if I plot a stress strain diagram for a material, a stress strain curve for a 300 K and at 100 Kelvin and if we see that, if I want to produce the same strain that means, I have got the same strain for these two temperatures, I will say that at lower temperatures, I get higher stress as compared to at higher temperatures. That means, the stress value for the same strain at 300 K is much less as compared to what it is for 100 Kelvin. So, if I want to produce same strain at low temperature, greater stress is required meaning which stress upon strain at 100 K is going to be more than stress upon strain at 300 K. In other words, to produce the same stress at low temperature, less strain is required, I can go in a reverse way now. If I want to have same stress, I will get less strain at 100 Kelvin and more strain at 300 Kelvin. So, my stress upon strain at lower temperature will be different than stress upon strain at higher temperatures. What does it mean? The stress upon strain at lower temperature is more and as a result of which, the Young's modulus will increase at lower temperature because my strain values are less at lower temperature for the strain. So, stress upon strain at lower temperature is going to be more as compared to higher temperature which means that Young's modulus will increase at lower temperature and in the same way, I can conclude that this particular show that the Young's modulus variation at lower temperature with the temperature variation. So, again you can see that there is increase in the Young's modulus at lower temperature. The Young's modulus of various commonly used material is as shown in this adjacent figure. The elastic moduli increases with the decrease in temperature and all the three elastic moduli follow the same strain. So, we will not study all the other moduli, but what we can understand from the Young's modulus is that all this elastic moduli increase at lower temperature. Having studied all these properties for metals, there are non-metals also used as we talked earlier and the non-metal which we want to study here is plastic. So, plastic or polymers, basically plastic are nothing but polymers are made of a long change of molecules that polymers are identified by the existence of long chain of molecules and each molecule has thousands of atoms held together and arranged in a tangled arrays. So, this particular shows the various molecules and they are together with small in arrays basically. Now, the intermolecular forces that unite this polymer molecule are very weak and they are basically van der Waals forces. This particular force keep them united together, all the molecules are kept united because of this particular force. Now, if you want to study the tensile strength behavior of plastics at low temperature, this particular curve shows this behavior. So, if I want to plot ultimate stress of different plastics at low temperature, again what you see is at lower temperature, the ultimate stress of this material increase. So, ultimate strength does show increase and we have got different material like mylar, teflon which is nothing but PTFE, kel F we got nylon, PVC etcetera. In all the cases what we have the ultimate strength increase at lower temperature. The strength of various commonly used plastics is as shown the strength increases with the decrease in temperature, but of all this material the most commonly used material in cryogenics is PTFE. So, of all this plastic PTFE is the only one which can be deformed plastically because it retains its plasticity at low enough temperature at lower temperature of around 4 Kelvin. So, the mostly used plastic in cryogenics is nothing but teflon or PTFE. So, as we saw earlier that mostly used material metal is stainless steel similarly, we can say that PTFE is the mostly used plastic in cryogenic application because it retains it has got good strength at lower temperature at the same time it retains it plasticity at lower temperature. The effect of stress on plastic or elastomer is very less as compared to metals all right. The metals show different behavior high stresses while the plastic do not show that because they yield partly by uncoiling the long chain of molecules and sliding over one another. The effect of stress actually does not show so much in case of plastics. This motion is also facilitated by the thermal energy possessed by this molecules and at low temperature material deformation is more difficult due to decrease in thermal energy all right. So, as you know that at low temperature the deformation is not possible because of the decrease in thermal energy. So, we talked in brief about plastic and we talked at length about the mechanical properties of different metals. If I were to summarize the whole lecture we will summarize as follows. We found that stainless steel is the best material or the most preferred material for the cryogenic applications. Carbon steel cannot be used at low temperatures as it undergoes a ductile to brittle transition existence or DBT or DBTT ductile to brittle transition temperature. We also saw that the ultimate and yield strength fatigue strength of any material increase at low temperature while the impact strength and ductility decrease at low temperature. They could still be acceptable for example, we saw that for stainless steel the impact strength and ductility is still acceptable at low temperature. PTFE or Teflon can be deformed plastically at 4 Kelvin as compared to other material and also therefore PTFE is the most preferred plastic at lower temperature. Again we have got a self assessment exercise is given after this slide. Kindly assess yourself for this lecture. So, we got around 12 questions for you. Please do self assessment for yourself honestly and we have given the answers also for those questions at the end. Thank you very much.


We are about 20 quests left So not too far, but this will be a long stream no matter what and we have to finish off all of this no dialogue as always So yeah, let's head over to mystery who is in this mysterious cave And we'll see what we have here How are you doing today Rose and Dylan? Hope you're doing well Such an ominous cave. I really love this cave. It's so cool. You're here like never, but it's so great basically Just a whole bunch of talking and we need to go to Hawkerete's so That is fun. Luckily. We have a port to the dock over there because I did that Yeah, I did. I don't know what what was happening. It's just I couldn't stream I could play the game perfectly fine It's just streaming was like nah, sorry not gonna happen not gonna happen But yeah, unfortunately tomorrow's stream on Twitch will be just an hour long Unfortunately, but we'll do probably a couple of side quests maybe one side quest on whiz instead of so basically what we were gonna Do today we'll do tomorrow on Twitch And we are doing this today. So that's what's gonna happen. I have a thing that I need to go to tomorrow unfortunately You're just vibing nice the snakes are late named mystery. I love it. I know it's great, isn't it? It's absolutely great. Let's leave a mark here. Hawkerete's. Hello, and We are going to familiar minimum minimum Basically the priest of Zeus is what I briefly heard over the dialogue But that I don't really care about because I've already listened to it. That is this way Do we have any friends online? No, we don't oh Nobody online scary have to do stuff by ourself today. Oh, yeah, we get to go up this But we get a like ascend through the brazier Don't know how that works, but it works Don't know how it works, but it works. It just works just happens The high temple of Zeus exactly got to put on my big boy pants. Look at him. Look at Zeus.  I always want to just present a photo man's even though that's not in this game We're getting the side quest Because we need some side quests we are up to 22 pages And we need more all of the side quests. How many do we need? We need at least one more side quest The immortals walked among us and taught us wonders It was an age of legends and great kings The greatest of those kings was Minos ruler of Nosos the greatest city in Sadly wealth and power bred hubris in the king's heart not content to be a mere king Mino sought to raise himself higher than the immortals All aquila paid the price for his arrogance Olympian Zeus Transformed Mino's son in two Immortal and vulnerable and consumed with hate for all that lives The beast slew his father and smashed his palace Mount their legs playing waste to the entire isle darkness fell upon aquila The immortals withdrew to Olympus War famine and terror The great monsters of old returned and the minotaur random Centuries passed a dark age that knew no home But in the fullness of time a new hero rose With us who tell the minotaur and founded the new empire The minotaur was seen in a great labyrinth Designed by Daedalus the oracle warned that if he ever escapes the immortals will forsake us again Minotaur was forgotten until the war with Troy on the eve of the invasion of Ilios offerings was Minotaur free Basically the rest of rest of aquila is about Minotaur and Argos, so yeah That was just a little inside of today's things I Wizards can see him anytime while our pirates can't so sad. I know We forget the minotaur was my noses son If the king never got greedy For power of the Sun would have had an all-life exactly.  Don't be a greedy king Just how it works Daedalus hello, hello there. Hi. Let's go see you in the lyceum. He's the guy that taught us how to build a mouse So he's really qualified to build a labyrinth as well. He built a mouse It's just how it works now we need to go and defeat I don't know why it says Ithaca that's funny That is not where we're going that is at the end of the end of the area Hi, Ali welcome. Hi Walter welcome. What an interesting story. Yes pirate has the most interesting story in my opinion Wiz is not as good as story as pirate at least for all of it apart from Valencia part two Which is not as good as everything else in my opinion, but that's fine And also Imperia steps up the game for Wiz a lot Yeah, how are you doing Ali?   I remember I remember where it is. You got your witch doctor to 16 nice congratulations Grats The life lesson is don't be a minotaur that is also another good life lesson there don't be a minotaur minotaur is a bad Unless you identify as a minotaur and then welcome, but you know minotaur is a bad especially in the story here Just started at the beginning of the week nice it it's not too it's not too long difficult to get up levels It definitely is slightly shorter Well, the story itself was shorter, but takes longer than was I would say or about the same time in my opinion If you're going up to level 100 and was I would say 1 to 70 and Pirate is about 1 to 100 and was in my opinion Yeah, let's hit off this way just because There's so many so many dungeons so many dungeons and hard fights that take forever as well But it's fun. It is fun. Let's head into the tunnel Into the tunnel First I tried with swashbuckler noise swashbuckler is fun I have a level what like 20 ish maybe 16 ish my arms washbuckler Where are we going with centaurs? I think they're up in the hey look, there's our chest It's our chest which we can't get because when you go around this way. Here's our chest that we keep getting Every time we hear we got to get that chest 404 gold. Oh, no gold not found. That's not good. I'm gonna go this way Where are we going into the city? No, that is another quest. This is the bad thing when you have so many side quests There's just too many x's you don't know where you're actually going What world do you think is longer cool ranch empire or chrysalis and was I would say cool ranch chrysalis is Long but like cool ranch is really long Really really long. So that's what I would say. I also find musu really really long and pirate as well Musu was frustratingly long in my opinion Um, I usually get burnt out at musu. It's just annoying. Who does Hippocrates. Hi. He's a hippo. Haha. That makes sense That makes sense. He's a hippo Um, okay, the hydra is somewhere along here. I think the hydra is up there. I believe I don't know for sure though. I can't remember exactly that fights fun um Me too, but I had to ask what level does cool ranch span across it goes from um It doesn't really have like the thing with pirate is like the levels are not like specifically set in stone um, but it's like from I would say around like 20 ish till about 40 um ish And then 40 to 50 is um around that 40 to 50 is um These are not the right things. I've just realized this is not good. This is not good. I have done the wrong thing I have done bad. These are not the right things. Whoopsie daisy Uh-oh um Yeah, and then moosh is level 40 to 50 um yeah Mission pirate looks pretty at at first, but the beauty goes away when you're there for a long time exactly exactly I completely agree with that statement Completely agree. I'm just gonna turn down the sound effects real quick because it's slightly loud Slightly loud and I don't like the birds screeching.  That's fine. Can you just block bonnie? Please that'd be great. Use your stalker salt I know you want to I know you want to use your stalker salt Also, don't know why I went into this fight knowing that it was not the right thing. Maybe I didn't who knows Maybe I didn't luckily. Hopefully this won't take too long Um, this is a nice vengeance here Nice we mega vengeance even better even better the mega vengeance boom boom right Then what we do is we are going to go and destroy these guys real fast. Um, this is perfect. Actually. No, it's not perfect um We're just gonna do this Bonnie can do that you can do actually You can do that you can just focus on him Done should be good Um, for some reason I've always wanted to see what cool ranch would be like and was same I would love that. I would really love that Would really love that that would be super cool Would be super cool Come on Gracie. I thought you'd be better than that. Oh disappointing Burst fire epic hit nice we get a double tap Nice here we go more more more hit more Bonnie do it you can I believe in you Bonnie do it Attack no don't block I want you to vengeance strike literally why I didn't give you dodge at all I gave you accuracy so you could vengeance strike them to the death Thank you Attack vengeance strike, please good. Luckily he also has a heal as well. So this is like the perfect person to have vengeance strike Like here's a really OP heal. I'll show you because I need to hear of him I was it's facing the duck of death after our pirate takes away his immunity. I'd love to see him Cast Lulu. Yeah, that would be great. That'd be really cool This guy these these birds don't like them at all Don't like them. I should have just fled but it's fine. We're gonna finish this fight Fair and square We ain't gonna flee because then we also have to walk all the way over here as well, which is not ideal not ideal at all Um, we're gonna do this. Uh, we will do this You can heal yourself. It heals up to 50 percent, which is really really cool Like it is such a good heal. I'll show you I will show you it is such a good heal It can only be cast on himself But it's just so ideal. It didn't even kill so sad Boom He's basically full health again. It's so good. Um, his casting animation should be him pointing the gun at the sky or at us. Yeah Yeah That'd be pretty cool Vengeance strike go Vengeance strike go. I don't know why it does too for these guys like I don't understand that at all That did so much. Holy moly Maybe it was for this Oh mega hit, okay Okay, bye Sorry, you did Um, he might die here. Avis might die. I might want to put a va on him real quick Bonnie is also taking a beating in a half here Okay, I need a team heal What is it? Oh my god Bonnie can heal herself, which is good Um However avis can no longer heal himself So what I will do is I am going to Via him Bonnie is going to heal. You can do that. You can do Actually, I want to get these two done down real fast Just block them off from bonnie Probably a good idea. Hi tacos.  I know I know they are and I thought they were the right things I don't know why I thought these look like centaurs because they don't Vengeance strike.   Get dead Yeah Dodge really please stop just don't dodge at all repel borders. Yeah, hurt me Vengeance strike.  I don't like them at all. Thank you. Finally the crits.  It's just how it works. Just how it works there Let's see how long will it take for Bonnie to be fully revived to put your answers in chat right now To be fully revived to put your answers in chat right now. How long do you think 12 hours or 13 hours? Um, how are you tacos? How are you? Oh look a side quest we're gonna have 23 pages. Isn't that fun? These are the centaurs by the way, um, who do we have to replace Bonnie who is away for five hours only five? Wow, we've got cat bed. We should be fine Um $100 away from getting a capture card. Nice. Nice Five hours. That's a new it's a new record really. That's a new record Um, right you can go there You can do that cat bed can move up We're gonna see how this goes. This is an interesting, um, setup here Very interesting setup I'm actually really surprised about that. I was expecting it only to be like to be like 12 hours or something Only five. What a miracle. I know I still might go to the miracle. Uh, I don't know though. Not sure yet Not sure yet though Oh, look at them. They're in a perfect position for me to absolutely destroy them It's so nice when they just go into the perfect position. It's great So good Just look at that. Oh, that's just beauty That is beauty absolute beauty Cat bed go cat bed is not really good at this fight at all Um, but it's fine. We'll just deal with cat bed. You know, I'm sure it'll be fine Sure, it will be fine when miracle match services aren't free. He is expensive to use. He is. Yes I have lots of gold. So I should be fine Go cat bed Fish slap him. Yeah, that's right. Use your fish. Use it. Use it good Good job. Good job cat bed. Good job Minus accuracy. Oops Um Oh, you're not too late. Not too late. We've only been going for like nearly half an hour. So you're not too bad You're not too bad. Not too late Not too late. You missed a really good poppet show though. You did miss a poppet show poppet shows are fun How are you today chariot? How's it going? Um, let's go for the This because that sounds good Just to get some excess damage on these guys Um Yeah, we'll just target the sky real quick.  Nice Okay, we've got to get all of this damage on But That did that did mess Okay, good job cat bed go. Thank you Thank you cat bed. I appreciate you epic hit. No No Hi, oh and welcome. How's it going? Zero. Yeah, that's right. You're bad Okay, that was not good. That was not ideal.  That's a shame.  Do you have bladestorm? No, you don't. I don't think you do. No, you don't But that's fine. Good job cat bed You did well. You did good bud. No, stop epic hitting. No.  Millie Dodge, okay Okay, then Not good Uh, who are we gonna go for? I think I should probably how much does this do? Okay Okay, gracey can do that. That'll be good. This is gonna do mass. Holy moly That is such a good strategy go for the fighting Fever or whatever it's called and then just go for a mess of backstab Oh cat bed. Yes Look at that cat bed putting in the work here. Jeez nice work noise work Slight chest movement dodge low on the empire exactly Exactly just how it works, you know just how it works Um, this is not good. Please just stop killing people. Not cool. Not cool Not cool at all Right, we're gonna go for we still have the fighting thing. I believe How long do we have that for? um Two rounds. So what we're gonna do Is we're gonna go for this real quick I think Yeah, we'll do that We'll do this should be good Yeah, okay. Oh, we're not really nice noise. That wasn't too bad You're loving pirate, but it feels so empty You made no friends so far. Yeah, that is the one downside. That is the one downside to pirate That's because they don't update the game enough to have people That used to be really really huge, but it just isn't anymore. Okay. I do need to heal next because we may have some more Casualties like cat bed here for example. Yep. Okay rip cat bed should have probably healed, but it's fine. We'll um We'll be fine. I guess maybe Yep, that's definitely a dodge there. Definitely a dodge right, um Let's go for that Actually, you can do that You can do that done Okay, that's a big boy heal Not too big, but a decent decent heal super hurt. Here we go Nice Yeah, that was good. That's really good really really good there Bladestorm can we crit the bladestorm? Yes, we can. Yes, we can into another bladestorm Easy peasy. Oh and a mega. Okay You didn't need to do it to them Gracie, but you did. I'm proud of you Gracie. Good job. Good job I don't know why but Gracie always gets good when someone has um Um been knocked knocked down. I don't know why just how just how it always works Gracie starts actually critting finally Um Not a lot of people play it now. That is true Very very true. Um, do we have focus fire? No, we don't. Um, we could just go for that. I guess Should be good. This guy should be dead soon Some random just added you. You're no longer alone. Nice Just like we are Be dead to arrows and I just said is true. That is very very true there Very very true Very very true Okay Oh, look at this. Now we can really just destroy this guy This is going to absolutely wreck. This is the first time i'm using this ever focus fire Epic hit. Here we go. Sorry buddy, but you're dead, mate. You're dead. Okay Thankfully we managed to actually not do too badly there Okay, just saying that and he dodges but that's fine That's fine. I guess are some ships faster than others. Yeah, as you get better ships, they get faster um So yes is the answer to that Okay, he should die.  Good job. Good job avis. You did well. You did good. Nice work Nice work. Okay. Do we have to defeat another one? Please say no We have to defeat more.  How long is um cat bed down for only five hours. I'm surprised that these are so um low Really surprised actually I feel like I don't really Know what i'm doing, but I haven't died yet. So you're feeling pretty positive. That's always good. That is always good Yeah, next time you should duck a little more bonnie. You heard him. You heard the man. You heard the man. Do it. You won't I mean, yeah, I mean in the you'll get used to it. You'll get used to it in the early stages if you die It's not really a big deal. Um, you shouldn't you don't really die that much either Um So you should be fine generally generally should be fine. Look at how pretty it looks down there So pretty. Um, right. We need to defeat these guys again. Let's do this Let's do this Okie dokie Let's try again. Do they have like return fire double tap Quick adjust. Okay. They're they're not actually too bad for musketeers to take out which is good Um, they're just in like a really odd position, which is not ideal. We're just gonna do that Gonna come up there. You can do that. I guess done should be okay. Hopefully this is good Um, it's as pretty as me Yup Sure thing Sure thing. Okay, that was good. That was really good I love it when they take damage for no reason. It's great. Absolutely great Oh, those three are in a great position Millie's taking use to it as well, which is dope Um, what I will do though is we're gonna go for big accuracy big accuracy buff I'm gonna let Gracie go for that one. You can go up there. Um, we're gonna put that there just because we can Because I think it's probably pretty useful to have that war golem again Um, just because last time Improved that we did kind of need it Noice war golem Noice easy peasy overwatch Bye. Sorry buddy Sorry bud overwatch Sorry bud Burst fire. Noice Okay, half health for one of them, which is really good Really really good there. Um, what is this war golem? Him? Okay, that's fine That is fine. He must be furious as his name states. He will be absolutely furious Uh, we're gonna go for a crit.  You however can do, um, this Done. Okay, that should be good Hopefully now everyone should crit. Look at that. We're getting some crits. Yay Crits are good. Crits for days Is great. Love me a good critting Crit. Nope. Dammit. Dammit. Gracie, you had one job and that was to crit Couldn't even manage that, could you?  Nice Noice boom What else do we have? Okay fires out and here we go. What are we gonna do? We can go for a You could probably do that there Do we have anything else that we would rather do? No, not really 205. It's not too bad. Bonnie can do that You can do that Gracie can come up there and do that.  I dare you to crit Absolutely. Dear you to crit Bonnie why so annoying? He's max level. Noice It's always good to have max level friends Um Yes, thank you Gracie. Crit all the time. I dare you Crit again. Thank you Good job And again No, okay. That's fine. Two was enough I agree with you there Gracie. Two was enough, you know We didn't need any more We haven't actually taken too much damage this time. I say as Bonnie slowly dies um Bonnie has no health though. So that's that's one of the reasons why she takes lots of damage Mega hit noice What is this Okay, he's so close to dead Bonnie can hopefully take him out next would be great Hopefully fingers crossed actually there's two that Bonnie could take out Um what we're gonna do How long does our accuracy last? It's gone. So we'll do accuracy then You can do that. You can do that. You can do that Done hopefully two of them should go away this round Hopefully hopefully Yes, no don't don't no Bonnie. Why why would you do that Bonnie? so annoying And if I didn't see um Gracie to do that, she would have not double tapped into that one It's just how it works. Just how it works honestly. Oh, well, it's fine It's fine We'll just be here for slightly longer Should I focus fire someone? 25 damage for one turn Let's just focus fire this guy real fast Let's just destroy this guy in one round sounds like a plan and a half Yep, that sounds like a great plan there Really gonna just absolutely be pummeled here basically That was not too bad at all. That was a good move. I think that was a good move. We'll go for a heal next Um Make it hurt. Yep. There we go nearly dead Of course the wall golem doesn't finish him off, but that's fine. Bonnie can do that. We're gonna go for a heal Real fast We do have a team heal, which is good. Bonnie can do that the other two can do that And we should basically be done Epic heal is always good Boom Double tap burst fight. No, no burst fire. That's a shame. That's a shame Gracie can you do it? I believe in you. I do not believe in you Gracie. You had one job.  The answer is no That means I have to come and steal the kill I'm basically full health, so we should be fine done 28 health Disappointing and a mega you didn't have to do them like that Didn't have to do them like that, but that's fine. We did it We did it. Look at us go. We did it. Nice work Did we get We only got one. Oh my god. This is annoying This is annoying. I don't like it at all This is not good Not good at all Not good at all. We're gonna be here forever Um, okay, hopefully this should be fine Hopefully we'll see This is a um, this is a privateer not a swashbuckler burst fire There's actually no swashbucklers in my team fun fact Absolutely no swashbucklers in my team Overwatch super hit. Hello. Where did your act? Where did your crits come from bonnie? Geez burst fire. Okay Okay, then Right, can I pet join that would be great. Uh, we're gonna go for this Bonnie can do two of anything so you can just do this guy Done. We'll summon the thing next actually. I probably should have done the crit thing Not the crit thing the um damage thing But it's fine. We'll just be accurate. I guess We'll just be super accurate. It should be fine Super accurate slightly dodgy At least you'll get a bladestorm and an epic bladestorm. No ice. No, it means another bladestorm Just a bladestorm chain So close to kill so close to kill Unlucky unlucky, but we tried there We tried it Overwatch What we'll do is go for these we will go for um now now this is just getting worse It's just getting worse. We're gonna go for that You can go like that. I guess Right double tap nice Only one double tap no burst fires or anything which is slightly annoying Creatures on the pirate team to live with the littlest bit of health. I know it's so annoying So annoying. It's the worst thing ever The absolute worst It also makes battles just take five million years like seriously I did Not know privateers could jewel world anybody can jewel world and pirate anybody can Most of the most of the weapons are jewel world. So Yeah, we can stock assault him. I didn't know stock assault had such a range Let's just do that. Sure. Why not? We'll see what happens Wow, okay Come on Gracie. Please just crit honestly Oh, right at least um bonnie can destroy that one real fast hopefully Uh, there's accuracy and dodge gone. We should probably redo that Um, we'll go for that one though Is there a celestia empire? No, there is not um Unfortunately Um, fortunately the only worlds that there are uh skull island monquista valencia cool ranch mooshu malibone aquila Those are the only worlds in the game and technically dragon spire, but I mean, you it's literally one skyway and you can't really do much in there. So technically dragon spire, but not really Um, we'll go for crit. I guess I guess crit. Um, you can do that It's gonna focus him real fast Just focus him real quick get some crits on nice work Double tap nice I'm surprised no burst fire for bonnie Really surprised about that, but hey we'll deal with okay. Can you just stop please? Just stop Stop impaling them not cool. Stop it Stop it Uh, what we'll do is we'll go for a heal because that's apparently where we need to what we need to do Um, you can just focus this guy again real fast Finally some burst fire. Nope only one So annoying mega hit finally some crits Thank you Thank you graesy. Thank you double bladestorm as well on the sky, which is good Nice two extra hits even better Mega hit hello bladestorm. Hello not too bad Right our damage is gone. So we're gonna go for that And this should hopefully kill Hopefully maybe we'll see Just don't Not hit basically it's the thing here. Just don't not hit dammit bonnie. You had one job honestly This fight is taking five million years. I hope we get the last three that we need millie. Thank you for joining finally You're a bit late buddy, but that's fine 300 Right, here we go. Here comes big boys Big boy plays here actually doing work. Here we go because my team is useless and can't do anything I have to do it all myself Yes, that's right That's how you do it boys watch and learn watch and learn Oh my god Oh Gosh, I hate this How did we only get one in that whole time? What the heck? What the heck? Not fear This game hates me Gosh This is worse than zafaria I don't like it worse than zafaria 0 out of 10. Please stop Game just be nice Just be nice Please. Right. Let's go for some of this We're gonna go like not like that. We'll just go like that And that you can summon your thing there done When you get only one of what you need out of a lot. Yeah I mean there's literally four of them in each fight So theoretically you can get four The most I've got them from one fight is two I don't understand how that is possible Don't understand how that is possible Statistically it doesn't work out Overwatch dodge unlucky return fire. Oh, no. All right Destroy please golem. Just go big and go home Um, do we do this we're gonna go crit first We'll do that real fast.  That's unfortunate Really really unfortunate Super hit. No, please stop If it's on me, it's fine though. I'm not too important. So it's fine if it's on me But just stop hitting my companions, please. I don't like it Really don't like it. Not ideal. Not good zero out of 10 Um, we'll go invisible Yeah, we'll go invisible. So then we will go for big damage Then we're just gonna go for a back stab Um And do that good stuff Mega hit Bop Bladestorm Bop Hey, at least that was good. That wasn't too bad. Epic hit. Please just stop Oh my god, he might have to heal himself. Luckily he can heal himself Luckily Yeah, he's gonna have to heal himself Definitely has to heal himself Okay, righty-ho. Let's do this Let's do this This one Um You can do that You can heal. You can do that We will also go for a heal dibloon Just because Just because there's the damage we need Um Here we go with the nice wee pew-pews He's gonna heal himself And he's gonna get basically all of us health back again, which is good Ippercat here from Gracie Cause Gracie's doing a great job Bladestorm. You should have bladestormed into the other guy Oh Gracie Disappointing really Right Please stop hitting him Hey, at least he moved. That's good idea. Good idea, buddy. Good idea Yeah, there we go. One down Only like five million to go Only three, but basically five million Um, we're gonna go for epic Epic big hit here Um, which does 10-19 to this guy Um, we'll do that that and you can do that Hopefully Actually, you can move up there. I'm hoping Bonnie can kill. I'm hoping Bonnie can kill. Hopefully Might have been a mistake because Bonnie of course would never never burst fire when I need to It's fine though. It's fine.  Hopefully it can. She can Hopefully Hopefully, hopefully Um We can do this we're gonna discard Um This real fast We're gonna do that on him. Hopefully Bonnie can destroy that Hopefully Sweet and a double double tap Um, which is good Burst fire. No dodge. Unlikely we need to get that dodge back. I'll do a dodge thing next. Um I think it's probably necessary at this point Bonnie is being blocked all the time, which is not ideal No, Gracie We'll get um, Bonnie to Kill that next Um unless Millie does Of course Millie would That's fine. It's fine. It's fine Millie. You did a good job. You did a good job today. Um, we'll get that We're gonna go for that And that's done. Hopefully this should nearly kill I think next round will be fine and hopefully we can get the last two In this fight, please Otherwise, I'm gonna be very sad Avis is actually putting in so much work here So much work Millie, good job. Right. Um Let's go For this And hopefully we kill Hopefully Can I crit? Nope. Can I relentless? I can Can you please kill? Thank you This is the last one, right? Please tell me this is the last one. It's not the last one It is not the last one. Fun fact. We have to defeat more You'd think oh six that'd be easy you get four every fight No, that's not how it works It is not easy You do not get For every fight I am mad Very very mad, but it's fine. We'll deal with it, right? They do they can take forever. They really can It's just annoying That's all like I I don't really mind. It's just that it's so annoying Because I don't really like fighting these guys because they're musketeers as well, which is really annoying This would be so much easier if they were um If they were like swashbucklers or buccaneers, I could have absolutely destroyed them But because they're not they just take forever and ever and ever and ever Uh, right. We're gonna do this Bonnie can destroy all of them like that You can do that and you can go for a critical there We're gonna discard that done righty-ho Can we do good, please? Would be good Also knowing that these guys don't really have relentless either Um, but then relentless never triggers. So it's like Is it really useful? No Luckily if Gracie can crit a bit she can get a lot of bladestones, which is good um Far as home, I would have Um, am I max which poor and destroy them? One old scratch buff and goodbye centaurs exactly Exactly Which doctors are really good for countering musketeers I don't most musketeers can also be pretty decent, but otherwise It's just so annoying countering musketeers. It just doesn't happen It just doesn't happen at all Just doesn't happen For at least in my experience Connection lost what?


Guys, welcome to the first Speedway Grand Prix quiz from the season 2022. 20 questions, the quickest of you will answer and give us the good answer. We'll score one point. Who won the opening round of the 2022 Speedway Grand Prix season? Smodlik, Matoch Smodlik. Okay, 1.4. Jack, but normally you should not score that point because I have to give you the three... I'll give you a warning. You have a warning, but you score that first point. Okay, second question. Who was crowned champion in 2022 but in SGP2? So, Victor Lampart. Jakub Miskovjak. Or Mateusz Cianniak. Good point for Freddie. Which Australian rider won a Speedway Grand Prix round in 2022? Answer A. Max Frick. B. Jason Doyle. Or C. Jacqueline. I would say Rob. Max. Good answer. Wrong. Wrong. Jack, come on! Hey! What? Right. How many Speedway Grand Prix rounds did Martin Vatulik win in 2022? Answer A. 1. Answer B. 2. Or answer C. 3. I think it was Freddie actually. Freddie. 2. Good answer for Freddie. 2.4. 3. Which of these countries did not reach the FIN Speedways of Nations in 2022? Answer A. Germany. Answer B. Finland. Answer C. Czech Republic. 3. 3. Great Rick. Oh, I see that. Germany. Good points. Well done. Poland won the SON2 event at Voyants in 2022. But which country took silver medal? Answer A. Denmark. Answer B. Great Britain. Answer C. Czech Republic. Great Britain. Did you just? In the World Cup. It's a wrong answer. Wrong answer. You have to press again. I hear what other things. Denmark. Great Britain. Or Czech Republic? Denmark. Czech Republic. You didn't press a buzzer. Czech Republic. Czech Republic. Guys, be careful. Frédéric is taking a little bit of an advantage. Rich Friday won the 2022 SGP3 final in Wroclaw. Answer A. Vilat Nagel. Answer B. Michel Anderson. Answer C. Casper Mania. Michel Anderson. One point for Rod. Questions for Theresa. Kim Nielsen won the 2022 FINGP challenge to qualify for Speedway Grand Prix series. But which rider did he beat in the run-off first place in Glasgow? Answer A. Rob Lombard. Answer B. Folder. Answer C. Dan Buly. Julie. One point for Jack. This one is maybe a tiny bit tricky. Trick. What's the lowest number of points in the championship Barthos Marslicks scored in the 2022 SGP round? Answer A. 10 points. Answer B. 11 points. Answer C. 12 points. Frédéric. 11 points. Wrong answer. Jack. 12 points. Good point. Anders Thompson won the Speedway Grand Prix in Gorshaw last year. But at which other 2022 round will you reach the final? Answer A. Roslav. Answer B. Croatia. Answer C. Warsaw. Jack. Croatia. Good point. Well done, Jack. Well done, Jack. Look at that finish. Right. At which round did Jason Doyle finish third in 2022? Answer A. Prague. Answer B. Gorshaw. Warsaw. Warsaw. Prague. Good answer from Jack Holder. Who takes the lead? What did Pavel Shepelski make his only SGP 2 semi-final in 2022? Answer A. Torun. Answer B. Molilla. Answer C. Warsaw. Molilla. Warsaw. Another point for Jack Holder. Fredric Lindgren and Rob Lombard tied on championship points. How many did they score? Answer A. 93 points. Answer B. 103 points. Answer C. 113 points. 103. That's a good answer from Fredric. No, we didn't have a next clue. Where did Rob Lombard, you again, reach his first SGP final in 2022? Answer A. Teterov. Answer B. Vroslav. Answer C. Teterov. If I didn't know that. Where did Patrick Dudek finish in the 22-22 Speedway GP World Championship? Answer A. Six. Answer B. Seventh. Answer C. Eight. Oh, that was really tight. I would say Fredric. Seventh. Good answer from Fredric. Which 2022 Speedway GP World Cards scored the most championship points? Answer A. Magie Zagar. Answer B. Casper Boina. Or answer C. Rasmus Jensen. Zagar. Rasmus Jensen. Good answer from Fredric. Was that close? I don't know the point. It was Rasmus. Which Speedway GP rider was crowned European champion in 2022? Answer A. Mikkel Mikkelsen. Answer B. Dan Buley. Answer C. Leon Madsen. Did you see? Mikkel. Rob. You can't. No. What was your answer? But now it's wrong. Ah, Leon. No, I'm out. I'll give him half a point. Okay. Rich Friday was crowned Australian champion in 2022. Answer A. Jason Dore. Answer B. Max Rick. Answer C. Jack Oler. Jack. Of course. Max.  It was in 2022. That's 23, yeah. So I left at 3, you boys. All right, I can't give this one to anyone because I have to answer.  Where did Tsai Mufin then achieve his best Speedway GP finish in 2022? Answer A. Prague. Answer B. Gorchev. Answer C. Prague. Good answer from Jack. And final question. Who won the SGP World Championship bronze medal in 2022? Answer A. For your clean run. Answer B. Dan Bully. Answer C. Were you looking at him this way? Yeah, no, I'm scared. I pressed it first. Get the replay. Can we have the final score, please? Oh, it's a draw. Change it. No, no, no. I'm off. I had that max-freak one. You know what? I'm going to take it. I have to get a bonus question from the 100 years of the Speedway Grand Prix to see who's got the most knowledge about your sport. You got to remember he's older than me. All right, let's go for these questions. Who was the first Speedway World Champions? Answer A. Jack Milner. Sorry for my pronunciation. Answer C. B. Bluey Wilkinson. Answer C. Lionel Von Pragg. And Alfonn Pragg. And the winner is... Congratulations. I thought you'd get it wrong.


So Frank, let me, we're gonna play a hypothetical game. Okay, let's go, let's go. Let's go look at the rotation for the Astro. They've been great. They've got the best ERA in the major leagues and it's been really not close, okay? They've been fantastic. But I'm gonna play a little game. What's the look towards the playoffs? Let's say the playoffs started tomorrow, big hurt, okay? You're not pitching all these guys in a series, I don't think. Who is going to the bullpen? Who is the odd man out? It's a tough call for me, but I'm gonna go with Lance McCullers just because he's hitting this stuff. He's breaking ball exceptional and when you get a guy to come out of the bullpen, you need someone to strike people out and Lance McCullers can get that done for you. Dallas-Kike-Wynne, Lance McCullers and McCullers might get more reps because he has the experience of being able to come in the middle of the game. Well, you're going two? Yeah, that's all they need. They got Justin Verlander, Cole and Morton. That's all you need. You're not gonna wait that long for Justin Verlander. He's gonna pitch game one and if there's a game four, he's back up there. All right, give me the explanation. Now why two? Go ahead, give it to me. Well, look, you got three of the best right handed arms right now in baseball as far as pure stuff and if they're able to rack up strikeouts, you're talking about in a three game set, they can rack up close to 40 strikeouts. Look, Dallas-Kike-Wynne, I love you. I know you got the beard going, but you gotta need to come sit down and go get another title, man, because right now you're looking at the numbers. If it continues like that, he's got a four ERA. That's almost three runs higher than Justin Verlander. So there's only a couple of people that can start in that rotation. This is not softball. So, hey, that's one of the numbers. Where is it going right now? Well, I think what's going to be the determining factor is going to be how many innings there are starters logged throughout the season. These guys are pitching so well, they're pitching deep into ball games every night. So come play off time, we'll see how rested certain arms are. Well, their bullpen has thrown the fewest innings of anybody in the league. So to your point, the starters have been so good, the bullpen hasn't thrown, and the bullpen's ERA is great. Partially, I think, because of that, right? Starters. But you were throwing out a scenario earlier, Frank. You may, maybe even, you see a scenario where all five of those guys get a start. You never know. Is that good? It's like, why change it? It's not broken. This is a great rotation these guys can pitch. How do you tell a side young guy to go to billpin? Because he got a four. Well, it doesn't matter.   That's the training them. I mean, it's the truth. I love Dallas Keikul, but we live in a day and age. What have you done for me lately? Let me ask this. So if Keikul, again, this is if everything goes well. I love you, though, man. I'm a lefty, too. Don't let them round me up and stuff like that. I'm down with you. I'm just keeping it 100 as a young people. That's your own answer. We didn't tell you to say that. It's the truth, though. It's the truth. If you have a four, if he finishes with a five ERA, when's he gonna start? The one thing I'll say is this, and this is a big if, trade deadline. We know what they did last year at the waiver deadline. They got Verlaner. If they don't go out and get a bullpen on them, right now, Rundome's the closer, right? They get help from within, don't they? With them of colors. I even think maybe Morton can go to the Pan-Vietta Andrew Miller. There's so many options here. It's kind of fascinating to me to see exactly what. It's a good problem to have. It is a good problem to have. All right, we'll revisit this. We'll check the tape. We'll see who's right down the line. Train, I'm gonna ask you the question about David Price, even though they didn't win tonight. Is he the most important piece of that rotation, maybe even of that team? When he's focused, he's a solid number two, and he can beat any number two in baseball. He can go on the road, give you quality, and then score deep in ball games. As long as he's not fighting with the media or ecstasy on the plane, or getting in that riff rap, he can pitch, and he loves to compete. I know him personally. Going to this game, he was six and up with a two ERA, last seven starts. So when he's healthy, and he's on the mound, and he's getting settled in his rotation, I like that rotation, especially with him in cell. That's a nice one, two punch. I can beat any team in baseball. God just gotta be himself. He's gotta be an ace. He's been paid a lot of money to pitch. If he pitches like he's capable of pitching, this is our only chance of going deep into the playoffs. Him and cell together, one and two, it's gonna be hard for any team to beat those guys back to back. I think this may be outrageous. I think he's the most important player on that team. Because Frank, piggybacking of what you're saying, you know, we saw it last year. He was hurt, he came back, he pitched out of the pen. He did a nice job in the limited time in that one series. I don't think they win the World Series or have a chance without it. They don't. He's gotta be great. And I hate to say that. That's a lot of pressure for any pitcher, but he has to be great. Boston's gonna go deep into the playoffs. When he's able to command his pitches on both sides, he's able to get quick outs and get that offense back in the dugout. And you like that, Frank.  That helps them and they score runs, especially helping them out. But if he's able to pitch quickly, get contact, stay healthy. I think it'll be just fine.