

Water Cooling Aluminum vs Copper

Posted by graham 27/05/2020 0 Comment(s)

Aluminum vs copper in a water cooled system.


This is a question we often see, so we are going to try and address it here, there is nothing at all wrong or bad in having aliminuim water cooling parts in your loop, in most cases it offers a cheaper option and is a great way to get into water cooling, alot of people seem to be under the impression that Aliminuim water blocks corrode, well this is kinda true as all metal will corode over time, even yes you guessed it copper, so why the fuss? well therse a thing called Galvanic Corrosion this is bad, very bad in a water cooling loop.


What is galvanic corrosion?

Simply speaking, galvanic corrosion is the damage or deterioration of metal that takes place between dissimilar metals because of an electrochemical reaction. Specifically, it occurs when two different metals come into contact with each other and have either been submerged or moistened by an electrolyte, with the corrosion taking place around the point where the two metals meet. Additionally, this reaction can be catalyzed by substances that increase the conductivity of water, like salt, and thus the rate of corrosion can vary based on the environment where the reaction takes place.

Galvanic corrosion occurs because each metal has its own electrical conductivity potential. This difference in electrode potential in turn drives a corrosive attack on the positively charged metal (anode), forcing it to dissolve into the electrolyte.

Most commonly, galvanic corrosion can be seen in plumbing systems where a copper pipe is directly connected to a steel or iron pipe. Once in contact both metals can undergo galvanic corrosion because of the electric or galvanic current that takes place at the anode and cathode of the pair of metals.


So basicly if you mix certain metals together you will get Galvanic corrosion, copper and steel would be another example see image below-


an example of Galvanic Corrosion



So If you mix aliminuim and copper in a water loop one will become active (ali) one will become passive (copper), the corrosion will then be incresed and the aliminum part of the loop will corrode at an increased rate, there are of course other factors involved such as coatings etc, but either don't mix metals in your water cooling loop or use metals that are close to each other on the Galvanic chart, this is well document in engenering and not just known in water cooling.