 Coring

Coring happens when a heated alloy, such as a Cu-Ni system, cools in non-equilibrium conditions.The center of each grain, which is the first
part to freeze, is rich in the high-melting element (e.g., nickel for this Cu–Ni system), whereas the concentration of the low-melting element increases with position
from this region to the grain boundary.This is termed a 'cored structure', which gives rise to less than the optimal properties.