segregation

Segregation in metallurgy refers to the uneven distribution of elements within a casting. This occurs because as molten metal solidifies, the solid phase that forms has a different composition than the remaining liquid. This process is analogous to how salt water freezes, with the ice being mostly pure water and the remaining liquid becoming saltier.1

While minor segregation is often insignificant, substantial differences in composition can create areas within a casting that are either unusually weak or strong. Both extremes can lead to premature failure of the part when subjected to stress. This phenomenon is a concern in the casting process, which involves pouring molten metal into a mold to create a desired shape.1