A metallurgical separation technique where an alloy or ore is heated to a temperature where only one component melts. The molten metal sweats out and drains away from the remaining solid mass. While historically used for refining raw ores and bullion, it also occurs accidentally as a defect in castings or welds when low-melting phases segregate and weaken the grain boundaries.
We're seeing liquation cracking in the heat-affected zone because the low-melting impurities pooled at the grain boundaries.
Related terms
Liquate
To separate a mixture of metals by heating it until the component with the lower melting point runs off.
Macrosegregation
Large-scale variations in chemical composition across a metal casting or ingot.
Microsegregation
The uneven distribution of alloying elements at the scale of individual crystalline grains.