Grain Boundary Sliding

During plastic deformation at elevated temperatures, grains move relative to each other which is referred to as grain boundary sliding (GBS). The amount of GBS is proportional to the creep strain with a proportionality constant that is known from finite element analyses, and found to agree with experiments for Cu. The most import effect of GBS is that it gives rise to the initiation of creep cavities, Chap. 10 . GBS is also the main mechanism for superplasticity. A basic model for superplasticity is presented.