However, certain grain boundaries, such as coherent boundaries or where structural features inhibit grain boundary movement, can slow down the rate of grain boundary sliding to the point where it needs to be taken into consideration. The processes underlying grain boundary sliding are the same as those causing diffusional creep
However, certain grain boundaries, such as coherent boundaries or structural features that hinder grain boundary movement, can reduce the rate of grain boundary sliding to a level where it must be taken into account. The mechanisms behind grain boundary sliding are identical to those responsible for diffusional creep.