Grain boundary sliding as a deformation mechanism during creep

A model for grain boundary sliding is developed in which sliding occurs by the movement of dislocations along, or adjacent to, the boundary by a combination of climb and glide. Under these conditions the strain rate due to sliding is proportional to sgrave2/d, where sgrave is the applied stress and d is the average grain diameter. It is shown that reports in theliterature of enhanced creep rates at low stresses and/or small grain sizes may be explained by assuming that the various deformation mechanisms, including sliding, operate independently.