Temperature dependence of cyclic creep behavior of a Cu–SiO2 bicrystal with a [0 1 1] 20° twist boundary Original Research Article

Temperature dependence of cyclic creep behavior has been studied using a Cu bicrystal containing dispersed SiO2 particles and a [0 1 1] 20° twist boundary. Failure occurred at shorter times with increasing temperature and stress amplitude. The fracture-mode of the bicrystals changed sharply from transgranular to intergranular at a certain critical stress amplitude. The brittle intergranular fracture that occurred below the critical stress amplitude caused discontinuous life shortening. The observed fracture-mode change at the critical stress amplitude is discussed in relation to grain-boundary sliding and grain-boundary cracking.