Interfacial Energy and the High Temperature Strength of Dispersion-Strengthened Gold - Al2O3 Alloys

摘要

High temperature, low-stress creep studies were conducted on dispersion-strengthened gold-alumina alloys in air. The results show two regions of diffusion creep where the strain rate is a linear function of applied stress. It is suggested that the first creep region in the vicinity of zero strain rate is associated with grain boundary-particle interactions while the second region of higher creep rate, in addition, is due to pore growth. An expression, based on the change in free energy involved in the detachment of grain boundaries pinned by inclusions, was derived to account for the observed threshold stress for creep. A comparison of the calculated values with experimental data shows reasonable quantitative agreement. (Author)