Effect of pre-deformation and phase transformation on the creep behaviour of Ag–1 wt% Cu alloy

Abstract

The plastic deformation behaviour of Ag–1wt% Cu alloy during phase transformation was investigated by studying the creep behaviour with and without different degrees of torsional pre-deformation, 12%, 24%, 36% and 48% at different ageing temperatures ranging from 633 to 693K. The stress sensitivity parameter m is found to decrease from 14.14 to 7.76 by increasing the ageing temperature. The values of m (at high and low temperature) show that the dominating two mechanisms are dislocation glide and dislocation climb, respectively. The steady state creep rate, ɛst, increased with increasing temperatures and stresses while decreased with increasing the degrees of torsional pre-deformation. The two observed temperature regions around the transformation temperature (663K). The energies activating steady state creep in the low and high temperature regions were found to be 48.4 and 79.2±3kJ/mol, respectively. The microstructures of the samples under investigation have been examined by X-ray diffraction analysis.