Effect of cyclic stress reduction on high temperature creep characteristics of solid solution Al−2·9 wt-Mg alloy

Abstract

Creep characteristics of solid solution Al−2·9 wt-Mg alloy have been investigated under the effect of cyclic stress reduction of different amplitudes (12·47−26·18 MPa) and frequencies (0·20−0·44 Hz) at different working temperatures ranging from 533 to 593 K. It was found that increasing both amplitude and frequency of cyclic stress reduction resulted in an increase in both transient and steady state creep stages. The enhancement of creep rate was observed above either a threshold stress or a threshold frequency. The activation energy values of the mechanisms operating in both transient and steady state creep stages were found to be 130 and 171 kJ mol−1 respectively.