A Comparison of Two Methods of Measuring Work-Softening by Low Cyclic Strains

Abstract

Low-strain cyclic hardening and softening in variously solution-treated and cold-rolled Al–4 % Mg alloy has been investigated by two methods: (1) monitoring cyclic strain during constant-load cycling; (2) cycling to saturation and subsequently tensile testing. Although considerable changes in flow stress were observed by the cyclic measurements, these were not detected in the subsequent tensile tests, which showed little difference in properties from the precycled condition. These results are interpreted in terms of low-strain softening mechanisms and it is concluded that the tensile-testing method is generally inadequate for low-strain cyclic deformation.