Characteristics of serrated flow in commercial Cu–Be–Co alloy

Abstract

Serrated yielding in a Cu–l·8Be–0·3Co (wt-%) alloy has been studied as a function of strain rate and temperature. Serration characteristics, e.g. type, stress drop δσ, frequency ν, vacancy concentrations–strain exponent m, mobile dislocation density–strain exponent β, and activation energy Qm for serrated yielding, have been determined. Strain rate sensitivity of flow stress δσ/∆ ln ɛ and activation volume V parameters have also been derived through strain rate change tests. The results have been interpreted in the light of the static strain aging model of the Portevin–Le Chatelier effect.MST/540