Deformation behaviour of two phase materials: Cu-Al system

Abstract

A study has been made of the deformation behaviour of a series of dual phase (α + β′) and α + eutectoid Cu-Al alloys. The effect of martensite or eutectoid as the second phase on flow stress, work hardening, and total elongation is described. It is seen that the strengthening effect of martensite becomes greater than that of eutectoid at larger strains. Analysis of stress–strain curves shows that the strain hardening exponent n changes continuously with strain and, as such, the analysis based on the Ludwik equation (σ = σ₀ + k′ε_p^n′) is performed. It is found that alloys showing higher ductility exhibit a three stage behaviour. An explanation for this stage behaviour in terms of the deformation mechanisms involved is presented.