Positron Annihilation Study of Deformation in a Two-phase (α+β) Cu - Zn Alloy

Abstract

Positron lifetimes have been measured as a function of the degree of deformation ε in a two-phase (α+τ) Cu–Zn alloy. In this alloy the increase of the mean positron lifetime τm with ε is slower and the saturation effect occurs at a larger deformation than that in most simple metals and alloys. With increasing ε the positron lifetime parameters τ1 Ι1 and Ι2 exhibit a rise or fall near ε ≈ 4% and 35%, and they change slowly for 4% < ε < 35%. These results are explained by the special structure of the α and β phases and the particular deformation mechanism in this alloy.