Mechano-structural characteristics of Cu72Au24Ag4 alloy subjected to severe plastic deformation combined with subsequent heat treatment

Abstract

Mechano-structural characteristics of the synthesized Cu72Au24Ag4 and commercial Cu59Au33Ag7Fe1 alloys subjected to preliminary severe plastic deformations (SPDs) by high-pressure torsion combined with subsequent annealings at different temperatures and holding times were studied by means of scanning and transmission electron microscopy as well as durometry. Due to SPDs, it was possible to refine the structure of the investigated alloys to submicro- and nanostructural state. As a result of certain annealing regimes, the atomic ordering processes began to occur in the alloys. The microstructural features and mechanical properties after preliminary SPDs and subsequent annealings were compared for the studied alloys. Influence of the deformation degree and subsequent annealing regimes on the kinetics of atomic ordering and changes in mechanical properties was shown. In addition, it was found the inhibition effect of the nanograin growth due to the barrier action of dispersed precipitates.