Effect of Accumulative Roll Bonding Cycles and Postprocessing Heat Treatment Temperature on Shape Memory Properties of Cu–Al–Ag Alloys

Abstract

In this study, Cu/Al/Ag layered composites with two silver powder concentrations (2 and 3 wt.%) were fabricated with the aid of accumulative roll bonding (ARB). The ARB‐ed samples were heat treated at different temperatures (750, 850, 950 and 1050 °C), times (30, 45 and 60 minutes) and cycles (1‐9 cycles) to produce Cu‐Al‐Ag shape memory alloys (SMAs). The samples were characterized by X‐ray diffraction (XRD), scanning electron microscope (SEM) and electron backscattering diffraction (EBSD). Phase transformation temperatures were measured by differential scanning calorimetry (DSC). Strain recovery and shape memory behavior were evaluated by bending and tensile tests, respectively. The results indicated that alloys containing 2 wt.% Ag, rolled till 9 cycles, heat treated at 950 °C for 60 min, and samples with 3 wt.% Ag, fabricated by 9 cycles, annealed at 850 °C for 60 min showed maximum β martensite phases amount. Strain recovery ratio of the first and second samples were 71.7% and 71.2%, respectively. Additionally, the tensile test showed that the residual plastic strain and the recovered strain for the first sample with 2 wt.% Ag was equal to 0.7% and 3.0%, respectively. These results for the second sample with 3 wt.% Ag were 1.2% and 3.4%, respectively.This article is protected by copyright. All rights reserved.