Influence of strain rate on mechanical properties of a CuAlMnTiB shape memory alloy

Abstract

Some applications of shape memory alloys (SMAs) require severe deformation of the ingot cast into thin circular, flat and tubular shapes. Therefore, the knowledge of the influence of the strain rate on the mechanical properties is fundamental to determine the thermomechanical conditions that should be imposed on the SMAs during the plastic forming step of these materials. Herein, a systematic investigation of the influence of strain rate for a CuAlMnTiB SMA, on stress-induced martensite, rupture strain, ultimate strength and residual strain were evaluated. The influence of the imposed strain on the shape recovery percentage after heating the samples was also discussed. The results revealed changes in the properties with strain rate, not only in mechanical properties but also in the micromechanisms of fracture and residual strain after cyclic mechanical testing. This analysis expands the spectrum of studies on mechanical properties and superelasticity for CuAlMn system alloys, indicating the strain rate conditions in which the alloy must be submitted to preserve the characteristics required in a given practical application.

Keywords

• Shape memory alloy
• Superelasticity
• Strain rate
• Fracture