The Effect of Heat Treatment on the Microstructure and Mechanical Properties of Cu-Al-Mn Shape Memory Alloy

Abstract

The 8-mm diameter bars of Cu-Al-Mn shape memory alloys were produced by continuous casting technique. The samples were characterised using optical microscopy and scanning electron microscopy along with EDX analysis. The continuous cast alloy revealed some martensitic phase, which, after quenching, led to the microstructure that is completely martensite. Quenching of samples had an effect on several mechanical properties and change in morphology of fracture. After ageing at 200 °C and 300 °C, the tensile strength increased and elongation drastically decreased. Morphology of fracture surface changed from primary ductile to a mixture of intergranular and ductile.

Keywords

• mechanical properties
• microstructure
• scanning electron microscopy (SEM)
• quenching
• shape memory alloys (SMAs)
• ageing