Properties of Cu-Al-Mn-Ti Shape-memory Alloy Processed by Selective Laser Melting

Abstract

The Cu-11.85Al-3.2Mn-0.1Ti(wt.%)alloy is processed by selective laser melting and the parameters are optimized with the relative density result measured by the Archimedes principle. The phase and microstructures are characterized, and the tensile specimens are formed by using the optimized process parameters. The mechanical properties are tested under different temperature. The phase transformation temperatures are carried out by DSC curves, and the shape memory properties are analyzed. The results show that when laser power, scanning speed, layer thickness and scanning space are 270 W, 500 mm/s, 0.025 mm, 0.1 mm, the maximum relative density of samples is close to 100%. The XRD results and microstructure pictures show that martensite and Cu2AlMn phase appeared in the samples and most of it is stacking fault structure. Besides, the higher tensile strength and elongation are 825.6 MPa and 20.3% at 200℃, the elongation increases with the temperature rises. Moreover, the austenite transformation temperature As and Af are 506℃, 532.5℃, and deformation recovery rate is over 57%.