Microstructural evolution and mechanical properties of nanostructured Cu-Al-Ni shape memory alloys

摘要

The melt spinning technique, with an applied cooling rate of about 10~6 K/s, was used to produce a nanostructured Cu+13.2Al+ 5.1Ni (in wt%) shape memory alloy. The properties of nanostructured ribbons were then compared with those of conventional coarse structure. The microstructural evolution was characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD) techniques. Microhardness measurements indicate a two-fold increase in hardness because of the produced nanos-tructure. Comparing to its coarse structure, the nanostructured Cu-Al-Ni shape memory alloy exhibited the enhanced mechanical properties including a ductility of 6.5% and a pronounced plateau in the stress-strain curve.