Effect of Direct Extrusion on the Microstructure, Microhardness, Surface Roughness and Mechanical Characteristics of Cu-Zn-Al Shape Memory Alloy, SMA.

Shape memory alloys (SMA) are now widely used in many engineering applications especially in robotic, aerospace and vibration control area.The main problem arises from the weakness of their mechanical characteristics. Therefore, this study is directed towards enhancing the mechanical properties through severe plastic deformation. In this paper, the direct extrusion process was chosen to provide the required cold work for this purpose. A direct extrusion die was designed and manufactured to be used in this investigation for improving mechanical behavior of the Cu-Zn-Al shape memory alloy was. The general microstructure, microhardness, surface roughness, and compression tests were performed on specimens from the produced Cu-Zn-Al shape memory alloy both in the as cast and after extrusion conditions. It was found that a pronounced enhancement in the mechanical characteristics of the produced Cu-Zn-Al shape memory alloy, after extrusion was achieved. The microhardness increased by 105.2 %, the flow stress was enhanced by 100 % at 0.2 strain and finally the surface roughness was reduced by 81.8 %.