Fabrication of Cu-Al-Ni Shape Memory Alloy by Selective Laser Melting Process

Abstract

Additive manufacturing (AM) is a prominent technology in the industrial fields such as aerospace, medical, automotive and so on. Especially, selective laser melting (SLM) process is available to create three-dimensional complicated structures of various alloys such as stainless steel, titanium alloy, aluminium alloy, nickel-based superalloy and so on. And also, copper and copper alloys are used as a material for products with complicated shape, electrical components, and a heat exchanger because of having the high electrical conductivity and the high thermal conductivity. It is known that copper alloys show a good shape memory behaviour by adding Al, Ni and Zn. Especially, Cu-Al-Ni alloy shows a good shape memory properties at high temperature. However, it is difficult to fabricate high-density Cu-Al-Ni alloy by the SLM process. This is mainly because Cu-Al-Ni alloy has high elastic anisotropy and brittleness in polycrystalline state. In this research, the optimum fabrication condition of Cu-Al-Ni alloy by SLM process was investigated. The optimum laser power and scan speed were able to be found by evaluating the surface morphology, density and microstructure of the as-build specimens.The maximum density of the as-built specimen was 99.47%.