Phase Identification and Microstructure of Ni-Ti-Cu and Ni35Ti50Cu10X5 (X= Fe, Sn, Cr, Nb, Co, Mo) Shape Memory Alloys

This paper reports the influence of Ni/Ti ratio in Ni-Ti-Cu alloys and of the addition of fourth elements (X) in the Ni35Ti50Cu10X5 (X= Fe, Sn, Cr, Nb, Co, Mo) quarternary alloys on the phases formed and microstructure of the respective alloy. The experimetal results showed that the larger Ni/Ti ratio in Ni-Ti-Cu alloys, the larger fraction of Ti0.4Ni0.565Cu0.035 precipitate phase and the lower workability of the alloys. The fourth element added into the Ni-Ti-Cu alloys modified the room temperature phases presented in the alloys by different ways, i.e. by deppressing both B19’(NiTi) and B19’(TiNi0.8Cu0.2) phases (for X=Fe, Co, Nb), by revealing precipitate phases (for X=Sn and Cr) and by deppressing B19’ (TiNi0.8Cu0.2) phases (for X=Mo). Proc. The 12th International Conference on QiR (Quality in Research), Bali 4-7 July 2011