Effects of Sn Addition on NiTi Shape Memory Alloys

摘要

NiTiSn shape memory alloys provide a cost-effective alternative to many NiTi-based low-temperature shape memory alloy systems such as NiTi: Cr, Co, and Nb. To demonstrate the viability of NiTiSn shape memory alloys for low-temperature actuator applications, the NiTiSn alloy system was investigated over the course of four alloy heats (Heats I-IV). The site preference of Sn in near-equiatomic NiTi was examined by substituting Sn for Ni in Heat I and Sn for Ti in Heat II up to 10 at.% Sn. The effects of solution annealing (Heat III) and Ni:Ti ratio adjustments (Heat IV) on the phase transformation behavior and microstructural morphology of NiTiSn shape memory alloys were also assessed.