Properties of Ni-Rich NiTi Alloys Produced by Powder Metallurgy Route

Abstract

This paper presents the processing of Nickel Titanium (NiTi) alloy from elemental powders of Nickel and Titanium by conventional powder metallurgy process. Two batches of feedstock containing 2 different formulations (1) Ti-50.4at% Ni and (2) Ti-50.8at% Ni were prepared. The feedstocks for each composition were warm-pressed and subsequently sintered in vacuum at 1150°C. Based on the XRD result, it clearly showed that the conventional sintering following warm-press method is promising in producing greater amount of the predominant NiTi (B2) phase and a minor fraction of martensitic NiTi (B19’) phase. The reversible phase transformation and the microstructure of the sintered samples have also been observed and discussed.