Effect of oxidation on transformation and deformation behavior in Ni-Ti alloy

Abstract

Effect of oxidation on transformation and deformation behavior was investigated in Ni-Ti alloy by comparing the as-oxidized specimen and the polished one. Ti's preferable reaction with oxygen results in the compounds such as Ni3Ti and Ni4Ti3, and the Ni-rich region between matrix and oxide. Martensitic transformation did not take place in the Ni-rich region due to the high Ni content while R phase transformation temperature decreased significantly. Oxidation deteriorated the superelasticity due to the formation of the compound as well as the Ni-rich region in which slip deformation occurs instead of induction of martensite.