Eur. Phys. J. Special Topics 158, 67-71 (2008)
https://doi.org/10.1140/epjst/e2008-00655-5

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

¹ Division of Materials Science and Engineering, Korea Institute of Science and Technology, Seoul, 136-791, Korea
² School of Materials Science and Engineering, Hongik University, Jochiwon, 339-800, Korea
³ Division of Metallurgical and Materials Engineering, Chosun University, Gwangju, 501-759, Korea

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.