Document 
Eur. Phys. J. Special Topics 158, 67-71 (2008)
DOI: 10.1140/epjst/e2008-00655-5
Effect of oxidation on transformation and deformation behavior in Ni-Ti alloy
K.S. Kim1, 2, K.K. Jee1, Y.B. Kim1, W.Y. Jang3 and S.H. Han11 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
(Published online: 1 May 2008)
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.
© EDP Sciences, Springer-Verlag 2008