Effect of Hafnium Addition in 60NiTi Alloy Hardened Under Open Atmosphere Conditions

被引：9

作者：

Khanlari K. ^{[1
]}

Ramezani M. ^{[1
]}

Kelly P. ^{[2
]}

Neitzert T. ^{[1
]}

机构：

[1] Department of Mechanical Engineering, Auckland University of Technology, Auckland

[2] Department of Engineering Science, University of Auckland, Auckland

来源：

Metallography, Microstructure, and Analysis | 2018年 / 7卷 / 04期

关键词：

60NiTi; Hf addition; Intermetallics; Open atmosphere heat treatment;

D O I：

10.1007/s13632-018-0462-1

中图分类号：

学科分类号：

摘要：

Vacuum furnaces or furnaces backfilled with inert argon gas are commonly employed to conduct hardening treatment on 60NiTi alloy. However, vacuum furnaces with the possibility of drop-quenching the solutionized parts are not easily available, and backfilling the furnaces with inert argon gas is costly. In this research, the hardening treatments were carried out in an air-exposed environment. As expected, reaction of Ti with oxygen gas existing in air during heat treatment resulted in formation of an oxide layer on the surface. This led to the depletion of Ti from the NiTi matrix and consequent formation of Ni-rich zones causing precipitation of soft Ni-rich phases. It was found that the addition of 1 at.% hafnium (Hf) prevented the soft Ni-rich phases formation in the matrix of the outer surface regions. This result suggests that Hf addition can be considered as a solution to harden a 60NiTi alloy under cost-effective open atmosphere heat treatment conditions. © 2018, Springer Science+Business Media, LLC, part of Springer Nature and ASM International.

引用

页码：476 / 486

页数：10

共 27 条

[1]

Dellacorte C., Nickel–titanium alloys: Corrosion “proof” alloys for space bearing, components and mechanism applications, Proceedings of the 40Th Aerospace Mechanisms Symposium, (2010)

[2]

DellaCorte C., Novel super-elastic materials for advanced bearing applications, Adv. Sci. Technol., 89, pp. 1-9, (2014)

[3]

Dellacorte C., Wozniak W.A., Design and manufacturing considerations for shockproof and corrosion-immune superelastic nickel–titanium bearings for a space station application, (2012)

[4]

Stanford M.K., Preliminary investigation of surface treatments to enhance the wear resistance of 60-nitinol, (2016)

[5]

Dellacorte C.L.E., Clifton J.S., The effect of pre-stressing on the static indentation load capacity of the superelastic 60NiTi, (2013)

[6]

Julien G.J., Manufacturing of Nitinol Parts and Forms, (2002)

[7]

Dellacorte C., The effect of indenter ball radius on the static load capacity of the superelastic 60NiTi for rolling element bearings, (2014)

[8]

Khanlari K., Ramezani M., Kelly P., 60NiTi: a review of recent research findings, potential for structural and mechanical applications, and areas of continued investigations, Trans. Indian Inst. Met., 71, pp. 1-19, (2017)

[9]

Dellacorte C., Nickel–titanium alloys for oil-lubricated bearing and mechanical component applications, Proceedings of the ASME/STLE 2009 International Joint Tribology Conference, pp. 293-300, (2009)

[10]

Stanford M.K., Hardness and microstructure of binary and ternary nitinol compounds, (2016)

← 1 2 3 →