Mechanical Performance of the Annealed NiTi Shape Memory Alloy Coating onto 316L Stainless Bio-Steel

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Abstract:

This paper presents the mechanical performance of the annealed NiTi Shape Memory Alloy (SMA) coating deposited onto 316L stainless steel substrate. The as-deposited SMA coating, Ni55.9 Ti44.1, showed an amorphous behaviour. The crystalline NiTi (SMA) coating was produced by annealing the as-deposited NiTi with a thickness about 2.0 µm, at above its crystallisation temperature in a vacuum ambient. The annealed NiTi coatings were characterised to determine the effect of the annealing parameters on their mechanical behaviour. The NiTi phases and structures were determined by x-ray diffraction (XRD) and scanning electron microscopy (SEM) whereas the mechanical properties were measured using the Rockwell C adhesion test. Three main phases; NiTi B2 parent phase, Ni3Ti and TiO2 were found in the annealed samples and the intensities of each phase were dependent on the annealing temperature and annealing time. Each phase significantly affected the mechanical behaviour of the coatings. Higher intensities of Ni3Ti and TiO2 phases were believed to contribute to the low adhesion of the annealed NiTi coatings due to their brittle properties. The annealing parameters; 600 °C for durations of 30 min was considered as the optimum parameter, yielding no fine cracks at the Rockwell C indentation interface compared to other samples at high magnification under the SEM. Adding a hard top layer of TiN would potentially provide a hard coating with an interlayer capable of absorbing impact which would be very suitable for ball joints used in hip replacement therapy.

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Periodical:

Defect and Diffusion Forum (Volumes 297-301)

Pages:

365-369

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Online since:

April 2010

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[1] K. Otsuka and X. Ren: Prog. Mater. Sci. Vol. 50 (2005), p.511.

Google Scholar

[2] S. Mändl, A. Fleischer, D. Manova and B. Rauschenbach: Surf. Coat. Technol. Vol. 200 (2006), p.6225.

Google Scholar

[3] Y. Zhang, Y. Cheng and D. S. Grummom: Surf. Coat. Technol. Vol. 202 (2007), p.998.

Google Scholar

[4] A. V. Sergueeva, C. Song, R. Z. Valiev and A. K. Mukherjee: Mater. Sci. Eng. A Vol. 339 (2003), p.159.

Google Scholar

[5] A. Kumar, D. Singh, R. N. Goyal and D. Kaur: Fabrication and nanoindentation properties of TiN/NiTi thin films and their applications in electrochemical sensing, Talanta (2009) in press.

DOI: 10.1016/j.talanta.2009.01.005

Google Scholar

[6] W. Ni, Y. Cheng, M. Lukitsch, A. M. Weiner, L. C. Lev and D. S. Grummon: Wear Vol. 259 (2005), p.842.

DOI: 10.1016/j.wear.2005.01.015

Google Scholar

[7] X. Cao, X. Cao and Q. Zhang: J. Alloys Compd. Vol. 465 (2008), p.491.

Google Scholar

[8] L. Zhang, C. Xie and J. Wu: J. Alloys Compd. Vol. 427 (2007), p.238.

Google Scholar

[9] A. A. C. Recco, I. C. Oliveira, M. Massi, H. S. Maciel and A. P. Tschiptschin: Surf. Coat. Technol. Vol. 202 (2007) p.1078.

Google Scholar

[10] F. F. Gong, H. M. Shen and Y. N. Wang: Appl. Phys. Lett. Vol. 69 (1996), p.2656.

Google Scholar

[11] M. Pohl, T. Glogowski, S. Kühn, C. Hessing and F. Unterumsberger: Mater. Sci. Eng. A Vol. 481-482 (2008), p.123.

Google Scholar

[12] T. Abubakar, M. Rahman, D. P. Dowling, J. Stokes and M.S.J. Hashmi: Surface Engineering sur449. 3d, (in press, available online 23 April 2009).

Google Scholar

[13] T. A. A. Bakar, M. Rahman, D. P. Dowling, J. Stokes and M.S.J. Hashmi: Proceedings of the IV ECCOMAS Thematic Conference on Smart Structures and Materials, edited by Alvaro Cunha et al. (July 2009, Porto, Portugal) p.463.

Google Scholar