Effect of Preheating Temperature and Chamber Pressure on the Properties of Porous NiTi Alloy Prepared by SHS Technique

The fabrication of porous NiTi shape memory alloys (SMAs) from elemental powder compacts was conducted by selfpropagating high temperature synthesis (SHS). Effects of the preheating temperature and the chamber pressure on the combustion characteristics as well as the final morphology and the composition of products were studied. The samples with porosity between 56.4 and 59.0% under preheating temperature in the range of 200-300°C and Ar-gas chamber pressure of 138 and 201 kPa were obtained. The pore structures were found to be dissimilar only in the samples processed with different preheating temperature. The major phase in the porous product is NiTi with small amounts of secondary phases, NiTi2 and Ni4Ti3. The preheating temperature and the chamber pressure have very little effect on the phase constituent. While the combustion temperature of the sample was notably increased by increasing the preheating temperature, they were slightly changed by varying the chamber pressure.





References:
[1] J.J. Moore and H. Feng, in Progress in Materials Science, 39, pp. 243.
[2] B.Y. Tay, C. W. Goh, M. S. Yong, A.M. Soutar, Q. Li, M. K. Ho, M. H.
Myint, Y.W. Gu and C. S. Lim, in SIMTech technical reports, 7, pp. 21-
25, 2006.
[3] D. Starosvetsky and I. Gotman in Biomaterials, 22, pp. 1853-1859,
2001.
[4] A. Kanapen, J. Ryhänen, A. Danilov, and J. Tuukkanen, in Biomaterials,
22, pp. 2475-2480, 2001.
[5] Y. H. Li, L. J. Rong, and Y. Y. Li, in J. Alloys Comp., 345, pp. 271-274,
2002.
[6] C. L. Yeh and W. Y. Sung, in J. Alloys Comp. ,376, pp. 79-88, 2004.
[7] B. Y. Li, L. J. Rong, Y. Y. Li, and V. E. Gjunter, in Acta Materialia. 48,
pp. 3895-3904, 2000.
[8] S. Wisutmethangoon, N. Denmud, L. Sikong and W. Suttisripok, in
Songklanakarin J. of Science and Technology 30, pp. 6, 2008.
[9] K. C. Patil, S. T. Aruna, and T. Mimani, in Solid State Mater. Sci. 6, pp.
507-512, 2002.
[10] C.L. Chu, B. Li, S.D. Wang, S.G. Zhang, X.X. Yang, and Z.D. Yin, in
Trans. Nonferrous Met. Soc. 7, 4, pp. 84, 1997.
[11] ASTM Standard B328. American Society for Testing and Materials,
Philadelphia, PA, 1987.
[12] R.M. Marin-Ayral, M.C., Dunez, and J.C. Tedenac, in Materials
Research Bulletin. 35, pp. 233-243, 2000.
[13] Z. A. Munir and L. L. Wang, in Proceedding of 1st US-Japanese
Workshop on Combustion Synthesis, eds Y. Kaieda and J. B. Holt, 123,
1990.
[14] C. L. Chu, C. Y. Chung, P. H. Lin, and S. D. Wang, in Mater. Sci. Eng
A. 366, pp. 114-119, 2004.
[15] L. L. Hench, in J. Am. Ceram. Soc. 74, pp. 1487-1510, 1991.