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International Journal of Metallurgical & Materials Engineering Volume 1 (2015), Article ID 1:IJMME-107, 4 pages
http://dx.doi.org/10.15344/2455-2372/2015/107
Research Article
Developing New Type of High Temperature Alloys–High Entropy Superalloys

A.C Yeh1*, T. K. Tsao1, Y.J.Chang1, K.C. Chang1, J.W. Yeh1, M.S. Chiou2, S.R. Jian2, C.M. Kuo3, W.R. Wang4 and H. Murakami5

1Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, 30013, Taiwan R.O.C.
2Department of Materials Science and Engineering, I-Shou University, Kaohsiung, 84001, Taiwan R.O.C.
3Department of Mechanical and Automation Engineering, I-Shou University, Kaohsiung, 84001, Taiwan R.O.C.
4Clean Energy and Eco-technology Center, Industrial Technology Research Institute, Tainan, 70955, Taiwan R.O.C.
5National Institute for Materials Science, Sengen 1-2-1, Tsukuba, Ibaraki, 305-0047, Japan
Prof. An-Chou Yeh, Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, 30013, Taiwan R.O.C.; E-mail: yehac@mx.nthu.edu.tw
25 March 2015; 23 June 2015; 25 June 2015
Yeh AC, Tsao TK, Chang YJ, Chang KC, Yeh JW, et al. (2015) Developing New Type of High Temperature Alloys–High Entropy Superalloys. Int J Metall Mater Eng 1: 107. doi: http://dx.doi.org/10.15344/2455-2372/2015/107
This work was supported by the Ministry of Science and Technology, Taiwan (R.O.C.), project grant number: 103- 2221-E-214 -035, 103-2218-E-007 -019.

Abstract

Novel high temperature alloys – high entropy superalloys (HESA) have been developed by elevating the mixing entropies of Ni-Al-Co-Cr-Fe-Ti systems, these alloys contain stable FCC γ matrix and L12 γ' precipitates; compositions spaces are outside the scopes of traditional Ni-base superalloys and equimolar high entropy alloys. The thermal stability of high entropy γ' precipitates can be enhanced through alloy design by thermodynamic calculation based on Thermo-Calc. HESAs have potentials to high temperature structural application; alloy densities are below 8.0 g/cm3 with lower cost of raw materials than those of conventional Ni-base superalloys.