Vol.47, No.8, 488 ~ 494, 2009
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Title |
A Study on the Synthesis and Consolidation of Ti3Al by Electro-Discharge |
장형순 Hyung Sun Jang , 조유정 Yu Jung Cho , 강태주 Tae Ju Kang , 김기범 Ki Beom Kim , 이원희 Won Hee Lee |
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Abstract |
Direct syntheses of bulk Ti3Al via electro-discharge-sintering (EDS) of a stoichiometric elemental powder mixture were investigated. A capacitor bank of 450 μF was charged with three input energies, 0.5, 1.0, and 1.5 kJ. The charged capacitor bank was then instantaneously discharged through 0.3 g of a Ti-25.0 at.%Al powder mixture for consolidation. Complete phase transformation occurred in less than 200 μsec by the discharge and a bulk Ti3Al compact was obtained. Compared with consolidated samples fabricated by conventional methods such as high vacuum sintering and casting, the electro-discharge-sintered Ti3Al compact shows a very fine microstructure with a hardness value of 425 Hv. Electro-discharge-sintering under a N2 atmosphere successfully modified the surface Ti oxide of the Ti3Al compact into Ti nitride, which concurred with the synthesis and consolidation of Ti3Al. Complete conversion yielding a single phase Ti3Al is primarily dominated by the fast solid state diffusion reaction. |
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Key Words |
Ti3Al, intermetallic compound, electro-discharge-sintering, phase transformation |
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