Abstract
Titanium aluminides Ti3Al and TiAl were synthesized by the use of TiH2+Al powder mixtures. Phase transformations occurring upon the decomposition of titanium hydride in vacuum and inert gas and synthesis of titanium aluminides were studied. It was shown that the use of titanium hydride instead of titanium in powder mixtures with aluminum results in a significant activation of diffusion processes, and leads to an accelerated production of single-phase titanium aluminides upon isothermal heating. This is attributable to the small particle size of the charge, high density of defects (including those due to hydrogen-phase hardening) in the titanium and aluminum lattices, and possible reduction of Al2O3 films by atomic hydrogen.
The type of atmosphere did not noticeably effect the rate of phase formation, however synthesis in vacuum appears to be more practical since hydrogen is completely removed with simultaneous formation of the aluminides. Due to the fact that aluminum reacted completely with titanium in the solid state, final products close to theoretical densities were obtained without the application of high pressure.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
J. C. Chessnut, J. A. Hall, and H. A. Lipsitt, “Titanium intermetallics—present and future,” in:Titanium’95: Science and Technology: Proc. 8th World Conference on Titanium, London (1996), pp. 70–79.
P. J. Bania, “An advanced alloy for elevated temperatures,”JOM,40, No. 3, 20–22 (1988).
Y. W. Kim and D. M. Dimiduk, “Progress in understanding gamma titanium aluminides,”JOM,43, No. 8, 40–47 (1991).
G. Leitner, M. Dahms, et al., “Reaction sintering of titanium aluminides at different contact areas Ti/Al,” in:Proc. World Congress on Powder Metallurgy (France, 1994), Les Editions de Physique, Paris (1994), pp. 1457–1460.
T. J. Jewett, G. X. Wang, U. Bohnenkamp, and M. Dahms, “Phase formation during annealing of cold-extruded elemental powders Ti−48Al and Ti−48Al−2Cr.,” in:Proc. World Congress on Powder Metallurgy (France, 1994), Les Editions de Physique, Paris (1994), pp. 1457–1460.
I. Morgenthal, X. Neubert, and B. Kieback, “Reactive HIP sintering of extruded Ti48Al2Cr2Nb elemental powder mixture,” in:Proc. World Congress on Powder Metallurgy (France, 1994), Les Editions de Physique, Paris (1994), pp. 1259–1262.
B. Dogan, G. X. Wang, and M. Dahms, “Tensile properties and fracture behavior of Ti−48Al and ti−48Al−2Cr prepared from elemental powders,”Scr. Met.,29, 943–948 (1993).
J. C. Ravers, W. R. Wrzesinski, E. K. Roub, and R. R. Broun, “TiAl−SiC conposites prepared by high temperature synthesis,”Mater. Sci. Tech.,6, Feb., 187–191 (1990).
V. A. Gol’tsov, N. M. Timofeev, and I. U. Magikina, “The phenomenon of hydrogen-phase hardening in hydride-forming metals and alloys,”Dokl. Akad. Nauk SSSR. 235, No. 5, 1060–1063 (1977).
M. Dahms, G. Leitner, and W. Poessnecker, “Pore formation during reactive sintering of extruded titanium-aluminum powder mixtures,”Zurn. Metallkd.,84, No. 5, 351–357 (1993).
Additional information
Institute of Metal Physics and Institute for Problems of Materials Science, Ukraine National Academy of Scienes, Kiev. Translated from Poroshkovaya Metallurgiya, Nos. 9–10(409), pp. 63–70, September–October, 1999.
Rights and permissions
About this article
Cite this article
Ivasishin, O.M., Demidik, A.N. & Savvakin, D.G. Use of titanium hydride for the synthesis of titanium aluminides from powder materials. Powder Metall Met Ceram 38, 482–487 (1999). https://doi.org/10.1007/BF02676065
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02676065