Formation and stability of Al{sub 3}Ti in the hyper-peritectic AlTi alloys after mechanical alloying
- Korea Inst. of Science and Technology, Seoul (Korea, Republic of). Div. of Metals
Mechanical alloying is an effective way to finely distribute inert dispersoids in Al-TM (TM is a transition metal element) systems. It is considered that high melting point aluminides are formed by precipitation from the supersaturated aluminum matrix. The analysis is based on the fact that much higher content of TM than the solubility limit can be dissolved in alpha aluminum during the high energy ball milling. Nonetheless, the role of undissolved TM particles affecting the formation of aluminides is not suitably considered. In this paper, authors present experimental observation on the formation of Al{sub 3}Ti particles from mechanically alloyed Al-Ti alloys in the hyper-peritectic region. This study showed that, in the mechanically alloyed Al-20wt%Ti specimen, intermediate phase of cubic Al{sub 3}Ti and tetragonal Al{sub 24}Ti{sub 8} formed at 300--400 C and 400--500 C, respectively, before the MA-state reaches to the global equilibrium at higher temperatures. The formation behavior of L1{sub 2}-Al{sub 3}Ti is interpreted by interdiffusion of Al and Ti in solid state based on the fact that large amount of nano-sized Ti particles exist in the milled powder. Present analysis indicated undissolved Ti particles of nanosize should have played an important role initiating the formation of Al{sub 3}Ti phase during annealing.
- OSTI ID:
- 367627
- Report Number(s):
- CONF-960202-; ISBN 0-87339-310-4; TRN: IM9640%%373
- Resource Relation:
- Conference: Annual meeting and exhibition of the Minerals, Metals and Materials Society (TMS), Anaheim, CA (United States), 4-8 Feb 1996; Other Information: PBD: 1996; Related Information: Is Part Of Design fundamentals of high temperature composites, intermetallics, and metal-ceramics systems; Lin, R.Y. [ed.] [Univ. of Cincinnati, OH (United States). Dept. of Materials Science and Engineering]; Chang, Y.A. [ed.] [Univ. of Wisconsin, Madison, WI (United States). Dept. of Materials Science and Engineering]; Reddy, R.G. [ed.] [Univ. of Nevada, Reno, NV (United States). Dept. of Chemical and Metallurgical Engineering]; Liu, C.T. [ed.] [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.]; PB: 461 p.
- Country of Publication:
- United States
- Language:
- English
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