Nitrogen-induced powder formation of titanium aluminides during mechanical alloying
2000; Elsevier BV; Volume: 8; Issue: 7 Linguagem: Inglês
10.1016/s0966-9795(00)00002-9
ISSN1879-0216
AutoresHitoshi Hashimoto, Toshihiko Abe, ZhengMing Sun,
Tópico(s)Advanced ceramic materials synthesis
ResumoThe authors formerly found that introduction of nitrogen gas into milling atmosphere improved drastically production yield of γ-based TiAl powder by mechanical alloying of a powder mix of Ti and Al. In this report, the role of nitrogen gas on the improvement in production yield of γ-based TiAl powder was investigated by three series of milling experiments. As a result, the authors found that: (1) nitrogen gas affects the formation of TiAl powder after milling in argon for a certain period; (2) TiAl powder formed by mechanical alloying has the crystal structure of Al supersaturated α-Ti phase; (3) the content of nitrogen gas in the milling atmosphere has a great influence on the yield; (4) concerning the mechanism, it is presumed that a layer of Al supersaturated α-phase was formed during milling in argon, and transformed into a solid-solution with nitrogen during milling under the existence of nitrogen gas, and thereby became brittle and was broken into the fine powder.
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