金属間化合物の粉末冶金と諸物性 Ｂ添加Ｎｉ３Ａｌ金属間化合物の無加圧燃焼合成の試み

Abstract

To realize combustion synthesis process of intermetallic compound, a method of synthesizing the dense products should be developed. In my previous paper, synthesis of full dense Ni3Al has been investigated. Consequently, the dense Ni3Al was synthesized in case of using fine powders as initial substances. Incidentally, it is known that Ni3Al intermetallic compound is brittle and that additive of B is effective for improvement of its ductility. In this paper, preparation of full dense B added Ni3Al by pressure less combustion synthesis process was investigated. Fine Ni, Al and B powders were mixed (Ni:Al=3:1 in atomic ratio, B=0.05-1.0mass%), and pressed into cylindrical compacts. The compacts were burned by thermal explosion reaction in a vacuum furnace. However, B added compacts fused during the synthesis. The meltdown might be due to over formation of liquid phase caused by B additive. Accordingly, the mixing ratio of Ni and Al powders was controlled, and then the nearly full dense B added Ni3Al was synthesized. By compressive strength test of the products, it was confirmed that the B added products exhibited ductility. Therefore, the combustion synthesis process is effective to compose Ni3Al intermetallic compound.