アルミニウム青銅の焼結に及ぼすAl-Ca系フッ化物添加の効果

抄録

In order to accelerate sintering of Al-Bronze powder covered with passive oxide film, we focused on the way to add Al-Ca fluoride consisting of AlF₃ and CaF₂, examined effect of CaF₂ mixing rate in Al-Ca fluoride, amount of added Al-Ca fluoride and sintering temperature on sintering properties of Al-Bronze powder and considered the mechanism of acceleration of sintering. Al-Bronze powder was sintered most effectively by adding Al-Ca fluoride with CaF₂ mixing rate of 20 mass%. If amount of added fluoride was over 0.05 mass% and sintering temperature was over 1123K, the acceleration of sintering of Al-Bronze powder began to appear. On the mechanism of acceleration of sintering, it was presumed that Al₂O₃ film on the surface of Al-Bronze particles was removed in process of the formation of gaseous AlOF by, the reaction with AlF₃, and the reaction was accelerated further by the presence of liquid phase appeared in Al-Ca fluoride.