Combustion Synthesis Process of Ag Added Al_3Ti Intermetallic Compound

摘要

The effect of Ag addition to the mixture of Al and Ti on the densification of synthesized Al-Ti intermetallic compounds was examined. By the Ag addition, ignition temperature to form Al_3Ti was lowered to the eutectic temperature of the Al-Ag alloy. When elemental powder mixture with 2% Ag was continuously heated to 973K under the uniaxial pressure of 1.0MPa, void ratio of sintered compact was reduced to 0.1% and the densification was enhanced by increasing the composition of Ag. Al_3Ti and AgiAl were formed in the as sintered compact and Ag_2Al decomposed to solve Ag into L1_2-Al_3Ti by further heating at 1073K for 14.4ks. Although Ag addition decreased the hardness of sintered compact lower than that of Al_3Ti, it still retained the hardness of about 400H_V for 12% Ag added specimen. The sintered compact was hardly damaged after oxidizing at 1273K for 230.4ks due to the formation of protective Al_2O_3 surface scale.