2003 年 21 巻 2 号 p. 302-309
In this study, diffusion bondings of tantalum to titanium were performed. Effect of the bonding temperature on the joint strength has been investigated. Main results obtained are as follows. β-(Ti-Ta)solid was formed in the bonded zone of the tantalum and the titanium, and(α+β)Ti solid was formed in the titanium base metal away from the bond interface. In the bonded zone of the tantalum to the titanium, Kirkendall voids were not observed though the diffusion of Ta into the titanium occurred over a wide range. The reason why the joint strength increased with bonding temperature is that the non-bonded areas were decreased with an increase in the bonding temperature. The joints of the tantalum and the titanium fractured at the base metal of the tantalum on the tensile test when the bonding was performed at temperatures ranging from 1173 K to 1473 K for a bonding time of 1.8 ks and a bonding pressure of 5.6 MPa. The strength of the joints of the tantalum and the titanium also increased with bonding pressure up to 20 MPa owing to a decrease of non-bonded area when bonding temperature was 1073K.