Diffusion bonding of Ti-6Al-4V to ZQSn10-10 with a copper Interlayer

The experimental investigation of the diffusion bonding of titanium alloy(Ti-6Al-4V) to Tin-bronze (ZQSn10-10) in vacuum was carried out by using pure copper as the transition metal. The microstructure of the joints was studied by SEM、EDS etc. and their mechanical properties were tested by tensile experiments. Experimental results show that using copper as interlayer, it can not only avoid some elements(Sn、Pb etc.) volatilizing but also prevent unwanted elements from diffusion. So the properties of joint can be improved by avoiding more intermetallic compound. The bonding of ZQSn10-10 to copper as interlayer metal is well formed, which intergradation zone can not obviously developed, but the intergradation zone well develop between copper and titanium alloy which intermetallic compound Cu₃Ti₂ concomitantly appear. The optimum bonding parameters were:bonding temperature T=850℃,bonding pressure P=10~15 MPa and bonding time t=30 min. So the strength of the joint without obvious shape change was up to 192MPa reaching to about 80% of the strength of base metal ZQSn10-10.