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 to produce more intermetallic compound. The bonding of ZQSn10-10 to copper as interlayer metal is well formed, so that intergradation zone would not obviously develop, but the intergradation zone well develops between copper and titanium alloy and the intermetallic compound Cu₃Ti₂ appears. The optimum bonding parameters are: bonding temperature 850°C, bonding pressure 10-15 MPa; bonding time 30 min. So the strength of the joint without obvious shape change is up to 192 MPa reaching to about 80% of the strength of base metal ZQSn10-10.