Effect of Cu66V34 filler thickness on the microstructure and properties of titanium/copper joint by electron beam welding

摘要

The joint with 1.0mm Cu66V34 filler metal produced a large amount of unmelted V alloy, weakening the joining quality of Ti/Cu joint. Due to the decreased thickness of filler metal, the melting quantity of Ti increased notably in the joint with 0.5mm Cu66V34 alloy, resulting in the formation of Ti-Cu compounds. The 0.7mm Cu66V34 filler metal could restrain the Ti-Cu compounds formed in the joint. The microstructure in zone A3 and FZ was mainly characterized by solid solution phases including (Ti,V) solid solution and Cu solid solution, improving the bonding strength at the interface of titanium side. The joint with 0.7mm Cu66V34 alloy presented the highest tensile strength of 384 MPa, approaching similar to 80% of that of the copper base metal, and fractured in the HAZ of copper side, due to local softening by grains coarsening.