Influence of electron-beam superposition welding on intermetallic layer of Cu/Ti joint
(State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China)
Abstract: QCr0.8 was electron-beam welded to TC4 and the effect of the intermetallic layer (IMC-layer) on the mechanical properties of the joint was investigated. The IMC-layers are joint weaknesses at the Cu fusion line in centered welding and at the Ti fusion line when the beam is deviated towards Cu. A new method referred to as electron-beam superposition welding was presented, and the optimal welding sequence was considered. The IMC-layer produced by centered welding was fragmented and remelted during Cu-side non-centered welding, giving a finely structured compound layer and improved mechanical properties of the joint. The tensile strength of joint is 276.0 MPa, 76.7% that of the base metal.
Key words: Cu alloy; Ti alloy; electron beam superposition welding; IMC-layer