Effect of Isolation Coatings on Mechanical Property of Electron Beam Welding Joint of Titanium Alloy to Stainless-steel

Electron beam welding, electron beam isolation welding, and electron beam isolation welding-brazing for the dissimilar combination of titanium alloy and stainless steel were studied. The results show that the brittle intermetallic compound formed in the welding process is the key factor to influence the joint properties. The penetrated crack is formed in the electron beam welding process and the electron beam isolation welding process directly leading to the unsuccessful joint. In the electron beam isolation welding-brazing process, the joints have the characteristics of welding and brazing and the metallurgically bonded joint is achieved without melting the titanium alloy sheet. Ag and Cu as filler material exhibit a good isolation layer which minimizes the formation of Ti/Fe intermetallics, and has a relaxation effect on the residual stress of the weld. The interalloying of dissimilar materials is well controlled, and a reaction zone is gained on the interface. The maximum tensile strength of titanium alloy/stainless-steel is up to 100 MPa. The welded seams are formed well in both sides of the joints and there is no crack and detected porosity in the joints through X-ray inspection.