Microstructure and mechanical properties of electron beam welded joints of titanium alloy and Kovar alloy with copper or silver interlayer

The electron beam welding experiments of TC4 titanium alloy and kovar alloy were carried out with Cu or Ag Interlayer. The microstructure and composition of the welded joint were analyzed by optical microscope, scanning electron microscope and x-ray diffraction. The mechanical properties of welded joints were evaluated by microhardness and tensile strength tests. The results show that when Cu is used as the interlayer, there are mainly Cu solid solution and TiFe ,Fe2Ti ,CuTi2 in the joint. The highest hardness of weld is 380HV and the tensile strength is 168 MPa. The joint welded with Ag interlayer exhibit brazing characteristics. The hardness ofjoint is slightly higher than pure silver, and the tensile strength is 243 MPa.