Microstructure characteristic and performance of bonding interface between titanium alloy/copper/GCr15

Difficulty for diffusion bonding of different structure of titanium alloy/bearing steel restricts the application of titanium alloy.The mechanical properties of Ti-6Al-4V/Cu/GCr15 joints were evaluated by electronic tensile machine.The microstructure characteristic and performance of the bonding interface were analyzed by scanning electron microscopy and EDX.Microhardness,the fracture characteristics and area of intermetallic compounds of the joints were analyzed by X-ray diffraction.The results indicated that the tensile strength of the joints under the bonding time 1.8 ks,pressure 4.9 MPa,rises with the bonding temperature,the tensile strength of joint reaches a maximum of 206 MPa in 1 273 K.The extension bonding time caused the intermetallic compound thickness to increase which would do harm to the joints performance.α-Ti(Cu) solid solution which was generated in bonding interface was advantageous to enhance the joints performance.However,the Ti_xMCu_y had more influence on joints performance which was Ti₂Cu,Ti₂Cu₃,(Ti₃Cu₄) FeTi,those caused the joint strength to go down.Copper foil should not be too thick to be as interlayer in titanium/GCr15.