Influnce of brazing temperature on microstructure of TC4 and Ti₃Al-Nb alloy brazed joint

TC4 and Ti₃Al-Nb alloys were brazed in vacuum by using powered filler metal of 50Ti-20Zr-20Ni-10Cu.Microstructure and property of the joint with different brazing temperature were investigated by scanning electron microscopy,energy dispersive spectroscopy,electron probe and tensile test.The results showed that the tensile strength of the joint do not raise with the brazing temperature.With different brazing temperature,the widmanstatten structure appears near TC4 alloy boundary in the brazed joint,and when the temperature raises,widmanstatten structure coarse degree will increase.In the brazed joint,the interaction degree between base metal of Ti₃Al-Nb alloy and filler metal was less than that of TC4 alloy and filler metal.