Microstructure characteristics of induction brazed TiAl/35CrMo joint with Ag-Cu-Ni-Li filler metal

Microstructure of the induction brazed TiAl/Ag Cu Ni Li/35CrMo joints was analyzed by means of scanning electron microscope,electron probe microanalysis and energy dispersive X ray spectrometry.The results show that there is a wide reaction zone and narrow reaction zone in the brazed seam along radial orientation of the brazed joints.The two zones are situated outside and inside of the brazing seam respectively.The boundary of two zones is obvious.The interface structure of the joint brazed at 900℃ for 5 min can be expressed as TiAl/the diffusion layer between TiAl and brazing filler metal/Ag rich,Cu rich phase/Ti(Cu,Al)₂/Ag rich phase/AlM₂Ti(M represents Fe,Cu,Ni)/the diffusion layer between brazing filler metal and 35CrMo/35CrMo.The morphoses of the reaction layer near TiAl side is equiax crystal and columnar crystal of Ti(Cu,Al)₂.There exists orientation relationship between and Ti(Cu,Al)₂ and TiAl.