The interfacial microstructure and properties for Ti(C,N)/Ni in diffusion bonding process

The microstructure and properties of Ti(C,N)/Ni interface in vacuum diffusion welding using Cu and Nb interlayer had been investigated.The results show that when diffusion welding temperature was lower than 1273 K the interface interlayer did not change,the interface microstructure was Cu/Nb layer structure,and Cu diffused into Ni with a little.But when the temperature was 1523 K,interface microstructures were Ni_8Nb metallic compound and dispersing deposition CuNi solid solution early,which were transformed into (Ti,Nb)(C,N)+ Nb_7(Ni,Ti,Cu)_6+NbNi_3 near Ti(C,N) and NiCu+NbNi_8 near Ni at last.It indicated that Cu is as transition liquid that dissolved Ni to form CuNi transition liquid,and then Nb is dissolved in CuNi transition liquid rapidly.Ti(C,N) can been wetted with NiNbCu transition liquid, and then a little (Ti,Nb)(C,N) solid solution are formed at interface,which increase interface combining capability.The interface shear strength may get to 140 MPa.