Research on microstructure and properties in interface of diffusion bonding for Cu-0.15Zr and GH3030 with Cu as interlayer

In this paper, Cu was applied as the interlayer, the Cu-0.15Zr was joined to GH3030 with vacuum diffusion bonding method at the temperature of 600℃,650℃,700℃,750℃ and 800℃for 45 min under 15MPa axial pressure. The microstructure and property of the joints bonded at different conditions were tested.The results showed that the width of diffusion zone was increased and the number of holes in diffusion zone reduced with the increase of the welding temperature.The α-Cu phases, rich Cr,Ni,Al carbide phases were uniform distribution in the interface. At 750℃,the number of strengthening phases increased,but many Kirkendall voids appeared,in addition,serious softened Cu-0.15Zr caused a big deformation of the joint. The tensile samples were fracture in Cu-0.15Zr side when temperature was too low or too high. The dimples were non-equiaxed and the snake slip line was apperaed in dimple wall at Cu-0.15Zr side.The second phases were present on both sides in the bottom of the dimples. The fracture type was intergranular ductile fracture. By considering the bonding rate,deformation and mechanical properties,it concluded that under the condition of 45 min and 15 MPa,700℃ was the best welding temperature parameter.