Microstructure And Properties Of GH4169 Superalloy TLP Bonding Joints

Based on the recent and extensive application of GH4169 nickel-base superalloy in aviation and aerospace,this paper analyzed the TLP development situation and optimized the traditional processes.Three different diffusion welding processes:constant pressure and temperature process,exerting pressure at low temperature process,diffusing at elevated temperature were designed and 45?m BNi-2 foil was used as interlayer.The microstructure and tensile strength of welding joints welded by these three processes were studied,The direction and basis of process optimizing were provided.The number,size,and distribution of precipitates were analyzed concretely,composition was analyzed by SEM and EDS.The width of ISZ and DZ,grain size,hardness,and room temperature tensile strength of three kinds welding joints were tested,and the connection of process-microstructure-property was analyzed.Used SEM,EDS,XRD,OM to clarify fracture position and pointed the weak position of joints.In the end,optimized the TLP bonding process curve and analyze the effects of welding pressure on microstructure and mechanical properties of welding joints welded with constant pressure and temperature process,and indicatethe negative effects on welding joints when increase isothermal solidification time.A new kind of precipitates was found In ISZ of welding joints welded with exerting pressure at low temperature process,cause of formation and disadvantage were illustrated,process parameters selective principles and process optimization were studied.