Study On Transient Liquid Phase Diffusion Bonding Of Ti(C,N)/intermediate Layer/40Cr Steel

Ti(C,N)-based cermets because of its high hardness, strength, wear resistance, goodchemical stability and resistance to creep properties, which are used in a variety ofindustries and fields such as machinery and metallurgy. But its brittleness, toughness andimpact resistance ability is poor, it’s difficult to make large size with complicated shape ofthe component. So it is great significance that the realization of Ti(C,N)-based cermets and40Cr steel are reliably connected. This topic have carried on the Ti(C,N)/Zr/Cu/Zr/40Crtransient liquid diffusion welding test, transient liquid phase diffusion bondingTi(C,N)-based ceramic test with the interlayer of Zr/Cu/Zr and Ti(C,N)/Zr/Cu/AgCu/40Crtransient liquid diffusion welding test, and so on, the three parts test. The microstructure ofwelding joint area, interface organization and four-point bending test, fracture analysis, etc,to study the different process parameters on the microstructure and mechanical properties ofjoint by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersiveX-ray detector (EDS).The Ti(C,N)/Zr/Cu/Zr/40Cr transient liquid diffusion welding test, to study thecharacteristics of joint microstructure and interface elements diffusion behavior, and holdingtime on microstructure of joint interface. The results showed that: Cu-Zr eutectic reactiontransition liquid phase formation, Fe, Zr, Cu, Ti and other elements in the interface regionmutual diffusion, form the interface transition layer, joint bending strength is136MPa. Butjoint side of40Cr generated FeZr2and Fe3Zr brittle metal compounds, the interfacecombined with the weak. With the extension of heat preservation time, the joint interface ofeach element interdiffusion fully, Cu-Zr liquid zone width, uniform interface transition,combining with density.Transient liquid phase diffusion bonding Ti(C,N)-based ceramic test with the interlayerof Zr/Cu/Zr, holding time on the element diffusion and interface is mainly studied theinfluence of the reaction products. The results showed that: under the condition of thespecific welding process, the interface element Ti, Al, Zr, Cu mutual diffusion, formed onTi(C,N)/CuZr2+CuZr+ZrO/Cu as the main organization of transitional interface, joint topbending strength of320MPa. The optimal process parameters for under950℃,3MPa, heatpreservation time15min~30min, uniform interface organization at this time, highmechanical properties of welded joint can be obtained.Ti(C,N)/Zr/Cu/AgCu/40Cr transient liquid diffusion welding test, analyzed the joint microstructure and the welding temperature, holding time on the microstructure of jointinterface.Through the comparative study on the bending strength joint fracture mechanismand optimum technological parameters were determined. The results showed that: interfaceTi, Al, Zr, Cu, Ag mutual diffusion, formed in the form of the mixed with the CuZr/CuZr2interface transition zone.The heating temperature of980℃,3MPa pressure, holding time at30min average maximum joint strength221MPa, the width of the element diffusion reactioncan be up to16μm including or so, this fracture way process specification for weldalternating with Ti(C,N) interface extension mixed fracture, in which can realize the Ti(C,N)fund of ceramic and40Cr steel connection reliability.