Preparation Of 42CrMo/alloy Alloy Compound Material By SPS And The Study Of Binding Interface

Copper alloys have excellent machinability,ductility,wear resistance and conductivity,and thermal conductivity.In industrial production,it is a common metal material,which is widely used in many fields.The wear-resistant parts commonly used in the plunger pump,such as the rotor and slipper,are made of pure copper or copper alloy,but compared with steel,the strength of copper is low and easy to be deformed.In the environment of bad working conditions,serious wear often occurs,which causes the failure of the parts to reach the life expectancy,which not only affects the normal work of the equipment but also causes the serious waste of the copper material,influencing the economic benefit.When copper or copper alloy is used as matrix and steel is used as lining,it is a way to solve the problem of making steel back copper matrix composite parts.The price of steel is relatively cheap.Besides,the steel has good mechanical and technological properties.If copper/steel composite can be used to make parts instead of traditional pure copper or copper alloy material,a large amount of precious metal copper will be saved.The cost of production will be reduced greatly.Good comprehensive performance will be widely used.In this paper,the wetting and spreading properties of copper alloy to 42 CrMo steel substrate were studied by the pedestal drop method.The wetting interface,micromorphology and element diffusion were detected by scanning electron microscope(SEM)and EDS spectrometer,and investigating the connectivity of 42 CrMo steel with copper alloy.On this basis,42 CrMo steel/lead bronze composite materials were prepared by melting casting method,then analyzed the structural characteristics and element distribution of the joint surface.From the SEM diagram,it is found that the lead block segregation area appears in the copper matrix.The bonding interface of lead bronze and 42 CrMo steel is well wetted,compact and no void,and the interface is the copper/iron interface formed by the wetting iron of copper liquid.The phenomenon of copper atoms permeating along grain boundaries is near the interface steel,which leads to the cracking of the local interface.The 42 CrMo steel and a complex copper alloy were used as the parent material.The 42 CrMo steel/copper alloy composite was prepared by SPS technology,then optimized the connection process parameters.The microstructure and properties of the interface were analyzed.The influence of temperature(650~770?),holding time(10~60 min)on the microstructure,element diffusion of 42 CrMo steel/copper alloy composites was investigated by metallographic microscope(OM),scanning electron microscope(SEM),EDS spectrometer and X ray diffractometer(XRD),analyzing the formation mechanism and mechanical properties of the binding surface.The best connection process parameters(temperature of 770?,pressure of 25 MPa,holding time of 60 min,cooling to 670? in 5 min,cooling to 570? in 4 min,cooling with furnace)were obtained.The analysis shows that there are no obvious cracks and pores in the interface under this parameter,the Fe diffuse sharply to the side of copper alloy,in which the transition layer near the binding surface is a 10~20 ?m wide tissue,the Fe of the transition layer continues to extend to the side of the copper alloy,forming an island like tissue area of 50~60 ?m,which is irregular in distribution.A lot of gray Island tissues were analyzed by EDS spectroscopy,which is a solid solution of Fe.By contrast,it is known that the SPS sintering technology is used to prepare 42 CrMo steel/ copper alloy bimetal composite.The thickness of the diffusion transition zone is thicker than the melting casting method,and the quality of the bonding surface is better.