Study On Modification Technology And Mechanism Of H62 Copper Alloy Layer By Friction Stir Surface Processing Technology And Implanting Particles

FSP(Friction stir processing)using the tool with a pin into the material inside to stirring of materials,make stirring area of metal plastic deformation occurs,refine the microstucture,so as to realize the outer layer of the metal modification.FSP is a kind of fast and convenient and can implement material modification methods.But traditional FSP technology affect internal microstructure property,and the modified layer adhesion strength is not strong,the implanted particle is not uneven,etc.In this paper,FSSP(Friction stir surface processing)is proposed because of the defects of the FSP.The material surface is modified by FSSP using the tool without pin.In this paper,the copper alloy is chosen as the experimental materials.The Si Cp,Wp,Tip,Nip implanting into the H62 copper alloy surface is innovatively proposed,the uniform particle dispersion,high volumetric content of particles modified layer is obtained,as well as the modified layer on the microstructure,hardness,wear resistance and corrosion resistance and the related mechanism are analyzed and studied.The main work and achievements are as follows:(1)Optimized the processing parameters of the copper alloy modified surface by FSSPAccording to the related literature and experience,the range of the processing parameters of the copper alloy modified surface by FSSP is determined.The tool of rotation speed is 800-1200 rpm,the tool of keep speed is 80-200 mm/min,the tool of the descending distance is 0.1-0.2 mm.In determining the range of the processing parameters selected corresponding processing parameters is done the copper alloy surface modification by FSSP.The result shows when the tool of rotation speed is 1200 rpm,the tool of keep speed is 150 mm/min,the tool of the descending distance is 0.2 mm.(2)Determined three different FSSP processing for the surface modification of H62 copper alloyThe three different FSSP processing method is determined,namely,the first processing method is FSSP copper alloy surface modification of one-time press the descending distance for?=0.2 mm.The second processing method is twice order total descending distance for?=0.2mm: the first?= 0.15 mm,the second?=0.05 mm.The third processing method is twice reverse order total descending distance for?=0.2 mm: the first?=0.15 mm,the second?=0.05 mm.Respectively using the method of the three processing of H62 copper alloy surface modification,to get the corresponding modification of the surface,and the modified surface layer respectively on microstructure,hardness,wear resistance and corrosion resistance were analyzed.(3)Determined the three different FSSP processing method for implanting Si C,W,Ti and Ni particles into H62 copper alloy surface modificationRespectively using the above three processing method by implanting Si C,W,Ti,Ni particles into H62 copper alloy for surface modification,respectively obtained Si Cp/H62,Wp/H62,Tip/H62 and Nip/H62 copper alloy modification layer surface,and the corresponding modified layer surface separately carried on the microstructure,hardness,wear resistance and corrosion resistance were analyzed.(4)Research on the mechanism FSSP for copper alloy modified surface layerPut forward to the head processing texture of the tool is a factor causing arc corrugation,and the flash formation mechanism is given,reveal FSSP modification of copper alloy surface,at the same time FSSP process approach for the analysis of different particles in different distribution rule in the process of modification.Finally using EBSD for copper alloy modified surface test,according to modification the surface grain size of copper alloy in submicron-nanometer level,and mainly by the high Angle grain boundary(15 °)or higher.