Research On Repairing Nickel-based Self-lubricating Wear-resistant Composite Coating Based On Motor Shaft Remanufacturing

Motors are the largest electricity consumption terminal in my country.The annual electricity consumption accounts for about 85%of the industrial electricity consumption and 60%of the national total electricity consumption.The total social ownership is extremely huge.Many motors are often used in harsh environments such as high temperature,humidity,and corrosion.Key components such as the main shaft are prone to failure due to wear and corrosion,and the service cycle is often shorter than expected,resulting in a huge waste of resources and energy.Advanced additive remanufacturing technology can prepare high-performance composite coatings with high temperature resistance,corrosion resistance,wear resistance and fatigue resistance to improve the service performance and service life of motor shaft parts Manufacturing repair provides the solution.This paper intends to develop high-performance composite coating materials for damaged motor shaft parts,and prepare self-lubricating composite coatings,which can improve the wear resistance of shaft parts and reduce the wear of their counterparts,so as to achieve the performance of the entire transmission system.Elevated design goals.The research of the subject is of great significance to the realization of high-performance maintenance and remanufacturing of industrial motor shaft parts.In this paper,three powder materials,Ni60-coated WC（Ni60-38WC）,nickel-coated graphite（25Ni-C）and nickel-coated titanium silicon carbide（25Ni-Ti3Si C2）,were selected to design and develop two different systems of spray powder materials.Two different systems of nickel-based wear-resistant and corrosion-resistant composite coatings were prepared on the surface of 45 steel substrate by sonic flame spraying（HVOF）.Scanning electron microscope（SEM）,X-ray diffractometer（XRD）and laser particle size distribution analyzer were used to observe and study the microscopic morphology and phase composition of the three powder raw materials.The microstructure and mechanical properties of the composite coatings were studied and analyzed by EDS),XRD,and microhardness tester.Research analysis;the results show that:（1）The Ni60-WC powder is spherical or ellipsoidal in shape,and its phase composition is mainly（Fe,Ni）₂₃C₆,B₆Fe₂₃,Ni,WC,W₂C,Cr₇C₃,Cr B,etc.;The phase composition includes Ni and graphite;the nickel-coated titanium silicon carbide powder is in the form of small spherical and irregular blocks,and the phase composition includes Ni and Ti₃Si C₂;the particle size distribution range of the three powders is 15?45μm,which meets the powder conditions required for thermal spraying Require.（2）The nickel-based composite coatings of the two different systems are closely combined with the 45 steel matrix,and there are no obvious pores,cracks and other defects;The graphite lubricating phase of the quality phase and black irregular shape is uniformly distributed,and the main phases are Ni,WC,Cr Si,Si C,Cr₂₃C₆,BFe and graphite phase;under different nickel-coated titanium-silicon carbide doping amounts,the composite coating is white in color The WC hard phase of the cube-like crystal and the black,fine and irregularly shaped titanium silicon carbide lubricating phase are evenly distributed,and the main phases are Ni,WC,Cr Si,Si C,Cr₂₃C₆,and Ti₃Si C₂phases.（3）The nickel-based composite coatings of the two different systems are closely combined with the substrate,and the porosity is low（about1?2%）,and with the increase of the doping amount of nickel-clad powder,the porosity of the composite coating will follow.increase.The microhardness of the composite coating under different doping amounts of nickel-coated graphite is about 650?800HV.With the increase of the doping amount of nickel-coated graphite,the microhardness of the composite coating decreases,and 15wt.%Ni is doped.The microhardness of the C composite coating is the lowest（664HV）;the microhardness of the composite coating under different nickel-coated titanium silicon carbide doping amounts is about 800?900HV,and the microhardness of the composite coating doped with 5wt.%Ni-Ti₃Si C₂Highest microhardness（905HV）.All in all,the hardness of the nickel-based composite coatings of the two different systems is high,which is higher than 650HV.（4）Within 120h,240h and 480h of the salt spray corrosion test,with the extension of the salt spray corrosion test time,the nickel-based composite coatings of the two different systems have different degrees of corrosion,but both have good corrosion resistance,and both The corrosion resistance performance is roughly the same.System 1:Doping15wt.%Ni-C composite coating has the lightest corrosion quality and lowest corrosion rate,showing the best corrosion resistance;System 2:Doping 5wt.%Ni-Ti₃Si C₂composite coating has The lightest corrosion quality and lowest corrosion rate,showing the best corrosion resistance.（5）During the friction and wear process under a load of 10N,the wear resistance of the composite coatings with different nickel-coated graphite doping amounts increased with the increase of the doping amount of nickel-coated graphite,but the wear volumes of the composite coatings were all the same.However,the wear resistance of the composite coatings with different doping amounts of Ni-Clad Ti₃Si C₂decreased with the increase of Ni-Clad Ti₃Si C₂doping amount.Among them,the wear volume of the doped 15wt.%Ni-C composite coating is0.55×10⁷μm³,which is one third of the wear volume of the Ni60-WC coating;the wear volume of the 5wt.%Ni-Ti₃Si C₂composite coating is0.29×10⁷μm³,which is one-fifth of the wear volume of Ni60-WC coating.In summary,the wear resistance of the doped 5wt.%Ni-Ti₃Si C₂composite coating is the best.The wear surface of the composite coating is smooth,without cracks or pits,and the friction coefficient is small.