Study On Properties Of Laser Cladding La₂O₃/WC/Ni Composite Coating

Abstract:Hydraulic components bear strong friction and wear under continuous working environment,the failure of hydraulic components makes the whole hydraulic system can not achieve the desired work,which put forward the high performance requirements of the material.As with oil hydraulic pump,the choice is limited,the price of materials is high,the processing process is poor.In this paper,45 steel was selected to replace the model 38CrMnAl,and the laser cladding technology was adopted to change the performance.In this paper,the La₂O₃/WC/Ni composite coating was prepared on the 45 steel by using the laser equipment,and the influence of laser processing parameters on the coating surface was analyzed by ANSYS simulation.Based on the analysis of the influence of rare earth La₂O₃ on the microstructure and interfacial bonding condition,the effect of rare earth La₂O₃ on the wear resistance and hardness of the coating was discussed.Results show:?1?Without La₂O₃,there is a small amount of micro cracks in the middle of the coating;adding 1.0%La₂O₃ has a small amount of hard WC particles melt adhesion hardness on the surface;the 2.0%La₂O₃ coating and the substrate are bonded well to form a silver white bright band.Add rare earth,the coating and the substrate combined with fastening,cracks and stomata greatly reduced,improve the quality of the coating surface.?2?Ni-coated WC and Co-coated WC composite powder added1.0%La₂O₃,phase:Fe₂₃?C,B?₆,?-?Fe,Ni?,FeNi₃,WC,W₂C,Cr₂₃C₆,Cr₄Ni₁₅W.The WC and W₂C carbides in the cladding layer play a key role in the crack arrest of cladding layer.Co-coated WC composite powder can prevent the oxidation and decarburization of WC and improve the hardness and wear resistance of the cladding layer.?3?EDS spectrum analysis of the coating,the white particles are WC.Hardness and wear resistance test results show that the hardness of Co-coated WC composite powder coating with 1%La₂O₃ is the highest,the wear resistance is the best.The average microhardness of the substrate is 440HV_0.1.The average hardness of the coating is 3 times higher than that of the substrate.