Study On Microstructure And Prope Rites Of Nickel-based Composite Coating Surface Laser Cladding Of45Steel

In this paper, using synchronous lateral powder feeding laser cladding, prepared Ni60WC25, Ni60WC35and Ni60WC35A11.2three kinds of WC particles reinforced composite coating in the45steel surfaces. Focus on analysis of the WC particle reinforced phase composite coating phase composition, morphology, and mechanical properties of microhardness and wear resistance, aiming to solve the45steel surface the inherent performance defects of hardness and wear resistance and provide theoretical basis and certain technology foundation by laser claddingThe phase qualitative of composite coating under different composition ratio of WC/Ni60by X-ray diffraction (XRD); The microstructure feature of composite coating under different composition ratio of WC/Ni60was characterized by scanning electrical microscope and energy (EDS). The microhardness of samples section was tested by microhardness instrument. The wear resistance of samples end was tested by MMU-5G wear instrument.The qualitative analysis to confirm the phase species. Ni60WC25and Ni60WC35main phase γ-(Ni,Fe),Cr7C3,Fe23(C,B)6,Ni2W4C,FeNi3, WC,B4Cr3; Ni60WC35Al1.2main phase γ-(Ni,Fe),Fe23(C,B)6,AlB12, FeNi3,Cr7C3,Al5Fe2,Ni2W4C,B4Cr3,WC.Ni60WC25most of the WC particles dissolved broken, undissolved of WC particles deposited on the bottom of the coating.the Ni60WC35and Ni60WC35Al1.2surface of WC particles occurred to a small dissolved, dissolution of WC particles surface formed around a region rich in W and C elements, the formation is Ni2W4C,M7C3and M23C6carbide and morphology was changing shape or needle shape. Three kinds of Ni60WC25, Ni60WC35and Ni60WC35Al1.2composite coating microhardness were HV0.2611, HV0.2670and HV0.2670; microhardness fluctuations decreases in turn, to prove that the latter two groups of hardness is more stableNi60WC25,Ni60WC35and Ni60WC35Al1.2three kinds of composite coating the average friction coefficient were fa=0.547,fa=0.519and fa=0.415; in turn reduce the fluctuations of the friction coefficient, amount of wear were3.1mg,1.8mg and1.4mg. Worn surface of Ni60WC35Al1.2composite coating exist a large number of needles, needle phase surround the WC particles that provided a strong parcel force, fine and uniform AlB12,Al5Fe2and Fe23(C,B)6phase uniform distributed makes coating process of friction and wear was more stable and had better wear resistance.