Study On The Fe Based Composite Coating Reinforced By TiC Particles Prepared Using Argon Tungsten-arc Cladding

High wear-resisting is often one of the basic properties for the mechanicalparts. Cladding is one of the surface strengthening treatments to deposite a highhardness and good wear resistant layer on the part surface to improve the service lifeof the part. In this paper, the composite coating of Fe-base self-fluxing alloyreinforced by TiC particles was prepared on the Q235low carbon steel by argontungsten-arc cladding process.The microstructure and composition of the cladding coating were analyzed bythe mean of the optical microscope (OM), X-ray diffraction (XRD), scanningelectron microscope (SEM) and Electron energy spectrum (EDS). The claddingcoating compositions, microstructures, microhardness and wear resistance propertywere analyzed by XRD, OPM, SEM, EDS, microhardness tester and pin-on-disktribometer. The mechanism of the composited cladding coating reinforced by TiCparticle was also discussed.The cladding process parameters, such as cladding speed and current, wereoptimized in order to obtain the cladding coating without defects such as porosity,crack, slag inclusion. The optimized process parameters of the cladding were thecladding speed of3mm/s, cladding current170A.The microanalysis results of the composited coating showed that thecomposite coating is composed of α-Fe dendrite and interdendritic (Fe, Cr)23(C,B)6,Fe3C eutectic structure and TiC reinforcement particles. When a small amount ofTiC particles was added, the wettability of TiC particles with the coating metal wasgood and the particles were dispersed within the cladding coating. But with theparticle amount increasing, agglomeration would happen with the shape of cross andradial stick. When the TiC amount was30%, the large agglomerates can be found in the coating. The wettability and the bonding strength of the agglomerates with thecoating metal become bad.The microhardness test results showed that the composited coating hardnessreinforced by TiC particles was significantly higher than that of Fe45claddingcoating. The hardness of the composited coating was continuously improved withthe increase of TiC particles. The highest hardness was up to980HV.The wear-resisting experiment results showed that the wear failure of thecladding coating was mainly adhesive wear when the addition of TiC particles wassmall. But if the amount of TiC particles was large, the TiC particles in the claddingcoating will fall off. When the amount of TiC particles was about20%TiC, thewear-resistance was12times higher than that of the substrate Q235steel,1.1timeshigher than that of Fe45cladding coating.