Research On TiC Particles Reinforced Aluminum Composite Coating By TIG Cladding

MMCs have high strength, high rigidity, high hardness, wear and impact resistant, forming aluminum matrix composite coating on the surface of aluminum alloy can improve its surface properties greatly. The formed of aluminum matrix composites by resurfacing welding have very important sense for reasonable use material, improve product performance, expand the scope of application of aluminum alloy and reduce production cost, but has yet to see the related research report. Therefore, it worth to test the preparation of TiC particles reinforced aluminum matrix composite coating by TIG.A kind of Ti, Al, graphite mixed powder as certain proportion, adopt preset this alloy powder or pressed it into a alloy powder block nearly 40mm×10mm×1mm. By TIG cladding, formed a Al-Ti-C system coating in pure aluminum (L1060) surface through adjusting welding technology parameters. Analysis all kinds of reactions could exist in welding pool from thermodynamics angle. Study the sample organiza-tion composition and phase analysis by Quant-200 scanning electron microscope and ED AX, analysis the phase of hardfacing layer by XRD rays, tests the hardness and wearability of the hardfacing layer.The results show that:adopt presets Al-Ti-C alloy powder on the surface of aluminum,with TIG, just formed a metallurgical combination cladding layer when use He gas; Adopt pressed this powder into a alloy powder block, by TIG cladding, the coating only contains white granular organization, but the TiC particles is very little, the reaction process of Al-Ti-C is that, first Al melt, then reacts with Ti or C formed Al3Ti or Al4C3, meanwhile the Al3Ti and Al4C3 decomposition under the high tempe-rature, then the Ti and C in the liquid aluminum diffusion and react formed TiC, there will form Al3Ti,Al4C3 and TiAlxCx when the react are incomplete; Adopt pressed this powder into a alloy powder block, and then placed this block in copper plates and make it melt in high temperature, the organization is the Al matrix and dispersion dis-tribution of TiC particle, the size of TiC particle is approximately 2-4μm, the weight percentage of TiC particles is about 14%, then placed the melt alloy on the aluminum plates by TIG, because the dilution of the matrix, the percentage of TiC particles in the aluminum matrix composites layer is about 3%-8%.The hardness and wearability of the coating has greatly improved than aluminum matrix, but as engineering materials, the wearability is still low. Future research should be considered increase the content of TiC, while increase the hardness of the hardfacing layer itself in the matrix.