Friction-wear performances and oxidation behaviors of Ti3AlC2 reinforced Co-based alloy coatings by laser cladding

摘要

Ti3AlC2 reinforced Co-based alloy coatings were fabricated on H13 steel using a laser cladding (LC). The morphologies, chemical elements and phases of obtained coatings was analyzed using a scanning electron microscope (SEM), energy dispersive spectroscope (EDS), and X-ray diffraction (XRD), respectively. The effects of Ti3AlC2 mass fraction on the microstructure and friction-wear performances at 600 degrees C were investigated, and the wear mechanism was also discussed. The results show that the average coefficients of friction (COFs) of Co-based alloy coatings decrease with the increase of Ti3AlC2 mass fraction, exhibiting the excellent friction reduction. The continuous friction layer is formed by the Ti3AlC2 and oxidation products of Co-based coatings at high temperature, which is the main factor of friction reduction. The wear rate of Co-based-5%Ti3AlC2 is the lowest among the three kinds of coatings, the wear mechanism is combined of oxidative wear, adhesive wear and abrasive wear. The O contents of Co-based alloy coatings increase with the increase of Ti3AlC2 mass fraction, which are less than 3% at 600 degrees C, presenting the outstanding oxidation resistance.