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

Abstract

Ti 3 AlC 2 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 Ti 3 AlC 2 mass fraction on the microstructure and friction–wear performances at 600 °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 Ti 3 AlC 2 mass fraction, exhibiting the excellent friction reduction. The continuous friction layer is formed by the Ti 3 AlC 2 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%Ti 3 AlC 2 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 Ti 3 AlC 2 mass fraction, which are less than 3% at 600 °C, presenting the outstanding oxidation resistance. • The rod–like grain shape of Co08 coating becomes coarse by addition of Ti 3 AlC 2 . • The wear mechanism of Ti 3 AlC 2 reinforced Co08 is oxidative wear, adhesive wear and abrasive wear. • The addition of Ti 3 AlC 2 improves the oxidation resistance of Co08 coating. • The Co08–5%Ti 3 AlC 2 coating significantly improves the hardness and wear resistance of Co08 coating.