Investigation on microstructure and tribological properties of Ti2AlC-Ni reinforced Fe-based prepared by high-speed laser cladding

Abstract

To address the problem of die steel wear failure, Fe-Ti2AlC-Ni composite coatings were fabricated on the Cr12MoV matrix by high-speed laser cladding. The mechanism of Ti2AlC on tribological properties was explored, providing ideas for the longevity of mould steel. The macroscopic morphology, microstructure, phase composition, hardness, and tribological properties of the composite coatings were also analyzed. Results showed that composite coatings with good surface quality and no internal cracks were obtained with Ti2AlC content between 5 and 10 wt%. The Fe-based coating without Ti2AlC only comprised the α and γ phases, whereas the composite coatings comprised the α and γ phases as well as the Ti2AlC self-lubrication phase, the TiC and Ti3Al hard phases. Hardness increase was predominantly attributed to the hard phases generated in situ. The lowest frictional coefficient and wear rate were obtained at Fe-based-10wt%Ti2AlC, which were 0.52 and 0.0112 mm3/N·m, respectively. The coating wear mechanism was primarily abrasive, adhesive, and oxidative wear. Moreover, with an increase in Ti2AlC content, the wear became slight under the collaborative cooperation of oxide film, self-lubricating and hard phases.