Influencing mechanism of laser specific energy on tribological properties of high performanceTi-Al/WCcompositecoating

Laser specific energy significantly impacts the quality of composite coatings. Ti-Al/WCcoatings were prepared on the TC21 alloy through laser cladding with specific energy ranging from 66.7 to 133.3 J/mm 2 . The results indicate that the composite coatings primarily comprised Ti 2 AlC, α 2 -Ti 3 Al, γ -TiAl, TiC, and W phases. A gradual increase in the relative intensity of the diffraction peaks of Ti 2 AlC, α 2 -Ti 3 Al, and TiCappeared with the increase of specific energy. When the specific energy was 116.7 J/mm b the Ti-Al/WC coated alloy achieved a maximum micro- hardness of HV 0.2 766.3, which represented an increase of 1.96 times compared with TC21 alloy, and the minimum wear rate decreased dramatically. Much improvement in tribological properties was attained through the fine-grained strengthening of the ( α 2 + γ ) matrix and the dispersion strengthening of self-lubricating Ti 2 AlC and intertwining TiC. This study provides valuable insights for the development of high-performance Ti-Al composite coatings.