Microstructure and performance of Ti-based wear-resistant laser cladding coatings with rare-earth oxides

TiC-reinforced Ti-based cladding coatings with good forming quality and wear resistance were successfully prepared on the surface of the Ti6Al4V alloy by adding 6 wt% Y2O3 into the NiCr-Cr3C2/Ti6Al4V powder. The forming quality, microstructure, and wear resistance of the resulting coatings were systematically investigated using advanced analytical methods. The composite coating was composed of the CrTi4 matrix and TiC rein-forcement phase, along with certain alpha-Ti and Y oxides. The Y oxides mainly existed in the form Y2O3 and Y2Ti2O7 and were mostly distributed at the phase boundaries. Significant differences were noted among the TiC rein-forcement phases in the surface, middle, and bonding zones of the coating, with a more developed microstructure in the middle zone and a more notable oriented growth in the bonding zone. Furthermore, the addition of 6 wt% Y2O3 significantly increased the hardness and wear resistance of the coating compared with those observed without Y2O3.