Study on the Influence of Laser Power Variation on the Hardness Uniformity and Wear Performance of Composite‐Reinforced Nickel‐Based Coatings

To improve the wear resistance of TC4 titanium alloy and address the issue of excessive hardness fluctuations in laser‐fabricated wear‐resistant coatings, a multiphase reinforced nickel‐based coating was prepared using laser cladding technology. The cladding powder consisted of nickel‐coated WC and IN718 nickel‐based alloy, with N ₂ as the protective gas. The results showed that the coating was primarily composed of dendrites, along with reinforcement phases such as TiN, WC, and W ₂ C. The content of TiN and TiC, resulting from the decomposition of WC and in situ synthesis, was significantly influenced by the laser power. The coating prepared at 1000 W exhibited the highest hardness, being 1.07 times and 1.04 times higher than the coatings prepared at 800 and 1200 W, respectively. Moreover, the coating prepared at 1200 W showed the smallest hardness fluctuation. Under room temperature conditions, the coating prepared at 1000 W had the lowest wear rate, with wear rates 0.36 and 0.6 times those of 800 and 1200 W, demonstrating the best wear resistance. The wear mechanisms of the coatings at room temperature were primarily abrasive wear and oxidative wear.