Effect of Laser Power Variation on Properties of In718/Ni60AA/Ni‐Graphite Composite Cladding Coatings

To address the poor wear resistance of TC4(Ti6Al4V) titanium alloy surfaces, In718/Ni60AA/Ni‐graphite composite cladding coatings were fabricated on TC4 substrates via laser cladding. The results show that the coatings prepared at laser powers ranging from 800 to 1000 W mainly consist of TiC, Ti 2 Ni, TiB 2 , α ‐Ti, and residual graphite. With increasing laser power, the microstructure exhibits a refining tendency due to the pinning effect of high‐melting‐point hard phases. The surface hardness of the coatings increases from 614.38 to 894.56 HV 0 . 5 with rising laser power. Owing to the combined friction‐reducing and anti‐wear effects during wear, the coating prepared at 800 W exhibits the optimal friction‐reducing and wear‐resistant performance. Compared with the TC4 substrate, the 900 W coating and the 1000 W coating, its average friction coefficient is reduced by 50.98%, 12.78%, and 25.87%, respectively; correspondingly, its wear rate is decreased by 46.23%, 19.96%, and 34.34%. The wear mechanisms of the coatings are dominated by abrasive wear and oxidative wear, both of which are gradually aggravated with increasing laser power.