Wear performance of ZrO2 reinforced stellite 6 matrix coatings prepared by laser cladding at elevated temperature

In order to modify the wear resistance of Stellite 6 superalloy as wear resistant coating at room temperature-1000 °C, the different contents (1.0, 2.5 and 4.0 wt%) of ZrO2 reinforced Stellite 6 matrix coatings were fabricated over the Inconel 718 nickel alloy substrate by laser cladding technology. The microstructure, hardness and high-temperature wear behavior of Stellite 6 matrix coatings with ZrO2 was systematically studied. The sliding wear test were done using a ball-on-disk tribometer against Si3N4 at room temperature-1000 °C. The results showed that the ZrO2 showed obvious fine-grain strengthening and dispersion strengthening effect. The hardness of coatings reinforced by ZrO2 were 470–540 Hv. A critical valve of ZrO2 content was existed for the wear performance of Stellite 6 matrix coatings. The coating with 2.5 wt% ZrO2 had the desirable wear resistance, and the wear rate was in the order of 10−5 mm3/N.m. This was attributed to the high microhardness and the formation of solid lubricants, as well as the friction film on the sliding surfaces. •ZrO2 reinforced Stellite 6 coatings were fabricated by laser cladding.•The wear performance of coatings was investigated at RT-1000 °C.•There existed a threshold content of ZrO2 for the tribological performance.•Wear resistance was due to the synergistic effect of high hardness and friction film.