A novel wear-resistance and long-life lubrication NiCr–Cr3C2 based sealing coating with Mo@Ag@Ni core-shell structure particles

Conventional sealing coatings exhibit significant wear and deterioration of service life under the harsh operating conditions of aviation rotary engines. Herein, we fabricate a novel wear-resistant sealing coating incorporating a core-shell structure additive via atmospheric plasma spraying. NiCr-Cr 3 C 2 -Mo@Ag@Ni composite coating possesses favorable structural integrity and mechanical properties. During the thermal cycling friction tests, the NiCr-Cr 3 C 2 -Mo@Ag@Ni composite coating consistently maintains lower friction coefficients and wear rates. After fifth thermal cycling friction test, the friction coefficient and wear rate of the NiCr-Cr 3 C 2 -Mo@Ag@Ni composite coating are as low as 0.1 and 1.699×10 -4 mm 3 /(N·m), respectively, representing reductions of 50% and 79.11% compared to the corresponding values of the NiCr-Cr 3 C 2 composite coating (0.2 and 8.134×10 -4 mm 3 /(N·m)). The superior performance is attributed to the sustained-release of lubricating phases from the Mo@Ag@Ni core-shell structure and tribo-thermally induced formation of continuous and dense composite nanocrystalline binary metal oxide lubricating films on the worn surface. These findings demonstrate that regulating the release kinetics of lubricating phases from Mo@Ag@Ni and the evolution of interfacial tribo-films enables a long-life balance between high wear resistance and lubrication effectiveness. Consequently, this study establishes a novel design pathway for sealing coatings used in high-efficiency, long-endurance aviation rotary engines.