Thermal ablation-resistant, wear-resistant, and friction-reducing coated piston ring, preparation method thereof and engine

A thermal ablation-resistant, wear-resistant, and friction-reducing coated piston ring, a preparation method thereof and an engine are provided. An outer circumferential surface of a piston ring material matrix includes, from bottom to top, a wear-resistant and friction-reducing layer and a protective layer, and the protective layer is a single nitride layer or a multi-element nitride layer. The piston ring is arranged with the wear-resistant and friction-reducing layer and the protective layer from bottom to top. When the piston ring is installed in the engine, the high-temperature and high-pressure gas flow impacts the piston ring and contacts the protective layer on the surface of the piston ring, while the inner diamond-like carbon coating (DLC) functional layer is completely “encapsulated” and protected by the outer protective layer. The protective layer possesses higher ablation resistance compared to the DLC layer, effectively preventing phase transformation in the internal DLC layer.