This product is also used for the first groove of aluminum piston ring of the internal combustion engine. It overcomes the problems which exist when the oil-cooling salt core and the wear-resisting ring are used on the same piston, such as the complexity of manufacturing, the high rejection rate, and the need for water-melting the salt core, and the environmental pollution. This product provides substantial strength at the piston head and ensures that the temperature does not exceed 230 ℃ at the first ring groove; in the meantime it can reduce fuel consumption, emission and is conducive to environmental protection. Because of its simplicity of the structure, easy to make, and the high rate of yielding, it is well accepted by the domestic and Southeast Asia piston manufacturers. The method is patented in China. Patent number is ZL0213556130.