一般汽油机和柴油机所使用的活塞环大都镀有一层硬质铬。但在使用含铅汽油和要求发动机寿命长的情况下，镀铬的耐磨性就不够。且随着排放法规的日趋严格，废气再循环的推广以及降低机油耗量等的要求，普通的活塞环在耐磨性、耐烧结性方面都无法满足。因此，开发了许多新的表面 Most of the piston rings used in gasoline engines and diesel engines are coated with a layer of hard chromium. However, the wear resistance of chrome plating is not enough when using leaded gasoline and requiring long engine life. And with the increasingly stringent emission regulations, the promotion of exhaust gas recirculation and reduce the oil consumption and other requirements, the ordinary piston ring wear resistance, resistance to sintering are not satisfied. Therefore, many new surfaces have been developed