| 摘要 |
Exemplary piston rings are disclosed, comprising a base portion formed of a metallic material, and an outer contact surface extending between opposing side faces of the piston ring. The piston ring may include a coating layer applied to the outer contact surface, with the coating layer including an inner layer and an outer layer. Exemplary methods of making a piston ring are also disclosed, comprising providing a base portion formed of a metallic material, applying an inner layer to an outer surface of the base portion, and applying an outer layer on top of the inner layer. |
