Abstract: A piston ring that is pre-treated by grit blasting to a defined roughness, followed by PVD coating with a metal nitride to a thickness of at least 10 ?m, leaving peaks and valleys in the coated piston ring. The coated piston ring is then lapped to remove the peaks without penetrating the coating, so that valleys and plateaus remain in the coated surface. The resulting piston ring exhibits superior coating retention due to the increased surface area created by the grit blasting, and yet also superior performance, as the cavities remaining increase the porosity of the coating and thus enhance the lubrication of the ring.

Abstract: A piston ring that is pre-treated by grit blasting to a defined roughness, followed by PVD coating with a metal nitride to a thickness of at least 10 ?m, leaving peaks and valleys in the coated piston ring. The coated piston ring is then lapped to remove the peaks without penetrating the coating, so that valleys and plateaus remain in the coated surface. The resulting piston ring exhibits superior coating retention due to the increased surface area created by the grit blasting, and yet also superior performance, as the cavities remaining increase the porosity of the coating and thus enhance the lubrication of the ring.

Abstract: A piston ring that is pre-treated by grit blasting to a defined roughness, followed by PVD coating with a metal nitride to a thickness of at least 10 ?m, leaving peaks and valleys in the coated piston ring. The coated piston ring is then lapped to remove the peaks without penetrating the coating, so that valleys and plateaus remain in the coated surface. The resulting piston ring exhibits superior coating retention due to the increased surface area created by the grit blasting, and yet also superior performance, as the cavities remaining increase the porosity of the coating and thus enhance the lubrication of the ring.

Abstract: A piston ring that is pre-treated by grit blasting to a defined roughness, followed by PVD coating with a metal nitride to a thickness of at least 10 ?m, leaving peaks and valleys in the coated piston ring. The coated piston ring is then lapped to remove the peaks without penetrating the coating, so that valleys and plateaus remain in the coated surface. The resulting piston ring exhibits superior coating retention due to the increased surface area created by the grit blasting, and yet also superior performance, as the cavities remaining increase the porosity of the coating and thus enhance the lubrication of the ring.