Patent ID: 9057442
Filing Date: 2015-06-16
Classification: F16J

Abstract:
1. A structure of a piston ring, comprising a matrix wherein a laminated intermediate layer is formed on an outer surface of the matrix from a hard chromium layer, a chromium nitride layer and a titanium carbide layer in order, and a diamond-like carbon film is coated on an outer periphery of the intermediate layer, wherein the hard chromium layer is in direct contact with the outer surface of the matrix, the chromium nitride layer is in direct contact with both the hard chromium layer and the titanium carbide layer, and the diamond-like carbon film is in direct contact with the titanium carbide layer, wherein the hard chromium layer, the chromium nitride layer, the titanium carbide layer and the diamond-like carbon film are processed to have a hardness which is progressively lowered from the diamond-like carbon film to the hard chromium layer in order.