Abstract: A structure of a piston ring to be installed in an engine includes a matrix. A laminated intermediate layer is formed on a surface of the matrix from hard chromium (Cr), chromium nitride (CrN) and titanium carbide (TiC) in order, and a diamond-like carbon film (DLC) is coated on an outer periphery of the intermediate layer. Thus, the piston ring is wrapped by a skin with a progressive structure having a gradient distribution of hardness. The structure formed from the diamond-like carbon film provides a low wear rate and a low friction coefficient, while applying a high bonding force to the matrix and making the piston ring have an improved normal service life that meets the related environmental regulations.

Abstract: A structure of a piston ring to be installed in an engine includes a matrix. A laminated intermediate layer is formed on a surface of the matrix from hard chromium (Cr), chromium nitride (CrN) and titanium carbide (TiC) in order, and a diamond-like carbon film (DLC) is coated on an outer periphery of the intermediate layer. Thus, the piston ring is wrapped by a skin with a progressive structure having a gradient distribution of hardness. The structure formed from the diamond-like carbon film provides a low wear rate and a low friction coefficient, while applying a high bonding force to the matrix and making the piston ring have an improved normal service life that meets the related environmental regulations.

Abstract: A structure of a titanium-alloy piston ring is configured to be installed in an engine and includes a titanium-alloy matrix. The titanium-alloy matrix has an outer periphery receiving a hardening treatment (such as receiving a nitrogen treatment, or being coated with a diamond-like carbon film, or receiving a nitrogen treatment and then being coated with a diamond-like carbon film), so as to make the piston ring have improved abrasion-resistant strength, hardness, and wear resistance, thereby extending the normal service life of the piston ring.

Abstract: A structure of a piston ring to be installed in an engine includes a matrix wherein a laminated intermediate layer is formed on a surface of the matrix from hard chromium (Cr), chromium nitride (CrN) and titanium carbide (TiC) in order, and a diamond-like carbon film (DLC) is coated on an outer periphery of the intermediate layer, so that the piston ring is wrapped by a skin with a progressive structure having gradient distribution of hardness. The structure formed from the diamond-like carbon film provides low wear rate and low friction coefficient, while applying a high bonding force to the matrix and making the piston ring have an improved normal service life that meets the related environmental regulations.