Abstract: A piston ring for an internal combustion engine may include a substantially annular base of a ferrous alloy upon which is applied a coating. The coating may have a first bonding layer and at least a first external layer or a second external layer deposited upon the first bonding layer up to a maximum of 100 micrometers in thickness of a plurality of sequentially deposited first and second external layers. The first external layer may include a nitride of a doped metal chemical element, a doping element being aluminum. The second external layer may include a nitride of the metal chemical element. The first external layer may have a thickness greater than at least once a thickness of the second external layer and less than ten times the thickness of the second external layer.

Abstract: A sliding element for internal combustion engines may include a ferrous base provided with a film applied upon a sliding surface. The film may have, sequentially, a metal connecting layer, a transitional layer, and a contact layer. The transitional layer may include a carbide containing a metal element. The contact layer may contain DLC (diamond-like carbon) doped with the metal element of the transitional layer, the DLC containing a maximum of 2% hydrogen by weight. An atomic ratio between metal and carbon in the contact layer in terms of a ratio Me/C is equal to or less than 0.1.

Abstract: An element with at least one slide surface with a coating for use on an internal combustion engine may include a base of a metallic alloy and at least one inner surface provided with a hard ceramic coating generated by physical vapor deposition. The element may include a porosity with a rate lower than 2 percent by volume, a Vickers hardness ranging from 1500 to 3000HV, and a compressive inner tension lower than 500 MPa.

Abstract: A sliding element for internal combustion engines may include a ferrous base provided with a film applied upon a sliding surface. The film may have, sequentially, a metal connecting layer, a transitional layer, and a contact layer. The transitional layer may include a carbide containing a metal element. The contact layer may contain DLC (diamond-like carbon) doped with the metal element of the transitional layer, the DLC containing a maximum of 2% hydrogen by weight. An atomic ratio between metal and carbon in the contact layer in terms of a ratio Me/C is equal to or less than 0.1.

Abstract: A piston ring for an internal combustion engine may include a substantially annular base of a ferrous alloy upon which is applied a coating. The coating may have a first bonding layer and at least a first external layer or a second external layer deposited upon the first bonding layer up to a maximum of 100 micrometers in thickness of a plurality of sequentially deposited first and second external layers. The first external layer may include a nitride of a doped metal chemical element, a doping element being aluminum. The second external layer may include a nitride of the metal chemical element. The first external layer may have a thickness greater than at least once a thickness of the second external layer and less than ten times the thickness of the second external layer.

Abstract: The present invention relates to an element (1) that works sliding, of an internal combustion engine and/or a compressor that undergoes friction and receives a coating of chrome nitride having an equiaxial morphology, with low porosity (lower than 1%) and with a crystallographic orientation predominantly (111), maintaining some reticulate in the orientation (200), so as to improve its resistance to wear and its toughness, prolonging the useful life of the element (1) that works sliding.

Abstract: A cylinder liner for an internal combustion engine may include a cylinder. The cylinder may include a first cylindrical portion coupled to a second cylindrical portion. The second portion may be positioned towards a region of combustion in relation to the first portion and define at least in part a combustion chamber. The first portion may include a length at least one half of a length of the cylinder. At least one of the first portion and the second portion may be composed of a ferrous alloy.

Abstract: An element with at least one slide surface with a coating for use on an internal combustion engine may include a base of a metallic alloy and at least one inner surface provided with a hard ceramic coating generated by physical vapor deposition. The element may include a porosity with a rate lower than 2 percent by volume, a Vickers hardness ranging from 1500 to 3000HV, and a compressive inner tension lower than 500 MPa.

Abstract: The present invention relates to an element (1) that works sliding, of an internal combustion engine and/or a compressor that undergoes friction and receives a coating of chrome nitride having an equiaxial morphology, with low porosity (lower than 1%) and with a crystallographic orientation predominantly (111), maintaining some reticulate in the orientation (200), so as to improve its resistance to wear and its toughness, prolonging the useful life of the element (1) that works sliding.

Abstract: Piston tops (1, 70), specially those provided with combustion chamber (2, 20) and ring zone (3, 30) have their cooling condition sensibly improved in such regions due to a better use of the cooling oil capacity by closing the cooling chamber (5, 50) and the region 2I under the combustion chamber by annular ring members (96, 13) in a resilient material, e.g., a polymeric material or, preferably a spring steel, which clamp under the cooling chamber (5, 50) and the region 2I with dimensional interference respectively with grooves (10, 100), notches (11, 110) and groove 15. Methods for the manufacture of such top portion having a reduced compression height are also described.