Diamond-like carbon coating applied to surface of piston ring, piston ring and manufacturing technology

Abstract

The invention relates to a diamond-like carbon coating applied to the surface of a piston ring. The diamond-like carbon coating includes a base layer, a gradient layer and an amplitude modulation layer sequentially from bottom to top, wherein the amplitude modulation layer is a diamond-like carbon coating body doped with doping elements, the doping elements include one or more than two of Cr, Si and Ti, and the doping element content of the amplitude modulation layer changes periodically in a sine wave fluctuation mode along with the thickness of the amplitude modulation layer. Compared with a traditional single-layer structure or gradient-layer structure, as the doping element content of the amplitude modulation layer changes periodically in the sine wave fluctuation mode along with the thickness of the amplitude modulation layer, the amplitude modulation layer of the diamond-like carbon coating is of a multi-layer cycle modulation structure; and on the basis of the high abrasion resistance and low friction coefficient, stress in the coating can be lowered advantageously, the toughness of the coating can be improved, it is ensured that the thickness of the diamond-like carbon coating is increased, and the durability of the piston ring of the diamond-like carbon coating is also improved.

Description

technical field [0001] The invention relates to the technical field of piston ring surface treatment, in particular to a diamond-like coating for the surface of a piston ring, a piston ring and a preparation process. Background technique [0002] As one of the key components of the internal combustion engine, the wear of the piston ring has a very important impact on the overall fuel consumption of the engine. At present, vehicle engines (especially diesel engines) are developing in the direction of high mechanical load, high output power (high heat load), low fuel consumption and low exhaust emissions. Therefore, the thickness of the piston ring becomes thinner and the weight becomes lighter, which requires the piston ring to have high strength (thermal fatigue strength), wear resistance, cylinder resistance, and sliding characteristics that do not cause too much wear to the cylinder liner. [0003] In order to improve the efficiency and life of the piston system, high-har...

AI Technical Summary

Problems solved by technology

Although these thinner diamond-like coatings exhibit excellent low-friction performance, the insufficient durability makes these diamond-like coatings unable to meet the long-term function realization of the engine on the piston ring surface under heavy load and high pressure conditions.

[0006] At present, the bottleneck restricting the application and popularization of diamond-like coatings mainly lies in the fact that the diamond-like coatings prepared by existing methods have high internal stress, and the greater the thickness of the coating, the greater the stress performance.

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