A kind of diamond-like coating for piston ring surface, piston ring and preparation process

Abstract

The invention relates to a diamond-like coating used on the surface of a piston ring. The diamond-like coating consists of a primer layer, a gradient layer and an amplitude modulation layer from bottom to top. The amplitude modulation layer is a diamond-like coating doped with doping elements. The doping element is one or more of Cr, Si and Ti, and the content of the doping element in the amplitude modulation layer changes periodically in the form of sinusoidal fluctuations with the thickness of the amplitude modulation layer. Compared with the traditional single-layer structure or gradient layer structure, because the content of doping elements in the amplitude modulation layer of the diamond-like coating changes periodically with the thickness of the amplitude modulation layer in the form of sinusoidal fluctuations, the amplitude modulation of the diamond-like coating The layer has a multi-layer cyclic modulation structure; on the basis of high wear resistance and low friction coefficient, it is beneficial to reduce the internal stress of the coating, improve the toughness of the coating, and ensure the increase of the thickness of the diamond-like coating, while improving the piston of the diamond-like coating. ring durability.

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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