Structural Evolution and Properties of Cr Coatings on Rings Deposited by High Power Pulsed Magnetron Sputtering

Abstract

The ring is a key component of the high-speed ring spinning machine, which is in sliding friction environment for a long time. A chromium coating with high hardness is usually prepared on rings surface by electroplating technology to improve the mechanical properties and the working life of rings in the current industrial field. However, the environ-mental pollution associated with electroplating technology has restricted its industrial production, and it is urgent to find a non-polluted coating preparation technology. In this paper, an environmentally friendly high power pulsed magnetron sputtering technology was used to prepare the pure Cr coatings with different thickness on the ring surface. The mi-crostructure, deposition rate, adhesion between film and substrate and tribological property of coatings were character-ized by different means. The results showed that with the prolongation of deposition time, the degree of crystallization of coatings was gradually enhanced, and the surface microstructure was gradually transformed from small and dispersed irregular polygonal structure to circular arc irregular cellular structure. When the deposition time were 120 mins, the film thickness was about 6.4 μm, and the average and instantaneous deposition rates of Cr coating were 53 nm/min and 267 nm/min, respectively The coating had the best film-substrate adhesion, low friction coefficient of 0.41 and the best wear resistance (mass wear rate of 1.8×10-4 g/s).