Influence of adhesion strength on cavitation erosion resistance of diamond-like carbon coating

Abstract

Purpose The disbonding of DLC coating is a main failure mode in the high-speed cavitation condition, which shortens the service life of the bearing. This study aims to investigate influence of adhesion strength on cavitation erosion resistance of DLC coating. Design/methodology/approach Three DLC coatings with different adhesion strengths were grown on the 304 steel surfaces by using a cathodic arc plasma deposition method. Cavitation tests were performed by using a vibratory test rig to investigate the influence of adhesion strength on cavitation erosion resistance of a DLC coating. The cavitation mechanism of the substrate-coating systems was further discussed by means of surface analyses. Findings The results indicated that, the residual stress decreased and then increased with the increasing DLC coating thickness from 1 µm to 2.9 µm, and the lower residual stress can improve the adhesion strength of the DLC coating to the substrate. It was also concluded that, the plastic deformation as well as the fracture occurred on the DLC coating surface at the same time, owing to higher residual stress and poorer adhesion strength. However, lower residual stress and better adhesion strength could help resist the occurrence of the coating fracture. Originality/value Cavitation tests were performed by using a vibratory test rig to investigate the influence of adhesion strength on cavitation erosion resistance of the DLC coating. The plastic deformation and the fracture occurred on the DLC coating surface at the same time, owing to higher residual stress and poorer adhesion of coating. Lower residual stress and better adhesion of coating could resist the occurrence of the DLC coating fracture.

Study of the Industrial Application of Diamond-Like Carbon Coatings Deposited on Advanced Tool Steels

“…The high compressive stress of hard DLC coatings often leads to poor adhesion with tool steel substrates, limiting its practical applications. Furthermore, the plastic deformation and fracture of DLC coatings have been attributed by Cheng et al [41] to higher residual stress and poorer adhesion strength, impacting the cavitation erosion resistance of DLC coatings. Figure 10 displays microscopy images that reveal the scratch test grooves.…”

Particle‐Induced Erosional Behaviors of Diamond‐Like Carbon Films

“…Cheng et al reported that the cavitation erosion resistance of these films is highly related with their micro defects and adhesion strengths with their substrates. [9,10] Gerke et al demonstrated that different substrate materials can influence the cavitation erosion behaviors of DLC films by affecting their reversible deformation and the film/substrate adhesion strengths. [11] Kanda et al studied the erosion of the fluorinated DLC films exposed to soft X-rays and found that the radiation can cause the uniform decrease in fluorine composition from film surface to substrate.…”