Rolling bearings operating under severe conditions such as insufficient lubrication are susceptible to various surface failure modes, including seizure, spalling, scuffing, and sliding-induced damage, which can significantly reduce bearing service life. Diamond-Like Carbon (DLC) coatings are widely recognized as an effective surface engineering technology for enhancing bearing resistance to surface damage owing to their high hardness, excellent wear resistance, and low coefficient of friction. However, conventional DLC coatings tend to suffer from delamination under high contact stress conditions, limiting their engineering applicability.
In this study, the delamination resistance of DLC coatings was improved through microstructural and mechanical property optimization. The Young’s modulus of the interlayer was tailored to achieve better deformation compatibility with the substrate, thereby reducing interfacial stress caused by deformation mismatch between the coating and substrate under external loading. In addition, silicon (Si) doping was introduced into the functional layer to effectively reduce the residual stress of the coating while maintaining high hardness. As a result, the delamination resistance of the DLC coating was significantly enhanced. Experimental results demonstrated that the optimized coating exhibited a delamination life more than 4.5 times longer than that of the conventional coating.
 

DLC coating; rolling bearing; delamination resistance; stress; silicon doping.