Diamond-coated tools often fail due to coating graphitization and delamination caused by poor coating adhesion, large contact stress, and thermochemical reactions. To address these issues, this research utilized a combination of micro-nano double-layer diamond coating, WS₂ coating, and micro-textures. The WS₂ coating inhibits the graphitization of the diamond coating through a transfer film mechanism, while the micro-textures and nanocrystalline diamond coating store WS₂, resulting in a prolonged lubrication life. Additionally, the influence of micro-texture on coating-substrate residual stress and coating-substrate mechanical interlocking was discussed, and it was proved that proper micro-textures effectively improve the coating adhesion. Under the same cutting flux conditions, taking coating peeling as the judging standard, the cutting distance of textured WS₂/Micro-Nano diamond coating tool is more than three times that of ordinary, diamond-coated tools, which greatly improves the service life of the tool.

Cyclic impacts in corrosive environments significantly affect the service life of ceramic coatings, greatly increasing their susceptibility to cracking and delamination. This study investigated the damage evolution behavior of Cr₂O₃-TiO₂ (CT) coatings under cyclic stress in a corrosive medium, and analyzed the effects of the nickel layer on coating stress, corrosion current, and crack propagation. The variations in corrosion potential and current were analyzed, and the formation patterns of interfacial corrosion cracks were observed. Pre-cracks were introduced on the ceramic coating surface using a Micro-Nano mechanical testing system, and cyclic impacts were applied to the samples in 5% diluted hydrochloric acid using SiC balls to induce damage evolution. The results indicate that the presence of the nickel interlayer reduced the corrosion current density from 9.197 × 10⁻⁶ A/cm² to 8.088 × 10⁻⁶ A/cm² and significantly decreased the stress between the coating and the substrate. The surface cracks gradually extended toward the interface under the coupling effect of corrosion and SiC ball impact. When cracks reached the interface, they provided channels for corrosive media, leading to stress corrosion cracking at the interface. The Ni intermediate layer suppressed the formation of interface cracks and greatly enhanced the impact damage resistance of the CT coating–substrate system in corrosive media.

Diamond-coated tools are suitable for CFRP machining because of their high hardness, sharp cutting edge, and good wear resistance. However, the anisotropic and heterogeneous nature of CFRP makes drilling-induced defects, such as burrs, tearing, fiber pull-out, and delamination, difficult to avoid, especially at the hole exit. In this study, an ice-supported drilling method was proposed for CFRP hole machining using diamond-coated drills. An ice layer was formed beneath the CFRP laminate to provide simultaneous low-temperature cooling and mechanical support during drilling. Comparative drilling experiments were conducted at spindle speeds of 400, 1200, and 2000 r/min. The results showed that the ice-supported drilling method markedly improved the hole surface quality and inner-wall integrity of CFRP laminates. Compared with conventional dry drilling, the drilling temperature was reduced by 22.03%, 10.70%, and 11.45% at 400, 1200, and 2000 r/min, respectively, while the hole-exit delamination factor decreased by 41.68%, 27.45%, and 57.04%, respectively. Moreover, after the same number of drilled holes, the diamond-coated drill used under ice-supported conditions exhibited less severe surface wear and cutting-edge blunting than that used under conventional dry conditions. The observed improvements were interpreted as being associated with the combined thermal-regulation and temporary mechanical-backing effects of the ice-supported condition.