Texturing of W-SiC composites via through-mask electrochemical machining for enhanced tribological performance

Tungsten (W), as a typical refractory metal, had been widely applied in the aerospace, nuclear industry and other extreme working conditions. Particle-reinforced W-based composites, such as W-SiC composites, exhibit higher hardness and superior wear resistance. Additionally, surface texturing can alter the contact state of friction interfaces, thereby reducing friction and wear. This study investigated the texturing of W-SiC composites via through-mask electrochemical machining (TMECM) and evaluated their tribological behavior. TMECM enables the fabrication of large-scale micro-dimple arrays with spacings ranging from 1.5 to 3 mm. These micro-dimples have an average diameter of 763–796 μm and an average depth of 31–88 μm. Increasing the spacing leads to larger dimensions due to a more intensive electrical field. Some micro-dimples feature an uneven bottom due to the Si enrichment in local regions. Compared to the raw sample, the textured W-SiC samples exhibit a lower average friction coefficient (AFC). Under both dry sliding friction and oil lubrication conditions, denser texture arrays with a 1.5 mm spacing reduce the AFC and wear volume. Under dry sliding friction, the texture arrays could trap the abrasive particles and mitigate the interface wear caused by particle rolling. Under oil lubrication, the textures act as reservoirs to release the lubricant and enhance the hydrodynamic effect to support the friction pair with a greater hydrodynamic force. Thus, surface texturing endows W-SiC composites with improved wear resistance and friction reduction.