Optimized a-C:Wx% coatings with enhanced tribological properties and improved micro-drilling performance

This study fabricates a series of a-C:Wx% coatings and measures their hardness, adhesion strength and elemental composition. The wear characteristics of cemented tungsten carbide–cobalt (WC–Co) substrates coated with the a-C:Wx% coatings are tested using an oscillating wear testing machine. Additionally, high-speed through-hole drilling tests are performed on PCB workpieces to investigate the machining performance of coated micro-drills. The experimental results show that the a-C:W8.8% coating has excellent tribological properties and represents the optimum coating for micro-drilling applications.