Design and fabrication of electrojet micro-printed checkerboard soft-hard composite coatings with enhanced performance for cutting tools

In this study, electrojet micro-printing was used to deposit a checkerboard-textured (CF x ) n /CaF₂/C-ZrO₂/TiO₂ soft-hard composite coating onto the rake face of the YT15 tool. The microstructure of the coating was characterised, and the influence of graphite content in the lubricating phase on cutting performance during dry machining of 304 stainless steel was explored. The results indicate that the incorporation of textured hard phases and graphite significantly improved cutting performance. Among the samples, the CBM2 coating, with higher carbon content, showed the lowest cutting forces and friction coefficients at cutting speeds of 50–150 m/min. In contrast, the CBM1 coating, with lower carbon content, exhibited the least tool wear and best performance at 200 m/min, due to the embrittlement of excess graphite at high temperatures.