Wear on SiC-Whiskers Reinforced Ceramic Inserts When Cutting Inconel With Waterjet Assistance

Applications of high-pressure waterjets directed onto the cutting tool have shown many advantages in metal machining. Tests have shown improvement in machinability of high-strength alloys using carbide tools. This paper presents an experimental investigation of the viability of having a 360 MPa waterjet directed onto the tool/chip interface when cutting a nickel-based superalloy with a SiCw-reinforced ceramic cutting insert. The resulting very localized cooling action was found to profoundly change the chip shape and tool wear behavior. Microscope studies of tools and chips indicate a significantly affected wear and cutting mechanism which can provide further knowledge of the mechanisms associated with this type of machining. The jet-cooling method was found to provide excellent chip-breaking and also enhanced the finish of the machined surface, although incorporating an accelerated tool wear rate due to a predominating thermal wear mechanism, which regularly determines the tool life. Concerning the notch wear—which normally determines the effective tool life for this type of insert—all tests utilizing jet cooling resulted in an accelerated notch wear rate independent of where on the tool/chip interface the jet was targeted.