Wear mechanisms and effects of monolithic Sialon ceramic tools in side milling of superalloy FGH96

Abstract FGH96 is one kind of nickel-based superalloy, being widely used in aero engine hot end components due to its superior mechanical properties, while its machinability has been a challenge because of rapid tool wear and low machining efficiency. Recently, ceramic tools have gained widespread attention for their superior performance maintained at high temperatures. This work aims to study the wear mechanisms and the wear effects of monolithic Sialon ceramic tool in the side milling of superalloy FGH96. The specific influences of average flank wear on the side milling forces, machining temperatures, surface quality and micro-hardness of subsurface and the wear modes in the early and serious stage are analyzed. The results indicate that the milling temperatures, machined surface roughness and the depth of hardening layer will increase as the wear increases. While parallel to the cutting direction, the machined surface roughness is about 1.8 μm without significant changes until entering the serious wear stage. The milling force tends to undergo a decrease when the VB is about 0.22 mm, since the temperature is close to the solute temperature of γ’ phase in this stage. The main wear modes of monolithic ceramic tools are adhesive wear and flanking in the flank surface.