Enhancing high-speed cutting performance of Inconel 718 superalloy via heat inhibiting with a bio-textured PcBN tool

Ni-based superalloy exhibits poor machinability due to low thermal conductivity and work hardening, leading to high cutting temperatures that accelerate tool wear and degrade surface quality. This work aimed to enhance high-speed cutting performance of superalloy via promoting heat inhibiting effect. A bionic micro-textured tool was proposed with the function of directional cutting fluid transport, facilitating efficient heat inhibiting of the cutting process. Micro-textures were created on PCBN tools via femtosecond laser machining. Droplet tests showed the bio-textured surface achieved directional fluid transport at ∼1 mm/s. The cutting performance was then evaluated. A significant decrease of cutting temperature was achieved owing to the heat inhibiting effect of the bio-textured tool, thus further improving tool wear, reducing cutting force, and increasing processed surface quality. Moreover, the bio-textured tool had superior cutting performance at high speed, featuring a max temperature drop of ∼60 °C at 300 m/min with the reductions of cutting force, processed surface roughness and flank wear width reduced by 17.7 %, 41 % and 37.3%, respectively. Finally, heat transfer mechanism of the bio-textured surface was investigated, which was related to the flow of both fluid and air. Heat exchange was mainly achieved with high-velocity directional fluid cooling. The acceleration of air flow also contributed effectively, promoting heat carrying via fluid pushing and vortex forming. These findings bring significant insight on high-speed cutting of superalloy by using functional bio-textured tool.