A novel bionic micro-textured tool with the function of directional cutting-fluid transport for cutting titanium alloy

Abstract

The need for high-precision titanium alloy components is rising exponentially in the biomedical engineering. However, ultra-precision cutting of titanium alloy is challenging due to the high cutting heat because of its low thermal conductivity, which results in severe tool wear and poor surface finish. Therefore, machining titanium alloys requires excellent cooling and lubricating solution. In this research, inspired by the microstructural surface of the Nepenthes' peristome, a bionic micro-texture (BMT) with the function of directional cutting-fluid transport is developed aiming to improve cooling and lubrication condition in cutting zone. The BMT is designed and fabricated by employing a femtosecond laser on the tool surface after theoretically evaluating the fluid transporting behavior of the BMT and its essential geometry parameters. From the directional fluid transport and ultra-precision cutting tests, it is found that the BMT surface offers a high directional fluid flow rate of 3.7 m/s. Moreover, the BMT tool produces lower cutting force, and generates defect-free morphology and nanoscaled roughness. Furthermore, the BMT tool results in reduced flank wear by 84% and 82% at a cumulative cutting distance of 900 m comparing with the none-texture (NT) and micro-groove-texture (MGT) tools respectively, and exhibits excellent chip adhesion resistance. Therefore, it is feasible and promising to apply the BMT tool in ultra-precision cutting of titanium alloys components.