Multiobjective optimization of chip removal performance of cutting fluid in large diameter titanium alloy deep hole trepanning

Abstract

Performing the deep hole trepanning of titanium alloy presents intricate challenges including complex chip breaking, chip removal, and rapid tool wear. This study investigates the performance of cutting fluid in facilitating chip removal during the multi-tooth deep hole trepanning process of Ti-6A-4V titanium alloy, employing a comprehensive approach that integrates both simulation analysis and experimental research. The parameters of the cutting fluid are optimized using the Response Surface Method (RSM). The independent variables are the flow rate, viscosity, and density of the cutting fluid, while the optimization objectives are the pressure and turbulent kinetic energy (TKE) of the first and second cutter tooth’s chip breaking grooves (CTCBG). The findings indicate that the influence on the pressure and TKE of the first CTCBG is sequentially determined by cutting fluid viscosity, flow rate, and density. The impact on the pressure of the second CTCBG is ranked in descending order by cutting fluid flow rate, viscosity, and density. The factors influencing the TKE of the second CTCBG adhere to the order of cutting fluid viscosity, flow rate, and density. Considering the four optimization indicators, the optimal parameters of the cutting fluid are a viscosity of 0.001 kg·m⁻¹·s⁻¹, a density of 1100 kg·m⁻³, and a flow rate of 180 L·min⁻¹. The application of these optimized cutting fluid parameters in deep hole trepanning can significantly shorten the length of chip morphology.