Investigation of heat partition and instantaneous temperature in milling of Ti-6Al-4V alloy

Cutting temperature is a critical factor which affects the thermal-mechanical behaviors of workpiece, the damage and wear of cutting tool. In this work, an analytical, numerical and experimental combined approach was developed to determine the heat partition to the milling tool. A thermo-mechanical model and the tool convective heat transfer model were established by an analytical method. The heat flux of the chip contact surface and the convective heat transfer coefficient of the milling cutter were predicted. To calculate the heat partition ratio to the milling tool, a finite element heat transfer simulation analysis of the temperature field of the milling cutter was carried out according to a milling kinematic analysis. A novel experimental method was designed to measure the instantaneous temperatures inside of tool, cutting edge and workpiece surface. The measured temperatures at different locations inside of the tool were applied to calibrate the heat distribution ratio to the milling tool. Additionally, the calculated instantaneous temperatures of the cutting edge by the heat partition ratios agreed well with the measured instantaneous temperatures of peripheral edges at various conditions, further validating the accuracy of the heat partition ratio. The temperature of the milling tool is proportional to the heat partition to the milling tool. The developed approach can provide effective method for controlling the performance of milling process according to the heat partition ratio.