A hybrid analytical-FEM model to predict machining response under oil-on-water MQL during high-speed milling of Ti-6Al-4 V alloy

Oil-on-water (Oow) is a promising cooling method to assist high speed milling of Ti-6Al-4 V which can achieve high efficiency and high quality. However, the high-speed milling of this difficult-to-cut material would cause a high temperature and milling force. Under these circumstances, the improper MQL parameter would generate a rapid wear of tools and deteriorative surface quality. Currently, there is hardly prediction model considering the effect of varying MQL parameter. This article proposes a hybrid analytical-FEM model for predicting machining response under different MQL parameters. By establishing the distribution model of lubricant droplets, the friction coefficient and heat transfer under different MQL parameter are calculated. Subsequently, 3-D finite element models are also established based on theoretical analysis to distill machining response. Finally, high-speed milling experiments were conducted to verify the accuracy of the proposed model under Oow condition. The milling force and residual stress values of the model were in good agreement with the experimental results. Besides, the simulated chip morphology was satisfactory compared with experimental results. This study is beneficial to well understand the effect of oil-on-water technology during high speed-milling of Ti-6Al-4 V alloy as well as to optimize MQL parameter for desirable result.