Mechanical behavior of material removal under various rake angle diamond tool ultra-precision cutting of titanium alloy

Abstract

The titanium alloy TC4 (Ti–6Al–4V) is widely applied in ultra-precision machining of aerospace optical components due to its high specific strength and thermal resistance. Understanding their material removal mechanisms enables optimization of machining parameters, enhancement of surface quality, expansion of advanced processing techniques, and fulfillment of performance demands in high-end applications. However, existing predictive models often neglect the coupled effects of mechanical, frictional, and fluid dynamic fields, limiting their applicability and predictive accuracy. To address this, this study proposes a cutting force prediction framework integrating the Oxley cutting model with the Johnson–Cook constitutive model. By incorporating a dynamic friction coefficient, the model's accuracy is experimentally validated. The effects of different lubrication modes on surface defects are quantified, and the chip formation and scratch morphologies are examined. The results show that the model achieves an average prediction error of 8.23 %, with a minimum error of 3.54 %. Both rake angle and lubrication mode jointly affect the material removal behavior of TC4: a reduced rake angle intensifies plowing and fracture, whereas the nanolubricant minimum quantity lubrication (NMQL) mode effectively reduces scratch depth. This approach provides a theoretical foundation for understanding cutting force evolution in machining TC4 and serves as a reference for tool design and machining parameter selection.