Investigation on cutting performance in ultrasonic assisted helical milling of Ti6Al4V alloy by various parameters and cooling strategies

Ti6Al4V alloy is one of the typical difficult-to-machine materials and often results in rapid tool wear, leading to poor machining quality aircraft assembling. Compared conventional helical milling, ultrasonic assistant milling (UAHM) process has indicated its superior performance; however, it still a great challenge improve hole surface accuracy. In addition, few studies have been conducted on effect different variables cooling strategies hole-making performance longitudinal-torsional assisted (LT-UAHM). This paper, for first time, reports effects geometric precision roughness LT-UAHM Ti6Al4V. lubrication/cooling mechanism simultaneous application MQL theoretically analyzed. The design approach Taguchi experiment was employed study how major such as cutting speed, tangential feed, axial workpiece hardness influence dimensional geometrical tolerances roughness. paper also discussed three strategies, i.e., dry condition, air coolant, minimum quantity lubrication (MQL) LT-UAHM. Theoretical analysis demonstrated that coolant can be nebulized into hyper-fine droplets owing resonant cavitation phenomenon. Combined with penetrating action caused by separate-cutting principles LT-UAHM, further enhanced. As result, had most positive circularity, cylindricity, nominal diameter, roughness, contributing 34%, 32%, 39%, 40%, respectively. second important factor 31%, 29%, 36%, 22%, feed negative accuracy,