Hybrid machining process: experimental and numerical analysis of hot ultrasonically assisted turning

© 2018 Springer-Verlag London Ltd., part of Springer Nature A hybrid turning is presented for turning of Ti-15V-3 Al-3 Cr-3 Sn alloy. In this technique, cutting insert is vibrated in velocity direction with the help of ultrasonic transducer and external heat is provided to the machined workpiece to gain collective benefits of both arrangements in cutting of hard-to-cut alloys. The studied alloy was investigated numerically and experimentally using hybrid turning process to determine its rewards in decline of measured cutting forces and enhancement in quality of machined surface. The assessment for thermal evolution in the cutting process was carried out both numerically and experimentally, and an accurate prediction of process zone temperatures is achieved. A significant improvement in dry turning of the studied alloy was achieved in terms of substantial decline in cutting forces and no substantial alterations in the metallurgy of the tested material. An elastoplastic thermo-mechanically coupled finite-element model for oblique-turning process is established to investigate the effect of heat and vibration on output parameters numerically. The developed model was used to explore the influence of selected machining parameters (depth-of-cut, feed rate, cutting speed, and tool nose radius) on three components of forces, stresses, and process zone temperature. Comparative case studies were executed with the developed models of conventional-turning, hot-conventional-turning, and hybrid turning and were confirmed by the outputs from tests carried out on the in house prototype available at Loughborough University, United Kingdom. The model was used for two-dimensional ultrasonic vibration in all three axis and resulted no significant drop in the cutting forces when compared to the studied hybrid turning process.