Abstract
The use of hardened steel in the automotive industry has increased of late. For longevity of the component under fatigue loading, residual stresses play an important role. The fatigue life of a machined component improves when the nature of the residual stress profile generated is compressive. In the present work, the machining forces, tool tip temperature and the nature of the residual stress generated have been studied in Vibrating Assisted Machining (VAM) conditions where the tool vibrates at low amplitude and high frequency. The vibration makes the tool create a constant engagement and disengagement motion with the workpiece. A three-dimensional thermo-mechanical FEM model has been developed to study the effects of VAM on turning of hardened (62 HRC) AISI 52100 steels. The model predicted the radial forces with sufficient accuracy for continuous turning. The air cooling of the tool during disengagement from the workpiece, gives rise to convective heat transfer to the surrounding, resulting in efficient the cooling of the tool. The same has been verified by analysing the effect of vibrating velocity (Vv) on tool tip temperature. The intermittent nature of VAM decreased the average tool tip temperature. The residual stress generated at different cutting speeds under vibration (Vv) was also predicted. For larger Vv, the residual stress profile became more compressive compared to that generated in the conventional hard turning simulations.
