Enhancing Orthogonal Finishing Machining of Ti6Al4V with Laser Modified Tools

Abstract

Finishing machining of Ti6Al4V, known for its high strength and heat conduction resistance, demands optimisation to achieve high-quality end products. This study explores modifying the chip contact length on the rake face and altering the flank face with a cavity to minimise process forces and temperatures, while maintaining cutting edge integrity. The research validates the manufacturability of laser-modified tools through ultra-short pulsed laser ablation, indicating potential for industrial scale-up. Extensive experimental evaluations under dry conditions assess the impact of tool modifications at various feed rates for planing and turning. Significant reductions in process forces and temperatures were observed with rake face modifications, particularly at a cavity distance of approximately \qty{34}{\micro\meter}. Ideal performance was noted for feed rates between \qtyrange[range-units=single]{0.035}{0.045}{\milli\meter} for planing and \qtyrange[range-units=single]{0.040}{0.045}{\milli\meter}/rev for turning. Smoothed Particle Hydrodynamics (SPH) simulations employing a Johnson-Cook material model were used to analyse chip formation and to predict the process forces. These simulations revealed a clear change in the chip formation and lower process forces and temperatures. The SPH results closely matched experimental outcomes, with a discrepancy of less than \qty{7}{\percent} in cutting forces for both tool types, although feed forces were underestimated by about \qty{50}{\percent}. The effect o the tool modification is reflected accurately at the specified feeds.