Investigation on the material removal and surface roughness in ultraprecision machining of Al/B<inf>4</inf>C/50p metal matrix composites

Abstract

Metal matrix composites (MMCs) are increasingly applied in various engineering industries because of their distinct physical and mechanical properties. While the precision machining of MMCs is less understood due to their complex microstructure and poor machinability, a comprehensive scientific understanding on their machining mechanics and the associated surface generation mechanisms is of great importance particularly for industrial scale applications of MMCs. This paper presents a simulation and experimental-based holistic investigation on cutting mechanics, material removal and surface roughness in ultraprecision machining of MMCs. B4C/Al2024 is selected as the targeted MMC material in this research. The thermal-mechanical-tribological integrated modelling and analysis are presented to investigate the effects of cutting speed, feed rate and depth of cut (DOC) on the material removal, chip formation mechanics and surface generation process. The simulation results indicate that the machined surface roughness in precision machining of particle reinforced MMCs can be reduced by increasing the cutting speed and decreasing the depth of cut. The surface flow waviness decreases, which contributes to a higher surface quality, while machining with a smaller feed rate. The well-designed machining trials are conducted under the same cutting conditions and process variables as those in simulations, which perform a good agreement with simulation results.