Characterization and optimization analysis on surface finish and energy consumption in turning of Al-4032/GMP MMC produced by stir casting

Abstract

Control of energy expenditure in computer numerical control (CNC) machining is needed for eco-friendly operation of machining operations. Production industries deeply emphasize the improvement of productivity and saving in cost. The aluminum-based metal matrix composites (AMCs) can be substituted for metals for their mechanical properties in several applications. However, to bring in composite to usage, generally demand certain machining operation, which is quite challenging. This paper presents fabrication, characterization, and machining (turning) of Al-4032/6%GMP (granite marble powder) composite. Optical micrographs (OM) and scanning electron microscopy (SEM) with energy dispersive x-ray analysis (EDAX) have been used for the portrayal of the composite microstructure, surface topography, and fracture behavior. Also, mechanical characterization (tensile strength, micro-hardness, and impact strength) of the fabricated AMC has been carried out. The AMC samples have been examined for machinability for CNC turning operation. Cutting speed, feed rate, and depth of cut are the cutting parameters selected for the machining experiments. The response surface methodology (RSM)-based desirability function has been used to obtain the best combination of parameters for achieving the desired objectives. Experimental results demonstrate the built-up edge (BUE) formation on cutting insert and interfacial bonding of particles on workpiece surface at low cutting speed. Generally, smooth cutting operation has been observed at cutting speeds above 100 m/min. Best surface finish (1.38 μm) and minimum energy consumption (0.27 kWh) have been observed at cutting speed 176 m/min, feed rate 0.15 mm/rev, and depth of cut 0.45 mm.