Optimization of Machining and Geometrical Parameters to Reduce Vibration While Milling Metal Matrix Composite

Abstract

During end milling of metal matrix composite (MMC), it is subjected to varying impact load and cutting force. This action induces vibration during machining, which results in poor surface finish and increased tool wear. In this study, an attempt has been made to determine the optimum level of geometrical parameters such as helix angle, nose radius and rake angle and machining parameters such as cutting speed, feed rate and depth of cut to obtain minimum vibration amplitude during end milling operation using particle swarm optimization (PSO). Machining was carried out on aluminum (Al 356)/silicon carbide (SiC) particulate MMC using high-speed steel end mill cutter. The experimental design adapted for conducting the experiments was L27 orthogonal design array. The experiments were conducted using vertical machining, and the vibration amplitudes were measured at two positions (spindle and workpiece holder) using a twin-channel piezoelectric accelerometer. The empirical regression model was developed by relating the input parameters and the output vibration amplitudes, and optimization of process parameters to obtain minimum acceleration amplitude was done using PSO. Scanning electron microscopic images of the milled surfaces were examined, and it indicated the presence of cracks and holes due to pulling out of SiC particles.