Optimization of external roller burnishing process on magnesium silicon carbide metal matrix composite using response surface methodology

This paper deals with the optimization of external roller burnishing operation using a CNC lathe for a Mg-SiC metal matrix. Magnesium metal was alloyed with 10% (w/w) of SiC particles as a reinforcement. The Stir casting process was used to cast the bars. CNC turning was then performed on these bars to prepare them for the roller burnishing process. The process parameters considered during burnishing are speed, feed rate, force and number of tool passes. Surface roughness, microhardness and out of roundness were the outputs of each experiment. The Taguchi methodology was used to design an experiment. This design yielded an L16 (44) Matrix. Response Surface Methodology was then used for procuring the optimized set of process parameters. Surface plots were studied to understand the impact of all the potential combinations of the process parameters. Regression equations were formulated between the input and output parameters. The optimum surface roughness of 0.1506 μm, surface hardness of 57.9996 HV and out of roundness of 0.0151 mm were obtained from the following burnishing parameters: speed of171 rpm, feed rate of 0.18 mm/rev, force of 21 N and 3 passes. The optimized parameters were found with the desirability factor of 0.9991.