Optimization of Surface Roughness in End Milling of Medium Carbon Steel under the Influence of Magnets Attached to the Machine Spindle

One of the major technological parameters in metal cutting is surface roughness. It is an unavoidable, and often, unwanted by-product of all machining operations, especially end milling. Surface roughness is directly related to product quality and performance, operation cost, machining accuracy, and chatter. Today’s stringent customer requirements demand machined parts with minimum (mirror finished) products. Hence, the prediction, modeling, and optimization of surface roughness is a quintessential concern in machining research and industrial endeavor. This research was undertaken in order to determine whether end milling of medium carbon steel performed using chosen ranges of cutting parameter and under magnetic field generated by permanent magnets could effectively improve surface roughness. A small central composite design with five levels and an alpha value of 1.4142, in Response Surface Methodology, was used in developing the relationship between cutting speed, feed, and depth of cut, with surface roughness. Design-Expert 6.0 software was utilized to develop the quadratic empirical mathematical model for surface roughness. The experiments were performed under two different conditions. The first condition was cutting under normal conditions, while the other one was cutting under the application of magnetic fields from two permanent magnets. Medium carbon steel was used as the work material. The resultant average surface roughness was found to be reduced by a maximum of 59% due to magnet application.