EXPERIMENTAL INVESTIGATIONS INTO THE FINISHING FORCE AND TORQUE IN MAGNETIC ABRASIVE FINISHING PROCESS

Magnetic abrasive finishing (MAF) is a finishing process in which surface is finished by removing the material in the form of micro-chips by the magnetic and abrasive particles in the presence of a magnetic field. In a finishing process, forces have direct influence on the generation of finished surface and accuracy of the workpiece. The magnitude of force or torque is also of importance as the surface integrity is affected. In the present research work, new design of electromagnet which gave relatively lesser force and torque as compared to conventional annular electromagnet was used to perform MAP. The measurements of normal force and finishing torque were carried out at different processing conditions using Kistler's dynamometer and were found in the order of 24 N and 8 Nm respectively. The experiments were planned using Taguchi's L-16 orthogonal array and supply voltage to electromagnet, rpm of electromagnet, finishing gap and abrasive weight percentage at four levels were considered as process parameters. Supply voltage to the electromagnet and finishing gap were found to be the significant factors affecting finishing force and torque in this work. The scanning electron microscopy (SEM) study of the finished workpiece showed that there was no surface or subsurface damage due to very low finishing force and torque.