Some Investigations Into Magnetorheological Finishing (MRF) of Hard Materials

Magnetorheological finishing (MRF) process is one of the fine abrasive finishing processes used to get better surface finish on a semi finished part. The present work is aimed at investigating the effectiveness and validity of magnetorheological finishing process and finding out the process parameters (such as finishing time, rotational speed of carrier wheel, abrasive concentration, and working gap) and their effectiveness on surface finish characteristics. MRF process is applied on brass and nonmagnetic stainless steel workpieces which were initially finished by the grinding process. The results of experiments were statistically analyzed by response surface methodology (RSM) to form an empirical model for the responses generated during the process. Also, an attempt has been made to model and simulate the finishing operation in MRF process. Apart from this, the micro structure of the mixture of magnetic and abrasive particles in magnetorheological polishing fluid (MR Fluid) has been proposed. Thereafter the normal force on the abrasive particles is calculated from the applied magnetic field and a model for the prediction of surface roughness has also been presented. Finally, theoretical results calculated using the proposed model, have been compared with the experimental results to validate the model developed.