Modelling of transient behaviour of roughness reduction in ball end magnetorheological finishing process

Ball end magnetorheological finishing (BEMRF) process provides nano level of surface finish for materials which are magnetic as well as non-magnetic in nature. The available literature on this process has been vastly limited to establishing its finishing capabilities on materials of different nature. This research work deals with theoretical investigations into surface roughness reduction in BEMRF process, performance of machining parameters during long time periods and providing their representation in mathematical terms. Starting with the mechanism of abrasive wear in BEMRF process, this work advances to find out prolonged effect of abrasive rubbing on a ferromagnetic workpiece surface. The study finds out a phenomenon termed as transient roughness reduction in which the material removal by abrasive wear in BEMRF process is diminished with time and a particular combination of machining parameters and fluid composition reduce roughness only up to a critical value, beyond which no further reduction is achieved. A mathematical model is developed to depict this transient roughness reduction phenomenon, the model is then experimentally verified and the close proximity of the experimental results with the theoretical ones validates the model and the transient roughness reduction phenomenon in BEMRF process.