An experimental study on the effect of magneto-rheological finishing on diamond turned surfaces

Magneto-rheological materials are a class of smart materials whose rheological properties can be rapidly varied by applying a magnetic field. Magneto-rheological finishing utilizes magneto-rheological fluid, which consists of magnetic particles, non-magnetic abrasives and some additives in water or other carrier to polish the materials. Single-point diamond turning is able to remove hundreds of microns of material and generate surface with micron accuracies. Residual turning marks are the most important factor limiting the performance in diamond turning process. Magneto-rheological finishing has inherent ability to improve micro-roughness, remove subsurface damage and reduce residual stresses induced during diamond turning process. Combining single-point diamond turning and magneto-rheological finishing creates a deterministic process for manufacturing highly finished surfaces. In this article, an attempt has been made to improve the finish of diamond turned surface with magneto-rheological finishing and to investigate the effects of parameters like current, spacing, wheel speed, feed rate and magnetic field on the final surface finish. Based on the parametric study, an optimum combination of process parameters is identified using analysis of variance. Various image processing techniques have been used for the comparison of the surface analysis of diamond turned surfaces and the magneto-rheological finished surfaces.