NANO-FINISHING OF STAINLESS-STEEL TUBES USING ROTATIONAL MAGNETORHEOLOGICAL ABRASIVE FLOW FINISHING PROCESS

Abstract

Abstract A new polishing method called Rotational (R)-Magnetorheological Abrasive Flow Finishing (MRAFF) process has been proposed by rotating a magnetic field applied to the Magnetorheological polishing (MRP) medium in addition to the reciprocating motion provided by the hydraulic unit to finish internal surface of cylindrical stainless steel (non-magnetic) workpiece. By intelligently controlling these two motions uniform smooth mirror-like finished surface in the range of nm has been achieved. For parametric analysis of the process, the experiments have been planned using design of experiments technique and response surface regression analysis is performed to analyze the effects of process parameters on finishing performance. Analysis of Variance (ANOVA) is conducted and contribution of each model term affecting percent improvement in surface finish is calculated. The experimental results are discussed and optimum finishing conditions are identified from optimization study. The present study shows that rotational speed of the magnet has most significant effect on output response (percentage improvement in surface roughness, %ΔR a ). The best surface finish obtained on stainless steel workpiece with R-MRAFF process is 16 nm. Keywords: magnetorheological fluidmirror finished surfaceMR finishingrotating magnetic fieldsurface roughness ACKNOWLEDGMENTS We acknowledge the Department of Science and Technology, New Delhi for their financial support for Project No. SR/S3/NERC/ 0072/2008 entitled “Rotational – magnetorheological abrasive flow finishing (R-MRAFF)” under which this work has been done. Notes *Machining conditions are given in Figure 5. *Length of travel in case of MRAFF is 43.5 mm. *Machining conditions are given in Figure 7. * – Significant term, ** – not significant. * – Significant term, ** – not significant term.