A study on the fabrication of curved surfaces using magnetorheological fluid finishing

Abstract

A fabrication method of curved surfaces on silicon-based micro-structures using magneto theological finishing is studied. Thorough explanations are made on the procedures for the evaluation and analysis of surface characteristics of a workpiece and on the fabrication method of the curved surface profile associated with the experiments using magnetorheological finishing. The effect of magnetic field around tool assembly on finished surface profiles is investigated using a finite element method (FEM). The analysis on the magnetic field is performed separately from that of the fluid flow field with the assumption that the field is weakly coupled to the working fluid at steady state with a certain geometric configuration adopted in this work. Several experiments were performed under controlled conditions and the results are demonstrated along with the physical interpretations thereof. The edge effect is turned out to be very important as the target workpiece gets smaller, which can be actively used for the fabrication of curved surfaces on millimeter-scale structures. Response surface methodology (RSM) is applied to predict the profile and roughness of the curved surface of the workpiece to be proceeded with a set of known experimental conditions. In order to use the RSM method, two control input and two response variables are chosen deliberately. Among the multi-regression models generally used in the modeling area, a second-order regression model is employed. The predicted results are verified through additional experiments performed independently. (C) 2007 Elsevier Ltd. All rights reserved.