Simulation study of magneto-rheological polishing fluid for nano finishing of micro-structures
The quality of surface is very significant parameter which affects the life and functionality of a product. Nano finishing is ultra-precision finishing process which is developed for obtaining nano-meter order surface finish. It can be classified into magnetic and non-magnetic. Magnetic finishing involves magnetic abrasive finishing, magnetorheological finishing and allied processes. Magnetorheological Finishing process utilizes magnetorheological polishing fluid to polish different kind of materials. Magnetorheological fluid consists of magnetic carbonyl iron particles (CIPs) and non-magnetic abrasive particles (NMAPs), a carrier liquid and surfactant. The finishing performance of magnetorheological (MR) fluid-based finishing process depends upon the composition of MR fluid. Change in rheological property of MR fluid due to the applied magnetic field affects finishing performance of Magnetic Field Assisted Finishing Process (MFAF). These rheological properties of MR fluid depend upon composition and concentration of different elements in MR fluid. So, composition of MR fluid is very critical part of finishing process. Simulation study of Magnetorheological polishing fluid is done for nano-finishing of micro-structures on various simulation softwares. Model is developed on the design software like PTC Creo and a finite element analysis of the polishing medium in the finishing zone is performed in Ansoft Maxwell to find out the direction and magnitude of magnetic field. Microstructure model for the mixture of magnetic and abrasive in MRP medium is proposed in order to calculate the forces acting on an active abrasive particle. The plots and graphs obtained from ansoft maxwell are analysed and then the placement of magnet is done accordingly to get the maximum magnetic field at the surface to be finished.
Keywords: nano-finishing, MFAF, MR fluid, Ansoft Maxwell.