Uniform Finishing of Complex Profiles using Rotational Magnetorheological Fluid-based Finishing R MRFF Process

Abstract

The surface roughness of any component is a major concern in the medical, automotive, aerospace, military, and other industries. The performance and life of the components depend primarily on their surface quality. The components explored in the current study for finishing purposes are miniature gear and poppet valve. The poppet valve accurately regulates the perfect air/fuel mixture into the combustion chamber of a gas propulsion engine or internal combustion (IC) engine to reduce hydrocarbon emissions. Miniature gears are used in biomedical devices for pumping, cutting, and various other works, also in small servo motors, which are widely used in the UAVs, automotive, and aerospace industries. Previous finishing methods (mentioned in the literature) generate defects like burrs, pits, scratches, dents, etc. The uniform nano-scale finishing on such components is tough to achieve due to constraints related to the fixture design and fixture material. The surface roughness requirement of these complex components is at the nanometer level and should be uniform over the entire surface. The rotational magnetorheological fluid-based finishing (R-MRFF) process is proposed in the present study to counteract the problems faced during finishing miniature gear and poppet valve profiles while providing the required uniform surface finish and surface characteristics. A novel flow restrictor and workpiece fixture are designed and developed to uniformly nano-finish SS316L miniature gear teeth profiles. Also, a novel magnet fixture is designed and developed to nano-finish Nickel-Al-Bronze alloy (AB2 grade) based poppet valve ridge profiles uniformly. Magnetorheological (MR) polishing fluid is used in the R-MRFF process to finish both components.