Magnetorheological finishing of WC-Co coating using iron-B4C-CNT composite abrasives

Abstract

Magnetorheological finishing (MRF) of WC-Co coating is performed with boron carbide (B4C) abrasives. A theoretical model of depth of deformed layer is proposed and verified with experiments. The lower gripping of B4C particles into the carbonyl iron particles (CIPs) chain structures limits wheel speed which leads to low material removal rate (MRR) and non-uniform finishing. To improve the effectiveness of MRF process, CIP–B4C composite abrasives are fabricated. Further, to take advantage of superior mechanical properties of carbon nanotubes (CNT), CIP–B4C-CNT hybrid composite abrasives are also incorporated. Composite abrasives transfer higher shear stress to the workpiece surface owing to strong bonding strength among the particles. This leads to a higher MRR and low surface roughness (Sa) of 122 nm.