Surface roughness modelling for Double Disk Magnetic Abrasive Finishing process

Abstract

Magnetic Abrasive Finishing (MAF) is a super finishing process having capability to produce surface finish in nano-meter level. The value of surface roughness obtained using MAF process depends upon the material properties of work piece and process factors. In the present work, a mathematical model has been proposed for Double Disk Magnetic Abrasive Finishing (DDMAF) process. DDMAF process is a process that can effectively finish even the flat paramagnetic work piece, which were considered ineffective to be finished by conventional MAF. In the present work, the surface roughness has been modelled as a function of workpiece material properties and process factors namely working gap, abrasive mesh number, percentage weight of abrasive, rotational speed and feed rate. The process model utilizes Lorentz force and Amperes law to estimate the finishing force experienced by an iron particle. The force so obtained has been used to calculate the finishing force transferred to the abrasive particle by using force equilibrium between iron and abrasive particle. The effect of normal distribution of abrasive particle size and the effect of frictional force on finishing forces have also been considered in this work. A MatLab code has been developed to include all the above aspects to determine the change in surface roughness. The model so obtained has been validated using experimental findings and thereafter used to study the effect of various process parameters.