A novel media properties-based material removal rate model for magnetic field-assisted finishing

Magnetic field assisted finishing (MFAF) is a category of non-conventional finishing processes that use magnetic field to manipulate finishing media typically consisting of magnetic particles and non-magnetic abrasives suspended in a carrier fluid.In order to better control the process, an improved understanding of the actual removal process is needed.This paper will introduce a new material removal rate model for magnetic fieldassisted finishing (MFAF) that will aim do so.The model considers the complexity of finishing media used in MFAF processes, where two different types of particles are presented and interact with each other.The proposed material removal rate expression is based on contact mechanics and is a function of the number of active magnetic particles, number of active abrasives, force per magnetic particle, and force per abrasive.Expressions for particle numbers have been developed by considering an ideal facecentred cubic configuration for the magnetic particle network, while expressions for forces have been developed based on a proposed framework for the particle interactions.The model has been verified experimentally for a double-magnet MFAF process by varying the abrasive size and abrasive concentration.When the abrasive size was increased from 0.6 μm to 15 μm, the material removal rate decreased which is consistent with the theoretical trend given by the model.Then, when abrasive concentration, given by the abrasives-to-carbonyl-iron volumetric ratio, was increased from 0 to 0.768, the material removal rate initially increased and then reached a maximum when the volume ratio is 0.259 before decreasing with further increase of the volume ratio.This is also in agreement with the theoretical trend given by the model.