Material removal mechanism of fused silica glass in magnetorheological finishing

The existing material removal model of magnetorheological finishing cannot predict the material removal during part processing due to the problems of low processing efficiency, uniform removal, and difficulty in process control. In this paper, a new MRR (material removal rate) model is established to study the removal mechanism of fused silica glass based on the fluid mechanics and Preston's equation, in which the influence of average load and magnetic interaction force is considered emphatically. To validate the validity of the MRR model, a suite of experiments is implemented on fused silica glass on separate process parameters, including the rotational speeds of workpieces, polishing time, machining gap, and X-direction deflection. A comparison is made between the experimental and model results, which are highly consistent. The results show that the expected load and magnetic interaction force are most responsive to the rotational speeds of the workpieces and machining gap, followed by the polishing time. At the same time, the X-direction deflection has marginal effects on the expected load and magnetic interaction force. Under irreversible experimental conditions of polishing time of 20 min, machining clearance of 2 mm, X-direction deflection of 10 mm, and workpiece rotation speed of 1000 rpm, the maximum MRR of the workpiece surface can be obtained as 0.497 & mu;m/min.