Magnetic field assisted finishing of ceramics - Part I: Thermal model

A thermal model for magnetic field assisted polishing of ceramic balls/rollers is presented. The hear source at the area of contact between the balls and the abrasives where material removal takes place is approximated to a disk. The disk heat source is considered as a combination of a series of concentric circular ring heat sources with different radii. Each ring in turn is considered as a combination of a series of infinitely small are segments and each are segment as a point heat source. Jaeger's classical moving heat source theory (Jaeger, 1942; Carslaw and Jaeger, 1959) is wed in the development of the model, starting from an instantaneous point heat source, to obtain the general solution (transient and steady-state) of the moving circular ring heat source problem and finally the moving disc heat source problem. Due to the formation of fine scratches during polishing ton the order of a few micrometers long), the conditions are found to be largely transient in nature. Calculation of the minimum flash temperatures and minimum flash times during polishing enables the determination if adequate temperatures can be generated far chemomechanical polishing or not. This model is applied in Part II for magnetic float polishing (MFP) of ceramic balls and in Part III for magnetic abrasive finishing (MAP) of ceramic rollers.