Mn-Zn (Manganese-Zinc) ferrite polycrystals have been widely used as a core material of magnetic heads in video cassette recorders or floppy disk drives of personal computers. In this research, slot grinding was performed to investigate the chipping generation mechanism at slot edge of Mn-Zn ferrite polycrystal with metal bonded diamond wheels. A high precision slicing machine with an air spindle of low friction and low thermal expansion was used. After grinding, the chippings at a slot edge was measured by means of a form tracer with a knife edge tip, and analyzed with a newly developed measurement method using a personal computer under various grinding conditions. On the other hand, by means of SEM observation, a material removal mechanism at the edge of Mn-Zn ferrite was investigated. The results are follows. Pre-process, such as lapping, before grinding can reduce chipping size. Most of chipping is generated by transgranular fracture. As chipping size depends on the removal per grain; qw=α·μ2 (Vw/Vs), a decrease in removal qw, chipping size after slot grinding could be reduced.
