| 摘要 |
PURPOSE:To obtain abrasive grains with a long life having a structure of bonding the grains of abrasives together with a metallic matrix by mixing metallic powder part of which is a ferromagnetic material with the grains of the abrasives and heating same with a plasma arc, at the time of manufacturing abrasive grains for magnetic polishing. CONSTITUTION:The abrasive grains for magnetic polishing have a structure of bonding the grains of abrasives together with a matrix composed of a metallic molten body containing a ferromagnetic material. As for the abrasives, the particles of an oxide, a carbide, a nitride, a boride, or a silicide having a compression strength of above 15X10<2>kgf/mm<2> are suitable. For example, these are Al2O3, ZrO2, TiC, ZrC, VC, NbC, WC, TaC, Si3N4, TiB2, and TaSi2, and two or more types of these may be mixedly used. The proper rate of the grains of abrasives and matrix metal in the abrasive grains is 40-90:60-10 on an average by vol%. As the mixture 1 of the grains of abrasives with metallic powder is fed into a plasma torch, the metallic powder is molten and turned into drips while taking in the grains of abrasives, to be turned into abrasive grain beads 2 on a positive electrode 4. |
