PURPOSE: To eliminate the tendency of a noble metal to sink into the bottom of a polishing vessel, efficiently polish the noble metal without unevenness and increase the amount of polishing at one time to enhance the work efficiency by polishing the noble metal with abrasives the specific gravity of which is equal to that of the metal.
CONSTITUTION: A barrel polishing machine polishes a noble metal with spherical abrasives the specific gravity of which is equal to that of the metal. As a result, the tendency of the noble metal to sink into the bottom of a polishing vessel is eliminated and the abrasives are uniformly stirred and the metal is efficiently polished without unevenness and the efficiency of work is bettered. To polish noble metals such as Au and Pt the use of W having equal specific gravity or W or the like plated with Cr is desirable; however, any material can be used only if, in addition to specific gravity, it has corrosion resistance, hardness and the property of being machined and molded into the form of abrasives; composite materials such as plated metals may also be employed.
MURAKISHI YUKIHIRO
KASAHARA KOJI
