MAGNETIC POLE FOR STEPPING MOTOR AND MANUFACTURE THEREOF

PURPOSE:To improve the corrosion resistance and soft magnetic characteristics of a sintered compact by a method wherein a magnetic pole formed of the sintered compact with a tooth profile prepared on the periphery thereof is subjected to a steam treatment. CONSTITUTION:Powder as raw material, for instance, pure iron powder is mixed with a lubricant and the mixture is put in a mold to form a powder compact in the form of a magnetic pole 1 with a number of teeth formed on the periphery of a disk. The powder compact is sintered in a reducing atmosphere to obtain a sintered compact. The compact is then subjected to a recompressing process, if necessary, after sintering so as to increase the accurary and density of the dimensions and shape of the sintered compact. The sintered compact is treated in steam at temperatures of 500-600 deg.C to obtain the magnetic pole 1. In so doing, a stable oxide film is formed on the surface of the sintered compact through the steam process while the soft magnetic characteristics are improved.