Abstract
Effects of powder sphericalization on DC biased properties of powder cores have been investigated and simulated using a nonmagnetic grain boundary (NMGB) model. Water atomized iron powder and Fe-6.5 mass % Si powder have been sphericalized by a powder surface modification system. Aspect ratio has got smaller depending on rotational speed. Aspect ratio of the former at rotational speed 8000rpm and 180 sec have gotten as 1.29 equivalent to gas atomized iron powder and DC biased property has been improved. They have been compared with values calculated by the NMGB model. The relative inaccuracy has been within 4.23 %. Aspect ratio of the latter (Fe-6.5 mass % Si powder) has had smaller with higher rotational speed, while DC biased property has not been improved. They have been compared with values calculated by the NMGB model. The relative inaccuracy has been within 4.68 %. The gap width distribution has been compared between calculated and measured values. The relative inaccuracy of the average gap width has been 5.17 % on the iron powder core and 78.3 % on the Fe-6.5 mass % Si powder core.
