MANUFACTURE OF METAL PELLETIZED POWDER FOR POWDER METALLURGY AND SINTERED BODY USING THE SAME

摘要

PURPOSE:To increase the fluidity of powder and to improve the saturated magnetic flux density and electrical resistivity of a sintered body by subjecting pelletized powder with optimum particle size constituted of metal fine powder having specified weight average size and a binder to compacting and sintering. CONSTITUTION:Metal powder having 1 to 18mum weight average is mixed with an organic binder, and this mixture is pelletized into metal powder for powder metallurgy having 40 to 200mum weight average size. This pelletized powder is subjected to compacting and sintering to obtain a sintered body having about =95% sintering density ratio. At this time, in the case the geometrical standard deviation in the size distribution of the pelletized powder is regulated to =1.7, its fluidity is improved, and in the case the shape factor in its spheroidicity is regulated to 2.0 to 2.2, the fluidity is furthermore increased. In the case the amt. of the organic binder is regulated to 6 to 34vol.%, good compactibity and fluidity can be obtd. As the compsn. of the metal fine powder, the one constituted of, by weight, 15 to 60% Co, 0.5 to 3.5% V and the balance Fe with inevitable impurities is preferably regulated.