A process for producing a sintered shaped bodies of an fe - p - alloy with magnetically soft properties.

摘要

PURPOSE:To improve soft magnetic characteristics by a method wherein the powder, having specific particle size and compound at a specific ratio, is injection-molded, the obtained molded body is debinder-treated, and after a sintering treatment has been conducted thereon, it is cooled slowly at a specific cooling speed. CONSTITUTION:A composition, consisting of the powder having the average grain diameter of 45mum or less and compounded in such a manner that P of 0.1 to 1wt.% and the remaining part substantially consisting of Fe, is injection-molded. The obtained molded body is debinder-treated, and after a sintering treatment has been conducted, the molded body is slowly cooled down at the cooling speed of 50 deg.C/min. or less. Polyethylene, wax and the like, for example, which are publicly known as the binder to be used for injection-molding powder metallurgy, can be used as the above-mentioned binder. As the method for removal of binder, degreasing by heating, degreasing by a solvent and other publicly known method can be used according to the kind of binder used. However, the method of degreasing by heating conducted in a nitrogen or hydrogen atmosphere or in a vacuum atmosphere. A sintering treatment is conducted at 1200 to 1400 deg.C in a hydrogen atmosphere or in a vacuum atmosphere for 30 to 180 minutes.