Patent ID: 6168754
Filing Date: 2001-01-02
Classification: B21H,B22F,B23P,C21D,Y10T

Abstract:
A method producing powder metal articles comprising: compacting and sintering a powder metal preform having an outer perimeter portion thereof of predetermined shape to be densified; providing a multi-stage forming tool having a plurality of axially spaced forming die plates with die openings of the same general shape as that of the outer perimeter portion of the preform but being progressively smaller in size; and forcing the preform through the die openings from largest to smallest and plastically and elastically deforming the outer perimeter portion in stepped progression through the die openings to size and densify the outer perimeter portion and impart compressive stresses to the preform with the spacing between the die plates allowing elastic springback of the preform material between successive die plates.