PURPOSE: To manufacture the screw improved in corrosion-resistance and wear resistance by inserting a core metal in a forming rubber mold to form a cylindri cal green compact of screw shape, inserting a connecting core metal into said green compact, and sintering it under a specified condition.
CONSTITUTION: The core metal 2 is inserted in the center axis of the forming rubber mold 1 the inner surface of which is formed in a screw shape in advance, and raw powder 3 (about ≤50μ) is packed into the clearance between them. The powder packed in the rubber mold is uniformly pressed to be formed by a cold static water pressure press. Then, a core metal 5 is inserted into inner hole of the green compact 4, which is sintered under vacuum or nonoxidizing atmosphere to connect the core metal with the pressed powder body 4, and a sintered body 6 is formed. In this case, the outer diameter of the core metal 5 is limited within 80W90% the inner diameter of the green compact 4. By grinding the sintered body 6 to finish in a specified dimension, a screw for a resin processing machine of superior corrosion-resistance and wear resistance is obtained.
NAKANO KAZUNORI
INOUE MASARU
KONDO YOSHIKAZU
| JPS50106844A | 1975-08-22 | |||
| JPS54102209A | 1979-08-11 | |||
| JPS5184711A | 1976-07-24 |