Method for the production of sintered powder ferrous metal preform
AssigneeKabushiki Kaisha Komatsu Seisakusho
InventorsEiji Ohno, Kazuo Chikugo
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Abstract
A method for the production of sintered powder metal preform employing a novel reduction step. As-water-atomized ferrous metal particles are coated by phenol resins by adding said phenol resins to said ferrous metal particles after heating the metal particles to about 130.degree. C. to 150.degree. C. Resin coated ferrous metal particles are then filled in a mold and compacted under high pressure to produce a compacted green preform sufficient to ensure adequate strength for handling after pressing. The green preform is then heated to a reduction temperature within the range of about 1100.degree. C. to 1250.degree. C. for a time sufficient to achieve reduction of said green preform.
Claims5
A method for the production of sintered powder ferrous metal preforms comprising the steps of;
- heating said ferrous metal particles to a temperature of about 130.degree. C. to 150.degree. C.;
- coating finely divided ferrous metal particles with thermoplastic phenol resins having an effective carbon content of 10 to 40 percent by adding said phenol resins to said ferrous metal particles, wherein said phenol resins are present from about 1.0 to 7.0 percent of the total mixture;
- cooling said resin coated ferrous metal particles by blowing cooling air thereto;
- packing a mold with said resin coated ferrous metal particles;
- compacting said resin coated ferrous metal particles in the mold by applying pressure of 3 to 5 tons/cm.sup.2 thereon to produce a compacted green preform sufficient to ensure adequate strength for handling after pressing;
- and
- heating said green preform in an oxidation free atomospheric current to a temperature within the range of about 1100.degree. C. to 1250.degree. C. for a time sufficient to achieve reduction and sintering of said green preform.
Dependencies are inferred from the claim text.