Method for the production of sintered powder ferrous metal preform
Patent 4202689 Issued on May 13, 1980. Estimated Expiration Date: 
August 7, 1998. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
August 7, 1998. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References Re25661 3148056 3264073 3625673 3811878 Production of powder metallurgical parts by formation of sintered preforms in thermally degradable molds Patent #: 3989518 InventorsAssigneeApplicationNo. 05/931320 filed on 08/07/1978US Classes:419/30, Powder pretreatment (prior to consolidation or sintering)419/35, Coating419/44, Pretreatment of consolidated powders75/252, Mixture contains particles of nonmetal75/369Purifying powdered metal or reducing powdered metal compound to free metalExaminersPrimary: Hunt, Brooks H.Attorney, Agent or FirmInternational ClassesB22F 1/00 (20060101)C22C 33/02 (20060101) Foreign Application Priority Data1977-08-05 JPAbstractA 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° C. to 150° 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° C. to 1250° C. for a time sufficient to achieve reduction of said green preform. | |
