Iron-based powder mixtures
AssigneeHoeganaes Corporation
InventorFrederick J. Semel
Life of this patent
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Abstract
An improved powder composition of an iron-based powder and an alloying powder is provided. Segregation and dusting of the alloying powder is eliminated or substantially reduced when the powder composition contains a polymeric binding agent which is an adherent film-former and which is insoluble in water.
Claims35
An improved metallurgical powder composition comprising (a) an iron-based powder having an average particle size less than about 80 microns selected from the group consisting of iron powders and steel powders, (b) a minor amount of at least one alloying powder, and (c) about 0.005-1% by weight of a binding agent for said iron-based and alloying powders, said composition having been formed by mechanically mixing said iron-based powder and said alloying powder with said binding agent, wherein the improvement is characterized in that the binding agent is a resin substantially insoluble in water selected from the group consisting of
- (1) Homopolymers of vinyl acetate or copolymers of vinyl acetate in which at least 70% of the monomeric units are vinyl acetate;
- (2) Cellulosic ester or ether resins;
- (3) Methacrylate polymers or copolymers;
- (4) Alkyd resins;
- (5) Polyurethane resins;
- and
- (6) Polyester resins.
An improved metallurgical powder composition comprising (a) an iron-based powder selected from the group consisting of iron powders and steel powders, (b) a minor amount of at least one alloying powder, and (c) about 0.005-1% by weight of a binding agent for said iron-based and alloying powders, said composition having been formed by mechanically mixing said iron-based powder and said alloying powder with said binding agent, wherein the improvement is characterized in that the binding agent is a resin substantially insoluble in water selected from the group consisting of
- (1) Homopolymers of vinyl acetate or copolymers of vinyl acetate in which at least 70% of the monomeric units are vinyl acetate;
- (2) Cellulosic ester or ether resins;
- (3) Methacrylate polymers or copolymers;
- (4) Alkyd resins;
- (5) Polyurethane resins;
- and
- (6) Polyester resins;
- and wherein the alloying powder has a mean particle size up to about 20 microns and the weight ratio of binding agent to alloying powder in the composition is dependent on the density of the alloying powder and is in accordance with the following schedule.
- ______________________________________ Density of Alloying Powder Weight Ratio of Binding (g/cc) Agent to Alloying Powder ______________________________________ .ltoreq.2.5 0.125 >2.5-4.5 0.100 >4.5-6.5 0.050 >6.5 0.025 ______________________________________
Dependencies are inferred from the claim text.