Process for producing finely divided spherical metal powders containing an iron group metal and a readily oxidizable metal

• US 4,802,915 A
• Filed: 04/25/1988
• Issued: 02/07/1989
• Est. Priority Date: 04/25/1988
• Status: Expired due to Fees

• Current Assignee: GTE Products Corporation
• Original Assignee: GTE Products Corporation
• Inventors: Johnson, Walter A., Kopatz, Nelson E., Ritsko, Joseph E.
• Primary Examiner(s): Stallard, Wayland
• Application Number:
  US07/185,713
• Time in Patent Office: 288 Days
• Field of Search: 75/0.5 AA, 75/0.5 BA, 75/0.5 BC, 75/0.5 AC
• US Class Current: 75/342
• CPC Class Codes: B22F 1/065 Spherical particles
• CPC Class Codes: C22C 33/0207 Using a mixture of prealloyed powders or a master alloy mixtures of metal powder in general B22F1/09

Abstract

Alloys of a first group of metals containing at least one iron group metal and one or more easily oxidizable metals can be formed by forming an aqueous solution of the first group of metals, forming solids containing the metals from the solution, reducing the solids to a metallic powder, converting the metallic powder to metallic alloy spherical powders, agglomeration the spherical powder with one or more easily oxidizable metals in a non-oxidizing atmosphere, thereafter the agglomerates are subjected to a sufficient temperatures under non-oxidizing conditions to form an alloy. Alternatively, the easily oxidizable metals can be agglomerated with the solids containing the iron group metal prior to converting the agglomerates to a spherical alloy powder.

Claims

1. A process comprising:

(a) forming an aqueous solution containing at least one metal from the iron group metal,

(b) forming from said solution a reducible solid material selected from salts of said iron group metal, oxides of said iron group metal, hydroxides of said iron group metal and mixtures thereof,

(c) reducing said material to form metallic powder particles,

(d) entraining at least a portion of said powder particle in a carrier gas,

(e) feeding said entrained particles and said carrier gas into a high temperature zone and maintaining said particles in said zone for a sufficient time to melt at least about 50% by weight of said particles, and to form droplets therefrom and

(f) cooling said droplets to form metal particles having essentially a spherical shape,

(g) combining said spherical shaped particles with finely divided particles of at least one easily oxidizable metal in a non-oxidizing atmosphere to form an agglomerate and,

(h) subjecting said agglomerates to a sufficient temperature in a non-oxidizing atmosphere to form an alloy.

2. A process according to claim 1 wherein said mineral acid is selected from the group consisting of hydrochloric, sulfuric and nitric acids.

3. A process according to claim 2 wherein said mineral acid is hydrochloric acid.

4. A process according to claim 1 wherein said alloying is achieved by entraining said agglomerates in a carrier gas and feeding said agglomerates and said gas into a high temperature zone for a time sufficient to form metallic alloy particles having essentially a spherical shape.

5. A process according to claim 1 wherein said agglomerates are formed by utilizing a binder and spray drying and then the binder is removed from said agglomerates.

6. A process according to claim 4 wherein said metals in said first group are selected from the iron group metals.

7. A process according to claim 5 wherein said metals from said first group are iron and cobalt and the metal from said second group is aluminum.

8. A process according to claim 4 wherein said high temperature zone is created by a plasma touch.

9. A process comprising:

(a) forming an aqueous solution containing at least one metal from the iron group metal,

(b) forming from said solution a reducible solid material selected from salts of said iron group metal, oxides of said iron group metal, hydroxides of said iron group metal and mixtures thereof,

(c) reducing said material to form metallic powder particles,

(d) combining said metallic powder particles with finely divided particles of at least one easily oxidizable metal in a non-oxidizing atmosphere to form agglomerates therefrom and,

(e) subjecting said agglomerates to a sufficient temperature in a non-oxidizing atmosphere to form an alloy.

10. A process according to claim 9 wherein said mineral acid is selected from the group consisting of hydrochloric, sulfuric and nitric acids.

11. A process according to claim 10 wherein said mineral acid is hydrochloric acid.

12. A process according to claim 9 wherein said alloying is achieved by entraining said agglomerates in a carrier gas and feeding said agglomerates and said gas into a high temperature zone for a time sufficient to form metallic alloy particles having essentially a spherical shape.

13. A process according to claim 9 wherein said agglomerates are formed by utilizing a binder and spray drying and then the binder is removed from said agglomerates.

14. A process according to claim 12 wherein said metals in said first group are selected from the iron group metals.

15. A process according to claim 13 wherein said metals from said first group are iron and cobalt and the metal from said second group is aluminum.

16. A process according to claim 12 wherein said high temperature zone is created by a plasma touch.