Non-lead, environmentally safe projectiles and explosives containers

• US 6,174,494 B1
• Filed: 03/20/1998
• Issued: 01/16/2001
• Est. Priority Date: 07/06/1993
• Status: Expired due to Term

• Current Assignee: UT-Battelle LLC
• Original Assignee: Lockheed Martin Energy Systems, Inc. (AES Corporation)
• Inventors: Dooley, Joseph B., Smith, Cyrus M., McCoig, Thomas M., Lowden, Richard A.
• Primary Examiner(s): MAI, NGOCLAN THI
• Application Number:
  US09/044,913
• Time in Patent Office: 1,033 Days
• Field of Search: 419/35, 419/38, 419/64, 419/65, 419/66, 427/214, 427/216-217, 102/517
• US Class Current: 419/66
• CPC Class Codes: B22F 1/09 Mixtures of metallic powders
• CPC Class Codes: B22F 1/17 Metallic particles coated with metal
• CPC Class Codes: B22F 1/18 Non-metallic particles coated with metal
• CPC Class Codes: B22F 2998/00 Supplementary information concerning processes or compositions relating to powder metallurgy
• CPC Class Codes: F42B 1/036 Manufacturing processes therefor F42B33/0214 - F42B33/0292 take precedence
• CPC Class Codes: F42B 12/74 of the core or solid body
• CPC Class Codes: F42B 3/28 Cartridge cases characterised by the material used, e.g. coatings for initiator cases F42B3/11
• CPC Class Codes: F42B 7/046 Pellets or shot therefor

Abstract

A solid object having controlled frangibility, such as a bullet or a container for explosives, is made by combining two different metals in proportions calculated to achieve a desired density, without using lead. A wetting material is deposited on the base constituent which is made of a relative dense, hard material. The wetting material enhances the wettability of the base constituent with the binder constituent, which is lighter and softer than the base constituent.

Claims

1. A method of making a projectile consisting essentially of the steps of:

combining a base constituent having a density greater than that of lead, a wetting constituent, and a lead-free binder constituent made of a metallic phase to form a blend; and

consolidating the blend with a consolidation force sufficient to form a solid body of desired shape,

the binder constituent having sufficient malleability and ductility to bind together with the base constituent and thereby form the solid body when subjected to the consolidation force.

2. A method according to claim 1, wherein the combining step consisting essentially of forming a coating of the wetting constituent on the base constituent.

3. A method according to claim 2, wherein the forming consisting essentially of dissolving copper and iron nitrates in water, mixing base constituent in the water to form a suspension, heating the suspension to drive off the water and thereby form a nitrate coating on the base constituent, and converting the nitrate to metal by reduction in hydrogen.

4. A method according to claim 1, wherein the combining step consisting essentially of forming a coating of the wetting constituent on the base constituent, and forming a coating of the binder constituent on the wetting constituent.

5. A method according to claim 1, wherein the base constituent and the binder constituent are powders, and the wetting constituent is a coating formed on the base constituent.

6. A method according to claim 1, wherein the base constituent is one of a metal, metal alloy, metal compound, and any mixtures thereof.

7. A method according to claim 6, wherein the base constituent is made of a material selected from the group consisting of tungsten, tungsten carbide, tantalum and any mixtures, alloys or compounds thereof.

8. A method according to claim 1, wherein the binder constituent is one of a metal, metal alloy, metal compound, and any mixtures thereof.

9. A method according to claim 8, wherein the binder constituent is selected from the group consisting of aluminum, bismuth, copper, tin, and zinc and any mixtures, alloys or compounds thereof.

10. A method according to claim 1, wherein the base constituent and the binder constituent are made of materials and provided in ratios selected to achieve a desired frangibility of the solid body.

11. A method according to claim 10, wherein the solid body has a theoretical density substantially similar to that of lead.

12. A method according to claim 1, wherein the base constituent and the binder constituent are made of materials, provided in ratios, and subjected to consolidation process parameters selected to achieve at least one of a desired density and frangibility of the solid body.

13. A method according to claim 1, wherein the base constituent is made of a material selected from the group consisting of tungsten, tungsten carbide, and tantalum, and the binder constituent is selected from the group consisting of aluminum, bismuth, copper, tin, zinc, and any mixtures, alloys or compounds thereof.

14. A method according to claim 1, wherein the base constituent is tungsten and the binder constituent is aluminum.

15. A method according to claim 1, wherein the base constituent is a tungsten powder having a diameter in the range of 500-1,000 μ

m, and the binder constituent is aluminum coated on each powder particle, each coating having a thickness of between 50-70 μ

m.

16. A method according to claim 1, wherein the amount of the base constituent relative to the binder constituent is about 1-99 weight percent.

17. A method according to claim 1, wherein the base constituent is one of a powder and a mixture of powders, and the binder constituent is one of a powder and a mixture of powders, the base constituent and the binder constituent being evenly distributed to form a blend prior to consolidation.

18. A method according to claim 17, wherein the base constituent comprises 1-99 weight percent of the blend.

19. A method according to claim 1, wherein the base constituent is tungsten and the binder constituent is tin.

20. A method according to claim 19, wherein the base constituent and the binder constituent are evenly distributed to form a blend prior to consolidation, and the blend comprises about 70 weight percent tungsten as the base constituent, and the remainder tin as the binder constituent, and the wetting constituent.

21. A method according to claim 19, wherein the tungsten powder is about 100 mesh and the tin powder is about 320 mesh.

22. A method according to claim 19, wherein the tungsten powder is about 100 mesh and the tin powder is about 100 mesh.

23. A method according to claim 14, wherein the base constituent and the binder constituent are evenly distributed powders which form a blend prior to consolidation, and the blend comprises about 95 weight percent tungsten as the base constituent and the remainder aluminum as the binder constituent, and the wetting constituent.

24. A method according to claim 23, wherein the tungsten powder is about 100 mesh and the aluminum powder is about 320 mesh.

25. A method according to claim 1 wherein the base constituent is tungsten and the binder constituent is copper.

26. A method according to claim 25, wherein the base constituent and the binder constituent are evenly distributed powders which form a blend prior to consolidation, and the blend comprises about 80 weight percent tungsten as the base constituent and the remainder copper as the binder constituent, and the wetting constituent.

27. A method according to claim 26, wherein the tungsten is a 100 mesh powder and the copper is a 320 mesh powder.

28. A method according to claim 1, wherein the base constituent is tungsten and the binder constituent is zinc.

29. A method according to claim 1, wherein the base constituent and the binder constituent are evenly distributed powders which form a blend prior to consolidation, and the blend comprises about 60 weight percent tungsten as the base constituent and the remainder zinc as the binder constituent, and the wetting constituent.

30. A method according to claim 29, wherein the tungsten is a 100 mesh powder and the zinc is a 100 mesh powder.

31. A method according to claim 1, wherein the base constituent is tungsten and the binder constituent is bismuth.

32. A method according to claim 31, wherein the base constituent and the binder constituent are evenly distributed powders which form a blend prior to consolidation, and the blend comprises about 30 weight percent tungsten as the base constituent and the remainder bismuth as the binder constituent, and the wetting constituent.

33. A method according to claim 32, wherein the tungsten is a 100 mesh powder and the bismuth is a 100 mesh powder.

34. A method according to claim 1, wherein the consolidating step consisting essentially of cold pressing the blend.

35. A method according to claim 1, wherein the combining step consisting essentially of dissolving at least one of a metal salt, nitrate and halide in water, adding the base constituent in powdered form to the water to form a solution, heating the solution to remove the water, and forming a metal coating on the base constituent by reduction.

36. A method according to claim 1, wherein the combining step consisting essentially of coating the base constituent with the wetting constituent by one of fluidized-bed CVD, tumbling-bed CVD, electroplating and reduction of a metal salt, nitrate or halide.