Non-lead, environmentally safe projectiles and method of making same

• US 5,760,331 A
• Filed: 12/06/1996
• Issued: 06/02/1998
• Est. Priority Date: 07/06/1994
• Status: Expired due to Term

• Current Assignee: Lockheed Martin Energy Research Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Energy Research Corporation (Martin Marietta Corporation)
• Inventors: Dooley, Joseph B., Lowden, Richard A., McCoig, Thomas M.
• Primary Examiner(s): TUDOR, HAROLD JAY
• Application Number:
  US08/761,550
• Time in Patent Office: 543 Days
• Field of Search: 102/389, 102/439, 102/448, 102/459, 102/473, 102/476, 102/491, 102/493-498, 102/501, 102/506-510, 102/514, 102/516, 102/517, 102/529, 419/30, 419/32, 419/35, 419/38, 75/228, 75/236, 75/245, 75/246, 75/247
• US Class Current: 102/506
• 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: B22F 2998/10 Processes characterised by the sequence of their steps
• CPC Class Codes: B22F 3/02 Compacting only
• CPC Class Codes: C22C 1/045 Alloys based on refractory metals
• CPC Class Codes: C22C 29/08 based on tungsten carbide
• CPC Class Codes: F42B 12/74 of the core or solid body
• CPC Class Codes: F42B 7/046 Pellets or shot therefor

Abstract

A projectile, such as a bullet, is made by combining two different metals in proportions calculated to achieve a desired density, without using lead. A base constituent, made of a material having density greater than lead, is combined with a binder constituent having less density. The binder constituent is malleable and ductile metallic phase material that forms projectile shapes when subjected to a consolidation force, such as compression. The metal constituents can be selected, rationed, and consolidated to achieve desired frangibility characteristics.

Claims

1. A lead-free non-sintered projectile to be projected from a gun barrel comprising:

a base constituent selected from the group consisting of tungsten, tungsten carbide, tantalum, and mixtures or alloys thereof; and

a lead-free binder constituent selected from the group consisting of aluminum, bismuth, copper, tin, zinc, and mixtures or alloys thereof and having sufficient malleability and ductility which bind together with the base constituent into a solid body of desired shape when cold pressed, and having, after cold pressing, a compressive strength of between 57 MPa and 220 MPa,

the base constituent being in powder or particulate form having a size of between 149 and 1,000 μ

m and the binder constituent being in a form selected from the group consisting of powder, particulate and coating having a size of between 45 and 149 μ

m.

2. A projectile according to claim 1, wherein the solid body has a theoretical density substantially similar to that of lead.

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

4. A projectile 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.

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

6. A projectile according to claim 1, wherein the base constituent is a tungsten powder and the binder constituent is a tin powder.

7. A projectile according to claim 6, wherein the base constituent and the binder constituent are evenly distributed powders which form a blend prior to consolidation, and the blend comprises about 70 weight percent tungsten and the remainder tin.

8. A projectile according to claim 7, wherein the tungsten powder is about 100 mesh and the tin powder is about 320 mesh.

9. A projectile according to claim 7, wherein the tungsten powder is about 100 mesh and the tin powder is about 100 mesh.

10. A projectile 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 95 weight percent tungsten powder and the remainder aluminum powder.

11. A projectile according to claim 10, wherein the tungsten powder is about 100 mesh and the aluminum powder is about 320 mesh.

12. A projectile according to claim 1, wherein the base constituent is tungsten and the binder constituent is copper.

13. A projectile according to claim 12, 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 and the remainder copper.

14. A projectile according to claim 12, wherein the tungsten is a 100 mesh powder and the copper is a 320 mesh powder.

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

16. A projectile according to claim 15, 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 and the remainder zinc.

17. A projectile according to claim 16, wherein the tungsten is a 100 mesh powder and the zinc is a 100 mesh powder.

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

19. A projectile according to claim 18, 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 and the remainder bismuth.

20. A projectile according to claim 18, wherein the tungsten is a 100 mesh powder and the bismuth is a 100 mesh powder.

21. A munitions cartridge comprising:

a casing having a primer disposed at one end and an opposite, bullet-receiving end and containing a charge between the two ends; and

a lead-free non-sintered bullet to be projected from a gun barrel mounted in the bullet-receiving end of the casing, the bullet comprising a base constituent selected from the group consisting of tungsten, tungsten carbide, tantalum, and mixtures or alloys thereof, and a lead-free binder constituent selected from the group consisting of aluminum, bismuth, copper, tin, zinc, and mixtures or alloys thereof and having sufficient malleability and ductility which bind together with the base constituent into a solid body of desired shape when cold pressed, and having, after cold pressing, a compressive strength of between 57 MPa and 220 MPa,

the base constituent being in powder or particulate form having a size of between 149 and 1,000 μ

m and the binder constituent being in a form selected from the group consisting of powder, particulate and coating having a size of between 45 and 149 μ

m.

22. A munitions cartridge according to claim 21, wherein the binder constituent is coated on the base constituent.

23. A munitions cartridge according to claim 21, wherein the base constituent is tungsten and the binder constituent is aluminum.

24. A munitions cartridge according to claim 21, wherein the base constituent and the binder constituent are made of materials, provided in ratios, and subjected to consolidation process parameters selected to achieve a desired density and frangibility of the solid body.

25. A lead-free projectile to be projected from a gun barrel comprising:

an outer jacket; and

a non-sintered core disposed at least partially within the outer jacket and having a base constituent selected from the group consisting of tungsten, tungsten carbide, tantalum, and mixtures or alloys thereof, and a lead-free binder constituent selected from the group consisting of aluminum, bismuth, copper, tin, zinc, and mixtures or alloys thereof and having sufficient malleability and ductility which bind together with the base constituent into a solid body of desired shape when cold pressed, and having, after cold pressing, a compressive strength of between 57 MPa and 220 MPa.

the base constituent being in powder or particulate form having a size of between 149 and 1,000 μ

m and the binder constituent being in a form selected from the group consisting of powder, particulate and coating having a size of between 45 and 149 μ

m.

26. A projectile according to claim 25, wherein the base constituent and the binder constituent are made of materials, provided in ratios, and subjected to consolidation process parameters selected to achieve a desired density and frangibility of the solid body.

27. A projectile according to claim 25, wherein the binder constituent is coated on the base constituent.

28. A projectile according to claim 25 wherein the outer member is a metal jacket.