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

• US 6,149,705 A
• Filed: 03/02/1998
• Issued: 11/21/2000
• Est. Priority Date: 07/06/1994
• Status: Expired due to Fees

• Current Assignee: UT-Battelle LLC
• Original Assignee: UT-Battelle LLC
• Inventors: Dooley, Joseph B., Lowden, Richard A., McCoig, Thomas M.
• Primary Examiner(s): Jenkins, Daniel J.
• Application Number:
  US09/032,832
• Time in Patent Office: 995 Days
• Field of Search: 419/66, 102/517, 75/240, 75/245, 75/248
• US Class Current: 75/240
• 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 weight prepared by cold pressing without sintering comprising:

a metallic base constituent having a density higher than lead; and

a lead-free binder constituent made of a metallic phase and having sufficient malleability and ductility to bind together with the base constituent into a solid body of desired shape and frangibility when subject to a consolidation force, wherein the sizes of the base and binder constituents, before consolidation, are sufficiently large to allow for consolidation during cold pressing without subsequent sintering.

2. A weight according to claim 1, wherein the base constituent is a powder, and the binder constituent is coated on the base constituent.

3. A weight according to claim 1, wherein the base constituent is one of a metal, metal alloy, metal compound, and a mixture of metals, metal alloys and metal compounds.

4. A weight according to claim 1, wherein the base constituent is made of a material selected from the group consisting of tungsten, tungsten carbide, and tantalum.

5. A weight according to claim 1, wherein the binder constituent is one of a metal, metal alloy, metal compound, and a mixture of metals, metal alloys and metal compounds.

6. A weight according to claim 5, wherein the binder constituent is selected from the group consisting of aluminum, bismuth, copper, tin, and zinc.

7. A weight 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 density of the solid body.

8. A weight according to claim 7, wherein the solid body has a theoretical density substantially similar to that of lead.

9. A weight 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 a desired density and frangibility of the solid body.

10. A weight 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, and zinc.

11. A lead-free weight prepared by cold consolidation of a metallic base constituent having a density higher than lead with a metallic binder constituent having malleability and ductility, wherein said weight is prepared without heat sintering and, before said consolidation, said base and said binder constituents have sizes sufficiently large which allow for said consolidation without use of said sintering to achieve suitable frangibility.

12. A lead-free weight according to claim 11, wherein said binder constituent is selected from the group consisting of aluminum, bismuth, copper, tin and zinc.

13. A lead-free weight according to claim 11, wherein said base constituent is selected from the group consisting of tungsten, tungsten carbide, and tantalum.

16. A lead-free weight according to claim 11, wherein the size of the base is 500-1,000 μ

m and the size of the binder is 50-70 μ

m.

14. A non-sintered lead-free weight comprising a metallic base phase having density higher than lead and a metallic binder phase having a density lower than lead, wherein said base phase is formed from a base powder having particle size sufficiently large so that heat sintering is not needed to prepare said weight.

15. A weight according to claim 14, wherein the interface between said base phase and said binder phase is generated by a low energy working technique.