Limited-life cartridge primers

• US 6,881,284 B2
• Filed: 10/19/2001
• Issued: 04/19/2005
• Est. Priority Date: 06/14/1995
• Status: Expired due to Fees

• Current Assignee: Lawrence Livermore National Security LLC (Government of the United States of America)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Rosen, Robert S., Makowiecki, Daniel M.
• Primary Examiner(s): FELTON, AILEEN BAKER
• Application Number:
  US10/032,758
• Publication Number:
  US 20020092438A1
• Time in Patent Office: 1,278 Days
• Field of Search: 149/15, 149/109.6
• US Class Current: 149/109.6
• CPC Class Codes: C06B 21/0066 by granulation, e.g. flaking
• CPC Class Codes: C06B 21/0091 Elimination of undesirable or temporary components of an intermediate or finished product, e.g. making porous or low density products, purifying, stabilising, drying; Deactivating; Reclaiming; porous inert particles or chemicals compounded for these purposes C06B23/00
• CPC Class Codes: C06B 45/14 a layer or zone containing an inorganic explosive or an inorganic explosive or an inorganic thermic component
• CPC Class Codes: C06C 9/00 Chemical contact igniters; Chemical lighters
• CPC Class Codes: F42C 19/10 Percussion caps

Abstract

A cartridge primer which utilizes an explosive that can be designed to become inactive in a predetermined period of time: a limited-life primer. The explosive or combustible material of the primer is an inorganic reactive multilayer (RML). The reaction products of the RML are sub-micron grains of non-corrosive inorganic compounds that would have no harmful effects on firearms or cartridge cases. Unlike use of primers containing lead components, primers utilizing RML'"'"'s would not present a hazard to the environment. The sensitivity of an RML is determined by the physical structure and the stored interfacial energy. The sensitivity lowers with time due to a decrease in interfacial energy resulting from interdiffusion of the elemental layers. Time-dependent interdiffusion is predictable, thereby enabling the functional lifetime of an RML primer to be predetermined by the initial thickness and materials selection of the reacting layers.

Claims

1. A process for producing limited-time cartridge primers, including:

forming an explosive for a cartridge primer from a quantity of inorganic reactive material by;

selecting at least two materials for said inorganic reactive material, said at least two materials of a type characterized by time-dependent interdiffusion of elements therebetween which reduces stored energy and reactivity in a metastable reactive interface thereof without producing a passivation layer; and

contacting said at least two materials with each other in an arrangement adapted to realize no more than a desired shelf life based on said known time-dependent interdiffusion characteristics of the selected at least two materials, thereby producing a limited-life of the explosive.

2. The process of claim 1, additionally including providing a quantity of tin in the inorganic reactive material.

3. The process of claim 1, wherein forming the explosive from a quantity of inorganic reactive material is carried out by depositing said at least two materials in a multilayer arrangement.

4. The process of claim 3, wherein forming the multilayer arrangement is carried out by forming alternating layers of the at least two materials wherein the interdiffusion of elements occurs at the metastable reactive interfaces thereof.

5. The process of claim 1, wherein the inorganic reactive material is formed as a powder.

6. The process of claim 5, wherein the powder is produced by contacting said at least two materials to form a highly stressed multilayer and disintegrating the stressed multilayer into a powder.

7. The process of claim 1, wherein forming the explosive of the inorganic reactive material is carried out by forming the inorganic reactive material on a foil, and then cutting quantities of selected sizes from the foil and the inorganic reactive material.

8. The process of claim 7, additionally including forming a film of tin on the foil before cutting into selected sizes.

9. The process of claim 1, additionally including depositing the inorganic reactive material in multilayers on a foil composed of materials selected from the group consisting of aluminum, nickel, and copper.

10. The process of claim 3, wherein the inorganic reactive material is deposited in multilayers of three different materials.

11. The process of claim 3, wherein the inorganic reactive material is deposited in a multilayer of alternating layers of two different materials.

12. The process of claim 3, wherein forming a multilayer of the inorganic reactive material is carried out by depositing alternating layers of material selected from the group consisting of Ti—

B, Zr—

B, Ta—

B, Nb—

B, B—

C, AL—

C, Hf—

C, Ti—

C, Ta—

C, Si—

C, Ni—

Al, Ti—

Al, Li—

B, Li—

Al, and Ni—

Ti.

13. The process of claim 12, wherein the depositing of the alternate layers of material is carried out by magnetron sputtering.

14. The process of claim 1, additionally including forming a multilayer of the inorganic reactive material which is carried out by depositing layers of three materials selected from the group consisting of Ti—

Al—

CuO, Ti—

C—

CuO, Be—

C—

CuO, and Al—

C—

CuO.

15. The process of claim 14, wherein the depositing of the inorganic reactive material is carried out by magnetron sputtering.

16. The process of claim 1, additionally including forming a multilayer of the inorganic reactive material which is carried out by depositing sequential layers of Ti, C, CuO, Cu, Ti, C, CuO, Cu.

17. The process of claim 1, additionally including forming a multilayer of the inorganic reactive material which is carried by depositing a multilayer structure having metal-carbon-oxide combinations.

18. The process of claim 17, wherein the metal-carbon-oxide combinations are selected from the group consisting of Al—

C—

CuO, Be—

C,—

CuO, and Ti—

Al—

CuO.

19. The process of claim 1, additional y includes forming a layer of tin, and then forming the multilayer of the inorganic reactive material on the layer of tin.

20. The process of claim 19, wherein the multilayer of inorganic reactive material is composed of alternating layers of Ti and B.

21. The process of claim 19, wherein the layer of tin is formed in cup portion of a primer assembly, and the multilayer is formed on the layer of tin.

22. A process for producing limited-time cartridge primers, consisting essentially of:

forming a layer of tin, and

forming an explosive on the layer of tin by contacting alternating layers of Ti and B with each other in a multilayer arrangement adapted to realize no more than a desired shelf life based on predetermined time-dependent interdiffusion characteristics between Ti and B, which reduces stored energy and reactivity in a metastable reactive interface thereof without producing a passivation layer, to form a limited-time cartridge primer.

23. The process of claim 22, wherein forming the explosive on the layer of tin is carried out by depositing a powder formed from alternating layers of Ti and B.

24. The process of claim 23, wherein depositing the alternating layers of Ti and B is carried out by magnetron sputtering.

25. The process of claim 22, additionally including forming the layer of tin in a cup portion of a primer assembly.