Boron carbide pyrotechnic time delay

Patent metadata

Field	Value
Publication number	US-9255040-B1
Application number	US-201414325613-A
Country	US
Kind code	B1
Filing date	Jul 8, 2014
Priority date	Jul 8, 2014
Publication date	Feb 9, 2016
Grant date	Feb 9, 2016

Abstract

A precise, slow burning, pyrotechnic delay composition composed of a ternary system of from about 8 to about 55 weight percent B 4 C fuel, 35 to about 82 weight percent NalO 4 oxidizer, and PTFE which acts as a pyrotechnic oxidizer and lubricant—such that the resulting composition has surprisingly good mechanical properties, i.e. it can be pressed to a desirably high consolidated density with ordinary loading force, and with minimal wear on the tooling used for pressing.

First claim

What is claimed is:

1. An environmentally friendly and easily compressed pyrotechnic delay composition, comprising:
a ternary mixture of B 4 C (boron carbide), NalO 4 (sodium periodate), and PTFE (polytetrafluoroethylene);
which mixture has an inverse burning rate from about 1.3 to about 20.8 s/cm when pressed into a consolidated column.

2. The delay composition of claim 1 , wherein the composition contains from about 8 to about 55 weight percent of the B 4 C; about 10 weight percent PTFE; and the balance NalO 4 .

3. The delay composition of claim 2 , whereupon when consolidated at 376.6 MPa results in a % TMD of about 70% to about 100%.

4. The delay composition of claim 1 , wherein the composition contains from about 8 to about 40 weight percent B 4 C fuel; about 10 weight percent PTFE; and the balance NalO 4 .

5. The delay composition of claim 1 , wherein the B 4 C is carbon rich, containing from 19.0 to 21.7 weight percent C.

6. The delay composition of claim 1 , wherein the B 4 C is 1500 grit, the NalO 4 is −325 mesh, and the PTFE has a typical bulk density of about 480 grams per liter and a mean particle size of about 17 microns.

7. The delay composition of claim 1 , wherein the delay composition is relatively easily compressed to relatively high % TMD with relatively ordinary loading pressures.

8. The delay composition of claim 7 , wherein the relatively high % TMD is from about 88 to about 98% TMD and the relatively ordinary loading pressures are from about 250 to about 500 MPa.

9. The delay composition of claim 1 , wherein when the pyrotechnic delay composition can be consolidated with minimal wear on the tooling used for the consolidation.

10. The delay composition of claim 1 , wherein composition has an inverse burning rate from about 7 to about 8.5 s/cm.

11. The delay composition of claim 1 , which provides repeatable delays of from 7-8.5 s/cm when consolidated in a large pancake-shaped HHS aluminum delay housing.

Assignees

• Shaw Anthony P
• Poret Jay C
• Csernica Christopher M
• Us Army

Inventors

• Shaw Anthony P
• Poret Jay C
• Csernica Christopher M

Classifications

• C06B29/02 Primary

  of an alkali metal · CPC title

• C06C5/06

  Fuse igniting means; Fuse connectors · CPC title

• C06B45/10

  the organic component containing a resin · CPC title

• C06B43/00 Primary

  Compositions characterised by explosive or thermic constituents not provided for in groups C06B25/00 - C06B41/00 · CPC title

• C06B45/06

  the solid solution or matrix containing an organic component · CPC title