US3890174A - Pyrotechnic composition - Google Patents

Abstract

A pyrotechnic composition which contains powders of (1) aluminum, (2) metal oxide, and (3) a metal which is iron, copper, silver, niobium, tungsten, or molybdenum, and which also contains (4) a source of gas which is either (a) a gas maintained under a pressure of 1.05 to 10 atmospheres or (b) a fluorocarbon which vaporizes or decomposes when exposed to the heat of the alloying and oxidizing reaction to generate a gas.

Description

United States Patent 1 Helms, Jr. et a1.

UNITED STATES PATENTS 3,565,706 2/1971 Waite 149/37 June 17, 1975 3,695,951 10/1972 Helms et a1 149/44 Primary Examiner-Stephen J. Lechert, Jr. Attorney. Agent, or Firm-R. S. Sciascia; J. A. Cooke [57] ABSTRACT A pyrotechnic composition which contains powders of (1) aluminum, (2) metal oxide, and (3) a metal which is iron, copper, silver, niobium, tungsten, or molybdenum, and which also contains (4) a source of gas which is either (a) a gas maintained under a pressure of 1.05 to 10 atmospheres or (b) a fluorocarbon which vaporizes or decomposes when exposed to the heat of the alloying and oxidizing reaction to generate a gas.

9 Claims, No Drawings PYROTECHNIC COMPOSITION CROSS-REFERENCE TO RELATED APPLICATION The present application is a continuation of copending application, Ser. No. 227,632, filed Feb. 18, 1972, entitled pyrotechnic composition, now abandoned.

BACKGROUND OF THE INVENTION This invention generally relates to pyrotechnic compositions and more particularly to pyrotechnic compositions containing aluminum.

Pyrotechnic torches which use gaseous, liquid or solid fuel components have been developed for cutting or severing purposes. Most of these torches, however, transfer the energy obtained from the device by means of a jet of hot gases. The heat generated from most existing torches, whether they be solid, liquid or gaseous, is usually the result of reaction between a fuel component and an oxidizer and in most cases large quantities of oxidizer are required. The large quantity of oxidizer needed in these compositions creates a very serious safety problem. Though these devices have found extensive use they are not always dependable, efficient or economical.

Combined exothermic alloying and oxidizing reactions which result in the evolution of large quantities of heat have been applied in the past to the pyrotechnic field as disclosed in US. Pat. No. 3,503,814, issued Mar. 31, 1970 to Horace H. Helms, .lr., and Alexander G. Rozner as well as Ser. No. 49,980, file June 25, 1970 entitled Pyrotechnic composition" by Horace H. Helms, Jr., and Alexander G. Rozner, now US. Pat. No. 3,695,951, issued Oct. 3, 1972. Although the materials disclosed therein are suitable for use in many pyrotechnic applications there is a need for improved materials in this area. For instance, there is a continuing need for materials having a controlled high energy output. There is also a need to replace the nickel of the hereinbefore referenced patent and application with an element or elements that are not subject to restricted usage caused by periodic shortages. There is also a need for pyrotechnic materials that produce a low magnetic signature.

Therefore continued research has been directed toward development of pyrotechnic compositions which overcome the above-mentioned shortcomings.

SUMMARY OF THE INVENTION Accordingly, one object of this invention is to provide a pyrotechnic composition.

Another object of this invention is to provide a pyrotechnic composition which is relatively safe to handle and store.

'Still another object of this invention is to provide a pyrotechnic composition which is easy to process.

Another object of this invention is to provide a pyrotechnic composition which uses readily available materials.

Yet another object of this invention is to provide a pyrotechnic composition which reacts at a controlled rate to give off a large quantity of heat which is in a readily usable form.

Another object is to provide a pyrotechnic composition wherein energy transfer is accomplished by a hign velocity jet of molten material rather than by gaseous ets.

A further object of this invention is to provide a pyrotechnic composition which is dependable,'efficient and economical.

A still further object of this invention is to provide a pyrotechnic composition which has a relatively low magnetic signature.

Yet another object of this invention is to provide a pyrotechnic composition suitable for use in a cutting torch.

Still another object of this invention is to provide a pyrotechnic composition which can be used as a heat producer.

Yet another object of this invention is to provide a pyrotechnic composition which can be used as a light producer.

These and other object of this invention are accomplished by providing a pyrotechnic composition comprising (1) aluminum, (2) metal oxide, (3) a metal selected from the group consisting of iron, copper, silver, niobium, molybdenum and v mixtures thereof which form a molten material during the alloying and oxidizing reaction and (4) a source of gas which when exposed to the heat of the alloying and oxidizing reaction provides a gas which forces the molten material out of a container.

DESCRIPTION OF THE PREFERRED EMBODIMENT The pyrotechnic composition of this invention as hereinbefore noted contains a number of different substituents.

The aluminum present in the instant composition should constitute from 5 to 35 weight percent of the composition with a range of 20 to 30 weight percent being preferred.

The metal oxide or mixture of metal oxides of this composition should constitute 20 to weight percent of the total composition with a range of 35 to 60 weight percent being preferred. The preferred metal oxides are Fe O Fe O CuO, Cr O C0 0,, and mixtures thereof. It should be noted that within the context of this invention the term metal oxide is intended to mean both one metal oxide and a mixture of more than one metal oxide.

The third component of this composition is a metal which constitutes l to 50 weight percent and preferably 5 to 30 weight percent of the composition. This metal is selected from the group consisting of iron, copper, silver, niobium, tungsten, molybdenum and mixtures thereof.

The fourth component is a source of gas. The term source of gas is intended to mean either one gas separately, a mixture of gases, a solid material separately, a mixture of solid materials, a liquid material separately, a mixture of liquid materials, mixtures of one gas and one liquid or several liquids, mixtures of several gases and one liquid or several liquids, mixtures of one gas and one solid or several solids, mixtures of several gases and one solid or several solids, as well as mixtures of one or several gases with one or several liquids and one or several solids. In other words source of gas is intended to include all combinations of one or more gases, one or more liquids, one or more solids and all mixtures thereof. With respect to the liquids and solids the liquids and solids included in the term source of gas are those which will produce a gas either by vaporization or decomposition when exposed to the heat of the alloying and oxidizing reaction.

When the source of gas is gaseous in nature the gas should be above atmospheric pressure. The preferred pressure range is about 1.05 atmospheres to 10 atmospheres. It should be noted however that the upper limit of pressure is determined by the pressure limitation of the container in which the composition is contained and is not related to the ingredients in the composition. Thus gases such as nitrogen, argon, helium, air or any mixtures thereof or any other gas preferably of an inert nature, or mixtures of gas will suffice. A suitable container may be of the type described in copending application Ser. No. 74,434 filed Sept. 22, 1970 entitled lncendiary Torch by Horace H. Helms, Jr.,Al-

exander i. Roznei' and Dana E. Spencer. When a con- 7 tainer such as disclosed in the copending application is used the material is sealed into said container so that the gas pressure is maintained. When ready for use the material within the container, which in this case is a torch, is ignited and the alloying and oxidizing reaction is initiated. When the pressure inside the container exceeds the strength of the diaphragm the diaphragm ruptures and the expanding gases force the molten material through the nozzle.

Alternatively one may, instead of directly adding a gas to the torch, add a material to the instant composition which will decompose into gas or vaporize into gas when exposed to the heat produced by the alloying and oxidizing reaction after ignition of the torch. One may add to the instant composition solid materials such as powdered polytetrafluoroethylene or other solid materials which will decompose and/or vaporize to form gas or one may add liquid materials which will vaporize and/or decompose to form gas when exposed to the heat of the alloying and oxidizing reaction. It should be noted that the actual nature of the gas used is not believed to be important since the main function of the gas is merely to expand with the increased temperature resulting from the alloying and oxidizing reaction thus creating a pressure which will force the molten pyrotechnic material out of the container in which the composition is present. However, certain sources of gas such as powdered polytetrafluroethylene are preferred because of their availability, ease of handling, efficiency and price.

The source of gas constitutes not more than 20 weight percent of the composition. When the source of gas contains a solid, liquid or mixture thereof it is preferred to have the solid, liquid or mixture thereof pres ent to constitute l20 weight percent of the composition with l5 weight percent being most preferred. Polytetrafluoroethylene is one preferred source of gas since it can be mixed in powder form with the other constituents of the instant invention and when compacted it imparts mechanical strength to the pellets made therefrom.

The general nature of the invention having been set forth, the following examples are presented as specific illustrations thereof. It will be understood that the invention is not limited to these specific examples, but is susceptible to various modifications that will be recog nized by one of ordinary skill in the art.

Typical compositions of this invention are as follows: (Percentages given by weight) EXAMPLE 1 Aluminum 23.95% Copper 18.80% Fe o 47.25% Polytetrafluoroethylene 10.00%

EXAMPLE ll Aluminum 21.65% Molybdenum 25.65% F8203 42.70% Polytetrafl uoroethylene 10.00%

EXAMPLE lll Aluminum 28.45% or iron 29.45% Fe O 42.10%

The compositions of this invention may be mixed and compacted into desired pellet shapes by using standard powder metallurgy techniques. Ignition of these compositions is accomplished by using any of the standard pyrotechnic ignition techniques.

Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described herein.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A pyrotechnic composite comprising (1 a mixture of powders of (a) aluminum, (b) a metal oxide selected from the group consisting of Fe O F e 0 CuO, Cr O C0 0 and mixtures thereof, and (c) a metal selected from the group consisting of iron, copper, silver, niobium, tungsten molybdenum and mixtures thereof and (2) a source of gas selected from the group consisting of (a) gas maintained under a pressure of 1.05-l0 atmospheres in a container, said gas expanding and forcing its way from the container when exposed to the heat of the alloying and oxidizing reaction, and (b) a fluorocarbon which is selected from the group consisting of (A) one solid substance, (B) a mixture of solid substances, (C) one liquid substance, (D) a mixture of liquid substances and (E) mixtures thereof provided that any substance that is to be a source of gas must either vaporize to form gas when exposed to the heat of the alloying and oxidizing reaction, decompose to form gas when exposed to the heat of the alloying and oxidizing reaction or form gas by both vaporizing and decomposing when exposed to the heat of the alloying and oxidizing reaction.

2. The composition of claim 1 wherein aluminum constitutes 5-35 weight percent, metal oxide constitutes 2O8O weight percent, the metal constitutes l-50 weight percent and the source of gas constitutes not more than 20 weight percent of the composition.

3. The composition of claim 2 wherein the source of the gas comprises a gas maintained under a pressure of 1.05-1O atmospheres in a container, said gas expanding and forcing its way from the container when exposed to the heat of the alloying and oxidizing reaction.

4. The composition of claim 3 wherein the source of gas is selected from the group consisting of air, nitrogen, inert gases and mixtures thereof.

5. The composition of claim 1 wherein the source of gas comprises a fluorocarbon selected from the group consisting of (a) one solid substance, (b) a mixture of solid substances, (c) one liquid substance, ((1) a mixture of liquid substances and (e) mixtures thereof provided that any substance that is to be a source of gas must either vaporize to form gas when exposed to the heat of the alloying and oxidizing reaction, decompose to form gas when exposed to the heat of the alloying and oxidizing reaction or form gas by both vaporizing and decomposing when exposed to the heat of the alloying and oxidizing reaction.

6. The composition of claim 2 wherein said source of gas constitutes 1-20 weight percent of the composition comprising a fluorocarbon selected from the group consisting of (a) one solid substance, (b) a mixture of solid substances, (c) one liquid substance, ((1) a mixture of liquid substances and (e) mixtures thereof provided that any substance that is to be a source of gas must vaporize to form gas when exposed to the heat of the alloying and oxidizing reaction, decompose to form gas when exposed to the heat of the alloying and oxidizing reaction or form gas by both vaporizing and decomposing when exposed to the heat of the alloying and oxidizing reaction.

7. The composition of claim 5 wherein the fluorocarbon is polytetrafluoroethylene.

8. The composition of claim 6 wherein the fluorocarbon is polytetrafluoroethylene.

9. A pyrotechnic composition comprising a mixture of powders of (1) aluminum, (2) a metal oxide selected from the group consisting of Fe O Fe O CuO, Cr O C0 0 and mixtures thereof, and (3) molybdenum.

. (5/69) UNITED STATES PATENT GFFICE QETIFICATE o c Patent 3 890 174 Dated 1 7 June 1975 Inventor(s) Horace H Helms Jr and Alexander G Rozner It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

9 Correct inventor name from "Alexander G Rosner" t0 Alexander G. Rozner $igned and if salad this 0 ninth ay 0? September 1975 [SEAL] Arrest:

Q RUTH C. MASON C. MARSHALL DANN Arresting Officer (mnmissimu'r u /Parems and Trademarks

Claims (10)

1. A PYROTECHNIC COMPOSITION COMPRISING (1) A MIXTURE OF POWDERS OF (A) ALUMINUM, (B) A METAL OXIDE SELECTED FROM THE GROUP CONSISTING OF FE2O3, FE3O4, CUO, CR2O3, CO3O4, AND MIXTURES THEREOF, AND (C) A METAL SELECTED FROM THE GROUP CONSISTING OF IRON, COPPER, SILVER, NIOBIUM, TUNGSTEM MOLYBDENUM AND MIXTURES THEREOF AND (2) A SOURCE OF GAS SELECTED FROM THE GROUP CONSISTING OF (A) GAS MAINTAINED UNDER A PRESSURE OF 1.05-10 ATMOSPHERES IN A CONTAINER, SAID GAS EXPANDING AND FORCING ITS WAY FROM THE CONTAINER, WHEN EXPOSED TO THE HEAT OF THEALLOYING AND OXIDIZING REACTION, AND (B) A FLUOROCARBON WHICH IS SELECTED FROM THE GROUP CONSISTING OF (A) ONE SOLID SUBSTANCE, (B) A MIXTURE OF SOLID SUBSTANCES, (C) ONE LIQUID SUBSTANCE, (D) A MIXTURE OF LIQUID SUBSTANCES AND (E) MIXTURES THEREOF PROVIDED THATANY SUBSTANCE THAT IS TO BE A SOURCE OF GAS MUST EITHER VAPORIZE TO FORM GAS WHEN EXPOSED TO THE HEAT OF THE ALLOYING AND OXIDIZING REACTION, DECOMPOSE TO FORM GAS WHEN EXPOSED TO THE HEAT OF THE ALLOYING AND OXIDIZING REACTION OR FORM GAS BY BOTH VAPORIZING AND DECOMPOSING WHEN EXPOSED TO THE HEAT OF THE ALLOYING AND OXIDIZING REACTION.

2. The composition of claim 1 wherein aluminum constitutes 5-35 weight percent, metal oxide constitutes 20-80 weight percent, the metal constitutes 1-50 weight percent and the source of gas constitutes not more than 20 weight percent of the composition.

3. The composition of claim 2 wherein the source of the gas comprises a gas maintained under a pressure of 1.05-10 atmospheres in a container, said gas expanding and forcing its way from the container when exposed to the heat of the alloying and oxidizing reaction.

4. The composition of claim 3 wherein the source of gas is selected from the group consisting of air, nitrogen, inert gases and mixtures thereof.

5. The composition of claim 1 wherein the source of gas comprises a fluorocarbon selected from the group consisting of (a) one solid substance, (b) a mixture of solid substances, (c) one liquid substance, (d) a mixture of liquid substances and (e) mixtures thereof provided that any substance that is to be a source of gas must either vaporize to form gas when exposed to the heat of the alloying and oxidizing reaction, decompose to form gas when exposed to the heat of the alloying and oxidizing reaction or form gas by both vaporizing and decomposing when exposed to the heat of the alloying and oxidizing reaction.

6. The composition of claim 2 wherein said source of gas constitutes 1-20 weight percent of the composition comprising a fluorocarbon selected from the group consisting of (a) one solid substance, (b) a mixture of solid substances, (c) one liquid substance, (d) a mixture of liquid substances and (e) mixtures thereof provided that any substance that is to be a source of gas must vaporize to form gas when exposed to the heat of the alloying and oxidizing reaction, decompose to form gas when exposed to the heat of the alloying and oxidizing reaction or form gas by both vaporizing and decomposing when exposed to the heat of the alloying and oxidizing reaction.

7. The composition of claim 5 wherein the fluorocarbon is polytetrafluoroethylene.

8. The composition of claim 6 wherein the fluorocarbon is polytetrafluoroethylene.

9. A pyrotechnic composition comprising a mixture of powders of (1) aluminum, (2) a metal oxide selected from the group consisting of Fe2O3, Fe3O4, CuO, Cr2O3, Co3O4, and mixtures thereof, and (3) molybdenum.

9. A PYROTECHNIC COMPOSITION COMPRISING A MIXTURE OF POWDERS OF (1) ALUMINUM, (2) A METAL OXIDE SELECTED FROM THE GROUP CONSISTING OF FE2O3, FE3O4, CUO, CR2O3, CO3O4, AND MIXTURES THEREOF, AND (3) MOLYBDENUM.