US2421029A - Starting mixture - Google Patents

Description

STARTHQG TKJRIE Sidney J. Magram, Baltimore, Md.

No Drawing. Application November 18, 1943, Serial No. 510,789

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3'10 0. G. 757) 1 Claim.

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to a composition particularly useful in the munition art for starting reactions which produce required effects of the munitions.

Munitions with which this invention deals particularly are those used for producing smoke clouds and those used for obtaining incendiary effects, as for example, magnesium bombs containing thermit type fillings, thermit incendiary bombs, thermit grenades, smoke shells, floats, pots and grenades. In general, the casings of such munitions have relatively thin walls to increase the agent containing efficiency; and in operation it is desirable to avoid scattering of the agent in order to obtain a concentrated effect. Hence, it is highly desirable that starters in such munitions be capable of burning in a confined space without reacting too violently, without forming gas, and without exploding.

An object of this invention is to provide a starting mixture adapted for munitions that produce little or no gas and that contain filling agents which have high ignition temperatures.

Another object of this invention is to provide a starting mixture which can be readily pressed into a bomb or munition canister and which is easily ignited in a highly compressed state by ordinary primers and fuzes.

Another object of this invention is to provide a starting mixture which is non-hygroscopic and has good stability against moisture.

A further obiect is to provide a starting mixture which produces a high-temperature slag. i. e., a slag having a white heat or a temperature of at least about 1400" C. with little or no volatilization and no substantial gas formation.

In accordance with the present invention, it was found that the foregoing objects are attained with starting mixtures characterized by the presence of metallic manganese or manganese alloy and a suitable oxidizing agent, more particularly, compositions characterized by the presence of manganese or manganese alloy with sulfur or a sulfide.

A series of mixtures were tested for stability against moisture, for ease of handling and loading into bombs, for ease of ignition, and for reaction effects on munition fillings. Such mixtures were also tested in loaded magnesium bombs containing thermit type fillings by dropping the bombs from an airplane at a height of 4,000 feet.

It was found that titanium-manganese alloy mixed with a heavy metal chromate, such as barium chromate, and that a mixture of manganese and sulfur with the chromate performed satisfactorily as starting mixtures in the bombs.

Tests showed that copper oxide mixed with manganese and sulfur or with titanium-manganese alloy in suitable proportions gives mixtures that are gasless and easily ignited by primers or fuzes. When a mixture of magnesium with copper oxide is ignited, the reaction is too violent, and such a combination tends to be explosive. However, small percentages of magnesium or aluminum can be added to mixtures of copper oxide, manganese and sulfur to make the mixture hotter; but amounts in excess of a few per cent produce a volatilizatlon of some of the starter products.

Manganese dioxide forms a satisfactory starter when mixed with titanium-manganese alloy and sulfur; but when mixed with magnesium and ignited, the reaction is too violent.

Sulfur may be mixed with manganese or titanium-manganese alloy to form starters that evolve very little gas, particularly if an excess of the metal is used.

The following mixtures are examples of starters which can be compressed, readily ignited by primers and fuzes and which produce a gasless, high-temperature slag without exploding in a confined space:

Example 1 Per cent Copper oxide 5'! Manganese 40 Sulfur 3 Example 2 Per cent Manganese dioxide i0 Titanium-manganese alloy 45 Sulfur 15 Example 3 Per cent Titanium-manganese alloy Sulfur 35 Finely divided manganese or manganese alloy may be used in a starting mixture with one or more oxidizing agents. They may be used together with titanium. They may be used with a sulfide, such as antimony trisulfide or iron sulfide, or with a combination of sulfides and sulfur.

The preferred oxidizing agents for use in the starting mixtures are substances which are nonhygroscopic and have little or no water solubility. Moreover, it is preferred that the starting mixtures be substantially free of any substance which tends to volatilize or any substance which tends to form gas in the burning reaction of the starting mixtures.

The starters described, in being substantially gasless, can burn in a confined space without exploding; and their products of combustion attain an extremely high temperature, partly due to the fact that there is substantially no cooling effect by the evolution of gases or vapors. The hightemperature molten slag products from these starters increase the heating eflect of the incendiary agent. These starters are readily loaded into an incendiary bomb in accordance with the practice of adding a mass of the starting mixture as an increment to the thermit filling and consolidating the mass by a ram under a high pressure of the order of 12,000 pounds per square inch. The loading of the described mixtures may be accomplished without the addition of volatile or hygroscopic binders to prevent segregation; but it is to be understood that other ingredients may be added to the mixtures, if desired.

Additional components having oxidizing, reducing or reaction-modifying properties, but which do not evolve much gas, may be present in the mixture.

Although the disclosed high-temperature, heatgenerating, gasiess starting mixtures are particularly well adapted for warfare munitions, they may also be used industrially for obtaining quick,

SIDNEY J. MAGRAM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,035,202 Lang Aug. 13, 1912 1,417,075 La Cour May 23, 1922 2,186,667 Churchill Jan. 9, 1940 2,261,221 Bruner Nov. 4, 1941 FOREIGN PATENTS Number Country Date 8,163 Great Britain 1909 OTHER REFERENCES Moisson, "Tracte de Chemie Minerale, (1905) volume 4;, page 492.