02-09-2017, 02:51 PM
An explosive material, also called explosive, is a reactive substance that contains a large amount of potential energy that can produce an explosion if it is released suddenly, usually accompanied by the production of light, heat, sound and pressure. An explosive charge is a measured amount of explosive material, which may be composed of a single ingredient or a combination of two or more.
The potential energy stored in an explosive material may be, for example,
• chemical energy, such as nitroglycerin or grain dust
• pressurized gas, such as a gas cylinder or aerosol can
• Nuclear energy, as in the fissionable isotopes uranium-235 and plutonium-239
Explosive materials can be classified by the speed at which they are expanded. The detonating materials (the front of the chemical reaction moves faster through the material than the speed of sound) are said to be "high explosives" and the materials that they ignite are said to be "low explosives". Explosives can also be classified by their sensitivity. Sensitive materials that can be initiated by a relatively small amount of heat or pressure are primary explosives and materials that are relatively insensitive are secondary or tertiary explosives.
A wide variety of chemicals can explode; a smaller number are manufactured specifically for the purpose of being used as explosives. The rest is too dangerous, sensitive, toxic, expensive, unstable or prone to decomposition or degradation in short periods of time.
On the contrary, some materials are simply combustible or flammable if they burn without exploding.
The distinction, however, is not clear. Certain materials - powders, powders, gases or volatile organic liquids - may be simply combustible or flammable under normal conditions, but become explosive in specific situations or forms, such as clouds dispersed in the air or confinement or sudden release.
The potential energy stored in an explosive material may be, for example,
• chemical energy, such as nitroglycerin or grain dust
• pressurized gas, such as a gas cylinder or aerosol can
• Nuclear energy, as in the fissionable isotopes uranium-235 and plutonium-239
Explosive materials can be classified by the speed at which they are expanded. The detonating materials (the front of the chemical reaction moves faster through the material than the speed of sound) are said to be "high explosives" and the materials that they ignite are said to be "low explosives". Explosives can also be classified by their sensitivity. Sensitive materials that can be initiated by a relatively small amount of heat or pressure are primary explosives and materials that are relatively insensitive are secondary or tertiary explosives.
A wide variety of chemicals can explode; a smaller number are manufactured specifically for the purpose of being used as explosives. The rest is too dangerous, sensitive, toxic, expensive, unstable or prone to decomposition or degradation in short periods of time.
On the contrary, some materials are simply combustible or flammable if they burn without exploding.
The distinction, however, is not clear. Certain materials - powders, powders, gases or volatile organic liquids - may be simply combustible or flammable under normal conditions, but become explosive in specific situations or forms, such as clouds dispersed in the air or confinement or sudden release.