|
Aluminum Powder
Aluminium powder is powdered aluminium. This was originally produced by mechanical means using a stamp mill to create flakes. Subsequently, a process of spraying molten aluminium to create a powder of droplets was developed by E. J. Hall in the 1920s. The resulting powder might then be processed further in a ball mill to flatten it into flakes for use as a coating or pigment. Aluminium powder features low density with high conductivity. Characteristics Powdered aluminium shares many of the physical characteristics of bulk aluminium such as its molecular weight of 26.981538 g mol−1, melting point of 660 °C, and a boiling point of 2460 °C. It combusts at a much faster rate to bulk aluminium, this is due to the fact that the gaps between the particles allow for more air and therefor faster oxidization. Usage * autoclave aerated concrete * cosmetic colourant * fingerprint powder * metallic paint * pyrotechnics (including the M-80 firecracker) * refractory * rocke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminium Pigment Powder
Aluminium (or aluminum in North American English) is a chemical element; it has symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has a great affinity towards oxygen, forming a protective layer of oxide on the surface when exposed to air. It visually resembles silver, both in its color and in its great ability to reflect light. It is soft, nonmagnetic, and ductile. It has one stable isotope, 27Al, which is highly abundant, making aluminium the 12th-most abundant element in the universe. The radioactivity of 26Al leads to it being used in radiometric dating. Chemically, aluminium is a post-transition metal in the boron group; as is common for the group, aluminium forms compounds primarily in the +3 oxidation state. The aluminium cation Al3+ is small and highly charged; as such, it has more polarizing power, and bonds formed by aluminium have a more covalent character. The strong af ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Refractory
In materials science, a refractory (or refractory material) is a material that is resistant to decomposition by heat or chemical attack and that retains its strength and rigidity at high temperatures. They are inorganic, non-metallic compounds that may be porous or non-porous, and their crystallinity varies widely: they may be crystalline, polycrystalline, amorphous, or composite. They are typically composed of oxides, carbides or nitrides of the following elements: silicon, aluminium, magnesium, calcium, boron, chromium and zirconium. Many refractories are ceramics, but some such as graphite are not, and some ceramics such as clay pottery are not considered refractory. Refractories are distinguished from the '' refractory metals'', which are elemental metals and their alloys that have high melting temperatures. Refractories are defined by ASTM C71 as "non-metallic materials having those chemical and physical properties that make them applicable for structures, o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminium
Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has a great affinity towards oxygen, passivation (chemistry), forming a protective layer of aluminium oxide, oxide on the surface when exposed to air. It visually resembles silver, both in its color and in its great ability to reflect light. It is soft, magnetism, nonmagnetic, and ductility, ductile. It has one stable isotope, 27Al, which is highly abundant, making aluminium the abundance of the chemical elements, 12th-most abundant element in the universe. The radioactive decay, radioactivity of aluminium-26, 26Al leads to it being used in radiometric dating. Chemically, aluminium is a post-transition metal in the boron group; as is common for the group, aluminium forms compounds primarily in the +3 oxidation state. The aluminium cation Al3+ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulmonary Fibrosis
Pulmonary fibrosis is a condition in which the lungs become scarred over time. Symptoms include shortness of breath, a dry cough, feeling tired, weight loss, and nail clubbing. Complications may include pulmonary hypertension, respiratory failure, pneumothorax, and lung cancer. Causes include environmental pollution, certain medications, connective tissue diseases, infections, and interstitial lung diseases. But in most cases the cause is unknown ( idiopathic pulmonary fibrosis). Diagnosis may be based on symptoms, medical imaging, lung biopsy, and lung function tests. No cure exists and treatment options are limited. Treatment is directed toward improving symptoms and may include oxygen therapy and pulmonary rehabilitation. Certain medications may slow the scarring. Lung transplantation may be an option. At least 5 million people are affected globally. Life expectancy is generally less than five years. Signs and symptoms Symptoms of pulmonary fibrosis are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminosis
Aluminosis (also known as aluminium lung) is a restrictive lung disease caused by exposure to aluminum-bearing dust. Aluminosis is a form of pneumoconiosis that can lead to pulmonary fibrosis. First cases of lung damage from aluminium exposure were reported in the 1930s in Germany. It can be detected by using high-resolution computed tomography. Findings may vary, showing nodular or slightly irregular opacities that may merge into more prominent forms, most frequently in the upper lung fields, sometimes in the lower lung fields, and less frequently a diffuse micro nodular pattern. In severe cases, pulmonary fibrosis with honeycombing was described. Workers exposed to aluminium dust are often involved in industries such as explosives manufacturing where aluminium powder is involved, aluminium welding Welding is a fabrication (metal), fabrication process that joins materials, usually metals or thermoplastics, primarily by using high temperature to melting, melt the part ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Improvised Explosive Device
An improvised explosive device (IED) is a bomb constructed and deployed in ways other than in conventional warfare, conventional military action. It may be constructed of conventional military explosives, such as an artillery shell, attached to a detonating mechanism. IEDs are commonly used as roadside bombs, or homemade bombs. The term "IED" was coined by the British Army during the Northern Ireland conflict to refer to booby traps made by the Provisional Irish Republican Army, IRA, and entered common use in the U.S. during the Iraq War. IEDs are generally utilized in terrorist operations or in asymmetric warfare, asymmetric unconventional warfare or urban warfare by insurgent guerrilla warfare, guerrillas or commando forces in a theater (warfare), theatre of operations. In the Iraq War (2003–2011), Iraqi insurgency (2003–2011), insurgents used IEDs extensively against U.S.-led forces, and by the end of 2007, IEDs were responsible for approximately 63% of Multi-National ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electromagnetic Shielding
In electrical engineering, electromagnetic shielding is the practice of reducing or redirecting the electromagnetic field (EMF) in a space with barriers made of conductive or magnetic materials. It is typically applied to enclosures, for isolating electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs (). Electromagnetic shielding that blocks radio frequency (RF) electromagnetic radiation is also known as RF shielding. EMF shielding serves to minimize electromagnetic interference. The shielding can reduce the coupling of radio waves, electromagnetic fields, and electrostatic fields. A conductive enclosure used to block electrostatic fields is also known as a '' Faraday cage''. The amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of holes in a shield to an incident elec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermite
Thermite () is a pyrotechnic composition of powder metallurgy, metal powder and metal oxide. When ignited by heat or chemical reaction, thermite undergoes an exothermic redox, reduction-oxidation (redox) reaction. Most varieties are not explosive, but can create brief bursts of heat and high temperature in a small area. Its form of action is similar to that of other fuel-oxidizer mixtures, such as gunpowder, black powder. Thermites have diverse compositions. Fuels include aluminium, aluminum, magnesium, titanium, zinc, silicon, and boron. Aluminum is common because of its high boiling point and low cost. Oxidizers include bismuth(III) oxide, boron(III) oxide, silicon(IV) oxide, chromium(III) oxide, manganese(IV) oxide, iron(III) oxide, iron(II,III) oxide, copper(II) oxide, and lead(II,IV) oxide. In a thermochemical survey comprising twenty-five metals and thirty-two metal oxides, 288 out of 800 binary combinations were characterized by adiabatic temperatures greater than 2000 K ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Shuttle
The Space Shuttle is a retired, partially reusable launch system, reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. Its official program name was the Space Transportation System (STS), taken from the 1969 plan led by U.S. vice president Spiro Agnew for a system of reusable spacecraft where it was the only item funded for development. The first (STS-1) of four orbital test flights occurred in 1981, leading to operational flights (STS-5) beginning in 1982. Five complete Space Shuttle orbiter vehicles were built and flown on a total of 135 missions from 1981 to 2011. They launched from the Kennedy Space Center (KSC) in Florida. Operational missions launched numerous satellites, interplanetary probes, and the Hubble Space Telescope (HST), conducted science experiments in orbit, participated in the Shuttle–Mir program, Shuttle-''Mir'' program with Russia, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solid Rocket Booster
A solid rocket booster (SRB) is a solid propellant motor used to provide thrust in spacecraft launches from initial launch through the first ascent. Many launch vehicles, including the Atlas V, SLS and Space Shuttle, have used SRBs to give launch vehicles much of the thrust required to place the vehicle into orbit. The Space Shuttle used two Space Shuttle SRBs, which were the largest solid propellant motors ever built until the Space Launch System and the first designed for recovery and reuse. The propellant for each solid rocket motor on the Space Shuttle weighed approximately 500,000 kilograms.. Advantages Compared to liquid propellant rockets, the solid-propellant motors (SRMs) have been capable of providing large amounts of thrust with a relatively simple design. They provide greater thrust without significant refrigeration and insulation requirements, and produce large amounts of thrust for their size. Adding detachable SRBs to a vehicle also powered by liquid-propel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
M-80 (explosive)
M-80s are an American class of large powerful firecrackers, sometimes called Salute (pyrotechnics), salutes. M-80s were originally made in the mid 20th century for the United States Armed Forces, U.S. military to simulate explosives or artillery fire. The "M" is designated by a U.S. military convention for "standard" equipment and "80" is for the 80 grains (5.2 grams) of flash powder within it. Later, M-80s were manufactured as consumer fireworks made from a small Cardboard (paper product), cardboard tube, often red, approximately long and inside diameter, with a fuse coming out of the side; this type of fuse is commonly known as cannon fuse or Visco fuse, after a company responsible for standardizing the product. The consumer version holds a reduced charge of 45 grains (approximately 3 grams) of pyrotechnic flash powder. Legality Canada M-80s are not authorized under the law, making importation, possession, transportation, storage, or manufacture of them illegal in Canada. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metal Powder
Metal powder is a metal that has been broken down into a powder form. Metals that can be found in powder form include aluminium powder, nickel powder, iron powder and many more. There are four different ways metals can be broken down into this powder form: * Direct reduction * Gas atomization * Ultrasonic atomization * Liquid atomization * Centrifugal atomization Processes The following processes can be used to produce metal powder: # Direct reduction is the result of blending carbon with iron oxide ore, heating the mixture, removing the sponge iron from the carbon, grinding it, annealing it, and regrinding to make the powder form usable for manufacturing. # Gas atomization occurs when a molten metal is passed through a passageway to a gas-filled chamber that cools the metal. As it falls, it is collected and annealed into a powder. # Ultrasonic metal atomization uses high-frequency sound waves to break molten metal into uniformly spherical droplets. It offers precise partic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
