Search results
Results from the WOW.Com Content Network
Thermite (/ ˈθɜːrmaɪt /) [ 1 ] is a pyrotechnic composition of metal powder and metal oxide. When ignited by heat or chemical reaction, thermite undergoes an exothermic reduction-oxidation (redox) reaction. Most varieties are not explosive, but can create brief bursts of heat and high temperature in a small area.
Bronze. Bronze is an alloy consisting primarily of copper, commonly with about 12–12.5% tin and often with the addition of other metals (including aluminium, manganese, nickel, or zinc) and sometimes non-metals, such as phosphorus, or metalloids, such as arsenic or silicon. These additions produce a range of alloys that may be harder than ...
Wrought iron. Rust is an iron oxide, a usually reddish-brown oxide formed by the reaction of iron and oxygen in the catalytic presence of water or air moisture. Rust consists of hydrous iron (III) oxides (Fe 2 O 3 ·nH 2 O) and iron (III) oxide-hydroxide (FeO (OH), Fe (OH) 3), and is typically associated with the corrosion of refined iron.
Fire making, fire lighting or fire craft is the process of artificially starting a fire. It requires completing the fire triangle , usually by heating tinder above its autoignition temperature . Fire is an essential tool for human survival and the use of fire was important in early human cultural history since the Lower Paleolithic .
Pyrite is used with flintstone and a form of tinder made of stringybark by the Kaurna people of South Australia, as a traditional method of starting fires. [17] Pyrite has been used since classical times to manufacture copperas (ferrous sulfate). Iron pyrite was heaped up and allowed to weather (an example of an early form of heap leaching ...
Tarnish is a product of a chemical reaction between a metal and a nonmetal compound, especially oxygen and sulfur dioxide. It is usually a metal oxide, the product of oxidation; sometimes it is a metal sulfide. The metal oxide sometimes reacts with water to make the hydroxide, or with carbon dioxide to make the carbonate. It is a chemical change.
Pitting corrosion. Appearance. Severe pitting corrosion problems caused by chloride ions on a truss beam of the Nandu River Iron Bridge (Hainan Province, China) leading to the complete rupture of a metallic element. Pitting corrosion, or pitting, is a form of extremely localized corrosion that leads to the random creation of small holes in metal.
Islamic Golden Age brass astrolabe Brass lectern with an eagle. Attributed to Aert van Tricht, Limburg (Netherlands), c. 1500.. Brass is an alloy of copper and zinc, in proportions which can be varied to achieve different colours and mechanical, electrical, acoustic and chemical properties, [1] but copper typically has the larger proportion, generally 66% copper and 34% zinc.