|
Chemical Coloring Of Metals
Chemical coloring of metals is the process of changing the color of metal surfaces with different chemical solutions. The chemical coloring of metals can be split into three types: *electroplating – coating the metal surface with another metal using electrolysis. *patination – chemically reacting the metal surface to form a colored oxide or salt (chemistry), salt. *anodizing – electrolytic passivation process used to increase the thickness of the natural oxide layer, producing a porous surface which can accept organic or inorganic dyes easily. In the case of titanium, niobium, and stainless steel, the colour formed is dependent on the thickness of the oxide (which is determined by the anodizing voltage). Chemically coloring a metal is distinct from simply coating it using a method such as gilding or mercury silvering, because chemical coloring involves a chemical reaction, whereas simple coating does not. History The processes of chemical coloring of metals are as old a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henry Moore, Family Group (1950)
Henry may refer to: People *Henry (given name) *Henry (surname) * Henry Lau, Canadian singer and musician who performs under the mononym Henry Royalty * Portuguese royalty ** King-Cardinal Henry, King of Portugal ** Henry, Count of Portugal, Henry of Burgundy, Count of Portugal (father of Portugal's first king) ** Prince Henry the Navigator, Infante of Portugal ** Infante Henrique, Duke of Coimbra (born 1949), the sixth in line to Portuguese throne * King of Germany **Henry the Fowler (876–936), first king of Germany * King of Scots (in name, at least) ** Henry Stuart, Lord Darnley (1545/6–1567), consort of Mary, queen of Scots ** Henry Benedict Stuart, the 'Cardinal Duke of York', brother of Bonnie Prince Charlie, who was hailed by Jacobites as Henry IX * Four kings of Castile: **Henry I of Castile **Henry II of Castile **Henry III of Castile **Henry IV of Castile * Five kings of France, spelt ''Henri'' in Modern French since the Renaissance to italianize the name and to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mannerist
Mannerism, which may also be known as Late Renaissance, is a style in European art that emerged in the later years of the Italian High Renaissance around 1520, spreading by about 1530 and lasting until about the end of the 16th century in Italy, when the Baroque style largely replaced it. Northern Mannerism continued into the early 17th century. Mannerism encompasses a variety of approaches influenced by, and reacting to, the harmonious ideals associated with artists such as Leonardo da Vinci, Raphael, Vasari, and early Michelangelo. Where High Renaissance art emphasizes proportion, balance, and ideal beauty, Mannerism exaggerates such qualities, often resulting in compositions that are asymmetrical or unnaturally elegant.Gombrich 1995, . Notable for its artificial (as opposed to naturalistic) qualities, this artistic style privileges compositional tension and instability rather than the balance and clarity of earlier Renaissance painting. Mannerism in literature and music is not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonium Carbonate
Ammonium carbonate is a salt with the chemical formula (NH4)2CO3. Since it readily degrades to gaseous ammonia and carbon dioxide upon heating, it is used as a leavening agent and also as smelling salt. It is also known as baker's ammonia and is a predecessor to the more modern leavening agents baking soda and baking powder. It is a component of what was formerly known as sal volatile and salt of hartshorn, and produces a pungent smell when baked. Production Ammonium carbonate is produced by combining carbon dioxide and aqueous ammonia. About 80,000 tons/year were produced as of 1997. An orthorhombic monohydrate is known. It crystallizes in an ammonia solution exposed in a carbon dioxide-rich atmosphere. Decomposition Ammonium carbonate slowly decomposes at standard temperature and pressure through two pathways. Thus any initially pure sample of ammonium carbonate will soon become a mixture including various byproducts. Ammonium carbonate can spontaneously decompose into ammo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Sulfide
Sodium sulfide is a chemical compound with the formula Na2 S, or more commonly its hydrate Na2S·9 H2O. Both the anhydrous and the hydrated salts in pure crystalline form are colorless solids, although technical grades of sodium sulfide are generally yellow to brick red owing to the presence of polysulfides and commonly supplied as a crystalline mass, in flake form, or as a fused solid. They are water-soluble, giving strongly alkaline solutions. When exposed to moist air, Na2S and its hydrates emit hydrogen sulfide, an extremely toxic, flammable and corrosive gas which smells like rotten eggs. Some commercial samples are specified as Na2S·''x''H2O, where a weight percentage of Na2S is specified. Commonly available grades have around 60% Na2S by weight, which means that ''x'' is around 3. These grades of sodium sulfide are often marketed as 'sodium sulfide flakes'. Structure Na2S adopts the antifluorite structure, which means that the Na+ centers occupy sites of the fluoride in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tantalum
Tantalum is a chemical element with the symbol Ta and atomic number 73. Previously known as ''tantalium'', it is named after Tantalus, a villain in Greek mythology. Tantalum is a very hard, ductile, lustrous, blue-gray transition metal that is highly corrosion-resistant. It is part of the refractory metals group, which are widely used as components of strong high-melting-point alloys. It is a group 5 element, along with vanadium and niobium, and it always occurs in geologic sources together with the chemically similar niobium, mainly in the mineral groups tantalite, columbite and coltan. The chemical inertness and very high melting point of tantalum make it valuable for laboratory and industrial equipment such as reaction vessels and vacuum furnaces. It is used in tantalum capacitors for electronic equipment such as computers. Tantalum is considered a technology-critical element by the European Commission. History Tantalum was discovered in Sweden in 1802 by Anders Ekeberg, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niobium
Niobium is a chemical element with chemical symbol Nb (formerly columbium, Cb) and atomic number 41. It is a light grey, crystalline, and ductile transition metal. Pure niobium has a Mohs hardness rating similar to pure titanium, and it has similar ductility to iron. Niobium oxidizes in Earth's atmosphere very slowly, hence its application in jewelry as a hypoallergenic alternative to nickel. Niobium is often found in the minerals pyrochlore and columbite, hence the former name "columbium". Its name comes from Greek mythology: Niobe, daughter of Tantalus, the namesake of tantalum. The name reflects the great similarity between the two elements in their physical and chemical properties, which makes them difficult to distinguish. English chemist Charles Hatchett reported a new element similar to tantalum in 1801 and named it columbium. In 1809, English chemist William Hyde Wollaston wrongly concluded that tantalum and columbium were identical. German chemist Heinrich Rose determin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titanium
Titanium is a chemical element with the symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corrosion in sea water, aqua regia, and chlorine. Titanium was discovered in Cornwall, Great Britain, by William Gregor in 1791 and was named by Martin Heinrich Klaproth after the Titans of Greek mythology. The element occurs within a number of minerals, principally rutile and ilmenite, which are widely distributed in the Earth's crust and lithosphere; it is found in almost all living things, as well as bodies of water, rocks, and soils. The metal is extracted from its principal mineral ores by the Kroll and Hunter processes. The most common compound, titanium dioxide, is a popular photocatalyst and is used in the manufacture of white pigments. Other compounds include titanium tetrachloride (TiCl4), a component of smoke screens and catalysts; and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Oxide
Black oxide or blackening is a conversion coating for ferrous materials, stainless steel, copper and copper based alloys, zinc, powdered metals, and silver solder. It is used to add mild corrosion resistance, for appearance, and to minimize light reflection. To achieve maximal corrosion resistance the black oxide must be impregnated with oil or wax. One of its advantages over other coatings is its minimal buildup. Ferrous material A standard black oxide is magnetite (FeO), which is more mechanically stable on the surface and provides better corrosion protection than red oxide (rust) FeO. Modern industrial approaches to forming black oxide include the hot and mid-temperature processes described below. Traditional methods are described in the article on bluing. They are of interest historically, and are also useful for hobbyists to form black oxide safely with little equipment and without toxic chemicals. Low temperature oxide, also described below, is not a conversion coatingâ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Richards Elkington
George Richards Elkington (17 October 1801 – 22 September 1865) was a manufacturer from Birmingham, England. He patented the first commercial electroplating process. Biography Elkington was born in Birmingham, the son of a spectacle manufacturer. Apprenticed to his uncles' silver plating business in 1815, he became, on their death, sole proprietor of the business, but subsequently took his cousin, Henry Elkington, into partnership. The science of electrometallurgy was then in its infancy, but the Elkingtons were quick to recognize its possibilities. They had already taken out certain patents for the application of electricity to metals when, in 1840, John Wright, a Birmingham surgeon, discovered the valuable properties of a solution of cyanide of silver in potassium cyanide for electroplating purposes. The Elkingtons purchased and patented Wright's process (British Patent 8447 : Improvements in Coating, Covering, or Plating certain Metals), subsequently acquiring the right ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rudolf Christian Böttger
Rudolf Christian Böttger (28 April 1806 – 29 April 1881) was a German inorganic chemist. He conducted most of his research at the University of Frankfurt am Main. He is credited with discovery of nitrocellulose in 1846, independently to Schönbein, and with the synthesis of the first organocopper compound copper(I) acetylide Cu2C2 in 1859. Life and work Böttger was born in Aschersleben, Germany in 1806. After attending the primary school there he joined the school of the Franksche Stiftung in Halle an der Saale at the age of eleven. In 1824, Böttger started to study theology, but in parallel also attended the science lectures at the University Halle. The lectures of Johann Salomo Christoph Schweigger had a strong influence on him. Böttger left the university in 1828 and worked as cleric and teacher at different locations. The contact with Schweigger never faded and in 1831 Böttger decided to leave the theology career. He was offered a job at the voluntary association for c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antoine César Becquerel
Antoine César Becquerel (7 March 178818 January 1878) was a French scientist and a pioneer in the study of electric and luminescent phenomena. Life He was born at Châtillon-sur-Loing (today Châtillon-Coligny). After passing through the École polytechnique he became engineer-officer in 1808, and saw active service with the imperial troops in Spain from 1810 to 1812, and again in France in 1814. He then resigned from the army and devoted the rest of his life to scientific investigation. In 1820, following the work of René Just Haüy, he found that pressure can induce electricity in every material, attributing the effect to surface interactions (this is not piezoelectricity). In 1825 he invented a differential galvanometer for the accurate measurement of electrical resistance. In 1829 he invented a constant-current electrochemical cell, the forerunner of the Daniell cell. In 1839, working with his son A. E. Becquerel, he discovered the photovoltaic effect on an electrode immersed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leopoldo Nobili
Leopoldo Nobili, born on 5 July 1784 in Trassilico (Toscana) and died on 22 August 1835 in Florence, was an Italian physicist who invented a number of instruments critical to investigating thermodynamics and electrochemistry. Born Trassilico, Garfagnana, after attending the Military Academy of Modena he became an artillery officer. He was awarded the Légion d'honneur for his service in Napoleon's invasion of Russia. In 1825 he developed the astatic galvanometer. He worked with Macedonio Melloni on the ''thermomultiplier'', a combination of thermopile and galvanometer, before being appointed professor of physics at the Reale Museo di Fisica e Storia Naturale (Royal Museum of Physics and Natural History) in Florence where he worked with Vincenzo Antinori on electromagnetic induction Electromagnetic or magnetic induction is the production of an electromotive force (emf) across an electrical conductor in a changing magnetic field. Michael Faraday is generally credited wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Chemical Coloring Of Metals")
