|
Copper
Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement. Copper is one of the few metals that can occur in nature in a directly usable, unalloyed metallic form. This means that copper is a native metal. This led to very early human use in several regions, from . Thousands of years later, it was the first metal to be smelted from sulfide ores, ; the first metal to be cast into a shape in a mold, ; and the first metal to be purposely alloyed with another metal, tin, to create bronze, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cupronickel
Cupronickel or copper–nickel (CuNi) is an alloy of copper with nickel, usually along with small quantities of other metals added for strength, such as iron and manganese. The copper content typically varies from 60 to 90 percent. ( Monel is a nickel–copper alloy that contains a minimum of 52 percent nickel.) Despite its high copper content, cupronickel is silver in colour. Cupronickel is highly resistant to corrosion by salt water, and is therefore used for piping, heat exchangers and condensers in seawater systems, as well as for marine hardware. It is sometimes used for the propellers, propeller shafts, and hulls of high-quality boats. Other uses include military equipment and chemical industry, petrochemical industry, and electrical industries. In decorative use, a cupronickel alloy called nickel silver is common, although it contains additional zinc but no silver. Another common 20th-century use of cupronickel was silver-coloured coins. For this use, the typical alloy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wood Preservative
Wood preservation refers to any method or process, or even technique, used to protect the wood and extend its service life. Most wood species are susceptible to both biological (''biotic'') and non-biological (''abiotic'') factors that cause decay and/or deterioration. Only a limited number of wood species possess natural durability, and even those may not be suitable for all environments. In general, wood benefits from appropriate preservation measures. In addition to structural design considerations, a variety of chemical preservatives and treatment processes — commonly known as timber treatment, lumber treatment, pressure treatment or modification treatment — are used to enhance the durability of wood and wood-based products, including engineered wood. These treatments may involve physical, chemical, thermal, and/or biological methodology aimed at protecting wood from degradation. They increase its resistance to biological agents such as fungi, termites, and insects, as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 some of which are harder than copper alone or have other useful properties, such as strength, ductility, or machinability. The archaeological period during which bronze was the hardest metal in widespread use is known as the Bronze Age. The beginning of the Bronze Age in western Eurasia is conventionally dated to the mid-4th millennium BCE (~3500 BCE), and to the early 2nd millennium BCE in China; elsewhere it gradually spread across regions. The Bronze Age was followed by the Iron Age, which started about 1300 BCE and reaching most of Eurasia by about 500 BCE, although bronze continued to be much more widely used than it is in modern times. Because historica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malachite
Malachite () is a copper Carbonate mineral, carbonate hydroxide mineral, with the chemical formula, formula Basic copper carbonate, Cu2CO3(OH)2. This opaque, green-banded mineral crystallizes in the monoclinic crystal system, and most often forms botryoidal, fibrous, or stalagmite, stalagmitic masses, in fractures and deep, underground spaces, where the water table and hydrothermal fluids provide the means for chemical precipitation. Individual crystals are rare, but occur as slender to Acicular (crystal habit), acicular prisms. Pseudomorphs after more tabular or blocky azurite crystals also occur. Etymology and history The stone's name derives (via , , and Middle English ''melochites'') from Greek language, Greek Μολοχίτης λίθος ''molochites lithos'', "mallow-green stone", from μολόχη ''molochē'', variant of μαλάχη ''malāchē'', "mallow". The mineral was given this name due to its resemblance to the leaves of the Malva, mallow plant. Copper (Cu2+) g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patina
Patina ( or ) is a thin layer that variously forms on the surface of copper, brass, bronze, and similar metals and metal alloys ( tarnish produced by oxidation or other chemical processes), or certain stones and wooden furniture (sheen produced by age, wear, and polishing), or any similar acquired change of a surface through age and exposure. Additionally, the term is used to describe the aging of high-quality leather. The patinas on leather goods are unique to the type of leather, frequency of use, and exposure. Patinas can provide a protective covering to materials that would otherwise be damaged by corrosion or weathering. They may also be aesthetically appealing. Usage On metal, patina is a coating of various chemical compounds such as oxides, carbonates, sulfides, or sulfates formed on the surface during exposure to atmospheric elements (oxygen, rain, acid rain, carbon dioxide, sulfur-bearing compounds). Patina also refers to accumulated changes in surface texture and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Conductivity
Electrical resistivity (also called volume resistivity or specific electrical resistance) is a fundamental specific property of a material that measures its electrical resistance or how strongly it resists electric current. A low resistivity indicates a material that readily allows electric current. Resistivity is commonly represented by the Greek alphabet, Greek letter (Rho (letter), rho). The SI unit of electrical resistivity is the ohm-metre (Ω⋅m). For example, if a solid cube of material has sheet contacts on two opposite faces, and the Electrical resistance, resistance between these contacts is , then the resistivity of the material is . Electrical conductivity (or specific conductance) is the reciprocal of electrical resistivity. It represents a material's ability to conduct electric current. It is commonly signified by the Greek letter (Sigma (letter), sigma), but (kappa) (especially in electrical engineering) and (gamma) are sometimes used. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smelting
Smelting is a process of applying heat and a chemical reducing agent to an ore to extract a desired base metal product. It is a form of extractive metallurgy that is used to obtain many metals such as iron-making, iron, copper extraction, copper, silver mining#Ore processing, silver, tin, lead smelting, lead and zinc smelting, zinc. Smelting uses heat and a chemical reducing agent to decompose the ore, driving off other elements as gases or slag and leaving the metal behind. The reducing agent is commonly a fossil-fuel source of carbon, such as carbon monoxide from incomplete combustion of coke (fuel), coke—or, in earlier times, of charcoal. The oxygen in the ore binds to carbon at high temperatures, as the Chemical energy, chemical potential energy of the bonds in carbon dioxide () is lower than that of the bonds in the ore. Sulfide ores such as those commonly used to obtain copper, zinc or lead, are roasting (metallurgy), roasted before smelting in order to convert the sulfid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper (color)
Copper is a reddish brown color that resembles the metal copper. The first recorded use of ''copper'' as a color name in English language, English was in 1594. Variations of copper Pale copper At right is displayed pale tone of copper that is called ''copper'' in Crayola crayons. This color was formulated by Crayola in 1903. Copper red At right is displayed the color copper red. The first recorded use of ''copper red'' as a color name in English language, English was in 1590. Copper penny At right is displayed the color copper penny. ''Copper penny'' is one of the colors in the special set of metallic Crayola crayons called List of Crayola crayon colors#Silver Swirls, Silver Swirls, the colors of which were formulated by Crayola in 1990. Copper rose At right is displayed the color copper rose. The first recorded use of ''copper rose'' as a color name in English language, English was in 1928. Copper in nature Plants * The copper-colored restrepia, Copper- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turquoise
Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium, with the chemical formula . It is rare and valuable in finer grades and has been prized as a gemstone for millennia due to its hue. The robin egg blue or sky blue color of the Persian turquoise mined near the modern city of Nishapur, Iran, has been used as a guiding reference for evaluating turquoise quality. Like most other opaque gems, turquoise has been devalued by the introduction of treatments, imitations, and synthetics into the market. Names The word ''turquoise'' dates to the 17th century and is derived from the Old French ''turquois'' meaning "Turkish" because the mineral was first brought to Europe through the Ottoman Empire.Turquoise . minerals.usgs.gov However, according to [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Verdigris
Verdigris () is a common name for any of a variety of somewhat toxic copper salt (chemistry), salts of acetic acid, which range in colour from green to a blue-green, bluish-green depending on their chemical composition.H. Kühn, Verdigris and Copper Resinate, in Artists' Pigments. A Handbook of Their History and Characteristics, Vol. 2: A. Roy (Ed.) Oxford University Press 1993, p. 131 – 158 Once used as a medicine and pharmaceutical preparation, verdigris occurs naturally, creating a patina on copper, bronze, and brass, and is the main component of a historic green pigment used for artistic purposes from antiquity until the late 20th century, including in Easel, easel painting, polychromatic sculptures, and illumination of maps. However, due to its instability, its popularity declined as other green pigments became readily available. The instability of its appearance stems from its Hydration number, hydration level and Base (chemistry), basicity, which change as the pigment inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alloy
An alloy is a mixture of chemical elements of which in most cases at least one is a metal, metallic element, although it is also sometimes used for mixtures of elements; herein only metallic alloys are described. Metallic alloys often have properties that differ from those of the pure elements from which they are made. The vast majority of metals used for commercial purposes are alloyed to improve their properties or behavior, such as increased strength, hardness or corrosion resistance. Metals may also be alloyed to reduce their overall cost, for instance alloys of gold and Copper(II) sulfate, copper. A typical example of an alloy is SAE 304 stainless steel, 304 grade stainless steel which is commonly used for kitchen utensils, pans, knives and forks. Sometime also known as 18/8, it as an alloy consisting broadly of 74% iron, 18% chromium and 8% nickel. The chromium and nickel alloying elements add strength and hardness to the majority iron element, but their main function is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azurite
Azurite or '' Azure spar''''Krivovichev V. G.'' Mineralogical glossary. Scientific editor A. G. Bulakh. — St.Petersburg: St.Petersburg Univ. Publ. House. 2009. — 556 p. — ISBN 978-5-288-04863-0. ''(in Russian)'' is a soft, deep-blue copper mineral produced by weathering of copper ore deposits. During the early 19th century, it was also known as chessylite, after the type locality at Chessy-les-Mines near Lyon, France. The mineral, a basic carbonate with the chemical formula Cu3(CO3)2(OH)2, has been known since ancient times, and was mentioned in Pliny the Elder's '' Natural History'' under the Greek name (κυανός: "deep blue," root of English cyan) and the Latin name '' caeruleum''. Copper (Cu2+) gives it its blue color. Mineralogy Azurite has the formula Cu3(CO3)2(OH)2, with the copper(II) cations linked to two different anions, carbonate and hydroxide. It is one of two relatively common basic copper(II) carbonate minerals, the other being bright green malach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
