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Surface Treatment
Surface finishing is a broad range of industrial processes that alter the surface of a manufactured item to achieve a certain property. Finishing processes may be employed to: improve appearance, adhesion or wettability, solderability, corrosion resistance, tarnish resistance, chemical resistance, wear resistance, hardness, modify electrical conductivity, remove burrs and other surface flaws, and control the surface friction.. In limited cases some of these techniques can be used to restore original dimensions to salvage or repair an item. An unfinished surface is often called '' mill finish''. Surface finishing processes can be categorized by how they affect the workpiece: *Removing or reshaping finishing *Adding or altering finishing Mechanical processes may also be categorized together because of similarities the final surface finish. Adding and altering *Blanching * Burnishing *Calendering *Case hardening *Ceramic glaze *Cladding *Corona treatment *Diffusion processes: **Carb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Industrial Process
Industrial processes are procedures involving chemical, physical, electrical or mechanical steps to aid in the manufacturing of an item or items, usually carried out on a very large scale. Industrial processes are the key components of heavy industry. Chemical processes by main basic material Certain chemical process yield important basic materials for society, e.g., (cement, steel, aluminum, and fertilizer). However, these chemical reactions contribute to climate change by emitting carbon dioxide, a greenhouse gas, through chemical reactions, as well as through the combustion of fossil fuels to generate the high temperatures needed to reach the activation energies of the chemical reactions. Cement (the paste within concrete) * Calcination – Limestone, which is largely composed of fossilized calcium carbonate (CaCO3), breaks down at high temperatures into useable calcium oxide (CaO) and carbon dioxide gas (), which gets released as a by-product. This chemical reaction, call ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corona Treatment
Corona treatment (sometimes referred to as air plasma) is a surface modification technique that uses a low temperature corona discharge plasma to impart changes in the properties of a surface. The corona plasma is generated by the application of high voltage to an electrode that has a sharp tip. The plasma forms at the tip. A linear array of electrodes is often used to create a curtain of corona plasma. Materials such as plastics, cloth, or paper may be passed through the corona plasma curtain in order to change the surface energy of the material. All materials have an inherent surface energy. Surface treatment systems are available for virtually any surface format including dimensional objects, sheets and roll goods that are handled in a web format. Corona treatment is a widely used surface treatment method in the plastic film, extrusion, and converting industries. History The corona treatment was invented by the Danish engineer Verner Eisby in 1951. Eisby had been asked by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bluing (steel)
Bluing is a passivation process in which steel is partially protected against rust using a black oxide coating. It is named after the blue-black appearance of the resulting protective finish. Bluing involves an electrochemical conversion coating resulting from an oxidizing chemical reaction with iron on the surface selectively forming magnetite (), the black oxide of iron. In comparison, rust, the red oxide of iron (), undergoes an extremely large volume change upon hydration; as a result, the oxide easily flakes off causing the typical reddish rusting away of iron. Black oxide provides minimal protection against corrosion, unless also treated with a water-displacing oil to reduce wetting and galvanic action. In colloquial use, thin coatings of black oxide are often termed 'gun bluing', while heavier coatings are termed 'black oxide'. Both refer to the same chemical process for providing true gun bluing. Overview Various processes are used for the oxidizing process. "Cold ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anodizing
Anodizing is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts. The process is called ''anodizing'' because the part to be treated forms the anode electrode of an electrolytic cell. Anodizing increases resistance to corrosion and wear, and provides better adhesion for paint primers and glues than bare metal does. Anodic films can also be used for several cosmetic effects, either with thick porous coatings that can absorb dyes or with thin transparent coatings that add reflected light wave interference effects. Anodizing is also used to prevent galling of threaded components and to make dielectric films for electrolytic capacitors. Anodic films are most commonly applied to protect aluminium alloys, although processes also exist for titanium, zinc, magnesium, niobium, zirconium, hafnium, and tantalum. Iron or carbon steel metal exfoliates when oxidized under neutral or alkaline micro-electrolytic conditio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conversion Coating
A conversion coating is a chemical or electro-chemical treatment applied to manufactured parts that superficially converts the material into a thin adhering coating of an insoluble compound. These coatings are commonly applied to protect the part against corrosion, to improve the adherence of other coatings, for lubrication, or for aesthetic purposes. Types The most common conversion coating processes for metal parts with industrial use include * Chromate (aluminum, steel) * Phosphate (steel) * Bluing (steel) * Black oxide (steel) * Anodizing Anodizing is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts. The process is called ''anodizing'' because the part to be treated forms the anode electrode of an electro ... (aluminum) * stannate conversion coating, Stannate (magnesium) * molybdate conversion coating, Molybdate (zinc, zinc-nickel) * zirconate conversion coating, Zirconate (steel, aluminum, mag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Passivation (chemistry)
Passivation, in physical chemistry and engineering, refers to coating a material so it becomes "passive", that is, less readily affected or corroded by the environment. Passivation involves creation of an outer layer of shield material that is applied as a microcoating, created by chemical reaction with the base material, or allowed to build by spontaneous oxidation in the air. As a technique, passivation is the use of a light coat of a protective material, such as metal oxide, to create a shield against corrosion. Passivation of silicon is used during fabrication of microelectronic devices. In electrochemical treatment of water, passivation reduces the effectiveness of the treatment by increasing the circuit resistance, and active measures are typically used to overcome this effect, the most common being polarity reversal, which results in limited rejection of the fouling layer. When exposed to air, many metals naturally form a hard, relatively inert surface layer, usually an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paint
Paint is any pigmented liquid, liquefiable, or solid mastic composition that, after application to a substrate in a thin layer, converts to a solid film. It is most commonly used to protect, color, or provide texture. Paint can be made in many colors—and in many different types. Paint is typically stored, sold, and applied as a liquid, but most types dry into a solid. Most paints are either oil-based or water-based and each has distinct characteristics. For one, it is illegal in most municipalities to discard oil-based paint down household drains or sewers. Clean-up solvents are also different for water-based paint than they are for oil-based paint. Water-based paints and oil-based paints will cure differently based on the outside ambient temperature of the object being painted (such as a house.) Usually, the object being painted must be over , although some manufacturers of external paints/primers claim they can be applied when temperatures are as low as . History Paint was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Knurling
Knurling is a manufacturing process, typically conducted on a lathe, whereby a pattern of straight, angled or crossed lines is rolled into the material. Etymology The terms ''knurl'' and ''knurled'' are from an earlier ''knur'' ‘knot in wood’ and the diminutive ''-le'', from Middle English ''knaur'' or ''knarre'' ‘knot in wood; twisted rock; crag’. This descends from Old English ''cnearra'' but the vowel in Middle English may have been influenced by Old Norse ''knǫrr'' ‘merchant ship’ which was known as ''cnearr'' in Old English. The modern ''gnarl'' is a back-formation of ''gnarled'' which itself is first attested in Shakespeare’s works and is apparently a variant of ''knurled''. Uses The operation is performed for producing indentations on a part of a workpiece. Knurling allows hands or fingers to get a better grip on the knurled object than would be provided by the originally smooth metal surface. Occasionally, the knurled pattern is a series of straight ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glaze (metallurgy)
Compacted oxide layer glaze describes the often shiny, wear-protective layer of oxide formed when two metals (or a metal and ceramic) are slid against each other at high temperature in an oxygen-containing atmosphere. The layer forms on either or both of the surfaces in contact and can protect against wear. Background A not often used definition of ''glaze'' is the highly sintered compacted oxide layer formed due to the sliding of either two metallic surfaces (or sometimes a metal surface and ceramic surface) at high temperatures (normally several hundred degrees Celsius) in oxidizing conditions. The sliding or tribological action generates oxide debris that can be compacted against one or both sliding surfaces and, under the correct conditions of load, sliding speed and oxide chemistry as well as (high) temperature, sinter together to form a 'glaze' layer. The 'glaze' formed in such cases is actually a crystalline oxide, with a very small crystal or grain size having been shown ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gilding
Gilding is a decorative technique for applying a very thin coating of gold over solid surfaces such as metal (most common), wood, porcelain, or stone. A gilded object is also described as "gilt". Where metal is gilded, the metal below was traditionally silver in the West, to make silver-gilt (or ''vermeil'') objects, but gilt-bronze is commonly used in China, and also called ormolu if it is Western. Methods of gilding include hand application and gluing, typically of gold leaf, chemical gilding, and electroplating, the last also called gold plating. Parcel-gilt (partial gilt) objects are only gilded over part of their surfaces. This may mean that all of the inside, and none of the outside, of a chalice or similar vessel is gilded, or that patterns or images are made up by using a combination of gilt and ungilted areas. Gilding gives an object a gold appearance at a fraction of the cost of creating a solid gold object. In addition, a solid gold piece would often be too soft or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galvanizing
Galvanization or galvanizing ( also spelled galvanisation or galvanising) is the process of applying a protective zinc coating to steel or iron, to prevent rusting. The most common method is hot-dip galvanizing, in which the parts are submerged in a bath of hot, molten zinc. Protective action The zinc coating, when intact, prevents corrosive substances from reaching the underlying iron. Additional electroplating such as a chromate conversion coating may be applied to provide further surface passivation to the substrate material. History and etymology The earliest known example of galvanized iron was encountered by Europeans on 17th-century Indian armour in the Royal Armouries Museum collection. The term "galvanized" continues to be used metaphorically of any stimulus which results in activity by a person or group of people. In modern usage, the term "galvanizing" has largely come to be associated with zinc coatings, to the exclusion of other metals. Galvanic paint, a prec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electroplating
Electroplating, also known as electrochemical deposition or electrodeposition, is a process for producing a metal coating on a solid substrate through the reduction of cations of that metal by means of a direct electric current. The part to be coated acts as the cathode (negative electrode) of an electrolytic cell; the electrolyte is a solution of a salt of the metal to be coated; and the anode (positive electrode) is usually either a block of that metal, or of some inert conductive material. The current is provided by an external power supply. Electroplating is widely used in industry and decorative arts to improve the surface qualities of objects—such as resistance to abrasion and corrosion, lubricity, reflectivity, electrical conductivity, or appearance. It is used to build up thickness on undersized or worn-out parts, or to manufacture metal plates with complex shape, a process called electroforming. It is used to deposit copper and other conductors in forming printe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
