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Immersion Zinc Plating
Immersion zinc plating is an electroless (non-electrolytic) coating process that deposits a thin layer of zinc on a less electronegative metal, by immersion in a solution containing a zinc or zincate ions, . A typical use is plating aluminum with zinc prior to electrolytic or electroless nickel plating. Immersion zinc plating involves the displacement of zinc from zincate by the underlying metal: :3 + 2 Al → 3 Zn + 2 + 4 OH− See also * Electrogalvanization (electrolytic zinc coating) * Immersion gold plating * Immersion copper plating * Immersion silver plating Immersion silver plating (or IAg plating) is a surface plating process that creates a thin layer of silver over copper objects. It consists in dipping the object briefly into a solution containing silver ions. Immersion silver plating is used by ... References Glenn O. Mallory, Juan B. Hajdu (1990), Electroless Plating: Fundamentals and Applications, American Electroplaters and Surface Finishers Society, , ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electroless Plating
Electroless plating, also known as chemical plating or autocatalytic plating, is a class of industrial chemical processes that create metal coatings on various materials by autocatalytic chemical reduction of metal cations in a liquid bath. This class is contrasted with electroplating processes, where the reduction is achieved by an externally generated electric current. The main technical advantage of electroless plating is that it creates an even layer of metal regardless of the geometry of the surface—in contrast to electroplating, which suffers from uneven current density due to the effect of substrate shape on the electrical resistance of the bath. Moreover, electroless plating can be applied to non-conductive surfaces and parts of the object that cannot be connected to the current source. Electroless plating has many industrial applications, from merely decorative to the prevention of corrosion and wear. It can even be used to coat individual grains of powdered materials ... [...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] |
Coating
A coating is a covering that is applied to the surface of an object, usually referred to as the Substrate (materials science), substrate. The purpose of applying the coating may be decorative, functional, or both. Coatings may be applied as liquids, gases or solids e.g. Powder coatings. Paints and lacquers are coatings that mostly have dual uses of protecting the substrate and being decorative, although some artists paints are only for decoration, and the paint on large industrial pipes is for preventing corrosion and identification e.g. blue for process water, red for fire-fighting control etc. Functional coatings may be applied to change the surface properties of the substrate, such as adhesion, Wetting, wettability, corrosion resistance, or wear resistance. In other cases, e.g. semiconductor device fabrication (where the substrate is a wafer (electronics), wafer), the coating adds a completely new property, such as a magnetic response or electrical conductivity, and forms an e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zinc
Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic table. In some respects, zinc is chemically similar to magnesium: both elements exhibit only one normal oxidation state (+2), and the Zn2+ and Mg2+ ions are of similar size.The elements are from different metal groups. See periodic table. Zinc is the 24th most abundant element in Earth's crust and has five stable isotopes. The most common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral. The largest workable lodes are in Australia, Asia, and the United States. Zinc is refined by froth flotation of the ore, roasting, and final extraction using electricity ( electrowinning). Zinc is an essential trace element for humans, animals, plants and for microorganisms and is necessary for prenatal and postnatal development. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronegativity
Electronegativity, symbolized as , is the tendency for an atom of a given chemical element to attract shared electrons (or electron density) when forming a chemical bond. An atom's electronegativity is affected by both its atomic number and the distance at which its valence electrons reside from the charged nucleus. The higher the associated electronegativity, the more an atom or a substituent group attracts electrons. Electronegativity serves as a simple way to quantitatively estimate the bond energy, and the sign and magnitude of a bond's chemical polarity, which characterizes a bond along the continuous scale from covalent to ionic bonding. The loosely defined term electropositivity is the opposite of electronegativity: it characterizes an element's tendency to donate valence electrons. On the most basic level, electronegativity is determined by factors like the nuclear charge (the more protons an atom has, the more "pull" it will have on electrons) and the number and location ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrahydroxozincate
In chemistry, tetrahydroxozincate or tetrahydroxidozincate is a divalent anion (negative ion) with formula , with a central zinc atom in the +2 or (II) valence state coordinated to four hydroxide groups. It has Sp3 hybridization. It is the most common of the zincate anions, and is often called just zincate. These names are also used for the salts containing that anion, such as sodium zincate Na2Zn(OH)4 and calcium zincate CaZn(OH)4·2H2O Zincate salts can be obtained by reaction of zinc oxide (ZnO) or zinc hydroxide () and a strong base like sodium hydroxide. It is now generally accepted that the resulting solutions contain the tetrahydroxozincate ion. Earlier Raman studies had been interpreted as indicating the existence of linear ions. Related anions and salts The name "zincate" may also refer to a polymeric anion with formula approaching []''n'', which forms salts such as ·, or to mixed oxides of zinc and less electronegativity, electronegative elements, such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminum
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has a great affinity towards oxygen, and forms a protective layer of oxide on the surface when exposed to air. Aluminium visually resembles silver, both in its color and in its great ability to reflect light. It is soft, non-magnetic and ductile. It has one stable isotope, 27Al; this isotope is very common, making aluminium the twelfth most common element in the Universe. The radioactivity of 26Al is used in radiodating. 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 is polarizing, and bonds aluminium forms tend towards covalency. The strong affinity towards ox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electroless Nickel Plating
Electroless nickel-phosphorus plating is a chemical process that deposits an even layer of nickel-phosphorus alloy on the surface of a solid substrate, like metal or plastic. The process involves dipping the substrate in a water solution containing nickel salt and a phosphorus-containing reducing agent, usually a hypophosphite salt. It is the most common version of electroless nickel plating (EN plating) and is often referred by that name. A similar process uses a borohydride reducing agent, yielding a nickel-boron coating instead. Unlike electroplating, electroless plating processes in general do not require passing an electric current through the bath and the substrate; the reduction of the metal cations in solution to metallic is achieved by purely chemical means, through an autocatalytic reaction. Thus electroless plating creates an even layer of metal regardless of the geometry of the surface – in contrast to electroplating which suffers from uneven current density due ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Displacement Reaction
A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the nuclei (no change to the elements present), and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive elements where both electronic and nuclear changes can occur. The substance (or substances) initially involved in a chemical reaction are called reactants or reagents. Chemical reactions are usually characterized by a chemical change, and they yield one or more products, which usually have properties different from the reactants. Reactions often consist of a sequence of individual sub-steps, the so-called elementary reactions, and the information on the precise course of acti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrogalvanization
Electrogalvanizing is a process in which a layer of zinc is bonded to steel in order to protect against corrosion. The process involves electroplating, running a current of electricity through a saline/zinc solution with a zinc anode and steel conductor. Such Zinc electroplating or Zinc alloy electroplating maintains a dominant position among other electroplating process options, based upon electroplated tonnage per annum. According to the International Zinc Association, more than 5 million tons are used yearly for both Hot-dip galvanizing, hot dip galvanizing and electroplating. The plating of zinc was developed at the beginning of the 20th century. At that time, the electrolyte was cyanide based. A significant innovation occurred in the 1960s, with the introduction of the first acid chloride based electrolyte. The 1980s saw a return to alkaline electrolytes, only this time, without the use of cyanide. The most commonly used electrogalvanized cold rolled steel is SECC, acronym of "St ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immersion Gold Plating
Electroless nickel immersion gold (ENIG or ENi/IAu), also known as immersion gold (Au), chemical Ni/Au or soft gold, is a metal plating process used in the manufacture of printed circuit boards (PCBs), to avoid oxidation and improve the solderability of copper contacts and plated through-holes. It consists of an electroless nickel plating, covered with a thin layer of gold, which protects the nickel from oxidation. The gold is typically applied by quick immersion in a solution containing gold salts. Some of the nickel is oxidized to while the gold is reduced to metallic state. A variant of this process adds a thin layer of electroless palladium over the nickel, a process known by the acronym ENEPIG. ENIG can be applied before or after the solder mask, also known as overall or selective chemical Ni/Au, respectively. The latter type is more common and significantly cheaper as less gold is needed to cover only the solder pads. Advantages and disadvantages ENIG and ENEPIG are mea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immersion Copper Plating
Immersion may refer to: The arts * "Immersion", a 2012 story by Aliette de Bodard * ''Immersion'', a French comic book series by Léo Quievreux * ''Immersion'' (album), the third album by Australian group Pendulum * ''Immersion'' (film), a 2021 Chilean thriller film * Immersion (series), a webseries which test the concepts of video games in real life, created by Rooster Teeth Productions * Immersion journalism, a style of journalism Science and technology * Immersion lithography or immersion microscopy, optical techniques in which liquid is between the objective and image plane in order to raise numerical aperture * Immersion (mathematics), a smooth map whose differential is everywhere injective, related to the mathematical concept of an embedding * Immersion (virtual reality), the perception of being physically present in a non-physical world, created by using VR Other uses * Immersion baptism, a type of baptism whereby the subject is immersed in water * Immersion Corporat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
