Mechanical plating

Mechanical Plating. Impact or peen plating is a mechanical process whereby the metal powder is compacted and welded to parts by mechanical energy. This process is limited to relatively small parts of no more than about one kilogram. The parts are placed ia a specially desigaed barrel... 

By far, the largest appHcation of zinc powder is for solution purification in electrolytic zinc plants. This appHcation consumed an estimated 17,700 t of powder in 1980. Zinc powder is also used in primary batteries, frictional materials, spray metallizing, mechanical plating, and chemical formulations. 

This chromatographic mode represents a simple on-off technique. The compound of interest is fished-out from a more complex mixture via a very selective interaction with a ligand immobilized on solid support. Once the entire sample is processed through the column and followed by washing, the captured compound is released using a strong eluent. Thanks to the simple binary separation mechanism, plate counts are not important and the development of devices mostly focuses on binding capacity and selectivity. 

Sect. 5.5.2) and can be plated mechanically (i.e. hot dipping, metal spraying, etc.) and electrochemicaUy. Mechanical plating is the preferred method for layers with thickness >25 pm [21] and in which hydrogen embrittlement represents a problem [22]. With modem processes, electroplating rates up to 700 m min can be achieved [23]. During the last few years, zinc alloys (see Sect. 5.5.4.G) with cobalt (0.8%), nickel (10-14%), iron, and tin have found increased interest due to their improved corrosion stability (e.g. automotive appKcations). 

Surface coating with another metal with better resistance against corrosion. The metal layer can be plated. Zinc plating is the most important example. But other methods are available to prepare a metal layer, e.g., mechanical plating, by dipping the parts into a liquid metal bath or spraying the metal. 

It is of interest to note that ASTM B69S for mechanical plating (which has an acid dip as part of the pretreatment) states The mild degree of embrittlement. . . with cleaning methods. . . normally is self-relieving within a day s time at room temperature. ... 

Copper and copper alloy powders are also used in such nonstmc-tural applications as brazing, cold soldering, and mechanical plating, as well as for medals and medallions, metal-plastic decorative products, and a variety of chemical and medical purposes. 

Earthquake source mechanisms Fault plane solutions Focal mechanisms Plate tectonics Seismic moment tensors Seismicity and tectonics... 

Mechanical plating Cold welding/layering of metal coating particles... 

Cold spray (thermal spray) A metal spray coating process where ductile metal particles are introduced into a supersonic jet of compressed gas, are accelerated to a high velocity, and then impinge on a surface, where they cold-weld into a coating. See also Mechanical plating. 

Impact plating Coating a surface by the transfer of material from impacting particles on the surface. The particles may be at a high velocity or be pounded on the surface by a tumbling action. Also called Mechanical plating. 

Sherardizing Coating with zinc by mechanically tumbling a part in hot zinc powder. See also Mechanical plating Peen plating. 

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