Plating

Plating is a surface covering in which a metal is deposited on a conductive surface. Plating has been done for hundreds of years; it is also critical for modern technology. Plating is used to decorate objects, for corrosion inhibition, to improve solderability, to harden, to improve wearability, to reduce friction, to improve paint adhesion, to alter conductivity, to improve IR reflectivity, for radiation shielding, and for other purposes. Jewelry typically uses plating to give a silver or gold finish. Thin-film deposition has plated objects as small as an atom, therefore plating finds uses in nanotechnology.

There are several plating methods, and many variations. In one method, a solid surface is covered with a metal sheet, and then heat and pressure are applied to fuse them (a version of this is Sheffield plate). Other plating techniques include vapor deposition under vacuum and sputter deposition. Recently, plating often refers to using liquids. Metallizing refers to coating metal on non-metallic objects.

Plating (geology)

In geology, plating is a hypothesized process whereby asthenospheric mantle hardens beneath crustal material, thereby becoming attached to it and thereafter moving together with the crustal material as part of the lithosphere.

A complementary process, although it does not necessarily always involve the upper mantle, is called delamination.

See also

Plating (philately)

Plating refers to the reconstruction of a pane or "sheet" of postage stamps printed from a single plate by using individual stamps and overlapping strips and blocks of stamps. Likewise, if a sheet 10 or 20 postal cards is typeset, the variations of the letters or design elements may allow reconstruction or plating of the sheets based on these differences.

Basics

For plating to be possible, there must be constant variants in details of the stamps printed from a single plate or lithographic stone so that one can identify the exact original position of each stamp. Evidence that may be used in plating includes defects or "flaws" occurring in the transfer of images, individual touch-ups by the engraver, recuttings of the plates, repairs, and accidental injuries to the plates. In addition, stamps may have be laid out in an irregular fashion on the plate with the result that differences in spacing and orientation of the stamps may be used to determine their plate positions. From their inception in 1840 until 1884, postage stamps from Great Britain incorporated control letters in the corners indicating the stamps's exact position on the sheet, e.g., A...C is first row, third stamp, and for a period also incorporated the number of the plate from which the stamps were printed. Other evidence such as color of the ink used or watermarks in the paper may be of use in reconstructing plates. In the absence of such evidence, plating is not possible. Because of the highly accurate methods of modern stamp production, most modern issues cannot be plated.