Electroplating in the context of "Gilding"

Thermal spraying techniques are coating processes in which melted (or heated) materials are sprayed onto a surface. The "feedstock" (coating precursor) is heated by electrical (plasma or arc) or chemical means (combustion flame).

Thermal spraying can provide thick coatings (approx. thickness range is 20 microns to several mm, depending on the process and feedstock), over a large area at high deposition rate as compared to other coating processes such as electroplating, physical and chemical vapor deposition. Coating materials available for thermal spraying include metals, alloys, ceramics, plastics and composites. They are fed in powder or wire form, heated to a molten or semimolten state and accelerated towards substrates in the form of micrometer-size particles. Combustion or electrical arc discharge is usually used as the source of energy for thermal spraying. Resulting coatings are made by the accumulation of numerous sprayed particles. The surface may not heat up significantly, allowing the coating of flammable substances.

Chromium is a chemical element; it has symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal.

Chromium is valued for its high corrosion resistance and hardness. A major development in steel production was the discovery that steel could be made highly resistant to corrosion and discoloration by adding metallic chromium to form stainless steel. Stainless steel and chrome plating (electroplating with chromium) together comprise 85% of the commercial use. Chromium is also greatly valued as a metal that is able to be highly polished while resisting tarnishing. Polished chromium reflects almost 70% of the visible spectrum, and almost 90% of infrared light. The name of the element is derived from the Greek word χρῶμα, chrōma, meaning color, because many chromium compounds are intensely colored.

Gold plating is a method of depositing a thin layer of gold onto the surface of another metal, most often copper or silver (to make silver-gilt), by a chemical or electrochemical (electroplating) process. Plating refers to modern coating methods, such as the ones used in the electronics industry, whereas gilding is the decorative covering of an object with gold, which typically involve more traditional methods and much larger objects.

Electrowinning, also called electroextraction, is the electrodeposition of metals from their ores that have been put in solution via a process commonly referred to as leaching. Electrorefining uses a similar process to remove impurities from a metal. However, in electrorefining, the overall electron balance is zero, whereas electrowinning shows a net positive electron consumption in the overall reaction. Both processes use electroplating on a large scale and are important techniques for the economical and straightforward purification of non-ferrous metals. The resulting metals are said to be electrowon.

In electrowinning, an electrical current is passed from an inert anode through a leach solution containing the dissolved metal ions so that the metal is recovered as it is reduced and deposited in an electroplating process onto the cathode. In electrorefining, the anode consists of the impure metal (e.g., copper) to be refined. The impure metallic anode is oxidized and the metal dissolves into solution. The metal ions migrate through the electrolyte towards the cathode where the pure metal is deposited. Insoluble solid impurities sedimenting below the anode often contain valuable rare elements such as gold, silver and selenium.

Chrome plating (less commonly chromium plating) is a technique of electroplating a thin layer of chromium onto a metal object. A chrome plated part is called chrome, or is said to have been chromed. The chromium layer can be decorative, provide corrosion resistance, facilitate cleaning, and increase surface hardness. Sometimes a less expensive substitute for chrome, such as nickel, may be used for aesthetic purposes.

Chromium compounds used in electroplating are toxic. In most countries, their disposal is tightly regulated. Some fume suppressants used to control the emission of airborne chromium from plating baths are also toxic, making disposal even more difficult.

The British decimal one penny (1p) coin is a unit of currency and denomination of sterling coinage worth 1⁄100 of one pound. Its obverse featured the profile of Queen Elizabeth II since the coin's introduction on 15 February 1971, the day British currency was decimalised, until her death on 8 September 2022. A new portrait featuring King Charles III was introduced on 30 September 2022, designed by Martin Jennings. Four different portraits of the Queen were used on the obverse; the last design by Jody Clark was introduced in 2015. The second reverse, designed by Matthew Dent, features a segment of the Royal Shield and was used from 2008 to 2022. The third and current reverse, featuring a hazel dormouse, was introduced in 2023 following the accession of Charles III. The penny is the lowest value coin (in real terms) ever to circulate in the United Kingdom.

The penny was originally minted from bronze, but since 1992 has been minted in copper-plated steel due to increasing copper prices.

Electroless nickel-phosphorus plating, also referred to as E-nickel, 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, 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. This 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 electric resistance of the bath and therefore on the current distribution within it. Moreover, it can be applied to non-conductive surfaces.