Metallizing

Last updated
Radiation hardened die of the 1886VE10 microcontroller prior to metalization etching 1886VE10-HD.jpg
Radiation hardened die of the 1886VE10 microcontroller prior to metalization etching
Radiation hardened die of the 1886VE10 microcontroller after a metalization etching process has been used 1886VE10-Si-HD.jpg
Radiation hardened die of the 1886VE10 microcontroller after a metalization etching process has been used
Gold-plated phone belonging to the dictator Batista at the Revolution Museum in Havana Museo de la Revolucion-Batista golden phone.jpg
Gold-plated phone belonging to the dictator Batista at the Revolution Museum in Havana

Metallizing is the general name for the technique of coating metal on the surface of objects. Metallic coatings may be decorative, protective or functional.

Techniques for metallization started as early as mirror making. In 1835, Justus von Liebig discovered the process of coating a glass surface with metallic silver, making the glass mirror one of the earliest items being metallized. Plating other non-metallic objects grew rapidly with introduction of ABS plastic. Because a non-metallic object tends to be a poor electrical conductor, the object's surface must be made conductive before plating can be performed. The plastic part is first etched chemically by a suitable process, such as dipping in a hot chromic acid-sulfuric acid mixture. The etched surface is sensitised and activated by first dipping in tin(II) chloride solution, then palladium chloride solution. The processed surface is then coated with electroless copper or nickel before further plating. This process gives useful (about 1 to 6  kgf/cm or 10 to 60  N/cm or 5 to 35  lbf/in) adhesion force, but is much weaker than actual metal-to-metal adhesion strength.

Vacuum metallizing involves heating the coating metal to its boiling point in a vacuum chamber, then letting condensation deposit the metal on the substrate's surface. Resistance heating, electron beam, or plasma heating is used to vaporize the coating metal. Vacuum metallizing was used to deposit aluminum on the large glass mirrors of reflecting telescopes, such as with the Hale Telescope.

Thermal spray processes are often referred to as metallizing. Metals applied in such a manner provide corrosion protection to steel for decades longer than paint alone. Zinc and aluminum are the most commonly used materials for metallizing steel structures. [1]

Cold sprayable metal technology is a metallizing process that seamlessly applies cold sprayable or putty able metal to almost any surface. The composite metal consists of two (water-based binder) or three different ingredients: metal powder, binder and hardener.

The mixture of the ingredients is cast or sprayed on the substrate at room temperature. The desired effect and the necessary final treatment define the thickness of the layer, which normally varies between 80 and 150  μm.

See also

Related Research Articles

<span class="mw-page-title-main">Electroplating</span> Creation of protective or decorative metallic coating on other metal with electric current

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 of an electrolytic cell; the electrolyte is a solution of a salt of the metal to be coated, and the anode is usually either a block of that metal, or of some inert conductive material. The current is provided by an external power supply.

<span class="mw-page-title-main">Gilding</span> Covering object with layer of gold

Gilding is a decorative technique for applying a very thin coating of gold over solid surfaces such as metal, 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 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 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.

<span class="mw-page-title-main">Chrome plating</span> Technique of electroplating

Chrome 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.

Plating is a finishing process in which a metal is deposited on a 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.

<span class="mw-page-title-main">Copper electroplating</span> Process of electroplating copper

Copper electroplating is the process of electroplating a layer of copper onto the surface of a metal object. Copper is used both as a standalone coating and as an undercoat onto which other metals are subsequently plated. The copper layer can be decorative, provide corrosion resistance, increase electrical and thermal conductivity, or improve the adhesion of additional deposits to the substrate.

<span class="mw-page-title-main">Coating</span> Substance spread over a surface

A coating is a covering that is applied to the surface of an object, or 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.

<span class="mw-page-title-main">Silvering</span> Silvering in mirrors

Silvering is the chemical process of coating a non-conductive substrate such as glass with a reflective substance, to produce a mirror. While the metal is often silver, the term is used for the application of any reflective metal.

<span class="mw-page-title-main">Surface finishing</span> Range of processes that alter the surface of an item to achieve a certain property

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.

<span class="mw-page-title-main">Powder coating</span> Type of coating applied as a free-flowing, dry powder

Powder coating is a type of coating that is applied as a free-flowing, dry powder. Unlike conventional liquid paint, which is delivered via an evaporating solvent, powder coating is typically applied electrostatically and then cured under heat or with ultraviolet light. The powder may be a thermoplastic or a thermoset polymer. It is usually used to create a thick, tough finish that is more durable than conventional paint. Powder coating is mainly used for coating of metal objects, particularly those subject to rough use. Advancements in powder coating technology like UV-curable powder coatings allow for other materials such as plastics, composites, carbon fiber, and MDF to be powder coated, as little heat or oven dwell time is required to process them.

<span class="mw-page-title-main">Ion plating</span> Method of coating solid surfaces with ions

Ion plating (IP) is a physical vapor deposition (PVD) process that is sometimes called ion assisted deposition (IAD) or ion vapor deposition (IVD) and is a modified version of vacuum deposition. Ion plating uses concurrent or periodic bombardment of the substrate, and deposits film by atomic-sized energetic particles called ions. Bombardment prior to deposition is used to sputter clean the substrate surface. During deposition the bombardment is used to modify and control the properties of the depositing film. It is important that the bombardment be continuous between the cleaning and the deposition portions of the process to maintain an atomically clean interface. If this interface is not properly cleaned, then it can result into a weaker coating or poor adhesion.

<span class="mw-page-title-main">Electroless deposition</span>

Electroless deposition (ED) or electroless plating is defined as the autocatalytic process through which metals and metal alloys are deposited onto conductive and nonconductive surfaces. These nonconductive surfaces include plastics, ceramics, and glass etc., which can then become decorative, anti-corrosive, and conductive depending on their final functions. Electroplating, unlike electroless deposition, only deposits on other conductive or semi-conductive materials when an external current is applied. Electroless deposition deposits metals onto 2D and 3D structures such as screws, nanofibers, and carbon nanotubes, unlike other plating methods such as Physical Vapor Deposition ( PVD), Chemical Vapor Deposition (CVD), and electroplating, which are limited to 2D surfaces. Commonly the surface of the substrate is characterized via pXRD, SEM-EDS, and XPS which relay set parameters based their final funtionality. These parameters are referred to a Key Performance Indicators crucial for a researcher’ or company's purpose. Electroless deposition continues to rise in importance within the microelectronic industry, oil and gas, and aerospace industry.

<span class="mw-page-title-main">Electroless nickel-phosphorus plating</span> Chemical-induced nickel coating of a surface

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 and is often referred by that name. A similar process uses a borohydride reducing agent, yielding a nickel-boron coating instead.

<span class="mw-page-title-main">Physical vapor deposition</span> Method of coating solid surfaces with thin films

Physical vapor deposition (PVD), sometimes called physical vapor transport (PVT), describes a variety of vacuum deposition methods which can be used to produce thin films and coatings on substrates including metals, ceramics, glass, and polymers. PVD is characterized by a process in which the material transitions from a condensed phase to a vapor phase and then back to a thin film condensed phase. The most common PVD processes are sputtering and evaporation. PVD is used in the manufacturing of items which require thin films for optical, mechanical, electrical, acoustic or chemical functions. Examples include semiconductor devices such as thin-film solar cells, microelectromechanical devices such as thin film bulk acoustic resonator, aluminized PET film for food packaging and balloons, and titanium nitride coated cutting tools for metalworking. Besides PVD tools for fabrication, special smaller tools used mainly for scientific purposes have been developed.

<span class="mw-page-title-main">Thermal spraying</span> Coating process for applying heated materials to a surface

Thermal spraying techniques are coating processes in which melted materials are sprayed onto a surface. The "feedstock" is heated by electrical or chemical means.

<span class="mw-page-title-main">Evaporation (deposition)</span> Common method of thin-film deposition

Evaporation is a common method of thin-film deposition. The source material is evaporated in a vacuum. The vacuum allows vapor particles to travel directly to the target object (substrate), where they condense back to a solid state. Evaporation is used in microfabrication, and to make macro-scale products such as metallized plastic film.

Substrate is a term used in materials science and engineering to describe the base material on which processing is conducted. Surfaces have different uses, including producing new film or layers of material and being a base to which another substance is bonded.

A molded interconnect device (MID) is an injection-molded thermoplastic part with integrated electronic circuit traces. The use of high temperature thermoplastics and their structured metallization opens a new dimension of circuit carrier design to the electronics industry. This technology combines plastic substrate/housing with circuitry into a single part by selective metallization.

Nickel electroplating is a technique of electroplating a thin layer of nickel onto a metal object. The nickel layer can be decorative, provide corrosion resistance, wear resistance, or used to build up worn or undersized parts for salvage purposes.

<span class="mw-page-title-main">Electroless nickel-boron plating</span> Metal plating process

Electroless nickel-boron coating is a metal plating process that can create a layer of a nickel-boron 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 boron-containing reducing agent, such as an alkylamineborane or sodium borohydride. It is a type of electroless nickel plating. A similar process, that uses a hypophosphite as a reducing agent, yields a nickel-phosphorus coating instead.

Electroless copper plating is a chemical process that deposits an even layer of copper on the surface of a solid substrate, like metal or plastic. The process involves dipping the substrate in a water solution containing copper salts and a reducing agent such as formaldehyde.

References

  1. Lohrey, Eric C. "Metalizing Steel Bridges in the Field". Journal of Protective Coatings and Linings. 12 (5). Steel Structures Painting Council: 39.