What is PVD?

PVD stands for Physical Vapour Deposition and describes a variety of vacuum deposition methods used to produce thin films and coatings. This metal deposition technique is when a selected solid metal is vaporized in a high vacuum chamber and then condensed back onto electrically conductive material called a substrate. The metals vaporised can be a pure metal or an alloy metal coating.

The most common PVD techniques are

Cathodic Arc Deposition
This is a high-power electric arc discharged at the target metal material which turns into a highly ionized vapour which is then deposited onto the work piece.

Sputter Deposition
This uses a glow plasma discharge which is located by magnets, which bombards the coating material, sputtering away atoms as a vapour for subsequent deposition onto the work piece.

Electron Beam Deposition
This is where the target metal is heated to a high vapour pressure by electron bombardment in a high vacuum, this is then transported by diffusion and deposited by condensation on the cooler work piece.

The PVD process will transfer the atomised coating material as a single atom or molecule level and provides an extremely pure and high performance coating which for many applications is a far superior coating when compared with electroplating.

PVD Coatings is an environmentally friendly process because of the lack of toxic substances used when compared to traditional plating processes. With electroplating the involved fluid precursors and toxic reactions caused by the chemicals used are extremely harmful to health. Also when chemicals are used in any electro bath process you also have the green and environmental impact caused by the waste produced.

PVD finishes have extremely good wear resistance to abrasion and chemicals and produces superior hardness. Physical vapour deposition coatings have low fiction characteristics which is ideal for high performance moving parts in engines etc. and is used widely by the aerospace and automotive industry.

These coatings are also used in the tooling industry and have made a huge difference in the lifespan of drills and cutting tools which was previously reliant on traditional hardening methods.

Surgical tools use PVD coating for its high purity. This technology is also used in microchips, gives glass a transparent heat saving coating and enables solar panels to produce green energy.

Because of the huge diversity of PVD coating, this technology is ideal for producing hundreds of decorative metal finishes. Due to its many merits PVD is used widely by luxury watch, bathroom, architectural, jewellery and sports brands because of its extremely hard wearing and scuff resistance plus the many attractive metal finishes available. Previous traditional coatings just cannot compare with these qualities. The luxury car industry uses this coating for decorative interior and exterior metal trim again because of its longevity and beauty of finish.

PVD finishing use a huge amount of metal and metal alloys as the plasma coating material, all producing different characteristics in finish and durability. Even the precious metals gold and silver can be used, and are by the watch industry who mix them with harder wearing metals to produce the product with more usability and longevity.

Some of the target metals and alloys used to coat
Chromium nitride = CrN
Copper = Cu
Zirconium = Zr
Chromium = Cr
Titanium aluminium nitride = TiAlN
Titanium = Ti
Aluminium Titanium Nitride =
Zirconium nitride = ZrN
Stainless steel = FeCrNe
Zirconium oxide = ZrO2
Titanium Aluminum =TiA
Gold = Ag
Silver = Au
Zirconium Carbon Nitride = ZrCN
Titanium Nitride = TiN
Titanium Carbon Nitride = TiCN
Chromium Carbon Nitride = CrCN

The above targets will produce a certain metal colour on their own, but if the plasma mist is then mixed with nitrogen, acetylene or oxygen gas then the colour changes and if you change the mix % the colour changes again so as you can see the possibilities are endless. This said the main colours for decorative metal finishes are still the traditional electro-plating finishes of gold, rose gold, nickel, brass and chrome which can all be easily achieved.

Nearly every metal can be used as a target material with all producing different colours, usability and with different characteristics. Some are chosen for their decorative finish, others for their hardness (tooling) and others for their low fiction qualities (ideal for engine moving parts etc).