PVD Gold VS Galvanic Gilding – Wich one to choose?

PVD (Physical Vapor Deposition) gold and galvanic gold plating (also called electrolytic gold plating) are two processes used to apply a thin gold layer to a surface.

In the PVD process, atoms or molecules of Titanium Nitride are transported and deposited on the substrate in the form of vapor. This metal compound, which is extremely dense and exceptionally hard, makes it possible to replicate the color of gold.

Galvanic gold plating is an electrochemical deposition process in which a layer of gold is applied to the surface of an object by electroplating. An electrolytic solution containing gold ions, which are present in different chemical forms that are chosen according to preference, is used.

There are also some fundamental differences between the two deposition methods.

Main differences

The differences between PVD gold and gold electroplating are many, starting with the process and leading to the physical characteristics of the finished product:

  • Deposition method: Galvanic gold plating involves an electrochemical reaction, while gold PVD involves physical vapor deposition of the coating material. These are two very different types of deposition, resulting in significant structural differences in the resulting coating.
  • Raw Materials: Through the use of electroplating, it is impossible to achieve the gold color without using pure gold ions. PVD on the other hand is commonly using raw materials that emulate the color of gold.
  • Layer Thickness: Galvanic gold plating can provide thicker gold layers in less time than PVD, but the latter offers more flexibility in adjusting thickness than other coating techniques.
  • Strength and durability: PVD tends to be stronger and more durable than electroplating; in fact, it creates a firmer layer that is more adherent to the surface and stronger.
  • Processing Cycles: a PVD processing cycle, has a lower cost than a galvanic treatment cycle.
pvd-oro-2

Eco-sustainability

Galvanic gold plating and gold PVD have another major difference, mainly related to the environmental sustainability of the process. During the galvanic gold plating process, electrolytic solutions containing gold ions are used. These solutions may also contain other chemical components, which are used to enhance the properties of the coating.

This can lead to the risk of releasing environmentally harmful residues if they are not properly disposed of. However, the environmental impact depends on the composition of the electrolyte solutions used in the electroplating process and the management of the waste generated.

PVD technology on the other hand does not release any toxic materials; it is a very nature-friendly coating technique that does not require any disposal process.

How is the process developed?

PVD is a physical vapor deposition process in which a thin layer of Titanium Nitride is applied to the surface of the material. The most common methodologies for making gold-plated thin films using the PVD technique are magnetron sputtering, cathodic arc, and thermal evaporation. 

In these processes, the material to be coated is placed in a vacuum chamber and a controlled environment is created, then the targets are bombarded by ions, which remove atoms from the material and deposit them on the surface of the substrate, forming a gold layer. This process creates a very strong bond with the base material, generating a surface that is resistant to wear and corrosion. PVD gold is often used for applications that require a durable and tough finish, such as high-end watches, jewelry, and electrical components.

Galvanic gold plating, on the other hand, is a process in which an object is immersed in a solution containing gold ions and acts as the cathode in an electrical circuit. When an electric current is applied, the gold ions in the solution are reduced and deposited on the surface of the object, where a thin layer is formed. Galvanic gold plating can be used on a wide range of materials, such as metals and plastics.

galvanica-e-pvd-v2-min

Advantages and Disadvantages

Both PVD gold coating and electroplating have advantages and disadvantages, related precisely to the technology by which they are produced:

Galvanic Gilding

  • Has high productivity, because it allows a large quantity of parts to be immersed at a time in galvanic tanks, because it is an in-line plant
  • Allows thicker coatings to be created in less time than other deposition methods
  • The cost of galvanic tanks is generally lower than other types of equipment

BUT

  • The deposited layer is susceptible to scratches and external stresses.
  • Precious metals must be used to recreate certain colorations, making processing cycles more expensive.
  • It is necessary to have a plan for disposing of waste generated by the deposition cycles in the tank.

PVD Gold

  • Resistant to scratches, fading or color changes, corrosion and is durable.
  • It is capable of recreating the appearance of precious metals, using other types of materials, to lower fixed costs related to the production process.
  • Better adhesion than other deposition methodologies.
  • Stable process, easily repeatable and controllable.

BUT

  • PVD always requires pretreatment to achieve its strength properties.
  • Managing high vacuum requires care in facility cleaning procedures.

In Conclusion

In general, the choice between electroplated gold plating and gold PVD depends on the specific needs of the application, spending possibilities, and aesthetic preferences.

PVD gold turns out to be a much more cost-effective process on the economic front, precisely because it allows the use of metallic materials that replicate the color of gold, allowing the same elegant and refined result to be achieved. The PVD technique also allows pure gold to be deposited, but leaves the choice of which type of metal or compound to use for the coating.

Electroplating is a process that performs well on the production side, but as far as coloration is concerned, it is an outdated technology that heavily impacts on fixed costs.

Both techniques have advantages and disadvantages, and can be used successfully in different situations, but in order to decide which solution to choose, you should first consult a professional in the field.