What you should know about PVD Coating

What is PVD Coating?

Hardcoating services

Physical Vapor Deposition, or PVD coating, is a process of protectively coating materials, particularly metal, with a thin, but durable and uniform, layer of a very pure metal. Metals most often used as the coating layer are titanium, zirconium, chromium, aluminum, or gold. High levels of heat between 150 and 500 °C are used to evaporate the coating metals in an enclosed vacuum while rotating the piece at different angles to be coated. Rotation ensures uniformity of the layer applied, which increases the durability.

This method, called evaporative deposition, is the most common method of PVD coating, although there are several other methods that exist. Other methods of PVD coating involve pulsed lasers, electrons bombarding the metal vapor to be deposited, plasma discharge powered by magnets, and electric arcs.

Preparation of the pieces to be coated include cleaning, removal of burrs and corrosion, and then heat treated at least 50 degrees higher than the coating process will use. Oils that leave a protective film should be avoided as they will prevent complete adhesion of the coating metal to the base metal from taking place. Only a water-soluble oil should be lightly used to provide protection against corrosion and rust. Cleaners that may leave residue should also be avoided for the same reason.

What are the Uses of PVD Coating

Metal parts that require constant use are good choices for PVD coating. These parts might include car and other motor parts, pistols and other firearms, knives, surgical tools, dental instruments, drill bits and saw blades, watch pieces, and other items that receive high levels of wear and tear during normal use. The PVD coating protects the base metal, allowing for sterilization to take place in the case of medical and dental implements, as well as for chemical cleaning to be less wearing to other pieces, as in the case of firearms and knives.

PVD coating dramatically decreases the wearing down of parts caused by friction, causing parts to last longer before needing to be replaced. In the case of auto parts, this can greatly increase the safety of the overall vehicle.

Is PVD Coating Similar to Electroplating?

PVD coating is similar in its effect as a coating, but the processed used are not the same as the process used for electroplating. Electroplating is less expensive than PVD coating, and does not wear as well, but with electroplating, one can be more confident that the plating is actually gold and not a gold colored mixture of non-gold metals. This can happen with PVD coating. A letter of authenticity should accompany jewelry and watches that have PVD coating detailing the quality of gold used in the coating.