The modern watch industry offers a wide range of products on the market, which can sometimes be quite difficult to understand. In the manufacture of Swiss watches, PVD coating is very often used. What is this, not everyone knows. But the above spraying plays a crucial role in protecting the product from moisture and not only.
In addition, there are other methods to increase the wear resistance of watches and their other characteristics. This, for example, gilding, plating with nickel and palladium, ion sputtering of steel and others. It is difficult for an inexperienced person to find out for himself which method is better and how the above methods differ from each other. Let's try to figure it out.
PVD coating - what is it?
Recently, watches having the above spraying have been widely used. What is a PVD coating? What it is?
Experts note that in the watch industry, the above type of coating is applied in a vacuum. That is, titanium nitride (superhard) is applied to the body of the product, on top of which a very thin layer of gold is coated.
There is also another designation for such a watch surface protection method as PVD coating. What it is? This is a coating method that is carried out under high pressure in a vacuum by ion bombardment, evaporation-condensation, metallization spraying.
It is thanks to the above chemical processes that such ultrafine spraying is obtained without any impurities.
Application of vacuum spraying
This type of spraying is used to create on the surface of tools, parts, coating equipment with functional overtones. For example, the production of frames with gold-plated glasses or watches with a PVD coating. This spraying has the following properties: corrosion-resistant, wear-resistant, conductive, erosion-resistant, insulating, barrier, antifriction.
The sputtering materials are metals such as titanium, tungsten, aluminum, molybdenum, nickel, iron, copper, chromium, graphite. Also, an active chemical gas is sometimes added to the process mixture. For example, oxygen, nitrogen or acetylene.
Using the above method of vacuum deposition, manufacturers are able to obtain ultrathin coatings with a thickness of 2 angstroms to 2 microns. Experts note that after applying the PVD coating, the surface of the product no longer requires additional processing.
What is the difference between PVD coating and gilding? Protective spraying methods
Both of the above methods of protecting the watch from moisture are widely used in industry. Experts say that the main difference between this coating and the usual gilding is precisely the thickness of the gold on the bracelet and watch case.
It should be noted that there is steel with a PVD coating - partial or full, yellow or white. Thanks to this coating, the watch case has excellent water-repellent properties and high wear resistance. The thickness of this spraying is in the range from 3 μm to 20 μm.
Experts say that gilding erases over time. According to the average statistics, the thickness of gold on the watch case decreases by about 1 micron per year.
There are also other methods of applying protective coatings:
- plating with palladium (a small admixture of nickel is used), which gives the product a bright white color;
- plating with palladium and nickel (differs from the previous method in that a larger percentage of nickel is used here);
- ion spraying of steel (watch case is white, but dull);
- ion sputtering of gold (gives the product all kinds of shades of yellow).
Among the methods of thermal spraying, the following are distinguished:
- laser beam evaporation;
- electron beam evaporation;
- vacuum arc evaporation;
- magnetron sputtering;
- implantation of ions.
Factors affecting coating durability
The durability of the coating significantly depends on:
- Clothing made from genuine leather. It reduces the service life of the coating by about half.
- The acidity of the sweat of the person who owns the watch. The housing can start to “corrode” on the sides and from the side of the back cover.
- The thickness of the coating itself.
- Compliance with stringent application technology.
- The metal to be coated (does it cause adhesion).
- Product operating conditions.
Key Features of PVD Coating
The above coating has the following features:
- ultra-thin (thickness from 1 to 3 microns);
- It is made without the presence of any impurities in the composition;
- has a high degree of resistance;
- strong enough;
- protects the product from scratches.
Watch PVD coating is one of the best ways to protect it. Thanks to this vacuum deposition, the operational characteristics of the products are increased.