What's on your wristwatch: The rise of PVD coating

For the most part of its long history, the clock has been an essential tool in not only telling time, but also in navigation. Due to war and improved globalization and commerce, the wristwatch gradually became important as a tool.

In more recent history, with the turn of better technology and improved design, the wristwatch has turned itself into more than just a tool. It has turned itself into a symbol and as a window into the persona of an individual. While the digital watch, and to an extent, the smartphone has become the go-to tool to which people use to tell time, there are people at the other end of the spectrum who still stay true to the elaborately crafted wristwatch as a symbol of luxury, affluence and timelessness. With that comes the need to preserve such expensive timepieces with technology called PVD.

PVD stands for Physical Vapor Deposition, and is essentially a very thin layer of chemicals coated onto certain parts of the watch that enables it certain benefits (think of armor, or a case for your cellphone). PVD coating is simply a process that is done to make things more durable in varying facets of its physical limitations. While it has already been in existence as early as 1838 when it was first used by Michael Faraday, it has found a wide variety of uses today in a number of products such as aerospace parts, fire arms, cutting tools, and recently, watch parts.

By coating watch parts with PVD coating, people should expect it to be more wear resistant or “harder" (resists scratches), which means that the watch also becomes more impervious to corrosion, and more impact resistant or “tougher” (resists damage from impact with other objects). Coating watches with PVD coating also allows for certain aesthetic improvements to the coated part as for what would normally be just a stainless steel or titanium brushed item can now acquire a certain “finish” (smoothness), and a certain color depending on the chemicals used in the coating. Because the coating process takes place at extremely high temperatures, the produced part also results in high heat resistance, and lasts longer compared to anodized parts or powder coated parts.

The PVD process basically consists of first placing the parts in a vacuum chamber where a negative charge is placed through them. Then, it is necessary to evaporate certain materials to be used as coating such as aluminum, chromium and titanium by heating them up and placing a positive charge through them. At the same time, a reactive gas like nitrogen (or a gas with carbon) is placed in the same vacuum where it chemically reacts with the previously evaporated chemicals to form the PVD coating which sticks to the item to be coated – similar to how magnets with opposing poles (positive and negative) attract each other.

In the future, developers of PVD will have to improve as more elaborate parts for wristwatches are invented. Incremental improvement in coating thickness as well as the development of various chemicals being put in the mixture in order to improve its current characteristics (hardness, toughness, heat resistance) in order to make the watches last longer, look better, and to aid watchmakers in the ever increasing demands of their craft. – Rappler.com

(Wristwatch image courtesy Shutterstock)