Chromium’s mirror finish will never go out of style. In fact, the opposite seems to be true. As some in the industry predict that “chrome is the new brass,” this is the perfect time for PVD chromium to become the new chrome. Let’s look at the facts:
Traditional chrome plating involves exposing parts to chromium baths that contain chromium trioxide (hex-chrome) and sulfuric acid. Unfortunately, hexavalent chromium and concentrated acids are toxic, and therefore highly regulated to protect worker safety and the environment. These regulations require manufacturers to maintain extensive safety controls, and in many countries require extensive permitting to expand operations.
To avoid environmental impact, improve worker safety, and reduce costs, manufacturers are looking for alternatives. That’s where physical vapor deposition (PVD) coatings come in. The PVD process can provide a simple, reliable coating alternative that is by its nature beautiful, durable, and safe.
PVD can deposit a durable decorative, pure chromium coating. The addition of elements such as nitrogen can also produce even more durable chrome alternatives such as chromium nitride (CrN) that greatly improve performance in high-wear applications.
Chromium PVD coating vs. electroplating
To create the best chrome-alternative process for the industry, we conducted experiments testing our VaporTech® chromium PVD coating against chrome electroplating. A range of coated sample steel plates was evaluated after exposure to the same elemental profiling. These samples differed in chrome application (hexavalent chrome electroplating vs. VaporTech PVD) and their nickel undercoats. Some PVD samples received base layers of pure chromium (Cr), while others received chromium nitride (CrN) at the beginning of the deposition process run. Our findings:
- Color is virtually identical.
- Equivalent hardness to chrome (1,000 Vickers) with options to further improve surface hardness (up to 2,200 Vickers).
- Equivalent or better abrasion resistance.
- Custom coatings can be designed to meet specific hardness, durability, and corrosion resistance specifications.
- 30%+ improvement in wear resistance possible with a harder chromium nitride base layer (see chart).
How does chromium PVD coating work?
People familiar with the plating process may not be familiar with the work necessary to use a PVD coating machine, but it’s not a complicated process:
- Stage your parts for coating.
- Send the parts through a cleaning process to remove any oils or debris.
- Dry the parts to remove any liquid.
- Load the parts onto racks.
- Load the racks into the chamber.
- 6. Select the custom chromium surface coating recipe from the touch screen.
- Close the chamber door and push the “Start” button.
- Receive notification that the finishing process is complete.
- Remove parts, inspect, and send to finished goods or final assembly.
- Open the (chamber) door to other functional, durable, and colorful coatings
With a PVD coating system in place, you’re not only selecting a more environmentally friendly option; you are also adding the capability to deposit a variety of decorative and functional finishes that can be applied to a broad range of parts and products. Vapor Technologies, Inc. manufactures PVD, PE-CVD (plasma enhanced chemical vapor deposition) and DLC (diamond-like carbon) coating systems, and you can use the same machine for multiple coating types.