Chrome plating, often referred to simply as chrome wheels, is a technique of electroplating a thin layer of chromium onto a metal object. The chromed layer is not only decorative, but can provide ease in cleaning. Most wheels today are cast aluminum wheels. Aluminum is a very active metal and is difficult to plate for electrochemical reasons. Before the chromium is applied the first step of the chrome process is to apply nickel to the surface. The nickel is the material that actually gives the wheel its color. The chromium simply protects the nickel from tarnishing. Because aluminum is so difficult to plate, manufactures only warrant chrome wheels against plating for one to two years. They are not warranted against pitting. Therefore manufacturers have been looking for a better way to get the look of chrome on an aluminum wheel with better results for a long lasting finish. PVD chrome wheels were the answer. Below is a description of the PVD process which some manufacturers like American Racing offer a two year warranty on the finish.
About PVD Coating
Physical Vapor Deposition (PVD) is a process to produce a metal vapor that can be deposited on electrically conductive materials as a thin highly adhered pure metal or alloy coating. The process is carried out in a vacuum chamber at high vacuum (10-6 torr) using a cathodic arc source.
Single or multi-layer coatings can be applied during the same process cycle. Additionally the metal vapor can be reacted with various gases to deposit Oxides, Nitrides, Carbides or Carbonitrides.
PVD Process
The parts to be coated are first cleaned. The cleaning process varies depending on the level of quality from the electroplater, substrate material and geometry. The parts are loaded into the vacuum chamber on custom fixtures designed to optimize the chamber load size and insure coating uniformity.
The vacuum chamber is evacuated to 10-6 torr (high vacuum) to remove any contaminants in the system. The vacuum chamber is backfilled with an inert gas argon and ionized, resulting in a glow discharge (plasma). This is the gas cleaning stage and prepares the parts for the initial metal deposition.
A high current, low voltage arc is initiated on the target (solid material used for deposition). The metal is evaporated and instantaneously ionized. These metal ions are accelerated at high energies into the vacuum through an inert gas or reactive gas and subsequently deposited on the part. The basic properties of the metal being evaporated (target) remain unchanged during the metal deposition cycle. Changing the volume of gas and type of gas during the reactive deposition cycle changes the nature of the coating producing ceramics like carbides, nitrides or oxides. For instance, zirconium nitride (ZrN) is a hard, yellow-gold colored coating with exceptional wear and corrosion resistance. Zirconium nitride has become predominant in the plumbing and door hardware industry as a lifetime brass color. Introducing measured amounts of nitrogen into the chamber during the zirconium deposition cycle produces zirconium nitride.
Chromium nitride is produced in much the same way. Simply by adding an additional gas such as acetylene (C2H2), you can create chromium carbonitride. This is a gray to black color.
The use and properties of the various coatings available from PVD coatings can, in many cases, be tailored to the individual customer application for custom PVD chrome wheels.
About PVD Coating
Physical Vapor Deposition (PVD) is a process to produce a metal vapor that can be deposited on electrically conductive materials as a thin highly adhered pure metal or alloy coating. The process is carried out in a vacuum chamber at high vacuum (10-6 torr) using a cathodic arc source.
Single or multi-layer coatings can be applied during the same process cycle. Additionally the metal vapor can be reacted with various gases to deposit Oxides, Nitrides, Carbides or Carbonitrides.
PVD Process
The parts to be coated are first cleaned. The cleaning process varies depending on the level of quality from the electroplater, substrate material and geometry. The parts are loaded into the vacuum chamber on custom fixtures designed to optimize the chamber load size and insure coating uniformity.
The vacuum chamber is evacuated to 10-6 torr (high vacuum) to remove any contaminants in the system. The vacuum chamber is backfilled with an inert gas argon and ionized, resulting in a glow discharge (plasma). This is the gas cleaning stage and prepares the parts for the initial metal deposition.
A high current, low voltage arc is initiated on the target (solid material used for deposition). The metal is evaporated and instantaneously ionized. These metal ions are accelerated at high energies into the vacuum through an inert gas or reactive gas and subsequently deposited on the part. The basic properties of the metal being evaporated (target) remain unchanged during the metal deposition cycle. Changing the volume of gas and type of gas during the reactive deposition cycle changes the nature of the coating producing ceramics like carbides, nitrides or oxides. For instance, zirconium nitride (ZrN) is a hard, yellow-gold colored coating with exceptional wear and corrosion resistance. Zirconium nitride has become predominant in the plumbing and door hardware industry as a lifetime brass color. Introducing measured amounts of nitrogen into the chamber during the zirconium deposition cycle produces zirconium nitride.
Chromium nitride is produced in much the same way. Simply by adding an additional gas such as acetylene (C2H2), you can create chromium carbonitride. This is a gray to black color.
The use and properties of the various coatings available from PVD coatings can, in many cases, be tailored to the individual customer application for custom PVD chrome wheels.
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