When one speaks of black chromium plating, often we imagine it combined with a lacquer and therefore inevitably of random accuracy. And yet when this operation is made properly, it provides important benefits both in terms of protection, hardness and aesthetics. Parts are finished once chromium plated and require no lacquer or any other further processing. Meeting in Corgémont with Christian Jungen, director of Bicrom SA, a company that places high chromium plating at the rank of irreplaceable treatment.
Mr. Jungen explaining the functioning of the baths
The company mainly carries out two operations, white chromium plating using the barrel process or on supports and black chromium plating where each part is placed on a dedicated support. To answer our question of the why of this distinction, Mr. Jungen says: “The different types of chromium plating require different chemical components and electrolytic reactions. This is the reason why it is not possible to plate with black chromium in bulk”.
Let’s see black chromium plating
Black chromium layer between 1.5 and 5 µ
The advantage of black chromium plating is the regularity of the layer. On specific parts, to master the thickness of the layer is paramount. M Jungen says: “When we realise a black chromium plating of a watch platinum for example, it is very important that the total thickness of the coating (including chromium plating and the pretreatments) is totally mastered”. The true functions of the assemblies rely on it. At the Visual level, a chromium plating operation strengthens the surface finishes such as beadwork, guillochage or Côte of Geneva.
The passion of the bath
Depending on the situation, the treatments in baths can range from a few minutes to several hours, some parts may require dozens of bath and nothing is left to chance. “Our customers generally have a problem and we’re here to solve it. It may be a difficulty due to corrosion, adhesion, aesthetics, thickness, capacity, reflection of light, hardness or other” adds Mr. Jungen.
Deemed to go further
This passion for chromium plating also passes through the development of specific holding systems allowing a perfect treatment on the part. Knowing that it must be supported, one may wonder how Bicrom does to ensure harmonious and regular treatment over the whole surface of the parts. Last example: black chromium plating of a hollow stainless steel sphere of 3 mm in diameter which presents a perfect black chromium treatment on its whole surface. Questioned on his tips for success such a tour de force, the director indeed don’t give his secrets because it is its know how that makes its strength.
Are you looking for a solution to a problem of surface finish? Bicrom offers second to none black chromium plating, white chromium plating or Crominox plating solutions.
To be completed in Eurotec…