What Is Alocrom?
Alocrom, sometimes referred to as Alodine is a Chromate Conversion Coating that offers increased corrosion protection for Aluminium Components. Silchrome offer Alocrom 1000 which produces a coating which is clear in appearance with a low electrical resistance which is often used as a base layer for paint and powder applications. We also offer Alocrom 1200 which is yellowish in colour and offers enhanced corrosion resistance in comparison with Alocrom 1000.
In order to meet environmental standards, processes which produce Hexavalent Chromium are coming under heavier restrictions. Alocrom is one such process. At the moment Silchrome still offer Alocorom but in the future you may wish to instead consider using Iridite NCP or other Trivalent Passivate systems.
What Is The Process?
Alocrom is a conversion coating for Aluminium Alloy Coatings. This means that where electro-plating forms on top of the base material, during the Alocrom process the naturally occurring oxide layer on the Aluminium component is expanded both above and below the surface. In order to obtain the best possible results, parts will first be subject to a number of pre-treatments depending on their material which are all carried out in house.
What Are The Advantages?
Alocrom is a versatile coating that provides enhanced corrosion resistance for Aluminium components, it’s able to combat damage that may occur through oxidisation, contact with water and weather as well chemical corrosion. Alocorom offers a small amount of wear protection but would not be suitable for use on components subject to higher levels of abrasion. Due to its Hexavalent Chromium content, Alocrom has a level of self-healing which allows it to effectively deal with minor amounts of damage such as small scratches.
Although Alocrom can be used as a standalone process, it is most often used to form a foundation for paint and powder coating due to its excellent adhesion characteristics. This in turn will give the top coating an improved flexibility.
Alocrom has extremely low electrical resistance and as such is often used in connection with electrical components. The contact electrical resistance is less than 5000 micro-ohms per square inch measured under an applied electrode pressure of 200 pounds per sq inch. (MIL-C-5541 method)
Alocrom 1200 is a yellow coloured finish containing Hexavalent Chrome and is approved to DEF STAN 03-18 and DTD 900/4413A in the UK and under the trade name Alodine 1200 is approved to US MIL SPEC MIL-C-5541 and all major aircraft manufacturers.
Alocrom 1000 is a clear finish containing Hexavalent Chrome is approved to MIL-C-5514/QPL-81706 and is generally used when corrosion resistance with high electrical conductivity is required or if the component is to be subsequently lacquered.
What We Offer
Alocrom 1000, Alocrom 1200 with a process capability window is 650 x 500 x 605 mm
All of our processes are carried in house at our production facility in Leeds and Silchrome Plating are IS0 9001 AND ISO 14001 approved.