VOL. 8 September ISSUE YEAR 2007


in Vol. 8 - September Issue - Year 2007
SURFACTS Presents Innovative Surface Technology Processes

Chromate-free corrosion protection and much more

Karlsruhe – As a showcase for innovative surface treatment processes, SURFACTS provides an overview of the latest developments in surface treatment. One particular focus is on processes for substituting corrosion protection and finishing systems containing chrome (VI) and heavy metals. The 4th International Trade Fair for Surface Technology will be held from 9 to 11 October 2007 in Karlsruhe. SURFACTS will also be integrated in INTERPART, the international supplier trade fair for the automotive, mechanical and plant construction industries. This will generate added value for both events, since many topics will interest exhibitors and visitors of both trade fairs.

As a cross-application technology, surface technology is playing an increasingly important role in almost all industrial sectors. A major factor here is corrosion protection, which will be occupying a prime position at this year's SURFACTS from 9 to 11 October in Karlsruhe. This is currently a hot topic in light of the new EU end-of-life vehicle legislation, which is set to come into effect on 1 July 2007 and bans the use of coatings containing chromate (VI) for automotive parts.

Chromate (VI)-free corrosion protection

The exhibitors at the international specialist trade fair for surface technology are to present new and modified solutions for the corrosion protection of the future. These are based on chromate (III) compounds or offered as fully chromate-free systems and include an inorganic zinc flake coating based on zinc and aluminium flakes. Free from chromate and heavy metals, this coating offers high cathodic corrosion protection without the risk of hydrogen embrittlement. This coating can be applied to the part multiple times, depending on corrosion protection requirements. The primary areas of application are connection elements and high-strength parts for the automotive and construction industries. The galvanic separation of highly corrosion resistant zinc-iron coatings combines functional corrosion protection with attractive surface design. This procedure can even be safely applied to materials which are difficult to coat, such as cast iron. Typical areas of use for zinc-iron coated components include the automotive and electrical industries, toolbuilding, mechanical engineering and sheet-metal forming. Galvanically separated zinc-nickel alloys are mainly used for components in environments which require an extremely high level of corrosion resistance at very high temperatures, such as engine compartments or the area surrounding brakes. Corrosion protection can be optimised through use organic or silica-based sealing, so-called top coats. Multifunctional layers, which set themselves apart through extremely high corrosion protection and an unusually stable wear protection at ultra-low friction coefficients, can also be created with new chromate-free coating procedures. Chemical nickel platings are distinguished by high corrosion and wear resistance, excellent strength, magnetic properties and good dimensional accuracy. In addition to the provisions of the EU end-of-life vehicles directive, they also fulfil the requirements of the German foodstuff commodities and drinking water ordinance (Lebensmittelbedarfsgegenstände- und Trinkwasserverordnung). Almost all metals and plastics used can be coated.

Surface finishing of light metals

The exhibitors at SURFACTS also offer different finishing systems for light metals such as aluminium and magnesium. These include passivations on the basis of chromate III compounds for aluminium. During this process, oxide hydrates of aluminium and chromate are generated on the surface. This coating temporarily protects the surface against oxidation and also forms a good base for varnishes and adhesives. There are also chromate-free systems available for treating aluminium and magnesium. These develop preservation layers on the surface of the material which provide good temporary corrosion protection. The layers are electroconductive and often serve as an intermediate layer for a varnish or adhesive. Anodisation and hard anodisation are further processes for finishing aluminium surfaces which will be presented at SURFACTS.

Chemical deburring and polishing

Companies are today faced with increasingly complex component geometries and the growing miniaturisation of workpieces, as well as their mechanical post-production work such as deburring and smoothing of surfaces or cleaning of laser cutting edges. SURFACTS also offers efficient solutions for these tasks. One such process is electropolishing. This procedure is, in effect, a reversal of the electroplating process. Under the influence of direct current, metal is removed from the surface of the workpiece in a special electrolyte. After the treatment, the surface is metallically pure, smooth, de-energised and free of cracks, even inside boreholes, apertures and undercuts. Even drilling and grinding burrs directed inwards are removed. These wet chemical procedures also offer advantages with dynamically loaded components, as they are able to remove defects from the surface, thereby increasing the service life of the components. New electropolishing procedures now also enable processing of aluminium die casting and "exotic" metals such as titanium, magnesium, cobalt, tantalum, tungsten, molybdenum and various others.

Added value through integration into the INTERPART supplier trade fair

This year, SURFACTS will be integrated into the INTERPART international supplier trade fair for the first time. This combination offers considerable added value over pure supplier or surface technology trade fairs, as the two events will offer information on supplier products and surface technology services from a single source at one time. In turn, this will increase the number of potential visitors and buyers for exhibitors at SURFACTS.
And alongside INTERPART and SURFACTS, the Karlsruhe Exhibition Centre is also hosting the WTT Expo, the 2nd international specialist trade fair for industrial heat exchanger and heat transfer technology - an industry sector with its own surface treatment requirements. For further information, visit www.surfacts.de.