Sintered metals: Sinter Surface Solutions

It is practically impossible to imagine today’s industry without sintered metals. However, despite the technological advantages they have as construction materials, they have considerable disadvantages when it comes to surface finishing, as sintered metallurgical construction components frequently absorb the liquids used during the finishing process and gradually release them later on. The resulting defect is known as “bleed-out”.
In the case of galvanic plating, such as zinc or zinc alloy processes, this phenomenon frequently results in salts being deposited on the surface of the product. Most alkaline materials attack the metal plating, causing localised corrosion damage. With Sinter Surface Solutions, the Holzapfel Group has developed a process that reliably prevents bleed-out. 
The innovative all-in-one solution comprising impregnation and plating was awarded the “Surface 2012 in Silver” prize by the Fraunhofer Institute for Manufacturing Engineering and Automation (IPA) and the Leipzig Galvanic Prize 2013 by the DGO regional groups of Saxony and Thuringia. Click here to read more about the award-winning process.

Coloured anodisation of your choice: Individual anodisation

A major project from the consumer goods industry presented us with the challenge of providing a wide range of colours for anodised surfaces – in reproducible quality. We succeeded in doing so by enhancing the technique for dyeing anodised layers, in which both the physical characteristics and the chemical properties involved in the process are taken into account.
Individually dyed, anodised surfaces have become standard with the introduction of “Anodised Individual”. Click here for more detailed information on “Individual anodisation”.

Anodisation with customised printing

Our Eloxal Individual Anodisation Surface Solutions (A.SS) make it possible to create individually customised metallic coatings, not only selecting the colour, but the entire visual design as well. Logos, texts, images, consecutive numbers, barcodes, etc. can now be integrated in the anodisation process, accurate in every detail. Lettering, images or logos are captured in the anodised aluminium layer and are thus protected within the material.

Anodisation for hybrid components

Anodised Individual Hybrid is a solution for the coloured anodisation of metal-plastic composites or hybrid components. The anodising process has been specially developed for coating components that have been back-injected with plastic and require highly decorative surface finishes. The anodisation of the previously back-injected components is performed as the final production step and therefore prevents the anodised layer from becoming ruptured by processes such as back-injecting or bonding performed after coating.

Selective anodic oxidation with partial plus anodisation

Partial plus anodisation is a selective anodising process for partial anodic oxidation and anodising with an integrated earthing point. This process creates a conductive earthing point and integrates it in the coating process, i.e. without needing an additional processing step. The process innovation was promoted and implemented in the course of a development project for small and medium-sized enterprises and nominated for the "Surface 2015" award presented by the Fraunhofer Institute for Manufacturing Engineering and Automation (IPA).

FleXXcor – bendable zinc-nickel plating

Pipes and tubes used in the automotive industry or in plant engineering are frequently given a zinc-nickel plating to protect them from corrosion. When it comes to the plating process, handling pipes which have already been bent is both tricky and expensive – for this reason a client of the Holzapfel Group presented us with the challenge of developing a zinc-nickel process that enabled the pipes to be bent after the plating had been applied. The task was to develop a plating capable of withstanding subsequent bending, but still display good corrosion resistance properties at the same time. 
Working in close cooperation with a process supplier and our customer, the Holzapfel Group developed the fleXXcor zinc-nickel process as a solution to this problem. With the bendable, formable corrosion protection on a zinc-nickel basis, pipes and hydraulic lines, crimped components or formed sheet metal parts such as spindle pipes and magnet housings can be bent or formed after the plating process.Click here for details about fleXXcor, the bendable zinc and nickel plating.

Cr-VI-free zinc-nickel layers with transcor

First developed in 2007, transcor technology provides an extremely robust anti-corrosion layer with a transparent Cr-VI-free surface. This process was also developed to meet the requirement of the EU End-of-Life Vehicle Directive for chrome-VI-free coatings to replace the previously used chrome-VI coatings.
The transparent zinc-nickel plating does not require additional sealing. Transcor is also cobalt-free and therefore already complies with increasingly strict environmental requirements going forward.

Ductile, formable CDC

Black surfaces with glossy, smooth optics are in high demand, particularly in the automotive industry. However, at the same time, they need to have the required technical properties. A particularly ductile CDC paint meets all these requirements: The CDC system used by the Holzapfel Group not only provides outstanding optics, but also extremely robust, hard surfaces (pencil hardness 4H+), which are considerably more impact- and scratch-resistant than conventional CDC paints and therefore more durable.
At the same time, the CDC surface has significantly improved anti-corrosion characteristics, especially on edges. Another significant advantage of the CDC system: The paint is extremely ductile and therefore formable. The CDC system ensures ductility of up to 8 mm in accordance with the Erichsen test and thus provides a high degree of deformation for downstream assembly steps. In addition, the coating system meets strict anti-corrosion requirements (e.g. BMW GS90011-LASW3), even with thin layers of 20 μm thickness. Even complex geometries such as cavities can be optimally coated thanks to the improved composition of the paint.

Technical special nickel / nickel sulphamate

With its technical special nickel, also known as pure nickel layer, nickel sulphamate or technical nickel, the Holzapfel Group offers a highly ductile, bendable surface finish. The electrolytically deposited pure nickel layer does not cause any disruptive organic deposits, and is used to protect surfaces from corrosion as well as wear and tear. 
The technical special nickel plating can be distributed in very even layer thicknesses between 10 µm and 1000 µm as a wearing surface. This makes the process developed by the Holzapfel Group an excellent solution for applications such as systems that generate hydrogen and oxygen, as well as for anodes, cathodes and twin-pole electrodes. Technical special nickel plating is also highly suitable for wear parts and the manufacture of injection moulds and die-casting moulds.

Solderable electroless nickel plating

With solderable electroless nickel plating we make it possible to use aluminium for aspects of lightweight design where the weight-saving base material could not be used previously, as it did not possess properties such as solderability.
For this reason, the tin-plated copper previously used to make cooling plates for brake control systems in the automotive sector can now be replaced with aluminium, thanks to solderable electroless nickel plating. Plated with electroless nickel and then soldered, aluminium ensures that the heat is conducted from the processors and that the heat dissipation plate is interconnected with the processor. Using a specially designed rack technology, the components are conveyed straight through the coating system and the soldered joints are aligned in such a way that they are reliably coated during the process.
Under certain conditions, which can be agreed in advance with the customer, we can also offer solderable electroless nickel layers which do not require the peripheral areas of the soldered joints to be subsequently cleaned.

Innovative coating processes developed by the Holzapfel Group

Developing new coating processes for specific applications is not just part of the job, but something we do with great pleasure. The Holzapfel Group welcomes the challenges of its customers and has already developed a great many innovative processes, custom-designed to ideally suit the coated products and their specifications. On the left you will find some examples of specially developed processes and the story of their origins.

Your contact to our innovation team