The quality requirements in the industrial, medical and automotive sectors are constantly increasing. Components are manufactured more precisely and the requirements and specifications are more closely tolerated. As a result, the electroplating industry also faces the great challenge of constantly improving its results and service.

selective hard anodizing in Faulquemont

For years, the Aalberts surface technologies team at the Faulquemont plant in France has been developing and optimizing the “sustainable high speed plating” process of selective hard anodizing of aluminum. They have decided to go completely new ways. First and foremost, the traditional process of galvanic bath coating was completely ignored and a new type of circulation system in the fully automatic coating plant was chosen.

The aluminum components are inserted into tool nests developed for this purpose and switched as the anode. An electrolyte optimized for this process is then used to wash the component at high speed and with high current density. Special seals press themselves against the component and define the area to be coated. This allows the electrolyte to be applied specifically to the areas where the functional coating is required. The electrolyte consumption is reduced to a minimum and is extremely economical. In addition, a costly “cover” of the components or mechanical reworking is not necessary and is therefore completely eliminated. Even complex geometries that require coating an internal area can be implemented with the SELGA-COAT® process.

advantages of the SELGA-COAT® process

A further focus is the process safety which is guaranteed by the following points. Each coating line has its own components such as control unit, rectifier and feed pump. Should a necessary component of the system fail, the other lines will still be able to function. Repairs can be carried out without affecting the ongoing production and the ability to deliver is still guaranteed. In addition, an automatic recognition of the tool tables is used. If these modular units are changed, the software detects this and uploads the necessary parameters. A faulty coating due to incorrect adjustment is avoided and the application of the system is made easier. At the same time, the coating process for each component is logged in the system and can be read out if required.

Sustainability is another important component of what the SELGA-COAT® process stands for. On the one hand, the use of chemicals is reduced to a minimum and used efficiently due to the precise coating. This enables us to use a small electrolyte tank with a capacity of only 250 liters. In order to prevent the carry-over of galvanic substances, several closed circuits are used. Firstly, the electrolyte circulates between the tank and the tool. But also the exhaust air and the rinsing water are continuously cleaned by a filter system. This prevents direct pollution of the employees and the environment.

implementation of the system at the customer

In order to reduce logistical routes and the associated time and costs, the system is designed to be implemented in the customer’s production process. The compact design and modularity allows an economic advantage for the customer even with average volumes.

Aalberts surface technologies has already put plants into operation in China, the USA, Brazil, Turkey and various EU countries. The plants are tailor-made according to the customer’s specifications. The installation is then carried out by our qualified personnel at the customer’s site, thus guaranteeing a smooth start of production.

We offer additional services for this process. These include electrolyte supply via riag Oberflächentechnik AG, a spare parts service and the option of concluding a maintenance contract.

future-oriented procedure

The technical properties of the surface also show a higher quality. Due to the fast layer build-up of approx. 12 µm in less than 1 minute, the surface obtains a homogeneous structure and, compared to traditional coating, allows a lower roughness of the surface. This also has an effect on the general performance characteristics of the produced hard anodizing. The treated components show an optimized corrosion protection, better electrical insulation values and higher hardness. At the same time, the tolerances of the coating thickness can be more closely defined.

Originally, this process was used for the refinement of engine pistons. Continuous further development and optimization has now established SELGA-COAT® for various components such as valve housings, heat exchangers, transmission components, valve units, steering systems and hydraulic units. The increasing demand in the field of e-mobility has led to additional applications such as DC-DC housings and busbars/contact plates.

Based on the fact that the requirements to reduce costs and to manufacture in a more environmentally friendly way are becoming more and more important in our industry, we at Aalberts surface technologies with the fully automated SELGA-COAT® process are already today trend-setting and sustainable.

any questions?

business development manager

Marcus Saul
business development manager