Surface Technology

Wet chemical surface treatment for better bonds and coatings

Wet chemical pre-treatment, often referred to as galvanization or galvanic technology, still occupies a key position in the field of surface pre-treatment in many industrial sectors, such as the aerospace industry, medical technology, or the automotive industry. Fraunhofer IFAM provides support in this field by developing and optimizing various processes and products for wet-chemical surface treatment for metals.


Wet chemistry brings along decisive advantages for pre-treatment of metals

Wet chemical pre-treatment can be used for various purposes. These include, among others:

  • Cleaning (removal of contaminants - also from previous process steps)
  • Etching and pickling (removal of non-defined layers, customization of the surface roughness and gloss level)
  • Protection and activation (conversion coatings, anodizing, plasma electrolytic oxidation [PEO])

In addition, wet chemistry has a decisive advantage over mechanical or physical methods in the pre-treatment of metals such as aluminum, magnesium, nickel or titanium, which can be relevant for specific processes. Wet chemistry can also be used to pre-treat or modify areas that cannot be reached using methods such as laser or plasma technology (e.g. internal cavities or complex or difficult-to-access structures). This also plays an important role for the 3D printing of metals.


Customized galvanic solutions for successful surface pre-treatment

In addition to pre-treatment before bonding and painting, wet chemical pre-treatment processes can be used to create different functional coatings, for example for biocompatibility, corrosion protection, wear protection or electrical insulation. Our experts develop customized solutions, taking into account our own market and literature research on the state of the art as well as the selection and optimization of suitable pre-treatment and coating processes.

We also optimize existing processes for galvanic surface treatment and deposition processes for functional coatings, e.g. for corrosion protection or adhesion promotion. Among other things, we also take into account possible strategies for cost reduction and time saving and can provide the best possible support through extensive in-process analytics.


REACh regulation and HSE guidelines: "Green" chemistry instead of chemicals that are harmful to health and environment

Many companies in the aerospace and automotive industries, as well as in the medical technology sector, will have to make significant changes in the coming years, as the use of various chemicals is no longer permitted or only permitted to a limited extent. Fraunhofer IFAM is already familiar with the needs of these industries from various bilateral partnerships and can therefore also include the sustainability aspect in the development of processes and products.

In doing so, we take into account the use of substances that are less hazardous to the environment and health and comply with EU-wide REACh and general HSE principles. Since the fundamental harmonization of chemicals legislation in 2007 (Regulation (EC) No. 1907/2006 REACh), which affects all EU member states, various industrial sectors and companies have been confronted with the principle of personal responsibility for substance registration. For example, the use of chromates or Cr(VI) compounds, isocyanates in coating systems and fluoride-containing compounds must be replaced or severely restricted in the near future. This represents a major challenge for the majority of the industries concerned, as an equivalent replacement of these substances is not readily possible.


Disinfecting corrosion protection coatings? We can also think out of the box

Through their strongly networked activities in the field of surface technology, our scientists are also practiced in developing alternative ideas and strategies, for example the use of corrosion or wear protection coatings as disinfecting surfaces or the application of coatings for wear protection in medical technology. In recently completed projects, Fraunhofer IFAM has successfully demonstrated the transferability of established wet chemical pre-treatment processes from the automotive industry to structurally highly stressed adhesive applications in the aerospace industry.