> Development of functional coatings in the areas:
> Characterisation of coatings and surfaces using various methods
Ths surface of a material is exposed to particular stresses. Apart from its improvement and adaptation, surface technologies can also provide various functional properties.
Not only deposition and coating techniques are considered but also any kind of physical or chemical modification technique. Thus optimization of the surface can also support the energy transition by conserving energy and resources. Additionally, modern coatings can increase the energy efficiency. This also facilitates increasing the competitive capacity of products and processes.
At DFI we employ various technologies for surface modification and treatment. Our range of products includes solutions starting with the development of coatings at the laboratory scale and leading up to consulting for industrial application of the process and/or the product at the customer's location.
With physical vapour deposition in the gas phase (PVD) we have a coating technology available which can provide additional properties to materials with a thickness of only few micrometers or nanometers. These PVD processes are clean and sustainable. The sputtering of various metals (with or without the presence of reactive gases) can add functional or decorative properties to materials. At DFI we develop coatings and processes for various applications such as tribology or photocatalysis.
The sol-gel technique is applied at DFI as a versatile synthesis method for the production of ceramic and glass materials. We use this technique for the synthesis of nanoparticles, for inorganic encapsulation of materials, and for the development of multi-functional surfaces. The resulting products of this process are ceramic materials based on inorganic oxides. Application via spray or dip coating processes facilitates targeted surface treatment and functionalisation (e.g. self-cleaning properties, i.e. super-hydrophobic or super-hydrophilic, anti-bacterial, photocatalytic layers).
The plasma-electrolytic oxidation procedure can, for example, increase the energy efficiency and the lifetime of a product. This electrochemical process creates plasma discharges at the component-electrolyte interface. The substrate surface is transformed into a hard and dense ceramic oxide layer. Especially for the treatment of Al, Mg, and Ti alloys the plasma-electrolytic oxidation represents an innovative part of surface technology. The procedure facilitates generating functional layers with improved corrosion resistance, lubrication and wear properties, bioactivity or photocatalytic properties.
Slurry and pack cementation is used for developing protective diffusion coatings for metallic materials which show excellent corrosion resistance even at high temperatures. In order to protect the base material at high temperatures, the material surface is modified and enriched with selected elements, for example aluminium. The development of functional protective high temperature coatings is relevant for the energy transition: Innovative thermal barrier coating concepts or coatings for solar thermal collectors increase the performance of electricity generation plants. Here we develop selective coatings on steel tubes with high absorption and low emission properties.