Laser- and Plasma-Assisted Vacuum Deposition Process
Layered coatings can improve or lend new properties to products and components. In order to produce layers, numerous different methods are currently available. The laser- and plasma-assisted coating methods used by the research group Functional Surfaces are made possible by specific physical and chemical processes, which occur during the interaction of a solid surface with laser beams or plasmas (ionized gas that consists of neutral gas atoms, ions and mobile electrons). The layers created range in thickness from a few nanometers to a few micrometers and can be applied to metallic, ceramic and polymeric base materials and composites. One of our core areas of expertise is in low-temperature coatings that can enable the production of the coatings at nearly room temperature.
Our offers include the development, characterization and production of functional layers and range from problem analyses, literature research and feasibility studies on to prototype creation and small series coating production. In the context of technology transfer projects, we support our partners in the placement and establishment of coating processes in-house.
Coating Processes and Plant Engineering
Using plasma-assisted chemical vapor deposition (PACVD), thin layers can be deposited directly from the plasma. A mechanism for coating the inner surface of tubing makes it possible to apply layers of polymer to inner surfaces of hoses and pipes. In a combined plasma system, planar substrates and three-dimensional components can be treated on the surface by: plasma etching, activation, coating and fluoridation.
Through the use of cathode sputtering, one of the PVD (Physical Vapor Deposition) methods, argon ions of plasma are used to atomize the coating material. The vapor thus generated is deposited as a coating on the substrate.
The process of Pulsed Laser Deposition (PLD) uses a pulsed laser to vaporize the coating material, which results in the deposition of a coating from the highly ionized plasma. The advantages of this method, which can be combined with conventional PVD processes, lie in its low process temperatures, which allow the coating of plastic parts, and in the large number of possible coating materials.
In addition to coating systems for laboratories that stand in the forefront of development at the Institute, demonstration coating exhibits are available that allow the surface treatment of components with up to 500 mm in diameter and 400 mm layer thickness. In the future, plasma coatings in a roll-to-roll process on polymer films should be available.
Coating Materials, Substrates and Applications
The functional coatings, which are only a few nanometers to a few micrometers thick and can be applied to metals, ceramics, plastics and composites, are desirable for their biocompatible, antibacterial, anti-adhesive (non-stick), adhesive, sensory, catalytic, tribological, wear-resistant, decorative, optical, electronic, electrical, anti-corrosive, gas-permeable or impermeable, or dielectric characteristics according to the different applications in which they are used.
The following coating materials can be produced:
- Metal coatings (Ti, Zr, Cr, Cu, Ag, Au, Mo, Wo, Pt, Al, Ni, Nb, Ta, Mg, alloys)
- Hard coatings
- Nitride layers (TiN, TiAlN, CrN, ZrN, AlN, silicon nitride)
- Carbide layers (TiC, CrC, ZrC, WC, SiC)
- Oxide layers aluminium oxide, chromium oxide, titanium oxide, zirconium oxide, molybdenum oxide, silicon oxide)
- Carbon layers (diamond-like carbon (DLC))
- Ultra-thin layers of carbon (graphene layers)
In terms of layering and structuring, the following coatings (layer architectures) can be produced:
- Monolayers (ultra-thin layers, nanolayers, thin films)
- Multi-layer coatings
- Gradient layers
- Multi-component layers
- Amorphous layers
- Crystalline and nanocristalline layers