Many branches of industry require highly wear-resistant coatings to protect and/or functionalize tools and components, for example. While classic hard coatings (e.g., titanium nitride) are already widely used in industry, the novel ta-C coatings are currently well on their way to becoming widely used due to their outstanding properties.
The ta-C coatings produced at the Laserinstitut Hochschule Mittweida are special types of diamond-like carbon (DLC) coatings, which are currently unmatched in terms of hardness. The coatings are produced here using pulsed laser deposition (PLD) and are nearly stress-free thanks to a patented process. With optimal deposition parameters, hardnesses of up to 70 GPa can be achieved with elastic moduli of 700 to 800 GPa, making the coatings extremely wear-resistant. Due to the low average surface roughness (Ra) of a few nanometers and the low coefficient of friction (max. 0.1), these coatings are also ideal for tribological applications. Using adhesion-promoting sublayers, it is possible to achieve high adhesion strengths on a wide variety of substrate materials. The low temperatures during layer production (< 90 °C) make it possible to coat not only different metals and alloys, but also temperature-sensitive materials (plastics, glass, etc.). In addition to their use for wear protection, ta-C coatings offer a wide range of other possible applications due to their chemical resistance, biocompatibility, and dopability, e.g., in medical technology, the food industry, or sensor technology. Pulsed laser deposition can be used to produce homogeneous layer thicknesses ranging from a few nanometers to several tens of micrometers, with the resulting layer hardness being almost freely selectable.