As part of a current joint industrial research project (IGF), scientists led by the AiF research association DECHEMA Gesellschaft für Chemische Technik und Biotechnologie e.V. have developed an oxidation and wear protection coating for titanium aluminide alloys and their use at high temperatures in oxidizing atmospheres.
Titanium aluminides (TiAl) are intermetallic compounds of titanium and aluminum. They are particularly important due to their excellent specific strengths at high temperatures. Turbine blades have to withstand temperatures of 400 to 700 °C. As temperatures rise, the wear rates increase considerably. Various coatings were tested in the IGF project. In particular, the so-called MAX phases, which can improve both the oxidation and wear behavior of TiAl as single and multi-layer protective coating systems, have proven themselves. The coated samples exhibited outstanding oxidation resistance at up to 800 °C as well as balanced mechanical properties at room temperature. MAX phases are considered to be the material of the future. It is light, temperature-resistant and hard like ceramics, but can be easily shaped like heated metals. In principle, this approach is also interesting for other alloy systems in high-temperature applications and can be used in lightweight construction.
