Special issue “MatCom‐ComMat: Materials Compounds from Composite Materials for Applications in Extreme Conditions”

This special issue comprises a total number of 14 manuscripts generated during the first period of the DFG funded research training group (RTG) 2561 MatCom-ComMat. The RTG is composed of research groups from the three institutions Dechema Research Institute Frankfurt, Technical University of Darmstadt and Karlsruhe Institute of Technology. Its main scope relates to the development, characterization and modelling of novel, revolutionary multi-phase composite systems capable of withstanding temperatures substantially beyond those of currently used Nickel-based superalloys. These alloys are designed for harsh environmental conditions (e.g., oxidative, corrosive, erosive atmospheres) and mechanical behaviour, to maximize their resistance and durability in operating temperatures of 1300°C and above. This will be achieved via a materials combination consisting of metallic/intermetallic alloys based on refractory metal silicide systems as substrates and polymer-derived ceramic nanocomposites based on Si(M)CY (M = B, Zr, Hf and Y = O, N) as materials of choice for graded coatings. The metallic/intermetallic alloys shall provide adequate deformability and toughness at ambient temperatures combined with excellent high-temperature microstructural stability and creep resistance. The graded polymer derived ceramic nanocomposite coatings will offer self-healing capability in addition to extremely low intrinsic thermal conductivities and excellent stability in aggressive operation conditions. Beside their unique property combinations, the two materials classes are highly attractive because of the possibility to adjust their coefficients of thermal expansion to perfectly match one another and consequently to keep thermomechanical stresses in the multi-layered systems at a minimum. This may give rise to an extended lifetime of components. After the start of the RTG in the spring of 2020, this special issue gives a representative overview over the current status of findings within this field of research. Many more articles have been produced during the first funding period, they can be found together with other information related to the research training group on our webpage https://www.iam.kit.edu/wk/grk2561.php. On May 8th 2024, the DFG senate committee recommended continuation of this RTG for the second funding period from October 2024 till March 2029, which we gratefully acknowledge. Martin Heilmaier, Karlsruhe