MatCom-ComMat: Materials Compounds from Composite Materials for Applications in Extreme Conditions
The main scope of the RTG relates to the development, characterization and modelling of novel, revolutionary multi-phase composite systems capable of withstanding temperatures substantially beyond 1300°C and harsh environmental conditions (e.g., oxidative, corrosive, erosive atmospheres) as far as mechanical behaviour, environmental resistance and durability are concerned. This will be achieved via a materials combination consisting of metallic/intermetallic alloys based on refractory metal silicide systems (e.g. Mo-Si-B-X, X = Nb, Fe, Ti, Hf…) 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 may provide adequate deformability and toughness at ambient temperatures combined with excellent high-temperature microstructural stability and creep resistance, whereas the graded polymer derived ceramic nanocomposite coatings will also offer self-healing capability in addition to extremely low intrinsic thermal conductivities and excellent stability in aggressive operation conditions, respectively. 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 target multi-layered systems at a minimum. This may give rise to an extended lifetime of components in foreseen application.