189. fabrication of high entropy ceramics: nitrides and carbonitrides
Name: Olivia Faye Dippo
Grad Year: 2020
In high-entropy alloys, the use of multiple principle alloying elements is known to entropically stabilize the material. Refractory nitrides and carbides of transition metals are widely known for their ultra high-temperature stability and their high hardness, properties which make them valuable materials for extreme environments such as coating the exterior of hypersonic flight vehicles as well as the interior of nuclear reactors. By creating entropy-stabilized solid solutions of nitrides and carbides, one can take advantage of the inherent favorable properties of these materials as well as increased thermal stability and solid solution strengthening. Bulk multicomponent refractory nitrides and carbonitrides were fabricated to demonstrate this concept, by using a combination of high-energy ball milling, spark plasma sintering, and hot pressing. The uniformity of the microstructures is characterized, and single-phase solid solutions are achieved, thus demonstrating the ability to entropically stabilize five-component random mixtures of refractory metal ceramics.
Industry Application Area(s)
Aerospace, Defense, Security | Materials