Institute of Materials Research
Topic
Development of novel entropy-stabilized ultra-high temperature ceramics with superior strength and plasticity
PhD. program
Advanced Materials
Year of admission
2024
Name of the supervisor
MSc. Tamás Csanádi, PhD.
Contact:
Receiving school
Prírodovedecká fakulta UPJŠ
Annotation
The topic of the dissertation work is very timely and challenging in materials science and is about the development of damage-tolerant and strong heat-resistant ceramics for hypersonic and space applications.
These materials are the so-called ultra-high temperature ceramics (UHTCs), as the only group of materials that can withstand temperatures exceeding 2000°C in oxidizing atmospheres, and are used for example in thermal protecting layers of spacecraft. Since only about a dozen UHTCs exist (e.g. HfC, ZrB2) and those are brittle at low temperatures (room temperature), the dissertation work focuses on the development of novel materials in the form of entropy-stabilized UHTCs, consisting of at least four different transition metals in the crystal lattice, with improved plasticity/deformability and strength. The topic includes material design, synthesis, structural characterization (e.g. XRD, SEM, EBSD) and mechanical testing from nano to macro scale, all of which the doctoral student gets familiarised with. However, the main task will be micro/nanomechanical testing (e.g. nanoindentation, micropillar compression) of grains and grain boundaries using a state-of-the-art nanoindenter device. The knowledge gathered from the deformation behaviour of grains will be used to design new entropy-stabilized compositions with superior strength and plasticity, accomplishing original and high-impact results.
These materials are the so-called ultra-high temperature ceramics (UHTCs), as the only group of materials that can withstand temperatures exceeding 2000°C in oxidizing atmospheres, and are used for example in thermal protecting layers of spacecraft. Since only about a dozen UHTCs exist (e.g. HfC, ZrB2) and those are brittle at low temperatures (room temperature), the dissertation work focuses on the development of novel materials in the form of entropy-stabilized UHTCs, consisting of at least four different transition metals in the crystal lattice, with improved plasticity/deformability and strength. The topic includes material design, synthesis, structural characterization (e.g. XRD, SEM, EBSD) and mechanical testing from nano to macro scale, all of which the doctoral student gets familiarised with. However, the main task will be micro/nanomechanical testing (e.g. nanoindentation, micropillar compression) of grains and grain boundaries using a state-of-the-art nanoindenter device. The knowledge gathered from the deformation behaviour of grains will be used to design new entropy-stabilized compositions with superior strength and plasticity, accomplishing original and high-impact results.