NSUF 23-4766: Proton Irradiation of High Entropy Carbide Ceramics

The objective of this RTE project is to use proton irradiation experiments at Michigan Ion Beam Laboratory to investigate the irradiation defect clusters and microstructural changes in high entropy carbide ceramics (HECC). The main scientific question is: how proton irradiation-induced defects affect the mechanical behavior and phonon transport in HECC? Unlike conventional monocarbide ceramics such as ZrC, TiC, and SiC, HECCs contain more than four metal elements in equal or non-equal concentrations in its metal sublattice positions, resulting in extreme disorder and composition range. The central hypothesis is that the extreme atomic-level disorder of metal elements may change the vacancy and interstitial migration energies, which may suppress the nucleation, migration, and growth of irradiation defect clusters (e.g., dislocation loops and voids).
The existing research of HECCs was limited to heavy ion irradiation experiments, which can only generate an effective irradiation damage depth of less than 2 µm. The surface damage layer is too thin even for small-scale mechanical tests (e.g., micropillar compression and microhardness tests) and thermal conductivity measurements. In contrast, proton irradiation can produce a uniformly damaged layer with a depth of several tens of µm, which is better for small-scale mechanical and thermal tests of the irradiated HECCs. In addition, the irradiation damage caused by protons is closer to that caused by neutrons than heavy ions.
To address the scientific questions, the proton irradiation effects of high-entropy carbides will be compared with monocarbides and the heavy ion irradiation results in the literature. Specifically, the proton irradiation defect formation and thermal transport in two HECCs will be compared with ZrC and TiC to elucidate the effect of increased disorder.

Additional Info

Field	Value
Abstract	The objective of this RTE project is to use proton irradiation experiments at Michigan Ion Beam Laboratory to investigate the irradiation defect clusters and microstructural changes in high entropy carbide ceramics (HECC). The main scientific question is: how proton irradiation-induced defects affect the mechanical behavior and phonon transport in HECC? Unlike conventional monocarbide ceramics such as ZrC, TiC, and SiC, HECCs contain more than four metal elements in equal or non-equal concentrations in its metal sublattice positions, resulting in extreme disorder and composition range. The central hypothesis is that the extreme atomic-level disorder of metal elements may change the vacancy and interstitial migration energies, which may suppress the nucleation, migration, and growth of irradiation defect clusters (e.g., dislocation loops and voids). The existing research of HECCs was limited to heavy ion irradiation experiments, which can only generate an effective irradiation damage depth of less than 2 µm. The surface damage layer is too thin even for small-scale mechanical tests (e.g., micropillar compression and microhardness tests) and thermal conductivity measurements. In contrast, proton irradiation can produce a uniformly damaged layer with a depth of several tens of µm, which is better for small-scale mechanical and thermal tests of the irradiated HECCs. In addition, the irradiation damage caused by protons is closer to that caused by neutrons than heavy ions. To address the scientific questions, the proton irradiation effects of high-entropy carbides will be compared with monocarbides and the heavy ion irradiation results in the literature. Specifically, the proton irradiation defect formation and thermal transport in two HECCs will be compared with ZrC and TiC to elucidate the effect of increased disorder.
Award Announced Date	2023-09-14T13:38:47.317
Awarded Institution	None
Facility	None
Facility Tech Lead	Alina Zackrone, Kevin Field
Irradiation Facility	Michigan Ion Beam Laboratory
PI	Bai Cui
PI Email	[email protected]
Project Type	RTE
RTE Number	None