NSUF 24-4986: Post Irradiation Examination of High Entropy Carbides

New high entropy carbides have favorable characteristics for high temperature advanced nuclear applications. The purpose of this Rapid Turnaround Experiment proposal is to perform the post irradiation examinations (PIE) of irradiated high entropy carbide specimens. Two high entropy carbide specimens have been irradiated via heavy ion implantation and are ready for PIE analyses. The proposed PIE will include the following characterization techniques, x-ray diffraction analysis (XRD), nanoindentation, Scanning Probe microscopy (SPM), scanning electron microscopy energy dispersive X-ray spectrometry (SEM-EDS), electron backscatter diffraction (SEM-EBSD), and transmission electron microscopy (TEM). The Center for Advanced Energy Studies (CAES) in Idaho Falls, ID is the desired location to perform the PIE. The current focus of this work is to observe and measure microstructural changes caused by irradiation using common microscopy techniques. Two small specimens from the same HEC mixture have been irradiated with 10-MeV Au ions with peak doses of 47 and 94 dpa respectively. A small corner of each specimen was covered with metal foil to shield against the ion irradiation. The following analyses will be performed to complete this work. Nanoindentation and XRD measurements of the irradiated specimens will be compared to those of non-irradiated specimens. Any radiation-induced changes are expected to be manifested as increased surface hardness and/or crystalline phase changes. Imaging results from the SEM-EDS & SEM-EBSD analyses will be used to measure any radiation-induced segregation and grain growth. Changes in the irradiated surfaces vs. shielded surfaces will be measured via the SPM analyses. Increased elevation of the irradiated surface would indicate radiation-induced volumetric swelling. And finally, small TEM lamella samples will be prepared from the irradiated specimens via SEM focused ion beam for TEM imaging. Bright field and dark field images from the TEM analyses will be used to observe and quantify crystal defects, stacking faults, and dislocations. Additionally, the TEM select area diffraction patterns will be used to determine changes to the crystal lattice constant and observe any amorphization. These measurements are expected to take approximately 3 weeks to complete. The observation of notable changes to the measured characteristics, as explained above, will show the susceptibility of these high entropy carbides to radiation-induced damage. This study will help to understand the potential for high entropy carbides to be a stable, radiation-resistance material suitable for advanced nuclear application. All data and findings will be published in peer-reviewed journal articles as well as my PhD dissertation thesis.

추가 정보

필드	값
Award Announced Date	2024-05-28T17:17:04.023
Awarded Institution	Idaho State University
Facility Tech Lead	Yaqiao Wu
Irradiation Facility
PI	Todd Sherman
PI Email	[email protected]
Project Type	RTE
RTE Number	None