Influences of sintering parameters on attainable hydrogen density and microstructure of YH2-x monoliths fabricated by spark plasma sintering

YH2 bulk is regarded as the most potential metal hydride to be used as neutron moderator of microreactors serving as likely space nuclear power. In this work, YH2-x monoliths are fabricated by spark plasma sintering (SPS) for the first time. Various properties of YH2-x monoliths, including density, density distribution, density uniformity, hydrogen content, and attainable hydrogen density, are measured and calculated systematically. A hydrogen release process is accompanied by the densifying process during SPS. The effective densifying temperature interval is among 700-1000 degrees C. Steep hydrogen release occurs once the sintering temperature exceeds 900 degrees C. The microstructural evolution of YH2-x monoliths is also related to the densifying process and the hydrogen release behaviors. Finally, a sintering process analysis of SPS for YH2-x monoliths is discussed and illustrated in detail. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study fabricated YH2-x monoliths for the first time using spark plasma sintering and systematically measured and calculated their various properties. The research found that the hydrogen release process is accompanied by the densifying process during sintering, and steep hydrogen release occurs once the sintering temperature exceeds 900 degrees C. Additionally, the microstructural evolution of YH2-x monoliths is related to the densifying process and the hydrogen release behaviors.