Heterogeneous microstructure of yttrium hydride and its relation to mechanical properties. Issue 8 (July 2023)

• Record Type: Journal Article
• Authors: Gietl, Hanns; Garrison, Ben; Sprouster, David J.; Koyanagi, Takaaki
• Is Part Of: Journal of the European Ceramic Society. Volume 43:Issue 8(2023)
• Page Start: 3216
• Page End: 3227
• Publication Date: 2023-07
• Subjects: Yttrium hydride -- Advanced data analysis; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2023.01.015
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: The goal of this study is to investigate the properties of yttrium hydride materials in relation to the microstructure, especially its homogeneity. High-throughput nanoindentation mapping was used to evaluate hardness distribution. Raman spectral imaging demonstrated its sensitivity to the presence of YH2 and impurities. Raman peak position maps were correlated with residual stress in the specimens. Electron backscatter diffraction mapping provided phase distributions with correlation to high-energy X-ray diffraction analysis. The experimental mapping data were combined and analyzed using unsupervised machine learning cluster procedures. The machine learning analysis revealed that yttrium hydride specimens contained a major δ-YH2 − x phase component and minor α-Y and δ-YH2 − x components with significant residual stress. The minor phase fraction decreased with increasing nominal H/Y ratio, which affected the nanoindentation and Vickers hardness. The multimodal mapping procedures described herein affect developing important microstructure–property relationships, as well as correlations in heterogeneity and mechanical properties.