Consolidation and high-temperature strength of monolithic lanthanum hexaboride

Dmytro Demirskyi*, Tohru S. Suzuki, Kyosuke Yoshimi, Oleg O. Vasylkiv

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

In this study we explored the densification, microstructure evolution, and high-temperature properties of bulk lanthanum hexaboride. LaB6 bulks were consolidated using spark-plasma sintering only in the temperature range between 1400°C and 1700°C. We adopted flash spark plasma sintering (SPS) of LaB6 using a direct current heating without a graphite die. We observed a peculiar grain-size gradient when coarse grains exceeding 300 μm were observed on the top side of the specimen, while the bottom side had a grain size of 15–20 μm. Such large grain was not observed using SPS at 2000°C, suggesting that these might originate from a local overheating. Based on the three-point flexural tests, it was observed that the toughness and strength of the LaB6 were acceptable at room-temperature (3.1 ± 0.2 MPa m1/2, 300 ± 20 MPa). However, at 1600°C, these parameters would decrease to 1.3 ± 0.1 MPa m1/2 and 120 ± 40 MPa, respectively.

Original languageEnglish
Pages (from-to)4277-4290
Number of pages14
JournalJournal of the American Ceramic Society
Volume105
Issue number6
DOIs
Publication statusAccepted/In press - 2022
Externally publishedYes

Keywords

  • borides
  • densification
  • flash sintering
  • grain growth
  • spark plasma sintering

ASJC Scopus subject areas

  • Ceramics and Composites
  • Materials Chemistry

Fingerprint

Dive into the research topics of 'Consolidation and high-temperature strength of monolithic lanthanum hexaboride'. Together they form a unique fingerprint.

Cite this