Fracture energy of 6H-SiC at the microscale: effects of testing geometry and notch preparation
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Micromechanical testing enables small-scale fracture energy measurements, but values depend strongly on ge
ometry and specimen preparation. Here, the fracture energy of the single-crystal 6H-SiC {10
10} plane was measured using microscale double cantilever beam (DCB) and single cantilever beam (SCB) geometries. DCBs showed stable crack growth under displacement control and obtained 7.5 ± 0.3 J/m². In contrast, SCBs notched by a Ga focused ion beam gave fracture energies over twice this value, indicating Ga implantation and near-notch residual stresses. Increasing the final notching current increased the measured fracture energy further. Although near-cryogenic notching limited ion-beam-induced damage, it did not reconcile SCB-derived values with DCB test results. Vacuum annealing substantially lowered the fracture energy and brought SCB results into close agreement with DCB measurements, whereas annealing in argon was less effective. Our findings highlight the importance of careful sample preparation and testing geometry selection for reliable fracture property measurement in ceramic materials.
ometry and specimen preparation. Here, the fracture energy of the single-crystal 6H-SiC {10
10} plane was measured using microscale double cantilever beam (DCB) and single cantilever beam (SCB) geometries. DCBs showed stable crack growth under displacement control and obtained 7.5 ± 0.3 J/m². In contrast, SCBs notched by a Ga focused ion beam gave fracture energies over twice this value, indicating Ga implantation and near-notch residual stresses. Increasing the final notching current increased the measured fracture energy further. Although near-cryogenic notching limited ion-beam-induced damage, it did not reconcile SCB-derived values with DCB test results. Vacuum annealing substantially lowered the fracture energy and brought SCB results into close agreement with DCB measurements, whereas annealing in argon was less effective. Our findings highlight the importance of careful sample preparation and testing geometry selection for reliable fracture property measurement in ceramic materials.
Date Issued
2026-12-01
Date Acceptance
2026-07-16
Citation
Journal of the European Ceramic Society, 2026, 46 (16)
ISSN
0955-2219
Publisher
Elsevier BV
Journal / Book Title
Journal of the European Ceramic Society
Volume
46
Issue
16
Copyright Statement
© 2026 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
License URL
Publication Status
Published
Article Number
118696
Date Publish Online
2026-07-17