2024-03-29T02:37:12Z
https://nagoya.repo.nii.ac.jp/oai
oai:nagoya.repo.nii.ac.jp:00007499
2023-01-16T03:53:02Z
320:321:322
Evaluation of Fracture Toughness of Porous Ceramics
SAKAIDA, Yoshihisa
TANAKA, Keisuke
open access
日本機械学会
本文データは学協会の許諾に基づきCiNiiから複製したものである。
Porous Ceramics
Fracture Toughness
Indentation Fracture Method
Single-edge Precrack Beam Method
Single-edge V-notched Beam Method
R-curve Behavior
The indentation fracture (IF) method, the single-edge precracked beam (SEPB) method, and the single-edge V-notched beam (SEVNB) method were applied to evaluate the fracture toughness of four kinds of porous ceramics of SiC, Al2O3 and Mg2Al4Si5O18 with porosity ranging from 37 to 43%. The microstructures of these materials were composed of ceramics grains, glassy grain boundaries and pores. Each grain was joined together with the glassy grain boundary phase. The IF and SEPB methods were not applicable because both precracks and indenter traces were not visible. On the other hand, the SEVNB method was applicable because the V-notch could be easily machined by grinding. In the case of the SEVNB method, the applied load versus back-face strain plots under four-point bending showed nonlinearity prior to the maximum load. The R-curve behavior was estimated from the compliance change of specimens. The fracture toughness of porous ceramics was smaller than that of dense ceramics, and increased with increasing crack extension. Since the stable crack predominantly propagated along glassy grain boundaries, the R-curve behavior depended on the loading rate and matrix grain size. The increment of the R-curve by grain bridging became larger for coarser-grain sized ceramics.
The Japan Society of Mechanical Engineers
2003-01
eng
journal article
VoR
http://hdl.handle.net/2237/9181
https://nagoya.repo.nii.ac.jp/records/7499
http://ci.nii.ac.jp/naid/10016190963/
1344-7912
JSME International Journal Series A
46
1
30
39
https://nagoya.repo.nii.ac.jp/record/7499/files/JSME_A_46-1-30.pdf
application/pdf
2.0 MB
2018-02-19