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Microstructure and indentation damage resistance of ZrB 2 ‐20 vol.%SiC ipo‐eutectic composites
Author(s) -
Zhou Jiamin,
Zhu Degui,
Zhang Haiwen,
Bogomol Iurii,
Grasso Salvatore,
Hu Chunfeng
Publication year - 2017
Publication title -
international journal of applied ceramic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 57
eISSN - 1744-7402
pISSN - 1546-542X
DOI - 10.1111/ijac.12838
Subject(s) - materials science , composite material , indentation , microstructure , spark plasma sintering , silicon carbide , vickers hardness test , zirconium diboride , eutectic system , phase (matter) , sintering , chemistry , organic chemistry
Zirconium diboride with 20 vol.% silicon carbide bulk composites were fabricated using directionally solidification ( DS ) and also by spark plasma sintering ( SPS ) of crushed DS ingots. During the DS the cooling front aligned the c ‐axis of ZrB 2 grains and its Lotgering factor of f (00 l ) was high as 0.98. The Vickers hardness was anisotropic and it was high as 17.6 GP a along the c ‐axis and 15.3 GP a when measured in an orthogonal direction. On both surfaces, even when using 100 N indentation load, no cracks were observed, suggesting a very high resistance to crack propagation. Such anomalous behavior was attributed to the hierarchical structure of DS sample where the ZrB 2 phase was under strong compression and the SiC phase was in tension. In the SPS ed sample, the microstructure was isotropic respect to the direction of applied pressure. Indentation cracks appeared around the indent corners but not emanated from the diagonals, confirming high damage resistance.