Microstructure and indentation damage resistance of ZrB2‐20 vol.%SiC ipo‐eutectic composites |
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| Authors: | Jiamin Zhou Degui Zhu Haiwen Zhang Iurii Bogomol Salvatore Grasso Chunfeng Hu |
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| Affiliation: | 1. Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, China;2. National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”, Kyiv, Ukraine;3. School of Engineering and Material Science, Queen Mary University of London, London, UK |
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| Abstract: | 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 ZrB2 grains and its Lotgering factor of f(00l) was high as 0.98. The Vickers hardness was anisotropic and it was high as 17.6 GPa along the c‐axis and 15.3 GPa 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 ZrB2 phase was under strong compression and the SiC phase was in tension. In the SPSed 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. |
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| Keywords: | damage resistance melt‐solidification microstructure spark plasma sintering ZrB2 |
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