Microstructure and indentation damage resistance of ZrB2-20vol.%SiC ipo-eutectic composites

作者：Zhou, Jiamin; Zhu, Degui; Zhang, Haiwen; Bogomol, Iurii; Grasso, Salvatore^*; Hu, Chunfeng^*

来源：International Journal of Applied Ceramic Technology, 2018, 15(3): 619-624.

DOI：10.1111/ijac.12838

• damage resistance
• melt-solidification
• microstructure
• spark plasma sintering
• ZrB2

Zirconium diboride with 20vol.% 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 17.6GPa along the c-axis and 15.3GPa when measured in an orthogonal direction. On both surfaces, even when using 100N 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.

• 出版日期2018-5
• 单位西南交通大学