Densification, microstructure and mechanical properties of ZrB 2SiCw ceramic composites
Densification, microstructure and mechanical properties of ZrB 2SiCw ceramic composites
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DOI：
10.1016/j.jeurceramsoc.2009.03.008
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发表时间：
2009-10
影响因子：
5.7
通讯作者：
T. Zhu;Lin Xu;Xinghong Zhang;W. Han;P. Hu;L. Weng
中科院分区：
文献类型：
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作者：
T. Zhu;Lin Xu;Xinghong Zhang;W. Han;P. Hu;L. Weng
以Al 2 O3和Y2 O3为烧结助剂，在1800°C低温热压烧结制备了ZrB 2-SiCw复合材料。分析表明，添加剂可与ZrB 2-SiCw复合材料中的杂质（表面氧杂质和残余金属杂质）反应形成过渡液相，从而促进ZrB 2-SiCw复合材料的烧结和致密化。添加剂的含量对ZrB 2-SiCw复合材料的烧结性能、显微结构和力学性能有显著影响。少量添加剂（3vol.%）制备的ZrB 2-SiCw复合材料结果表明，该复合材料具有最佳的显微结构（相对密度为98.3%）和优异的力学性能（抗弯强度为783 MPa，断裂韧性为6.7MPam1/2）。随着添加剂的进一步加入，SiC晶须倾向于聚集在一起，并被过量的液体包裹形成核-环结构，导致力学性能几乎没有下降。
ZrB2–SiCw composites were prepared through hot-pressing at a low temperature of 1800°C, and Al2O3plus Y2O3were added as sintering aids. Analysis revealed that additives may react with impurities (i.e. surface oxygen impurities and residual metallic impurities) to form a transient liquid phase, thus promote the sintering and densification of ZrB2–SiCw composites. The content of additives was found to have a significant influence on the sinterability, microstructure and mechanical properties of ZrB2–SiCw composites. ZrB2–SiCw composite prepared with a small amount of additives (3vol.%) provided the optimal combination of microstructure (relative density of 98.3%) and excellent properties, including flexural strength of 783MPa and fracture toughness of 6.7MPam1/2. With further addition of additives, SiC whiskers were inclined to gather together and be enveloped by excessive liquids to form core-rim-like structures, which lead to little decrease in mechanical properties.