Al2O3/TiB2/SiCw三元复合材料的力学性能及显微结构
MECHANICAL PROPERTIES AND MICROSTRUCTURE OF Al2O3/TiB2/SiCw COMPOSITES
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摘要: 以Al2O3为基体,SiC晶须和TiB2颗粒两种增韧剂,采用热压烧结工艺制备了Al2O3/TiB2/SiCw三元复合陶瓷材料。研究了热压工艺参数对材料致密度的影响和晶须含量对该复合材料的力学性能和显微结构的影响。结果表明;随晶须含量的增加,该复合材料的热压温度和保温时间需要相应的增加;晶须拔出、裂纹偏转和晶须的桥接为该复合材料的主要增韧机理;随晶须含量的增加,该材料的室温断裂韧性增加;该材料的断裂韧性随温度的升高而呈增大趋势,并且晶须含量越高,材料的高温断裂韧性增幅越大。Abstract: Al2O3/TiB2/SiCw composite was fabricated by hot pressing with SiC whiskers and TiB2 as toughening phase. The mechanical properties and microstructure as well as toughening mechanisms were investigated. Results showed that the sintering temperature and the temperature holding time should be increased as the SiCw content increased. Significant improvement in fracture toughness will be obtained for the Al2O3/TiB2/SiCw composite, in comparison with Al2O3/TiB2 composite. Toughening mechanisms in the composite are mainly pullout of SiC whiskers crack deflection by TiB2 grains and whiskers bridging.Considerable improvement in fracture toughness at high temperature was observed for the composite.
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Key words:
- SiC whisker /
- composite /
- mechanical properties /
- multiphase ceramic /
- whisker toughening
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