Polytypes, Grain Growth, and Fracture Toughness of Metal Boride Particulate SiC Composites
Polytypes, Grain Growth, and Fracture Toughness of Metal Boride Particulate SiC Composites
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金属硼化物颗粒 SiC 复合材料的多型体、晶粒生长和断裂韧性
DOI：
10.1111/j.1151-2916.1995.tb08473.x
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发表时间：
1995
影响因子：
3.9
通讯作者：
N. Iyi
中科院分区：
文献类型：
--
作者：
Hidehiko Tanaka;N. Iyi
为了了解碳化硅材料的微观结构与增韧行为的关系，采用常压烧结法制备了NbB2、TaB2、TiB2和ZrB2颗粒碳化硅复合材料。在该复合材料中，以β(立方体)-碳化硅粉末为基材。β-碳化硅粉末在烧结过程中转变为α(非立方)相。相变的行为受金属硼化物颗粒的存在的影响，并伴随着正常或夸大的晶粒长大。金属硼化物颗粒抑制了碳化硅的大规模夸大晶粒长大，并有以较大的碳化硅颗粒长径比模拟晶粒长大的趋势。随着碳化硅颗粒尺寸和长径比的增大，复合材料的断裂韧性也随之提高。根据晶界桥联机理讨论了其增韧行为。
In order to understand the relation between microstructure and toughening behavior in SiC materials, NbB 2 , TaB 2 , TiB 2 , and ZrB 2 particulate SiC composites were fabricated with pressureless sintering. In the composites, β(cubic)-SiC powder was used as starting material for the matrix. The β-SiC powder transformed to α(noncubic) phase during sintering. The transformation, the behavior of which was influenced by the existence of metal boride particles, was accompanied by normal or exaggerated grain growth. The metal boride particles suppressed large-scale exaggerated grain growth of SiC, and it had a tendency to simulate grain growth with a high aspect ratio of the SiC grains. Increase in the fracture toughness of the composites was observed when the grain size and the aspect ratio of the SiC grains increased together. The toughening behavior is discussed based on a grain bridging mechanism