Improved toughness of ZrB2-SiC composites with nanopowders obtained by mechanical alloying
Improved toughness of ZrB2-SiC composites with nanopowders obtained by mechanical alloying
复制标题
机械合金化纳米粉末提高 ZrB2-SiC 复合材料的韧性
DOI：
10.1016/j.jpcs.2019.109153
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发表时间：
2020
影响因子：
4
通讯作者：
Li Yawei
中科院分区：
文献类型：
--
作者：
Liao Ning;Jia Dechang;Yang Zhihua;Li Yawei
本研究采用机械合金化法制备纳米粉末，以提高复合材料的断裂韧性。系统地研究了所制备的复合材料的物相组成、显微组织、力学性能、抗热震性能和抗氧化性能。结果表明，添加 体积%碳化硅和 体积分数的Si2BC3N陶瓷的断裂韧性分别提高到7.8 M1/2和8.21 M1/2。韧性的提高归因于原位生成的BN和石墨板的增韧作用，以及沿细小颗粒的裂纹扩展路径延长。此外， -20%Si2BC3N陶瓷具有较高的热应力抗力，这是由于裂纹沿扩展的弱结合界面呈之字形扩展所致。原位生成的BN和石墨板的存在有助于提高热震试验后的残余强度，在1000 °C的温差下，残余应力为113.2 Mpa 。
In this study, the fracture toughness of ZrB2–SiC compoksites was enhanced by using nanopowders prepared by mechanical alloying. The phase compositions, microstructures, mechanical properties, thermal shock resistance, and oxidation resistance of the prepared ZrB2–SiC composites were systematically investigated. The results showed that the fracture toughness of ZrB2-20 vol% SiC and ZrB2-20 vol% Si2BC3N ceramics improved significantly to 7.80 MPa m1/2and 8.21 MPa m1/2, respectively. The enhanced toughness was attributable to the toughening effects ofin-situdeveloped BN and graphite plates, and prolonged crack propagation paths along the finer particles. In addition, the ZrB2-20 vol% Si2BC3N ceramics exhibited higher thermal stress resistance due to the zigzag propagation of cracks alongside the extended weak bonding interfaces. The presence of thein-situdeveloped BN and graphite plates contributed to the higher residual strength after thermal shock tests, where the residual stress was 113.2 MPa at a temperature difference of 1000 °C.