Microstructural features and properties of the nano-crystalline SiC/BN(C) composite ceramic prepared from the mechanically alloyed SiBCN powder
Microstructural features and properties of the nano-crystalline SiC/BN(C) composite ceramic prepared from the mechanically alloyed SiBCN powder
复制标题
机械合金化SiBCN粉末制备纳米晶SiC/BN(C)复合陶瓷的显微结构特征及性能
DOI：
10.1016/j.jallcom.2012.05.073
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发表时间：
2012-10-05
影响因子：
6.2
通讯作者：
Zhou, Yu
中科院分区：
文献类型：
--
作者：
Zhang, Pengfei;Jia, Dechang;Zhou, Yu
以机械合金化的非晶SiBCN粉末为原料，在1900 ℃、80 MPa、氮气气氛下热压30 min，制备了纳米SiC/BN（C）陶瓷。采用XRD、TEM（SAED、HRTEM和EFTEM）、EELS和性能测试等手段对所制备陶瓷的显微结构和性能进行了研究。结果表明，陶瓷由β-SiC、α-SiC和BN（C）组成。SiC具有约78.2 +/-32.4nm的平均晶粒尺寸，其中大多数具有许多堆垛层错。BN（C）具有尺寸小、形状不固定的乱层结构，由t-C层、t-BN层和掺B的t-C层不均匀分布而成。它在陶瓷中分布均匀，阻碍了原子扩散，使晶粒细化。该陶瓷的室温密度、弯曲强度、杨氏模量和断裂韧性分别为2.6g/cm（3）、331.1MPa、139.4GPa和2.8MPa·m（1/2）。对热压SiC/BN（C）陶瓷的详细研究有助于进一步研究该材料及其他陶瓷材料的高温应用。(C)2012爱思唯尔有限公司版权所有。
Nano SiC/BN(C) ceramic was prepared from the mechanically-alloyed amorphous SiBCN powder, hot pressed at 1900 degrees C under 80 MPa in the nitrogen atmosphere for 30 min. The microstructures and the properties of the prepared ceramic were carefully studied by XRD, TEM (SAED, HRTEM and EFTEM), EELS and property testing. Results show that the ceramic consists of beta-SiC, alpha-SiC and BN(C). SiC has an average grain size of about 78.2 +/- 32.4 nm, most of which have numerous stacking faults. BN(C) has small size, no fixed shape and turbostratic structure with heterogeneously distributed t-carbon layers, t-BN layers and B-doped t-carbon layers. It has uniform distribution in the ceramic, retarding the atomic diffusion and being responsible for the fine grains. The ceramic has room-temperature density, flexural strength, Young's modulus and fracture toughness of 2.6 g/cm(3), 331.1 MPa, 139.4 GPa and 2.8 MPa m(1/2), respectively. The detailed investigation of the hot-pressed SiC/BN(C) ceramic is helpful for the further study of this material and other ceramics, targeted for the high-temperature applications. (C) 2012 Elsevier B.V. All rights reserved.