Mullite–Boron Nitride Composite with High Strength and Low Elasticity
Mullite–Boron Nitride Composite with High Strength and Low Elasticity
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DOI：
10.1111/j.1551-2916.2004.00296.x
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发表时间：
2004-02
影响因子：
3.9
通讯作者：
Guo‐Jun Zhang;Jianfeng Yang;M. Ando;T. Ohji;S. Kanzaki
中科院分区：
文献类型：
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作者：
Guo‐Jun Zhang;Jianfeng Yang;M. Ando;T. Ohji;S. Kanzaki
以硼酸铝（9Al2O3·2B2O3 和 2Al2O3·B2O3）和氮化硅为起始材料，通过反应热压（RHP）制备了具有高强度、低杨氏模量和显着改善的应变耐受性的莫来石-氮化硼（BN）复合材料。与整体莫来石相比，复合材料RHPed在1800°C下的强度提高了1.64倍（540 MPa），杨氏模量提高了70%（153 GPa），应变耐受性提高了2.34倍（3.53 × 10−3）。透射电镜观察表明，该复合材料具有各向同性的微观结构，其中莫来石基体晶粒尺寸小于1μm，纳米级六方BN（h-BN）片晶长度约为200 nm，厚度为60-80 nm。高强度归因于基体晶粒尺寸的减小和 h-BN 片晶的小增韧作用。
Mullite–boron nitride (BN) composite with high strength, low Young's modulus, and highly improved strain tolerance was prepared by reactive hot pressing (RHP) using aluminum borates (9Al2O3·2B2O3 and 2Al2O3·B2O3) and silicon nitride as starting materials. Compared with the monolithic mullite, the composite RHPed at 1800°C showed 1.64 times (540 MPa) the strength, 70% (153 GPa) the Young's modulus, and 2.34 times (3.53 × 10−3) the strain tolerance. Transmission electron microscopy observation revealed that the composite had an isotropic microstructure with a fine mullite matrix grain size of less than 1 μm and nanosized hexagonal BN (h-BN) platelets of about 200 nm in length and 60–80 nm in thickness. The high strength was suggested to be from the reduced matrix grain size and the small toughening effect by the h-BN platelets.