Abstract Boron nitride and silicon carbide interfacial coatings were deposited by chemical vapor infiltration to prepare SiC/SiC minicomposites by the precursor infiltration and pyrolysis process. The tensile properties of the SiC/SiC minicomposites were assessed by the acoustic emission method. A single-layered BN coating increased the strength of the uncoated minicomposite from 416.4 MPa to 478.6 MPa, while the strengths of the BN/SiC-1 and BN/SiC-2 samples with a double-layered coating were 582.3 and 638.1 MPa, respectively. The total thickness of the BN/SiC-2 coating was the same as that of BN/SiC-1, while the BN/SiC-2 sample had a thicker BN layer. Besides the release of residual stress and elastic deformation stages, the stress-strain curve of minicomposite with interfacial coating contains a non-linear stage corresponding to the matrix crack generation, propagation, and deflection. Moreover, minimal fiber debonding was observed in the uncoated minicomposite, whereas fiber debonding of BN and BN/SiC-1 minicomposites occurred at the interface between the BN coating and fibers. In the double-layered BN/SiC-2 minicomposites, following matrix crack generation and propagation into the BN coating, cracks deflected both between the sublayers and at the interface between BN and fibers, where the debonding occurred.

中文翻译：

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BN/SiC界面涂层对PIP制备的SiC/SiC微复合材料拉伸性能的影响

摘要 通过化学气相渗透沉积氮化硼和碳化硅界面涂层，通过前驱体渗透和热解工艺制备SiC/SiC微型复合材料。碳化硅/碳化硅微型复合材料的拉伸性能通过声发射法进行评估。单层 BN 涂层将未涂层微复合材料的强度从 416.4 MPa 提高到 478.6 MPa，而具有双层涂层的 BN/SiC-1 和 BN/SiC-2 样品的强度分别为 582.3 和 638.1 MPa . BN/SiC-2 涂层的总厚度与 BN/SiC-1 相同，而 BN/SiC-2 样品具有更厚的 BN 层。除了释放残余应力和弹性变形阶段，具有界面涂层的微型复合材料的应力-应变曲线包含一个非线性阶段，对应于基体裂纹的产生、扩展和偏转。此外，在未涂覆的微型复合材料中观察到最小的纤维剥离，而 BN 和 BN/SiC-1 微型复合材料的纤维剥离发生在 BN 涂层和纤维之间的界面。在双层 BN/SiC-2 微型复合材料中，在基体裂纹产生并传播到 BN 涂层后，裂纹在亚层之间以及在 BN 和纤维之间的界面处发生偏转，在那里发生脱粘。