Mechanical properties of SiCf/SiC composites with alternating PyC/BN multilayer interfaces |
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| Authors: | Yuxin Chai Huayu Zhang Xingui Zhou |
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| Affiliation: | 1. Shenzhen Key Laboratory for Advanced Materials and Department of Material Science and Engineering, Shenzhen Graduate School, Harbin Institute of Technology, University Town, Shenzhen, China;2. Science and Technology on Advanced Ceramic Fibers and Composites Laboratory, National University of Defense Technology, Changsha, China;3. Science and Technology on Advanced Ceramic Fibers and Composites Laboratory, National University of Defense Technology, Changsha, China |
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| Abstract: | Alternating pyrolytic carbon/boron nitride (PyC/BN)n multilayer coatings were applied to the KD–II silicon carbide (SiC) fibres by chemical vapour deposition technique to fabricate continuous SiC fibre-reinforced SiC matrix (SiCf/SiC) composites with improved flexural strength and fracture toughness. Three-dimensional SiCf/SiC composites with different interfaces were fabricated by polymer infiltration and pyrolysis process. The microstructure of the coating was characterised by scanning electron microscopy, X–photoelectron spectroscopy and transmission electron microscopy. The interfacial shear strength was determined by the single-fibre push-out test. Single-edge notched beam (SENB) test and three-point bending test were used to evaluate the influence of multilayer interfaces on the mechanical properties of SiCf/SiC composites. The results indicated that the (PyC/BN)n multilayer interface led to optimum flexural strength and fracture toughness of 566.0?MPa and 21.5?MPa?m1/2, respectively, thus the fracture toughness of the composites was significantly improved. |
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| Keywords: | PyC CVD BN interface SiCf/SiC interfacial shear strength mechanical properties |
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