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Improvement of high-temperature stability of PIP SiCf/SiC material through in situ grown BNNTs |
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| Authors: | Shenwei Xu Huiling Pi Pengfei Wu Xiaozhong Huang Yuan Shi Longbiao Li Haitang Yang |
| Affiliation: | 1. Powder Metallurgy Research Institute, Central South University, Changsha, Hunan, China
State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan, China Hunan Province Key Laboratory of New Specialty Fibers and Composite Material, Central South University, Changsha, Hunan, China;2. Science and Technology on Thermostructural Composite Materials Laboratory, Northwestern Polytechnical University, Xian, Shanxi, China;3. School of Aeronautics and Astronautics, Central South University, Changsha, Hunan, China;4. Institute of Structures and Design, German Aerospace Center Stuttgart, Stuttgart, Germany;5. College of Civil Aviation, Nanjing University of Aeronautics and Astronautics, Nanjing, PR China;6. Powder Metallurgy Research Institute, Central South University, Changsha, Hunan, China |
| Abstract: | In this paper, the effect of in situ grown boron nitride nanotubes (BNNTs) and preparation temperature on mechanical behavior of PIP (Precursor Infiltration and Pyrolysis) SiCf/SiC minicomposites under monotonic and compliance tensile is investigated. In situ BNNTs are grown on the surface of SiC fibers using ball milling–annealing process. Composite elastic modulus, tensile strength, fracture strain, tangent modulus, and loading/unloading inverse tangent modulus (ITM) are obtained and adopted to characterize the mechanical properties of the composites. Microstructures of in situ grown BNNTs and tensile fracture surfaces are observed under scanning electronic microscopic (SEM). For SiCf/SiC minicomposites with BNNTs, the elastic modulus, tensile strength, and fracture strain are all lower than those of SiCf/SiC minicomposites without BNNTs, mainly due to high preparation temperature and the oxidation of the PyC interphase during the annealing process. Tensile stress–strain curves of SiCf/SiC minicomposites with and without BNNTs are predicted using the developed micromechanical constitutive model. The predicted results agreed with experimental data. This work will provide guidance for predicting the service life of SiCf/SiC composite materials and may enable these materials to become a backbone for thermal structure systems in aerospace applications. |
| Keywords: | boron nitride nanotubes (BNNTs) ceramic-matrix composites (CMCs) mechanical behavior precursor infiltration and pyrolysis (PIP) |
