Synthesis of SiBNC-Al ceramics with different aluminum contents via polymer-derived method |
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Authors: | Zicheng Tang Shaofei Wang Rogers Tusiime Jidong Hu Haikun Chen Yifan Zhang Hui Zhang Yong Liu |
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Affiliation: | 1. Shanghai Collaborative Innovation Center of High Performance Fibers and Composites (Province-Minitry Joint), College of Materials Science and Engineering, Donghua University, Shanghai, P. R. China;2. Science and Technology on Advanced Functional Composites Laboratory, Aerospace Research Institute of Materials and Processing Technology, Beijing, China;3. Shanghai Collaborative Innovation Center of High Performance Fibers and Composites (Province-Minitry Joint), College of Materials Science and Engineering, Donghua University, Shanghai, P. R. China The Key Laboratory of High-Performance Fiber and Product, Ministry of Education, Donghua University, Shanghai, P. R. China |
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Abstract: | This study reports the synthesis of three types of aluminium (Al)-modified polyborosilazane ceramic precursors (PBSAZ) from C8H19Al/HSiCl3/HMDZ/BCl3 and their thermal conversion to SiBNC-Al ceramics at 1000°C. FT-IR, nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA) are used to characterize the structures and properties of the PBSAZ. PBSAZ is found to be built up of the Si─N─B framework, with Al successfully introduced into the ceramic network structures. The ceramic yield is 63.5 wt.% for the Al-poor polymers (PBSAZ-5) and 65.1 wt.% for the Al-rich polymers (PBSAZ-1). The high-temperature cracking behavior and the crystal phase structures of the ceramics were characterized by XRD and Raman, which revealed that SiBNC-Al ceramics contained Si4N3, SiC, and AlN (+SiC) crystals after heat treatment at 1600°C. The oxidation behavior of SiBNC and SiBNC-Al ceramics at 1500°C shows that the introduction of Al improves the quality of the oxide layer, effectively suppresses the oxide layer cracking phenomenon, and reduces gas bubble generation. |
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Keywords: | high-temperature oxidation resistance polymer-derived method polymerization mechanism SiBNC-Al ceramics |
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