The Degradation Behavior of SiC f /SiO 2 Composites in High-Temperature Environment
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The Degradation Behavior of SiCf/SiO2 Composites in High-Temperature Environment Xiang Yang 1 & Feng Cao 1 & Wang Qing 1,2 & Zhi-hang Peng 1 & Yi Wang 3
Received: 30 May 2017 / Accepted: 28 June 2017 # Springer Science+Business Media B.V. 2017
Abstract SiCf/SiO2 composites had been fabricated efficiently by Sol-Gel method. The oxidation behavior, thermal shock property and ablation behavior of SiCf/SiO2 composites was investigated. SiCf/SiO2 composites showed higher oxidation resistance in oxidation atmosphere, the flexural strength retention ratio was larger than 90.00%. After 1300 °C thermal shock, the mass retention ratio was 97.00%, and the flexural strength retention ratio was 92.60%, while after 1500 °C thermal shock, the mass retention ratio was 95.37%, and the flexural strength retention ratio was 83.34%. After 15 s ablation, the mass loss rate was 0.049 g/s and recession loss rate was 0.067 mm/s. The SiO2 matrix was melted in priority and becomes loosen and porous. With the ablation going on, the oxides were washed away by the shearing action of the oxyacetylene flame. The evaporation of SiO2 took away large amount of heat, which is also beneficial to the protection for SiCf/SiO2 composites. Keywords SiCf/SiO2 . Microstructural . Mechanical property . Oxidation . Thermal shock . Ablation
1 Introduction Due to the excellent oxidation resistance, higher strength, and higher chemical corrosion resistance, silicon carbide (SiC) fibers are widely used as reinforcement in ceramics matrix composites (CMCs) [1, 2].
* Xiang Yang [email protected]
1
Science and Technology on Advanced Ceramic Fibers and Composites Laboratory, National University of Defense Technology, Changsha 410073 Hunan, People’s Republic of China
2
The People’s Liberation Army Troops 96879, Baoji 721000 Shanxi, People’s Republic of China
3
Equipment Academy of the Rocket Force, Beijing 100094, People’s Republic of China
Appl Compos Mater
Compared to other ceramics, oxide ceramics showed better oxidation resistance in oxidizing atmosphere [3], the oxide ceramics possessed high tensile strength and modulus, and were stable against oxidation at higher-temperature. Oxides ceramics were mostly based on alumina or silicon dioxide (SiO2), which had higher melting point. Although SiC fibers-reinforced oxide matrix composites had been reported in the literature [4, 5], studies on oxidation resistance of these composites had rarely been investigated in detail. CMCs had been prepared by Chemical Vapor Infiltration (CVI) [6], Polymer Impregnation Pyrolysis (PIP) [7], Sol-Gel techniques [8] and so on. CVI and PIP required a long manufacturing time, which could leaded to high production cost. Furthermore, the composites fabricated by these processes contained voids, which resulted in their poor mechanical and thermal properties. Sol-Gel process was one of the most convenient, effective, and economical techniques to produce high quality composites, which could be used to prepare large continuous fiberreinforced products with complex shapes and ge
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