1. Effects of oxidation cross-linking and sintering additives (TiN, B) on the formation and heat-resistant performance of polymer-derived SiC(Ti, B) films.
- Author
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Xu, Xiaohui, Mao, Yu, Chen, Fen, Yao, Rongqian, Feng, Zude, Chen, Lifu, and Zhang, Ying
- Subjects
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OXIDATION , *SILICON carbide films , *SINTERING , *ADDITIVES , *HEAT resistant materials , *MICROSTRUCTURE , *CROSSLINKING (Polymerization) , *CHEMICAL synthesis , *SILICON carbide - Abstract
Effects of oxidation cross-linking and sintering additives (TiN, B) on the microstructure formation and heat-resistant performance of freestanding SiC(Ti, B) films synthesized from Ti, B-containing polycarbosilane (TiB-PCS) precursor were investigated. TiB-PCS green films were first cross-linked for 1 h, 2 h, 3 h and 4 h, respectively, and then pre-sintered at 950 °C. Finally, they were sintered at 1800 °C to complete the conversion from organic films to inorganic SiC(Ti, B) films. The results reveal that curing time has a great impact on the uniformity and density of SiC(Ti, B) films. TiB-PCS films cured for 3 h yield the best quality SiC(Ti, B) films, which are composed of β-SiC crystals, C clusters, α-SiC nano-crystals, a small amount of TiB 2 and B 4 C. TiB 2 and B 4 C are both steady phases which can inhibit abnormal growth of β-SiC, effectively reduce sintering temperature and help consume excess C from decomposition of amorphous SiO x C y . After high temperature annealing at 1500 °C, 1600 °C and 1700 °C in argon, SiC(Ti, B) films still keep excellent mechanical properties, which makes them attractive candidate materials for microelectromechanical systems (MEMS) used at ultra-high temperatures (exceeding 1500 °C). [ABSTRACT FROM AUTHOR]
- Published
- 2016
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