Effects of CVI SiC amount and deposition rates on properties of SiCf/SiC composites fabricated by hybrid chemical vapor infiltration (CVI) and precursor infiltration and pyrolysis (PIP) routes. Issue 19 (1st October 2021)

• Record Type: Journal Article
• Authors: Liu, Rongjun; Wang, Fu; Zhang, Jiaping; Chen, Jing; Wan, Fan; Wang, Yanfei
• Is Part Of: Ceramics international. Volume 47:Issue 19(2021)
• Page Start: 26971
• Page End: 26977
• Publication Date: 2021-10-01
• Subjects: SiCf/SiC composites -- Hybrid technique -- Chemical vapor infiltration -- Precursor infiltration and pyrolysis; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2021.06.110
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: The SiCf /SiC composites have been manufactured by a hybrid route combining chemical vapor infiltration (CVI) and precursor infiltration and pyrolysis (PIP) techniques. A relatively low deposition rate of CVI SiC matrix is favored ascribing to that its rapid deposition tends to cause a 'surface sealing' effect, which generates plenty of closed pores and severely damages the microstructural homogeneity of final composites. For a given fiber preform, there exists an optimized value of CVI SiC matrix to be introduced, at which the flexural strength of resultant composites reaches a peak value, which is almost twice of that for composites manufactured from the single PIP or CVI route. Further, this optimized CVI SiC amount is unveiled to be determined by a critical thickness t 0, which relates to the average fiber distance in fiber preforms. While the deposited SiC thickness on fibers exceeds t 0, closed pores will be generated, hence damaging the microstructural homogeneity of final composites. By applying an optimized CVI SiC deposition rate and amount, the prepared SiCf /SiC composites exhibit increased densities, reduced porosity, superior mechanical properties, increased microstructural homogeneity and thus reduced mechanical property deviations, suggesting a hybrid CVI and PIP route is a promising technique to manufacture SiCf /SiC composites for industrial applications.