MATERIALS CHARACTERIZATION 59(2008)975-978 SUMATERIALS ELSEVIER Short communication The fabrication of 2D C/sic composite by a modified PIP process using active al powders as active filler Yunzhou Zhu,,, Zhengren Huang, Shaoming Dong, Ming Yuan", Dongliang Jiang shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, PR China School of Graduate, Chinese Academy of Sciences, Beiying 100049, PR China ARTICLE DATA ABSTRACT history: 2D C/SiC composites were fabricated by a modified polymer infiltration and pyrolysis(PIP) Received 26 August 2006 process. The effect of multilayered PyC on the mechanical and physical properties of the Received in revised form composites was investigated. The space in the fibrous preform was first filled with Sic and 7 March 2007 Al powder by a pressure infiltration process to enhance the ceramic yield. The results Accepted 24 July 2007 indicate that Al incorporation decreased the chances of micro-crack formation in the matrix. The multilayered PyC interphase was more effective in property modification, in Keywords comparison with the single pyrocarbon interphase of the same thickness e 2007 Elsevier Inc. All rights reserved. Composite Mechanical properties Introduction for the layered microtexture parallel to the fiber axis. However, Continuous fiber reinforced ceramic matrix composites(CFCCs) logically results in difficulty for crack deflection inside the show superior performance to monolithic ceramics under single Pyc interphase. The nanoscale PyC/Sic multilayered severe conditions such as high-temperature and high-stress interphase deposited by pressure-pulsed chemical vapor applications in aerospace, hot engine and energy conversion infiltration(PCvl) has been previously investigated by Ber facilities. In particular, the C//Sic composites have been trand and coworkers (2, 3]. Crack deflection which is beneficial investigated in previous studies. They have several unique for the toughening mechanism, was observed in the Pyc advantages such as relatively low cost, large scale production sublayers. To our knowledge, no studies on multilayered Pyc and good thermal stability at elevated temperature interphase have been reported in the literature, althoug The characteristics of fiber/matrix bonding has significant crack deflection can also be expected in such an interphase nfluence on the mechanical properties of the composites 1 Recently, studies on CFCCs fabricated by polymerinfiltration a third phase is usually deposited on the fiber surface before and pyrolysis(PIp) have been widely reported (4, 5]. A major composite fabrication to obtain sound interfacial character drawback for the process is the large volume shrinkage of up to istics. Pyrocarbon(Pyc)is the most commonly used interphase 60% and ceramic yield of usually lower than 70% during material and is deposited by chemical vapor deposition(CvD) pyrolysis process. A new approach of active-filler-controlled Corresponding author. Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, PR China Tel. +86 21 52411032: fax:+862152413903 E-mail address: yunzhouzhu@mail sic accn(Y. Zhu) 1044-5803/s-see front matter c 2007 Elsevier Inc. All rights reserved. doi:10.1016/ j. matcha.200707.014Short communication The fabrication of 2D Cf/SiC composite by a modified PIP process using active Al powders as active filler Yunzhou Zhua,b,⁎, Zhengren Huanga , Shaoming Donga , Ming Yuana,b, Dongliang Jianga a Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, PR China bSchool of Graduate, Chinese Academy of Sciences, Beijing 100049, PR China ARTICLE DATA ABSTRACT Article history: Received 26 August 2006 Received in revised form 7 March 2007 Accepted 24 July 2007 2D Cf/SiC composites were fabricated by a modified polymer infiltration and pyrolysis (PIP) process. The effect of multilayered PyC on the mechanical and physical properties of the composites was investigated. The space in the fibrous preform was first filled with SiC and Al powder by a pressure infiltration process to enhance the ceramic yield. The results indicate that Al incorporation decreased the chances of micro-crack formation in the matrix. The multilayered PyC interphase was more effective in property modification, in comparison with the single pyrocarbon interphase of the same thickness. © 2007 Elsevier Inc. All rights reserved. Keywords: AFCOP Porosity Composite Mechanical properties 1. Introduction Continuous fiber reinforced ceramic matrix composites (CFCCs) show superior performance to monolithic ceramics under severe conditions such as high-temperature and high-stress applications in aerospace, hot engine and energy conversion facilities. In particular, the Cf/SiC composites have been investigated in previous studies. They have several unique advantages such as relatively low cost, large scale production and good thermal stability at elevated temperature. The characteristics of fiber/matrix bonding has significant influence on the mechanical properties of the composites [1]. A third phase is usually deposited on the fiber surface before composite fabrication to obtain sound interfacial character￾istics. Pyrocarbon (PyC) is the most commonly used interphase material and is deposited by chemical vapor deposition (CVD) for the layered microtexture parallel to the fiber axis. However, the PyC microstructure is rather disorganized [2], which logically results in difficulty for crack deflection inside the single PyC interphase. The nanoscale PyC/SiC multilayered interphase deposited by pressure-pulsed chemical vapor infiltration (PCVI) has been previously investigated by Ber￾trand and coworkers [2,3]. Crack deflection which is beneficial for the toughening mechanism, was observed in the PyC sublayers. To our knowledge, no studies on multilayered PyC interphase have been reported in the literature, although crack deflection can also be expected in such an interphase. Recently, studies on CFCCs fabricated by polymer infiltration and pyrolysis (PIP) have been widely reported [4,5]. A major drawback for the process is the large volume shrinkage of up to 60% and ceramic yield of usually lower than 70% during pyrolysis process. A new approach of active-filler-controlled MATERIALS CHARACTERIZATION 59 (2008) 975 – 978 ⁎ Corresponding author. Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, PR China. Tel.: +86 21 52411032; fax: +86 21 52413903. E-mail address: yunzhouzhu@mail.sic.ac.cn (Y. Zhu). 1044-5803/$ – see front matter © 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.matchar.2007.07.014