Fracture Behavior of SiC/SiC Composites with Different Interfaces

doi:10.15541/jim20150278

Abstract

Abstract:

SiC fiber reinforced SiC matrix composites (SiC/SiC) are promising materials for high temperature structural applications. In this work, SiC/SiC composites with Pyrolytic Carbon (PyC) interface or Carbon Nanotubes (CNTs) interface were fabricated by polymer infiltration and pyrolysis (PIP) process. Overall mechanical properties and interfacial shear strength of the SiC/SiC composites were characterized and crack growth processes were observed in situ by scanning electron microscope (SEM). The results indicate that flexural strengths of two types of SiC/SiC composites are similar, but the fracture toughness of the SiC/SiC composite with PyC interface is twice as much as that of the SiC/SiC composite with CNTs interface. Cracks propagate along the fibre-matrix interface in the SiC/SiC composite with PyC interface, which can be deflected or arrested by the PyC interface, hence the composite exhibits a pseudo-ductile fracture behavior. However, the CNTs interface fails to cease the crack in the SiC/SiC composite with CNTs interface, so the initial crack propagates rapidly through the fibers leading to final main crack, and a brittle fracture mode.

Key words: SiC/SiC composite, interface, mechanical properties, fracture behavior, in situ observation

CLC Number:

TB232

ZHAO Shuang, YANG Zi-Chun, ZHOU Xin-Gui. Fracture Behavior of SiC/SiC Composites with Different Interfaces[J]. Journal of Inorganic Materials, 2016, 31(1): 58-62.

Figures/Tables 7

Fig. 1 SEM images of (a) PyC coating and (b) CNTs on the SiC fiber surfaces

Table1 Mechanical properties of SiC/SiC composites

Composites	P-SiC/SiC	C-SiC/SiC
Interface	PyC	CNTs
Flexural strength /MPa	330.2	324.4
Fracture toughness /(MPa∙m^1/2)	15.6	7.7
Interfacial shear strength /MPa	105.9	72.1

Fig. 2 Load/displacement curves of the SiC/SiC composites

Fig. 3 Fracture surface of the SiC/SiC composites (a, b) P-SiC/SiC composite, (c, d) C-SiC/SiC composite

Fig. 4 Schematic diagram of the double-cantilever specimen

Fig. 5 Crack initiation and propagation in P-SiC/SiC composite

Fig. 6 Crack initiation and propagation in C-SiC/SiC composite

References 17

[1]	MADAR ROLAND.Materials science: silicon carbide in contention.Nature, 2004, 430(7003): 974-975.
[2]	NASLAIN ROGER.Design, preparation and properties of non-oxide CMCs for application in engines and nuclear reactors: an overview.Composites Science and Technology, 2004, 64(2): 155-170.
[3]	IVEKOVIĆ ALJAŽ, NOVAK SAŠA, DRAŽIĆ GORAN, et al. Current status and prospects of SiCf/SiC for fusion structural applications.Journal of European Ceramic Society, 2013, 33(10): 1577-1589.
[4]	ZHU S, KAGAWA Y, MIZUNO M, et al.In situ observation of cyclic fatigue crack propagation of SiC-fiber/SiC composite at room temperature.Materials Science and Engineering: A, 1996, 220(1/2): 100-108.
[5]	MIYASHITA Y, KANDA K, ZHU S, et al.Observations of fatigue damage process in SiC/SiC composites at room and elevated temperatures.International Journal of Fatigue, 2002, 24(2/3/4): 241-248.
[6]	CHATEAU C, GÉlébart L, BORNERT M, et al.In situ X-ray microtomography characterization of damage in SiCf/SiC minicomposites.Composites Science and Technology, 2011, 71(6): 916-924.
[7]	SHIBAYAMA T, MATSUO G, HAMADA K, et al.In-situ observation of fracture behavior on nano structure in NITE SiC/SiC composite by HVEM.IOP Conference Series: Materials Science and Engineering, 2011, 18(16): 162013-162016.
[8]	ZHAO SHUANG, YANG ZI-CHUN, ZHOU XIN-GUI, et al.Design, fabrication, characterization and simulation of PIP-SiC/SiC composites.CMC: Computers, Materials & Continua, 2014, 42(2): 103-124.
[9]	YANG WEN, ARAKI HIROSHI, TANG CHENG-CHUN, et al.Single-crystal SiC nanowires with a thin carbon coating for stronger and tougher ceramic composites.Advanced Materials, 2005, 17(12): 1519-1523.
[10]	YU HAI-JIAO, ZHOU XIN-GUI, ZHANG WEI, et al.Properties of carbon nano-tubes-Cf/SiC composite by precursor infiltration and pyrolysis process.Materials and Design, 2011, 32(6): 3516-3520.
[11]	KÖNIG KATJA, NOVAK SAŠA, IVEKOVIĆ ALJAŽ, et al. Fabrication of CNT-SiC/SiC composites by electrophoretic deposition.Journal of the European Ceramic Society, 2010, 30(5): 1131-1137.
[12]	SUN KE, YU JIN-SHAN, ZHANG CHANG-RUI, et al.In situ growth carbon nanotube reinforced SiCf/SiC composite.Materials Letters, 2011, 66(1): 92-95.
[13]	WANG DE-YIN, SONG YONG-CAI, JIAN KE.Effect of composition and structure on the specific resistivity of continuous silicon carbide fibers.Journal of Inorganic Materials, 2012, 27(2): 162-168.
[14]	WANG DE-YIN, MAO XIAN-HE, SONG YONG-CAI, et al.Preparation and properties of sic fiber with a stable excess carbon layer on the surface.Journal of Inorganic Materials, 2009, 24(6): 1209-1213.
[15]	YU HAI-JIAO, ZHOU XIN-GUI, ZHANG WEI, et al.Mechanical properties of 3D KD-I SiCf/SiC composites with engineered fibre matrix interfaces.Composites Science and Technology, 2011, 71(5): 699-704.
[16]	ZHAO SHUANG, YANG ZI-CHUN, ZHOU XIN-GUI, et al.Microstructure and mechanical properties of compact sic/sic composite fabricated with an infiltrative liquid precursor.Journal of the American Ceramic Society, 2015, 98(4): 1332-1337.
[17]	ZHAO SHUANG, ZHOU XIN-GUI, YU JIN-SHAN, et al.SiC/SiC composite fabricated with carbon nanotube interface layer and a novel precursor LPVCS.Fusion Engineering and Design, 2014, 89(2): 131-136.