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Mechanical behaviour and microstructural characterization of 3D four‐directional braided SiO 2 f /SiO 2 composites
Author(s) -
LIU Y.,
ZHU J.,
CHEN Z.,
LI C.,
BOAFO F. E.
Publication year - 2012
Publication title -
fatigue and fracture of engineering materials and structures
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 84
eISSN - 1460-2695
pISSN - 8756-758X
DOI - 10.1111/j.1460-2695.2012.01682.x
Subject(s) - materials science , composite material , flexural strength , ultimate tensile strength , microstructure , composite number , sintering , shear (geology)
In this paper, SiO 2 f /SiO 2 composites reinforced by 3D four‐directional braided quartz preform were prepared by the silica sol‐infiltration‐sintering method in a relatively low sintering temperature (450 °C). To characterize the mechanical properties of the composites, mechanical testing was carried out under various loading conditions, including tensile, flexural and shear loading. The microstructure and the fracture behaviour of the 3D four‐directional braided SiO 2 f /SiO 2 composites were studied. The tensile strength, flexural strength and the in‐plane shear strength were 30.8 MPa, 64.0 MPa and 22.0 MPa, respectively. The as‐fabricated composite exhibited highly nonlinear stress–strain behaviour under all the three types of loading. The tensile and flexural fracture mechanisms were fully discussed. The fracture mode of the 3D four‐directional braided SiO 2 f /SiO 2 composite in the Iosipescu shear testing was based on a mixed mechanism because of the multi‐directivity of the composite. Owing to low sintered temperature, the fibre/matrix interfacial strength was weak. The SiO 2 f /SiO 2 composites showed non‐catastrophic behaviour resulting from extensive fibre pull‐out during the failure process.