Flexural properties of a hybrid polymer matrix composite containing carbon and silicon carbide fibres

Abstract

The flexural properties of hybrid unidirectional fibre reinforced polymer (FRP) composites containing a mixture of carbon (C) and silicon carbide (SiC) fibres were evaluated at span-to-depth (S/d) ratios of 16, 32, and 64. The flexural strength generally increased with increasing S/d ratio with a maximum value of 2316 MPa being achieved for the specimen with nominally equal volume fractions of C and SiC fibre. However, even replacing 12.5 vol% of the C fibres by SiC fibres increased the flexural strength by 22%. The mechanical property most strongly influenced by the incorporation of SiC fibres was the work of fracture with a maximum value of 206.5 kJ m-2 (compared to 78.8 kJ m-2 for the specimen containing only C fibres). First estimate values for the SiC fibre compressive strength, elastic modulus, and strain to failure were 3.46 GPa, 157 GPa, and 0.018, respectively.