The influence of internal defects on the mechanical behavior of filament wound SiC/SiC composite tubes under uniaxial tension

Abstract

SiC/SiC composites are resistant to high temperatures making them excellent candidates for aeronautical or nuclear applications. The robustness of the mechanical behavior of CVI-SiC/SiC tubes for fuel cladding was examined in this paper. The loading direction was parallel to the tube axis, and the fibers were oriented to ±45° with respect to the tube axis. The tensile behavior was analyzed considering the tube as a unidirectional composite. The tensile behavior exhibits the conventional non-linear deformations investigated in earlier works. Mechanical response could be differentiated according to features of the stress–strain behavior. In particular, one set of specimens displayed a distinctly decreased elastic modulus, slower rate of shear damage and premature saturation of slippage at fiber/matrix interface cracks. Various mitigating factors, including the presence of free Si in the matrix, differences in local dimensions and proportion of constituents were examined.