Effects of Thickness on Mechanical Properties of 2D C/SiC Torque Tube

Different failure modes and morphologies were found in the chemical vapor infiltration (CVI) 2D C/SiC torque tubes with different thickness. To characterize the density and porosity of the ceramic matrix composite (CMC) torque tube, a CT test was conducted. The archimedes drainage method was used to measure the density and porosity, and by adopting FEM software, the stress distribution and failure strength of the ceramic matrix composite torque tubes were calculated. A universal material test machine was used to implement torsional tests. Different torsional behaviors of CMC torque tubes with two different thicknesses were showed in the stress-strain curves. To analyze the predominant failure factors, SEM was used to observe the failure morphologies and cracks. 5 mm thickness CMC torque tube has reasonable fracture morphologies and a higher maximum shear strength and modulus.