Mechanical and thermal properties of 2D and 3D SiC/SiC composites

SiC fiber-reinforced SiC composites (SiC/SiC), whose preforms had 3D satin weave or 2D non-woven fabric, were fabricated by chemical vapor infiltratio n (CVI) or polymer impregnation and pyrolysis (PIP). The 3D satin texture m ade from Hi-Nicalon Type S fiber was successfully woven although the fiber has high elastic modulus. Both CVI and PIP SiC/SiC composites of Type S fib er had higher thermal conductivity than those of Hi-Nicalon fiber. These re sults can be ascribed to higher thermal conductivity of Type S fiber. The t hermal conductivity of the 3D PIP SiC/SiC composites was increased after an nealing at 1400 degreesC in vacuum. The bend strength of the 2D CVI SiC/SiC composites of non-coated Hi-Nicalon fiber was higher than that of non-coat ed Type S fiber, indicating that interfacial modification for Type S fiber is needed to obtain good mechanical properties. (C) 2000 Elsevier Science B .V. Ail rights reserved.