Mechanical behavior of 2.5D (shallow bend-joint) and 3D orthogonal quartzf/silica composites by silicasol-infiltration-sintering

The effect of two different fiber architectures on the mechanical properties of the quartz fiber-reinforced silica composites processed by silicasol-infiltration-sintering (SIS) has been investigated. The composites were sintered at relatively low temperature (450 degrees C). The characteristics of 2.5D (shallow bend-joint) structure and 3D orthogonal structure were determined. The microstructures, flexural strength, shear strength and failure mechanisms of both 2.5D (shallow bend-joint) and 3D orthogonal composites were characterized. It was found that the fiber placement in the preform will strongly affect the mechanical property and failure behavior of the composite. The results of the tests and microstructural observations indicated that 2.5D (shallow bend-joint) quartz(f)/silica (Q(f)/S) composites had better mechanical properties than 3D orthogonal quartz(f)/silica composites. (C) 2011 Elsevier B.V. All rights reserved.