Abstract
Eutectic AlSi alloy was pressure infiltrated into a porous C/C skeleton to develop a low cost new C/C composite for application without extreme high temperature. C/C composite possessed a density of 1.7 g/cm3 was prepared for comparison. The effects of filling AlSi with and without Al-Ti-C grain refiner on the microstructure and properties of C/C composites were mainly studied. Result indicated that the introduced AlSi interpenetrated with C/C skeleton and made the composites compact. In comparison with C/C composite, the compressive strength and particle erosion resistance were greatly enhanced while the density and thermal expansion coefficient (CTE) increased slightly. After adding the refiner, Si network involved dendritic Al in C/C-AlSi was transformed to refined mixed AlSi, Al bulk and Si surrounded dendritic Al, and two kinds of micro-cracks came into being, which resulted in the decreased strength, improved erosion property and increased CTE of C/C-AlSiR. Both AlSi textures and micro-cracks in the modified C/C composites determined the crack propagation and led to their different compressive behaviors and anti-erosion abilities.
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