MECHANICAL BEHAVIOR OF INTERPENETRATING Al-SiC COMPOSITES DERIVED FROM WOOD TEMPLATES

Biomorphic silicon carbide stands as a new class of materials fabricated by reactive infiltration of molten silicon in carbonaceous preforms obtained from wood pyrolysis [1]. The basic material is a Si/SiC composite, in which the SiC forms a skeleton that replicates the wood microstructure and the unreacted Si fills the pores. Silicon can be removed from the composite creating a highly porous SiC material that can be refilled with an Al alloy to create cermets with an interpenetrating structure [2]. Wood precursors are diverse, resulting in different densities and microstructures, and leading to cermets with different microstructures. The mechanical behavior at ambient and elevated temperature of these materials was determined and correlated to the microstructure.