Biomimetic synthesis of cellular SiC based ceramics from plant precursor

A novel biomimetic approach in designing and fabricating engineering ceramic materials has gained much interest in recent times. Following this approach, synthesis has been made of dense Si -SiC duplex ceramic composites and highly porous SiC ceramics in the image of the morphological features inherent in the caudex stem of a local monocotyledonous plant. The process route involves making of a carbonaceous biopre- form and its subsequent reaction with an infiltrating silicon melt to yield the biomorphic Si -SiC ceramic composites with flexural strength and Young's modulus of 264 MPa and 247 Gpa, respectively and loss in weight of only ~ 9% during oxidative heating up to 1200°C in flowing air. The Si-SiC composites were transformed into porous (49 vol.%) SiC ceramics with complete preservation of microcellular anatomy of the parent plant, by depleting residual silicon phase in channel pores through re- action with carbon. SiC based materials so derived can be used in structural applications and in designing high temperature filters and catalyst supports.