Biomimetic synthesis and properties of cellular SiC

Abstract

Biomorphous beta-SiC ceramics were produced from several species of wood such as ash, wild cherry, black alder, Persian walnut, sessile oak and European hornbeam. The wood was pyrolysed, impregnated with tetraethyl orthosilicate (TEOS) sol in repeated cycles and thermally treated at 1800 degrees C in vacuum. Four specimen groups included charcoal and three groups with 1, 3 and 5 cycles of impregnation were analyzed. Flexural and compressional strength of charcoal and woodlike SiC ceramics were measured using three-point and compression testing in different directions. Experimental results showed that mechanical properties of woodceramics were improved by repeating of impregnation cycles. Porosity measurement, dilatometric analysis, XRD and SEM analysis were used to study the macroscopical and microscopical properties of the resulting biomorphic SiC ceramics.