Manufacturing of cellular β-SiAlON/β-SiC composite ceramics from cardboard

Light-weight, cellular β-SiAlON/SiC ceramics were produced via dip-coating of an Al/Si-powder containing preceramic polymer slurry into corrugated cardboard. The coated cardboard preforms were pyrolyzed in Ar-atmosphere at 1200◦C, where the cellulose fibres decomposed into carbon. Simultaneously the Al/Si melt infiltrated into the porous carbon and formed β-SiC. Subsequent nitridation at temperatures between 1200–1530◦C resulted in the formation of a β-SiC-containing β-Si6−zAIzOzN8−z composite. Different pre-oxidation treatment resulted in a variation of the oxygen content in the solid solution phase (z = 0.6–1.2). C 2006 Springer Science + Business Media, Inc