EFFECTS OF NH₄HCO₃ CONTENTS ON THE PROPERTIES OF SiC POROUS CERAMICS REINFORCED WITH WHISKERS

Abstract

SiC porous ceramics (SPCs) were prepared from crystalline silicon cutting slurry waste with NH₄HCO₃ (NHC) as the pore-forming agent. The effects of NHC contents on the properties of the as-prepared SPCs were investigated. It was found that the main crystalline phase of the SPCs was β-SiC. The SPCs consisted of SiC particles and SiC whiskers. The thermal shock resistance of the SPCs was obviously strengthened due to the formation of the SiC whisker. When NHC contents were increased to 30 wt.%, the cold compressive strength and thermal shock resistance of the SPCs with porosity of around 63.76% were found to be favourable to the application in the molten metal filtration field.