CAST (SELF-FLOW) CERAMIC CASTABLES. PT.4. SPREADABILITY OF MOULDING SYSTEMS AND SOME PROPERTIES OF MULLITE-SILICON CARBIDE CERAMIC CASTABLES

The rheological properties of moulding systems are shown to depend on the spreadability of the mixture under the action of its own mass; some of the factors influencing the self-flow are determined, namely, the moisture content, the content of the filler, and the temperature of the mixture. The described self-flow castables based on a mullite HCBS and a SiC filler have a porosity of 18% after drying and 16-16.5% after heat treatment. Their ultimate bending strength is 45 MPa and the ultimate compressive strength is 110 MPa, which is higher than those of the known refractories of similar compositions. The temperature of 4% deformation of mullite-SiC refractory heat treated at 1350 C and having CVf = 0.4 is 1710-1720 C, which is 70-80 C higher than that of a similar material moulded by pressing and heat treated at 1500 C. 15 refs.