Optimization of the composition of coarse-grained ceramics

Physical models of filling of the unit volume of space by a substance can be used to establish a correlation between the composition, macrostructure, and physical and mechanical properties of building ceramics and refractories made from coarse-grained masses. In such materials, the coarse-grained component plays the role of filler or reinforcement, while the clay constituent acts as the continuous phase or matrix in the transition to the glassy state. In general, the flow rate of the matrix, Vm, for preparing a unit volume of material (1 m3) is determined by the relation Vm = 1 - Vrein, so that the volume fraction of reinforcement, Vrein, must be increased to decrease the flow rate. The relationship between reinforcement and matrix is examined, the calculations are used to optimise the compositions of coarse-grained masses containing monolithic (SiO2, Carborundum, SiC) or porous (fireclay) reinforcements in a clay matrix. Rational use of the fractions of ground materials enhances the properties of the moulded products. 3 refs.