Determination of the fractal dimension of porous ceramic materials

Porous ceramics were synthesized with open porosities of up to 65.84 %. The porosity was achieved mainly by thermal dissociation of CaCO₃ and graphite burning. The main phases observed in the compositions of the highest porosity were as follows: corundum, gelenite and calcium-aluminate. The values of the coefficient of fractal dimension (D) of the samples were determined. A special computer program was developed to determine the fractal coefficient (D). It used the surface image to make the necessary calculations. The main physico-mechanical properties of the samples were determined. The measured values of the hardness and the modulus of elasticity showed that the samples had a sufficient strength and could be used as a filtration material (hardness of 360 MPa and a modulus of materials elasticity of 13,537 GPa). The dependence of the fractal coefficient D on two of the basic physico-mechanical properties, the Vickers hardness and the modulus of elasticity, was established. The lower values of D indicated increased hardness and modulus of elasticity. This provided to conclude that D values could be used to predict the main physico-mechanical properties of the ceramic samples.Keywords: porous ceramics, fractal analysis, coefficient of fractal dimension, physico-mechanical properties.