Characterization of ceramics materials mixed with Co3O4

We have performed the preparation, structural, electrical and mechanical characterizations of ceramic materials composed of kaolinite Al2(Si2O5)(OH)4 and alumina (Al2O3) mixed with different concentrations of cobalt oxide (Co3O4). Ceramic samples were prepared from a base concentration of alumina 30% and kaolinite 70%, mixed with various concentrations of cobalt oxide in steps of 4% up to a value of 20%. The samples were sintered by the standard solid-state reaction method at a temperature of 1350 °C. In all samples with cobalt was found the presence of mullite. It was determined that alumina and cristobalite decreased when the cobalt concentration was increased due to the formation of the cobalt spinel. In order to determine the crystal structure of the samples, crystallographic analysis from X-ray diffraction experiments and also the semi-quantitative phase analysis were performed. Results were compared with theoretical parameters through the PowderCell 2.4 software. By increasing the concentration of cobalt oxide was found a significant increase in the resistance of materials to friction wear and a small decrease on the mean value of the dielectric constant. Through flexion measurements is observed the increases of the elasticity modulus by about 45% for the sample with 4% of cobalt oxide when compared with the samples without cobalt.