Production, characterization and calculating effective diffusion constant of alumina, zirconia and alumina-zirconia composite material

Because of technological development, is need more specific materials. So study of the composite material production is increased at last few years. Two or more materials come together to make a better material is called composite material. In this study, Al2O3, ZrO2, Al2O3-ZrO2 composite material were produced by sol-gel method, then, produced materials were calsined at 700 oC and they were characterized, and after, calculated effective diffusion coefficient and adsorption equilibrium constant by using single pellet moment technique. The produced materials were characterized to crystal phases observed by XRD, to termal stability analysed by DSC-TGA, to microstructure examinated by SEM-EDS, to specific surface area and pore diameter determined by BET method, to density measured by He pycnometer. For diffusivity of gases, specific surface area and pore diameter are very important parameter. Specific surface area of Al2O3, ZrO2, Al2O3-ZrO2 composite material are respectively; 52.55 m2/g, 9.5 m2/g, 126.5 m2/g. For single pellet moment technique, the produced materials pressed in to the ring with two different height. For this process Wicke-Kallenbach type diffusion cell was used. Experimental conditions are 1 atm pressure and 25 oC temperature. N2 is transporter gas, He and H2 are tracer gas. Top flow rate and referans flow rate is constant, but bottom flow rate is change during the study. The effective diffusion coefficient of Al2O3, ZrO2, Al2O3-ZrO2 composite material are for He respectively; 0.0205 cm2/s, 0.0064 cm2/s, 0.0084 cm2/s; for H2 respectively; 0.0307 cm2/s, 0.0077 cm2/s, 0.01 cm2/s. Adsorption equilibrium constant of Al2O3, ZrO2 and Al2O3-ZrO2 composite material are for H2 respectively; 0.033 cm3/g, 0.014 cm3/g , 0.011 cm3/g