The subject of the study was the production and characterization of three ceramic-metal graded composites, which differed in addition of the metallic phase. The following composites systems were investigated: Al2O3-Mo, Al2O3-Cu, Al2O3-W. Composites were produced by centrifugal slip casting method. This technique combines the classic casting of the slurry into porous molds with the action of centrifugal force. As a result, sleeve-shaped shapes with a metallic phase gradient were obtained. X-ray phase analysis have not revealed new phases in the produced composites. The type of metallic phase and its distribution in the ceramic matrix influenced the hardness of the produced composites.
The work presents results of solution combustion method utilization for yttria (Y2O3) nanopowder fabrication. Experiments were carried out with four different reducing agents: urea, glycine, citric acid and malonic acid added in stoichiometric ratio. The reactions were investigated using simultaneous DSC/DTA thermal analysis. After synthesis the reaction products were calcined at temperature range of 800-1100°C and analyzed in terms of particle size, specific surface area and morphology. Best results were obtained for nanoyttria powder produced from glycine. After calcination at temperature of 1100°C the powder exhibits in a form of nanometric, globular particles of diameter <100 nm, according to SEM analysis. The dBET for thus obtained powder is 104 nm, however the powder is agglomerated as the particle size measured by dynamic light scattering analysis is 1190 nm (dV50).