The influence of metal phase composition on microstructure and mechanical properties of Al2O3-Cu-Cr ceramic metal composites

Abstract

Ceramic metal composites from the ternary Al2O3-Cu-Cr system were fabricated with the use of the slip casting method. Densities of the obtained composites with 15 vol.% of metal content and different percentage composition of Cu and Cr were examined by the Archimedes method. The samples’ microstructures, observed by scanning electron microscope, were analysed with image analysis program in order to determine size distribution of the metallic areas in the structure. Phase composition of the sintered samples was examined by X-ray diffraction analysis. Vickers hardness of the samples was tested along with their fracture toughness with the use of the Vickers indentation technique. The conducted research revealed the correlation between the microstructure and mechanical properties of the obtained specimens. It has demonstrated the possibility of manufacturing composites from ternary system with the use of the slip casting method. It was revealed that the addition of the chromium particles to the metallic phase enhances hardness of the composites. Also, the metallic phase composition of the samples affects mechanism of the crack propagation in the material. Although the mechanical properties have been improved, it was found that the density of the samples was not satisfying and the need for further analysis has been identified.