Fabrication and characterization of ZrO2/Ni composites

This paper focuses on a research on the influence of nickel content in zirconia matrix and its impact on the mechanical properties of obtained composites. ZrO2/Ni mixed powders were uniaxially pressed and sintered in a nitrogen atmosphere to obtain ZrO2/Ni composites that were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDS). The stereological analysis allows obtaining information about the size distribution of zirconia grains in the sintered composites. Relative density, hardness, fracture toughness, and bending strength were also analyzed. The results revealed that the presence of Ni particles in the composites affects the mechanical properties of the materials. An increased Ni concentration caused a decrease in Vickers hardness and increased the fracture toughness of the ZrO2/Ni composites compared to the ZrO2 samples. This kind of composite is of interest for temperature and flow sensors, thermal barrier coatings for gas turbines and supersonic propulsion systems of spacecrafts, as well as as a material for anode in solid oxide fuel cell.