ENHANCED OXIDATION RESISTANCE AND MICROHARDNESS OF NI-YSZ COMPOSITES VIA THE FORGING IN AIR.

Nickel-ceramics composites are very promising materials for various industrial applications. Significant progress was achieved in the field of composite nickel-ceramic coatings development. However, in case of bulk nickel-ceramics composites the available information is quite insufficient. In this study the effect of forging on the microstructure, oxidation resistance, and microhardness of Ni-8Y2O3-92ZrO2 (Ni-YSZ) composites was revealed. Nickel-YSZ composites were manufactured by powder metallurgy technique with following vacuum annealing at 1250 °C; in addition, forging at 1000 °C was applied. Oxidation behavior was studied by termogravimetry in air. The microstructure of the composites was investigated via SEM, XRD, and EBSD analysis. It was shown that forged composites do not undergo oxidation in the temperature range 20-950 °C. Forged Ni-YSZ composites exhibited improved Vickers hardness (HV) compared to bulk nickel. [ABSTRACT FROM AUTHOR]