Influence of Reducing Media on the Structure and Physicomechanical Properties of Ceramics of the ZrO.sub.2-Y.sub.2O.sub.3-Al.sub.2O.sub.3-NiO - CuO System

We study the regularities of changes in the microstructure, strength, electric conductivity, and micromechanism of fracture of 50% (ZrO.sub.2-8 mole% Y.sub.2O.sub.3-2 wt.% Al.sub.2O.sub.3) + 50% (NiO-5 wt.% CuO) ceramics and the corresponding cermet [intended for manufacturing of the anodes (substrates) in solid-oxide fuel cells] caused by reduction in high-temperature (600°Ð¡) Ar-5% H.sub.2 and N.sub.2-10% H.sub.2-5% CO.sub.2 gas mixtures. It is shown that the investigated cermet has a higher strength and electric conductivity if the calcination temperature of the initial powders is lowered from 900°Ð¡ to 700°Ð¡ and their sintering temperature is lowered from 1450°Ð¡ to 1400°Ð¡. The signs of pollution of this material with carbon compounds were not detected. We also did not reveal any decrease in its strength and electric conductivity after reduction carried out at 600°Ð¡ in a N.sub.2-10% H.sub.2-5% CO.sub.2 gas mixture as compared to the characteristics of the same material reduced in an Ar-5% H.sub.2 mixture.