Catalyst enhancing aluminum titanate for increasing strength of nickel-zirconia cermets

Abstract

Aluminum titanate (ALT), a catalyst-enhancing phase in nickel-zirconia SOFC anodes, has been observed to have the secondary benefit of increasing flexure strength. Ni-YSZ cermet discs doped with 5wt% ALT exhibit 150% of stress at failure of non-doped samples in equibiaxial flexure tests. Also observed is a ∼25% increase in toughness, which may be related to the localized introduction of tetragonal zirconia, or alternatively, that the sintering enhancement effect of ALT yields modified flaw geometry at cermet interfaces. Comparison of non-doped and doped Ni-YSZ σ50% values indicates that the thickness of ALT enhanced anodes could be reduced by ∼20% while maintaining the flexural strength of an unmodified anode.