EFFECT OF ALUMINA ON SINTERING BEHAVIOR AND ELECTRICAL-CONDUCTIVITY OF HIGH-PURITY YTTRIA-STABILIZED ZIRCONIA

The sintering behavior and electrical conductivity of high-purity 8-mol% Y2O3-stabilized ZrO2 (8YSZ) with Al2O3 additions were investigated. The addition of 1 wt% Al2O3 to 8YSZ provided dense, sintered samples with 94% relative density at 1400-degrees-C without a holding time. Addition of 1 wt% SiO2 enhanced the sinterability of 8YSZ. Na2O addition of 0.1 wt% remarkably lowered it. Electrical conductivity at 1000-degrees-C in air increased slightly with increased Al2O3 content up to 1 wt% and then monotonously decreased. 8YSZ with 1 wt% Al2O3 showed the maximum conductivity of 0.16 S/cm at 1000-degrees-C.