Microstructural, mechanical, and electrical characteristics of alumina-reinforced ytterbia-stabilized cubic zirconia-based composites

Abstract

Al 2 O 3 -dispersed Yb 2 O 3 -stabilized cubic-ZrO 2 (YbSZ) composites are fabricated by pressureless sintering of composite powders to obtain fine and homogeneous microstructures by the solution chemistry route. Al 2 O 3 particles are deposited on ZrO 2 powders by the precipitation of aluminum nitrate followed by calcination in air. The sinterability of the composites was affected by the calcination temperature. Microstructures of the sintered bodies are dependent on the Al 2 O 3 content. For the 5 vol% Al 2 O 3 -dispersed composite, fine Al 2 O 3 particles were mainly located inside the grains of zirconia, whereas relatively large Al 2 O 3 particles almost dispersed at the grain boundaries when the Al 2 O 3 content was increased. The grain growth of YbSZ was suppressed by the Al 2 O 3 addition, and the refinement of the matrix grain improved the fracture strength of YbSZ. The YbSZ and YbSZ/Al 2 O 3 composites exhibited almost similar ionic conductivity at high temperatures of around 1000°C.

Ion Transport and Thermomechanical Properties of SrFe(Al)O[sub 3−δ]–SrAl[sub 2]O[sub 4] Composite Membranes

“…Analogous improvement in the mechanical properties, including the fractural strength, fractural toughness, and thermal shock resistance, is well known for the stabilized ZrO 2 -␣-Al 2 O 3 composites. [29][30][31] In the latter case, such behavior can be attributed to several factors, namely, suppressed grain growth, load sharing effect, and crack deflection by the dispersed alumina particles. The same effects may also be expected for ͑SrFe͒ 1−x ͑SrAl 2 ͒ x O z ceramics consisting of homogeneously distributed fine grains of the two phases ͑Fig.…”

Microstructural and Electrical Conductivity Relationships in Alumina- Containing Yttria Stabilized Cubic Zirconia Used as a Solid Electrolyte in Solid Oxide Fuel Cells

“…Despite these advantages, room and high temperature mechanical properties of the cubic zirconia are rather low. Therefore, it is necessary to improve the mechanical properties of cubic zirconia to guarantee the lifetime and reliability of the solid oxide fuel cell system (10). Generally, the properties of ceramics depend on the microstructure.…”

“…Generally, the properties of ceramics depend on the microstructure. Many researcher have shown (10,11) that dispersion of nano-sized particles into matrix grains is an effective technique for improving mechanical properties of ceramics without deteriorating electrical conductivity.…”