Yttria mechanical strength

As can be seen, the mechanical strength of the partially stabilized body is approximately twice that of the fully stabilized and the thermal expansion is approximately 30% lower. Because of this, the thermal shock resistance of the PSZ body is greatly improved. The ionic conductivity of the PSZ body is lower but is still adequate for automotive applications. Figure 10 compares the conductivity of a yttria partially stabilized zirconia body with several fully stabilized bodies. 

Electrolyte Yttria stabilised Zirconia (30 0 pm thickness) by EVD technique Oxygen ion conductivity Mechanical strength Gas tightness... 

Ivaschenko O.V., Vasilev A.D., Peitchev V.G. et al. Fracture mechanisms, and strength of zirconia stabilized partially with yttria. Physical and chemical mechanics of materials, 1992, v.28, N6, p.46-50, in Russian. 

The use of yttria ceramics as standalone materials for structural applications is rather limited by their poor mechanical properties. For example, the commercially available 99.9% polycrystalline yttria CeraDoy (Ceradyne Inc.) has a flexural strength of 99 MPa, a hardness of 5.85 GPa, and a fiacture toughness of 1.4MPam. The hardness and fracture toughness of polycrystalline yttria are virtually grain-size... 

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