Phase structure and thermal conductivities of Er2O3 stabilized ZrO2 toughened Gd2Zr2O7 ceramics for thermal barrier coatings

3.5 mol% Er2O3 stabilized ZrO2 (ErSZ) and Gd2Zr2O7 powders were produced by a chemical co-precipitation and calcination method, and ErSZ was used to toughen Gd2Zr2O7. The phase structure, toughness and thermal conductivities of ErSZ toughened Gd2Zr2O7 ceramics were investigated. When the ErSZ content was below 15 mol%, the compound consisted of pyrochlore phase, the ordering degree of which decreased with the increase of the ErSZ content. High ErSZ doping led to the formation of metastable tetragonal (t′) phase in the compound. The addition of ErSZ in Gd2Zr2O7 benefited its toughness, mainly attributable to the presence of t′ phase in the compound. With the increase of the ErSZ content in the compound, the thermal conductivity first decreased and then showed an upward tendency, and 10 mol% ErSZ toughened Gd2Zr2O7 exhibited the lowest thermal conductivity.