Effect of pore structure and phase composition on thermal shock resistance of zirconia materials

Authors：Zhang, Yibo; Gu, Huazhi; Fu, Lvping^*; Huang, Ao; Zhang, Meijie

Source：Ceramics International, 2023, 49(24): 40120-40130.

DOI：10.1016/j.ceramint.2023.09.343

• Pore structure
• Phase composition
• Thermal shock resistance
• Nano-zirconia

This study aims to clarify the effect of pore structure and phase composition on the thermal shock resistance of zirconia materials. The results revealed that the presence of pores effectively mitigated thermal expansion. However, excessive apparent porosity significantly degrades the mechanical properties of the material. In contrast, closed pores play pinning and deflection roles in cracks, enhancing the mechanical properties of the material. During sintering, Mg2+ ions infiltrate the m-ZrO2 lattice, forming a c-Zr0.8Mg0.2O1.8 solid solution. This solid solution effectively prevented cracking and damage caused by thermal stress because of its lower thermal expansion coefficient, thereby improving the thermal shock stability of the material. The introduction of nano-zirconia enhanced closed porosity, leading to uniform distribution and a smaller pore size. In addition, owing to its high sintering activity, nano-zirconia promoted the transformation of m-ZrO2 to c-Zr0.8Mg0.2O1.8.