Synthesis of Alumina-Zirconia-Yttria Ceramics and Correlation of Mechanical Properties with Phase Formation and Microstructure

Abstract

Phase formation dependence of microstructure and mechanical properties were studied in 0.65Al₂O_3–0.35ZrO₂ with 2 to 8 wt.% Y₂O₃ addition (AZY). Phase composition of the samples were characterized by x-ray diffraction (XRD) technique. It was found that the major phase was the rhombohedral-Al₂O₃, while the minor phase consisted of the monoclinic (m)-ZrO₂, tetragonal (t)-rO_2, cubic (c)-ZrO₂ and monoclinic (m)- Y₂O₃. It has been found that the optimal contents of Y₂O₃ prohibited growth of grain in ceramics and obtained highly dense ceramics. It was found that the smaller grains had high fracture toughness. The maximum fracture toughness of 4.204 MPa m^1/2 was obtained from 8 wt% Y₂O₃. Refinement of lattice parameters using Rietveld analysis revealed that the quantitative phases of AZY ceramics. This shows that under Y₂O₃ addition conditions the proportion of tetragonal-ZrO₂ phase play an important role for the mechanical properties of AZY ceramics.

Keywords:

• XRD
• fracture toughness
• 0.65Al₂O_3–0.35ZrO₂

Acknowledgments

The work is carried out with financial assistance from Faculty of Science, Mahasarakham University and Division of Research, Mahasarakham University, Thailand.