Preparation and Characterization of Alumina Zirconia Composite Ceramics

Abstract

The composite ceramics between Al₂O₃ (6 mol%MgO) and ZrO₂ (4 mol%Y₂O₃) were prepared in the Al₂O₃ (6 mol%MgO added: ZrO₂ (4 mol%Y₂O₃ added) ratios of 20:80, 35:65, 50:50, 65:35 and 80:20. All of samples were sintered using two stage sintering routes with the first temperature (T₁) at 1600 °C for 30 min and the second temperature (T₂) at 1450 °C for 5 h. The physical properties were characterized from percentage of shrinkage and bulk density. It can be found their tend to decrease with Al₂O₃ (6 mol%MgO) content increase. XRD patterns were showed combination main phase of rhombohedral of Al₂O₃ and monoclinic, cubic, tetragonal of ZrO₂. Rietveld refinement were used to calculate the percentage of phase composition. All of samples were revealed weight percentage of main composition as m-ZrO₂ c-ZrO₂ t-ZrO₂ and r- Al₂O₃ in different ratios. It can be found, sample with more content of ZrO₂ was showed higher weight percentage of c-ZrO₂. The high intensity of Al₂O₃ peak was appeared from sample with high Al₂O₃ concentration. SEM micrographs reveal morphology of grain such as grain shape and size of grains. The average grain size value is between 0.81 and 1.07 µm and the size of grain tend to increase with high Al₂O₃ content. EDX technique were analyzed element compositions of Al₂O₃ (6 mol%MgO): ZrO₂ (4 mol%Y₂O₃) and EDX spectra were showed wt.% element of Al, Zr, O Y and Mg which is confirmed molecular formular. Moreover, EDX method is identified square shape of Al₂O₃ (6 mol%MgO) and round shape of ZrO₂ (4 mol%Y₂O₃). The mechanical properties were measured by Vickers and Knoop hardness that were used for calculating the fracture toughness value. It can be found that the optimum mechanical properties were obtained from composite ceramic of 0.35Al₂O₃ (6 mol%MgO): 0.65ZrO₂ (4 mol%Y₂O₃) which is showed the highest of fracture toughness value about 0.38 GPa.m^1/2.

Keywords:

• ZrO₂
• Y₂O₃
• MgO
• Al₂O₃
• mechanical properties
• Rietveld refinement

Disclosure Statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research project was financially supported by Thailand Science Research and Innovation (TSRI) and Mahasarakham University, Thailand.