Effect of magnesia rich spinel on densification and stabilization behavior of monoclinic zirconia |
Mahmoud Abdelgawad1,3, S. M. A. El-Gamal2, Emad M. M. Ewais1, Shufeng Li3 |
1Refractory and Ceramic Materials Department, Central Metallurgical Research and Development Institute, Cairo, Egypt 2Faculty of Science, Ain Shams University, Cairo, Egypt 3School of Materials Science and Engineering, Xian University of Technology, Xian, China |
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Received: August 14, 2020; Revised: October 25, 2020 Accepted: October 28, 2020. Published online: May 31, 2021. |
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ABSTRACT |
Fully cubic-stabilized zirconia ceramic composites have been successfully fabricated by conventional sintering technique using commercial monoclinic zirconia, Yttrium oxide and waste-derived magnesia-rich spinel (MMA) powder mixtures. In this study, effect of MMA content and sintering temperature on stabilization and densification properties of zirconia has been duly considered. The obtained results showed that m-ZrO2 in MMA-free Z0 reference specimen is partially stabilized upon temperature rising into tetragonal phase by Y3+ ions diffusion inside zirconia structure. MMA-free Z0 reference specimen sintered at 1600 ºC showed m- and t-ZrO2 dual-phase structure with a relative density of 80.2%. Unlike, upon rising the sintering temperature, Z10–Z50 composites containing 10–50 wt% MMA demonstrated higher relative density of more than 99% and showed variant behavior, where their m-ZrO2 is transformed and stabilized into cubic form by diffusion of Y3+, Mg2+ and Al3+ ions inside zirconia lattice structure. The outcomes indicate that MMA has significantly improved both the densification and stabilization behavior of m-ZrO2 through facilitating Y3+ diffusion inside zirconia lattice structure. |
Key words:
Yttria-stabilized zirconia · MMA-stabilized zirconia · Conventional sintering |
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