Grain size dependence, mechanical properties and surface nanoeutectic modification of Al2O3-ZrO2 ceramic
| Autor: | Zhi-Gang Wang, Yang Wang, Yujin Wang, Yong-Hui Ma, Ling-Yun Xie, Jia-Hu Ouyang, Zhan-Guo Liu, Abdelkhalek Henniche |
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| Rok vydání: | 2019 |
| Předmět: |
010302 applied physics
Toughness Materials science Process Chemistry and Technology Sintering 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Grain size Surfaces Coatings and Films Electronic Optical and Magnetic Materials Grain growth Flexural strength visual_art 0103 physical sciences Particle-size distribution Materials Chemistry Ceramics and Composites visual_art.visual_art_medium Ceramic Composite material 0210 nano-technology Eutectic system |
| Zdroj: | Ceramics International. 45:14297-14304 |
| ISSN: | 0272-8842 |
| Popis: | The present work aims to provide fundamental insights into the grain size dependence and mechanical behavior of hot-pressed Al2O3-ZrO2 ceramic at its eutectic composition, and further to explore the hardening effect of laser-induced surface nanoeutectic layer. The underlying correlations between densification behavior, grain size distribution and mechanical properties were elucidated. Sintering at 1550 °C promotes the densification without extensive grain growth, and in this case the sample exhibits a critical density of 99.3 %. The average grain size is tailored into a range of 0.6–0.9 μm, and the measured flexural strength and toughness reach 1100 MPa and 11 MPa·m1/2, respectively. The metastable t-ZrO2 grains indeed play a pivotal role in energy dissipation at the crack tip through crack deflection and branching. In addition, the mechanical behavior is reasonably explained through constructing a multilevel toughening mechanism map associated with grain size distribution of ZrO2. Particularly, surface nanocrystallized Al2O3-ZrO2 eutectic layer with a thickness of 1000 μm free of pores and cracks is achieved by a rapid laser melting process. The outmost laser-modified nanoeutectic layer exhibits a fine cellular structure with an interphase spacing of only 105 nm and a hardness of as high as 26.1 GPa, which provides a promising potential in enhancing significantly the hardness and wear resistance for applications as sliding ceramic components. |
| Databáze: | OpenAIRE |
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