Role of Zr(OH)4 hard agglomerates in fabricating porous ZrO2 ceramics and the reinforcing mechanisms |
| |
| Affiliation: | 1. Synergy Ceramics Laboratory, Fine Ceramics Research Association, Nagoya 463-8687, Japan;2. Synergy Materials Research Center, National Institute of Advanced Industrial Science and Technology, Nagoya 463-8687, Japan;1. Departamento de Anatomia e Imagem, Universidade Federal de Minas Gerais, Alameda Alfredo Balena, 190, 30130-100 Belo Horizonte, MG, Brazil;2. Departamento de Engenharia Nuclear, Universidade Federal de Minas Gerais, Avenida Antônio Carlos, 6627, 31270-901 Belo Horizonte, MG, Brazil;3. Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN), Belo Horizonte, MG, Brazil;1. Department of Material and Environmental Chemistry, Graduate School of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya-shi, Tochigi 321-8585, Japan;2. Tatsumori Ltd., 50 Minami-Kawada, Kami-Yukiai, Tamura-cho, Koriyama-shi, Fukushima 963-0724, Japan;3. Graduate School of Engineering, Tohoku University, 6-6-04 Aramaki Aoba, Sendai-shi, Miyagi 980-8579, Japan;1. Institute of Solid State Physics, University of Latvia, Latvia;2. Elgootech, Latvia;3. Institute of Inorganic Chemistry, Riga Technical University, Latvia;1. Ural Federal University, 19 Mira Street, 620002 Yekaterinburg, Russia;2. Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Science, Novosibirsk 630090 Russia;3. Institute of Semiconductor Physics, Siberian Branch of Russian Academy of Sciences, Novosibirsk 630090 Russia;4. Novosibirsk National Research University, 2 Pirogova Street, 630090 Novosibirsk, Russia;5. Institute of Physics, University of Tartu, 14c Ravila, 50411 Tartu, Estonia;1. Department of Physics, Jnanabharathi Campus, Bangalore University, Bangalore 560 056, India;2. Department of Physics (S & H), PES Institute of Technology, 100 Feet Ring Road, Banashankari 3rd Stage, Bangalore 560085, India;3. Inter University Accelerator Centre, P.O. Box No. 10502, New Delhi 110 067, India;1. School of Physics, REVA University, Yelahanka, Bangalore 560 064, India;2. Prof. C.N.R. Rao Centre for Advanced Materials Research, Tumkur University, Tumkur 572 103, India;3. Department of Physics, Savitribai Phule Pune University, Pune 411 007, India |
| |
| Abstract: | Porous ZrO2 ceramics were fabricated by adding Zr(OH)4 hard agglomerates to ZrO2 powder, followed by pressureless sintering. The mechanical properties of porous ceramics sintered from pure ZrO2 powder were poor. The addition of Zr(OH)4 increased the strength and fracture toughness of the porous ZrO2 ceramics for sintered specimens containing lower porosity. However, the Young’s modulus had little change so that the strain to failure of porous ZrO2 ceramics increased with the incorporation of Zr(OH)4. Scanning electron microscopy (SEM) observations revealed that microstructures of the green compacts prepared from pure ZrO2 powder were nonuniform due to the ZrO2 soft agglomeration, which resulted in a localized nonuniform shrinkage during densification. The localized nonuniform shrinkage led to a weaker grain bonding and degraded the mechanical properties of porous ZrO2 ceramics. In this work, we found that this microstructure nonuniformity could be eliminated by the addition of Zr(OH)4, because the bimodal particle size distribution confined the formation of ZrO2 soft agglomerates due to a space constraint and an internal friction between the Zr(OH)4 hard agglomerates during compaction. As Zr(OH)4 decomposed into ZrO2 grains during heating, the Zr(OH)4 hard agglomerates disappeared before sintering occurred. The present study indicates that Zr(OH)4 hard agglomerate is a unique agent to improve the mechanical properties of porous ZrO2 ceramics. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
