Fabrication of submicron alumina ceramics by pulse electric current sintering using M2+ (M=Mg, Ca, Ni)-doped alumina nanopowders
| Autor: | Seiichi Taruta, Tomohiro Yamaguchi, Masahiro Hida, Kunio Kitajima, Atsushi Odaka |
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| Rok vydání: | 2009 |
| Předmět: |
Sol-gel processes
Materials science Dopant Process Chemistry and Technology Metallurgy Composite number Sintering Microstructure Grain size Nanocrystalline material Surfaces Coatings and Films Electronic Optical and Magnetic Materials Chemical engineering Materials Chemistry Ceramics and Composites Relative density Ball mill Al(2)O(3) |
| Zdroj: | Ceramics International. 35:1845-1850 |
| ISSN: | 0272-8842 |
| DOI: | 10.1016/j.ceramint.2008.10.007 |
| Popis: | Dense submicron-grained alumina ceramics were fabricated by pulse electric current sintering (PECS) using M(2+)(M: Mg, Ca, Ni)-doped alumina nanopowders at 1250 degrees C under a uniaxial pressure of 80 MPa. The M(2+)-doped alumina nanopowders (0-0.10 mass%) were prepared through a new sol-gel route using high-purity polyhydroxoaluminum (PHA) and MCl(2) solutions as starting materials. The composite gels obtained were calcined at 900 degrees C and ground by planetary ball milling. The powders were re-calcined at 900 degrees C to increase the content of a-alumina particles, which act as seeding for low-temperature densification. Densification and microstructural development depend on the M(2+) dopant species. Dense alumina ceramics (relative density >= 99.0%) thus obtained had a uniform microstructure composed of fine grains, where the average grain size developed for non-doped, Ni-doped, Mg-doped and Ca-doped samples was 0.67, 0.67, 0.47 and 0.30 mu m, respectively, showing that Ca-doping is the most promising method for tailoring of nanocrystalline alumina ceramics. (c) 2008 Elsevier Ltd and Techna Group S.r.l. All rights reserved. Article CERAMICS INTERNATIONAL. 35(5):1845-1850 (2009) |
| Databáze: | OpenAIRE |
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