Effect of microwave sintering temperature on the microstructure and fracture toughness of La2O3/Nb2O5 doped Al2O3 ceramics

DOI

10.2991/meita-15.2015.86How to use a DOI?

Keywords

Al2O3 ceramics; microwave sintering temperature; columnar grains; fracture toughness; Nb2O5/La2O3

Abstract

Al2O3 ceramics doped with 15%Nb2O5 and 7.5%La2O3 (volume percent) were prepared by microwave sintering at 1450 1550 for 30min. The effect of sintering temperature on the microstructure, especially Al2O3 columnar grains, and the fracture toughness were investigated. The results show that the phases of sintered samples were -Al2O3, LaNbO4 and Nb2O5, without La2O3. During the sintering period, the in-situ reacted LaNbO4, and the remained Nb2O5 after reacting, changed to liquid which promoted the growth of Al2O3 columnar grains and sintering densification. With the increase of sintering temperature, more and more columnar Al2O3 grains grew instead of equiaxial grains, and the columnar grains length increased from 8 m to 22 m. The average ratio of length to diameter of columnar grains increased firstly and reached to the maximum of 5:1 at 1500 , then keep unchanged. The fracture toughness increased with the increase of sintering temperature, from 4.83 to 6.48 MPa•m1/2.

Copyright

© 2015, the Authors. Published by Atlantis Press.

Open Access

This is an open access article distributed under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).

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TY  - CONF
AU  - Changhong Liu
AU  - Yunlong Ai
PY  - 2015/08
DA  - 2015/08
TI  - Effect of microwave sintering temperature on the microstructure and fracture toughness of La2O3/Nb2O5 doped Al2O3 ceramics
BT  - Proceedings of the 2015 International Conference on Materials Engineering and Information Technology Applications
PB  - Atlantis Press
SP  - 475
EP  - 479
SN  - 2352-5401
UR  - https://doi.org/10.2991/meita-15.2015.86
DO  - 10.2991/meita-15.2015.86
ID  - Liu2015/08
ER  -