Effect of Al₂O₃ Addition on Microstructure, Thermal Expansion and Mechanical Properties of Ta₂O₅ Ceramics

Abstract:

The Ta₂O₅-based ceramics were prepared by dry pressing/sintering technique using Ta₂O₅ and Al₂O₃ as the starting materials. The present work investigated the effect of alumina (Al₂O₃) additions on the composition, microstructure, thermal expansion coefficient (TEC) and bending strength of Ta₂O₅ ceramics. The thermal expansion of the samples was measured by the dilatometry method. It was found that Al₂O₃ additions can effectively inhibit the β to α phase transformation in Ta₂O₅ ceramics. Orthorhombic AlTaO₄ as the minor phase formed when 2.5 and 7.0 wt% Al₂O₃ was added. The addition of Al₂O₃ results in obvious change of TEC and an increase of bending strength. This work demonstrated that the addition of Al₂O₃ is an effective way to modify the TEC and mechanical strength of Ta₂O₅ ceramics.

• Periodical: Key Engineering Materials (Volumes 512-515)
• Pages: 631-634
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.512-515.631
• Online since: June 2012
• Authors: Jian Er Zhou, Jing Zhang, Xiao Zhen Zhang, Xue Bing Hu
• Keywords: Alumina, Bending Strength, Phase Transformation, Tantalum Pentoxide, Thermal Expansion Coefficient

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