Effects of Rare Earth Oxides on Microstructures and Properties of Magnesia Refractories

Abstract:

The effects of Y2O3, La2O3 and Nd2O3 on the sintering, microstructure and mechanical properties of magnesia refractories were investigated. Addition of rare earth oxide (ReO) to magnesia refractories increases the bulk density, decreases the porosity and improves the mechanical strength of the refractories. The improved sinterability was attributable to the vacancies generation associated with the solid-solution reactions between MgO and ReO. In the samples with ReO, rare earth silicate phases form at magnesia grain boundaries, providing additional bonding between magnesia grains and between magnesia grains and matrix. Consequently, the samples with ReO showed much higher high temperature strengths than those without ReO.

• Periodical: Key Engineering Materials (Volumes 368-372)
• Pages: 1158-1160
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.368-372.1158
• Online since: February 2008
• Authors: Bao Guo Zhang, Zhou Fu Wang, Shao Wei Zhang, Xi Tang Wang, Zi Wei Xu
• Keywords: Magnesia Refractory, Microstructure, Rare Earth Oxide, Sintering

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