LaPO4 as a toughening agent for rare earth zirconate ceramics

Publication date: 5 December 2016
Source:Materials & Design, Volume 111
Author(s): Caimei Wang, Lei Guo, Fuxing Ye
Gd2Zr2O7−x mol% LaPO4 (x=0, 10, 20, 30, 40, 50, 60, 100) composites were produced, and their phase constitution and toughness were investigated. XRD and Raman spectra results revealed that Gd2Zr2O7 pyrochlore and LaPO4 monazite phases were compatible in Gd2Zr2O7-LaPO4 composite, and no chemical reaction occurred. TEM analysis demonstrated the coexistence of Gd2Zr2O7 and LaPO4 phases. The toughness of Gd2Zr2O7-LaPO4 composite first increased with the increase of the LaPO4 content, followed by a downward trend. The layer-structure of LaPO4 phase and its weak bond with Gd2Zr2O7 matrix could cause the initial increase in the toughness, and the growth of LaPO4 grains might contribute to the reduced toughness. Considering the fact that rare earth zirconates have similar structure and properties, it could be expected that LaPO4 can be designed as a toughening agent for all the compounds, but there exists an optimal LaPO4 addition content for desirable toughness.

Graphical abstract

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