The mechanical and thermophysical properties of La2(Zr1-xCex)2O7 ceramics
The mechanical and thermophysical properties of La2(Zr1-xCex)2O7 ceramics
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La2(Zr1-xCex)2O7陶瓷的力学和热物理性能
DOI：
10.1016/j.jallcom.2015.11.092
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发表时间：
2016-03-05
影响因子：
6.2
通讯作者：
Wang, Jun
中科院分区：
文献类型：
--
作者：
Ma, Wen;Li, Xiaoying;Wang, Jun
采用共沉淀-煅烧法合成了La-2（Zr 1-xCex）（2）O-7（x = 0，0.3，0.5，1.0）粉体。XRD结果表明，La-2（Zr0.5Ce0.5）（2）O-7由La 2Ce 2 O 7和La 2 Zr 2 O 7组成，而在1400 ℃合成了具有烧绿石结构的单相La-2（Zr0.7Ce0.3）（2）O-7。La-2（Zr 1-xCex）（2）O-7（x = 0.3，0.5，1.0）在1600 ℃下烧结，在1450 ℃下表现出优异的相稳定性。La 2Ce 2 O 7在烧结态和1450 ℃热处理不同时间后的显微硬度最高，其次是La-2（Zr0.5Ce0.5）（2）O-7和La-2（Zr0.Ce0.7（0.3））（2）O-7。La-2（Zr0.5Ce0.5）（2）O-7在烧结态具有最高的断裂韧性，为3.8 ± 0.2 MPa m（1/2），其次是La-2（Zr0.7Ce0.3）（2）O-7（3.5 +/-0.2MPa m（1/2））和La 2Ce 2 O 7（2.6 +/-0.3MPa m（1/2）），其比La 2 Zr 2 O 7和8 YSZ高得多。La-2（Zr 0.7Ce 0.3）（2）O-7完全抑制了La_2Ce_2 O_7热膨胀的突然下降。La-2（Zr0.7Ce0.3）（2）O-7在1400 ℃时的烧结速率最低，为1.13 × 10（-7）s（-1），在900 ℃时的热导率最低，为1.06 Wm（-1）K-1。(C)2015 Elsevier B. V.版权所有。
The La-2(Zr1-xCex)(2)O-7 (x = 0, 0.3, 0.5, 1.0) powders were synthesized by coprecipitation-calcination method. The XRD results indicated that La-2(Zr0.5Ce0.5)(2)O-7 comprised of La2Ce2O7 and La2Zr2O7, whereas single phase La-2(Zr0.7Ce0.3)(2)O-7 with pyrochlore structure was synthesized at 1400 degrees C. The bulk La-2(Zr1-xCex)(2)O-7 (x = 0.3, 0.5, 1.0) were sintered at 1600 degrees C and showed excellent phase stability at 1450 degrees C. The La2Ce2O7 possessed the highest microhardness both in as-sintered state and after heat treatment at 1450 degrees C for different times, followed by La-2(Zr0.5Ce0.5)(2)O-7 and La-2(Zr-0.Ce-7(0.3))(2)O-7. The La-2(Zr0.5Ce0.5)(2)O-7 had the highest fracture toughness of 3.8 +/- 0.2 MPa m(1/2) in as-sintered state, followed by La-2(Zr0.7Ce0.3)(2)O-7 (3.5 +/- 0.2 MPa m(1/2)) and La2Ce2O7 (2.6 +/- 0.3 MPa m(1/2)), which are much higher than that of La2Zr2O7 and 8YSZ. The sudden thermal expansion decrease of La2Ce2O7 was fully suppressed in La-2(Zr0.7Ce0.3)(2)O-7. The La-2(Zr0.7Ce0.3)(2)O-7 also had the lowest sintering rate of 1.13 x 10(-7) s(-1) at 1400 degrees C, as well as the lowest thermal conductivity of 1.06 Wm(-1) K-1 at 900 degrees C. (C) 2015 Elsevier B.V. All rights reserved.