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专业: 高分子合成化学

[交流] 通过DMA对氧化陶瓷的相转变和黏弹松弛进行研究已有1人参与

DMA is commonly used to study modulus and damping behavior of soft materials with relatively low stiffness. In this paper, we demonstrate that Dynamic Mechanical Analyzer (DMA) Q800 can be used as easy and convenient method to study phase transformations and anelastic relaxation in ceramics with high elastic modulus. By measuring storage modulus (stiffness), loss modulus and damping (tan δ) simultaneously using DMA, influence of structural changes caused by phase transformations or anelastic relaxation on mechanical behavior can be studied directly. Doped oxide ceramics, such as 10 mol% Sc2O3 – 1 mol% CeO2 stabilized ZrO2 (ScCeSZ), are excellent solid ionic conductors commonly used as electrolytes in solid oxide fuel cells (SOFCs). Understanding their thermo-mechanical properties is essential for the reliability and durability of SOFCs. In this article, the effect of anelastic relaxation and phase transformation of ScCeSZ on changes in its elastic moduli with temperature were studied using a DMA Q800. Temperature sweep, multi-frequency, constant amplitude and single cantilever set up are used. Two loss modulus peaks are associated with anelastic relaxations of structural defect complexes (i.e. cation-oxygen vacancy dipoles) while the other two are found to be caused by reversible phase transformations. At the same time a sudden drop of storage modulus was observed in the temperature range that corresponds to phase transformations or maximum loss due to anelastic relaxation.

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