Influence of Aging on Mechanical Properties of Yttria-Doped Zirconia

Abstract

We evaluated the influence of aging on mechanical properties of 8% yttria-doped zirconia (8YSZ) from room temperature to 1200 K. The temperature dependence of the dynamic Young’s and shear moduli of 8YSZ with and without the aging treatment was investigated by using a resonance method. The dynamic Young’s and shear moduli of 8YSZ without the aging treatment decreased by 33% below 700 K and gradually increased at higher temperatures with increasing temperature. On the other hand, those with the aging treatments decreased by around 20% below 600 K while did not significantly change above 600 K with increasing temperature. These demonstrated the effect of aging on the dynamic Young’s and shear moduli of 8YSZ was most remarkable at intermediate temperatures (600~1000 K). Although it was suggested that the existence ratio of the metastable tetragonal phase was increased during the aging treatment, it is likely that the influence of this phase transition on the dynamic Young’s and shear moduli was not significant. It seemed that the difference in the dynamic Young’s and shear moduli of 8YSZ with and without the aging treatment at intermediate temperatures was due to the local ordering of the oxygen vacancies.

Frontiers of Flash Sintering and Functional Activation by Electric Field Application

“…ュ焼結中に岩塩構造の ZrO が生成することが報告されてい る (19) ．さらに，8YSZ 系セラミックスにおいて，AC 強電場 を用いたフラッシュ現象を起こすことにより，室温で擬弾性 的挙動を示すようになることがナノインデンテーション計測 により明らかとなった (20) ．これは YSZ で従来報告されてい るような，300°C～700°Cで認められる内部摩擦の増加や弾 性定数の低下 (21)…”

In Situ Evaluation of the Influence of Interstitial Oxygen on the Elastic Modulus of La2NiO4

“…r rep, eq r 0 rep, eq −4 (18) where r 0 rep,eq and A 0 are the representative distance and the constant A at standard conditions. The relationship between A and the electrostatic potential in the crystal, U e , is expressed as follows:…”

“…Many SOFC component materials are known to change their crystal structure and oxygen nonstoichiometry, δ, depending on temperature and oxygen partial pressure (P(O 2 )), i.e., µ O , and those changes have a substantial impact on their mechanical properties [11][12][13][14][15][16][17][18][19][20][21][22]. In particular, the mechanical properties of cathode and interlayer materials are reported to Metals 2021, 11, 1889 2 of 14 be greatly influenced by changes in oxygen nonstoichiometry.…”

“…The resonance method is a dynamic measuring method by which elastic moduli are obtained from the resonance frequencies of a sample. The resonance method is a non-destructive method, and hence the temperature and P(O 2 ) dependence of the elastic moduli can be systematically measured with high accuracy using a single sample [13,18,21,22]. Additionally, this dynamic measuring method can provide the internal friction of the sample, which allows us to evaluate the degree of the non-elastic behavior of the material.…”

Long-Term Conductivity Stability of Electrolytic Membranes of Scandia Stabilized Zirconia Co-Doped with Ytterbia

“…Yttria-stabilized zirconia (YSZ) is still widely used as a solid electrolyte. The aging of YSZ solid electrolytes was considered in [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. When studying YSZ ceramic samples, it was noted that in addition to volumetric degradation, there is also a change in the resistance of grain boundaries, which, in combination with a change in bulk conductivity, affects the degradation of the total conductivity of solid solutions.…”