Size-induced room temperature softening of nanocrystalline yttria stabilized zirconia
Size-induced room temperature softening of nanocrystalline yttria stabilized zirconia
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纳米晶氧化钇稳定氧化锆的尺寸诱导室温软化
DOI：
10.1016/j.jeurceramsoc.2020.01.046
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发表时间：
2020-05
影响因子：
5.7
通讯作者：
Ricardo H.R. Castro
中科院分区：
文献类型：
--
作者：
Lin Feng;Arseniy Bokov;Shen J. Dillon;Ricardo H.R. Castro
纳米晶氧化物表现出优异的抗塑性变形性，表现出增加的强度和硬度，同时降低了晶粒尺寸，定性地遵循所谓的Hall-Petch关系。然而，低于临界晶粒尺寸，软化已被观察到发生，在所谓的逆Hall-Petch制度。这些现象背后的机制在氧化物中仍然没有很好的理解。在这里，我们观察到，使用纳米柱压缩，最初的屈服强度增加，降低晶粒尺寸的氧化钇稳定的氧化锆陶瓷高压放电等离子烧结。当晶粒尺寸小于1.21 nm时，发生硬化-软化转变。实验表明，这种转变取决于应变速率，屈服强度的下降发生在任何剪切断裂开始之前。纳米柱压缩结合原位电子衍射表明软化的发生与每单位应变的晶体旋转量的增加相一致，表明变形机制的变化。
Nanocrystalline oxides exhibit exceptional resistance to plastic deformation, manifesting increased strength and hardness with reduced grain size that qualitatively follows the so-called Hall-Petch relationships. However, below a critical grain size, softening has been observed to occur, in the so-called inverse Hall-Petch regime. The mechanisms underlying these phenomena are still not well understood in oxides. Here we observe, using nanopillar compression, that the yield strength initially increases with decreasing grain size for yttria-stabilized zirconia ceramics produced by high-pressure spark plasma sintering. A hardening-to-softening transition occurs at grain sizes below ≈21 nm. The experiments indicate that this transition depends on strain rate, and the onset of the decrease in yield strength occurs before any shear fracture begins. Nanopillar compression combined with in situ electron diffraction demonstrates the onset of softening coincides with an increase in the amount of crystallographic rotation per unit strain, suggesting a change in deformation mechanism.
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影响因子：
1
作者：
A. Domínguez-Rodríguez;A. Heuer;J. Castaing
通讯作者：
A. Domínguez-Rodríguez;A. Heuer;J. Castaing
影响因子：
6
作者：
M. Sokol;M. Halabi;Y. Mordekovitz;S. Kalabukhov;S. Hayun;N. Frage
通讯作者：
M. Sokol;M. Halabi;Y. Mordekovitz;S. Kalabukhov;S. Hayun;N. Frage
影响因子：
3.7
作者：
Vo, N. Q.;Averback, R. S.;Caro, A.
通讯作者：
Caro, A.
影响因子：
3.9
作者：
Drazin, John W.;Castro, Ricardo H. R.
通讯作者：
Castro, Ricardo H. R.
DOI：
10.1007/bf00405047
发表时间：
1994
期刊：
Journal of Materials Science Letters
影响因子：
--
作者：
R. Rice
通讯作者：
R. Rice