Decoupling grain growth from densification during sintering of oxide nanoparticles
Decoupling grain growth from densification during sintering of oxide nanoparticles
复制标题
氧化物纳米粒子烧结过程中晶粒生长与致密化的脱钩
DOI：
10.1039/c5ra27844a
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发表时间：
2016
期刊：
影响因子：
3.9
通讯作者：
K. Kobayashi
中科院分区：
文献类型：
--
作者：
Y. Kinemuchi;H. Nakano;K. Kato;K. Ozaki;K. Kobayashi
当外部压力施加在氧化物纳米颗粒（NP）上时，它们在低于其熔化温度一半的温度下致密化而不表现出显著的晶粒生长。这种类型的致密化行为与致密化过程中观察到的通常的烧结行为相矛盾，通常的烧结行为不可避免地伴随着晶粒生长。已经发现，包括ZnO、CuO、TiO2、SnO2、Fe2O3和BaTiO3的各种氧化物的NP在远低于其熔化温度的一半的温度下显示出轻微的低温致密化（LTD），即使当不施加外部压力时。在这里，我们报告说，有限责任公司是至关重要的致密化的纳米粒子在压力烧结过程中：没有有限责任公司，致密化没有充分的进展，即使当压力高达2 GPa的应用。LTD的现象可以归因于在NP中的表面和/或边界扩散，因为LTD的低热活化能以及其对NP表面形态变化的敏感性。氧化物纳米颗粒中晶粒生长与致密化的解耦可能与LTD辅助的屈服变形有关，即表面原子的迁移，这并不伴随着显著的晶格扩散。
When external pressure is exerted on oxide nanoparticles (NPs), they densify without exhibiting significant grain growth at temperatures lower than half their melting temperature. This type of densification behavior contradicts the usual sintering behavior observed during densification, which is inevitably accompanied by grain growth. It has been found that NPs of various oxides, including ZnO, CuO, TiO2, SnO2, Fe2O3, and BaTiO3, show slight low-temperature densification (LTD) at temperatures much lower than half their melting temperature, even when an external pressure is not applied. Here we report that LTD is crucial for the densification of NPs during pressure sintering: without LTD, densification does not progress sufficiently even when a pressure as high as 2 GPa is applied. The phenomenon of LTD can be ascribed to surface and/or boundary diffusion in the NPs because of the low thermal activation energy of LTD as well as its sensitivity to changes in the NP surface morphology. It is likely that the decoupling of grain growth from densification in oxide NPs is related to LTD-assisted yield deformation, that is, the migration of surface atoms, which is not accompanied by significant lattice diffusion.
影响因子：
3.1
作者：
H. Nakano;M. Yamada;M. Fukumoto;E. Yamaguchi
通讯作者：
H. Nakano;M. Yamada;M. Fukumoto;E. Yamaguchi