Low-Temperature Spark Plasma Sintering of Yttria Ceramics with Ultrafine Grain Size
Low-Temperature Spark Plasma Sintering of Yttria Ceramics with Ultrafine Grain Size
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DOI：
10.1111/j.1551-2916.2011.04583.x
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发表时间：
2011-10
影响因子：
3.9
通讯作者：
H. Yoshida;K. Morita;Byung‐Nam Kim;K. Hiraga;K. Yamanaka;K. Soga;Takahisa Yamamoto
中科院分区：
文献类型：
--
作者：
H. Yoshida;K. Morita;Byung‐Nam Kim;K. Hiraga;K. Yamanaka;K. Soga;Takahisa Yamamoto
通过放电等离子烧结 (SPS) 结合低烧结温度 (850°–1050°C) 和低加热速率 (2–50°C/min) 研究了不含任何添加剂的高纯度纳米晶 Y2O3 的可烧结性。在950℃的烧结温度和2℃/min的加热速率下，SPS产生相对密度为99％、平均晶粒尺寸为190nm的多晶Y2O3。以2°C/min的加热速率在950°和1050°C下烧结1小时的Y2O3体在400-800 nm的波长范围内表现出6%-46%的在线透射率。高分辨率透射电子显微镜观察和能量色散X射线光谱仪化学分析表明，烧结的Y2O3体是单相材料，没有任何晶界非晶层或杂质污染。等温 SPS 实验表明，SPS 显着增强了晶界迁移率。电子能量损失谱分析表明，SPS 改变了晶界的原子构型。 Y2O3 烧结性的提高归因于 SPS 激活的缺陷反应引起的扩散增强。
The sinterability of high‐purity, nanocrystalline Y2O3without any additives was investigated by spark plasma sintering (SPS) for a combination of low sintering temperatures (850°–1050°C) and low heating rates (2–50°C/min). At a sintering temperature of 950°C and a heating rate of 2°C/min, the SPS yielded a polycrystalline Y2O3having a relative density of 99% and an average grain size of 190 nm. The Y2O3bodies sintered at 950° and 1050°C for 1h at the heating rate of 2°C/min exhibited an in‐line transmittance of 6%–46% in a wavelength range of 400–800 nm. A high‐resolution transmission electron microscopy observation and chemical analysis by an energy‐dispersive X‐ray spectrometer revealed that the sintered Y2O3bodies were single‐phase materials without any grain‐boundary amorphous layer or impurity contamination. An isothermal SPS experiment indicated that the grain‐boundary mobility is significantly enhanced by the SPS. An electron energy loss spectrometry indicated that SPS changed atomic configuration of the grain boundaries. The improved sinterability of Y2O3is attributed to the enhanced diffusion that arises from defect reactions activated by the SPS.