Hot-pressed Si3N4 ceramics with Lu2O3 additives: Grain-boundary phase and strength
Hot-pressed Si3N4 ceramics with Lu2O3 additives: Grain-boundary phase and strength
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DOI：
10.1016/j.msea.2005.05.025
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发表时间：
2005-11
期刊：
影响因子：
6.4
通讯作者：
Shuqi Guo;N. Hirosaki;Yoshinobu Yamamoto;T. Nishimura;Y. Kagawa
中科院分区：
文献类型：
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作者：
Shuqi Guo;N. Hirosaki;Yoshinobu Yamamoto;T. Nishimura;Y. Kagawa
使用透射电子显微镜对热压 Lu2Si2O7-Si3N4 和 Lu4Si2O7N2-Si3N4 组合物的晶界相进行了表征。在Lu2Si2O7-Si3N4组合物的情况下，多晶粒结袋是完全结晶的，而在Lu4Si2O7N2-Si3N4情况下，袋是部分结晶的。两种组合物中，两种晶粒交界处呈现的晶粒间非晶薄膜很常见。 Lu 2 Si 2 O 7 -Si 3 N 4 组合物的薄膜厚度为0.5-1.0 nm，Lu 4 Si 2 O 7 N 2 -Si 3 N 4 组合物的薄膜厚度为1.6-2.3 nm。另一方面，这两种组合物在 25 至 1600 摄氏度之间的温度下以四点弯曲方式断裂。 C、在干燥的N2气氛中。 1400度及以下C，对于每种组合物仅观察到线性应力-应变响应。在 1500 度及以上的温度下，在应力-应变曲线中观察到非线性响应。 C 为 Lu4Si2O7N2-Si3N4 组合物，而这种响应是在 1600 ℃ 下观察到的。 C为Lu2Si2O7-Si3N4组成。与 Lu2Si2O7-Si3N4 组合物相比，Lu4Si2O7N2-Si3N4 组合物的弯曲强度更大
The grain-boundary phase of hot-pressed Lu2Si2O7-Si3N4 and Lu4Si2O7N2-Si3N4 compositions was characterized using a transmission electron microscopy. In the case of the Lu2Si2O7-Si3N4 composition the multiple-grain junction pockets were completely crystalline and in the Lu4Si2O7N2-Si3N4 case the pockets were partially crystalline. The thin intergranular amorphous film presented at two-grain junctions was common in the two compositions. The thickness of the thin film was 0.5-1.0 nm for the Lu2Si2O7-Si3N4 composition and 1.6-2.3 nm for the Lu4Si2O7N2-Si3N4 composition. On the other hand, the two compositions were fractured in four-point flexure, at temperatures between 25 and 1600 deg. C, in a dry N2 atmosphere. At and below 1400 deg. C, only linear stress-strain response was observed for each composition. Nonlinear response was observed in the stress-strain curves for temperatures at and above 1500 deg. C for the Lu4Si2O7N2-Si3N4 composition, while this response was observed at 1600 deg. C for the Lu2Si2O7-Si3N4 composition. The flexural strength of the Lu4Si2O7N2-Si3N4 composition was greater, compared to that of the Lu2Si2O7-Si3N4 composition