Sintering densification and microstructure formation of bulk Al2O3/YAG eutectic ceramics by hot pressing based on fine eutectic structure
Sintering densification and microstructure formation of bulk Al2O3/YAG eutectic ceramics by hot pressing based on fine eutectic structure
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DOI：
10.1016/j.matdes.2015.12.017
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发表时间：
2016-02
影响因子：
8.4
通讯作者：
Bin Yao;H. Su;Jun Zhang;Q. Ren;Weidan Ma;Lin Liu;H. Fu
中科院分区：
文献类型：
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作者：
Bin Yao;H. Su;Jun Zhang;Q. Ren;Weidan Ma;Lin Liu;H. Fu
Highly-dense Al2O3/YAG bulk eutectic ceramics with fine irregular eutectic structure are produced by a facile way of hot pressing method based on a unique micro-eutectic structure. The densification behavior and microstructure formation are investigated. The eutectic particles with different sizes (< 4 μm, 4–10 μm, < 25 μm) and homogenous micro-eutectic structure are first prepared by pulverizing Al2O3/YAG eutectic rods solidified by laser floating zone and then are consolidated by hot pressing under different sintering temperatures (1450–1650 °C). The results show that the initial eutectic particle size and sintering temperature importantly affect the full-eutectic structure formation during hot pressing. Using the sintering temperature above 1650 °C and eutectic particles of 4–10 μm, dense bulk eutectic ceramics (99.1%) are obtained, particularly well remaining the initial eutectic structure without grain boundaries, comparable to eutectic ceramics prepared by melt growth method. The < 25 μm and < 4 μm eutectic particles are preferred to achieve higher densification (> 99.5%) but are difficult to reproduce repeatable full-eutectic microstructure in whole composite. Moreover, the formation mechanism of the full-eutectic structure for the ceramics by sintering is discussed. This method paves a facile and cost-effective way to manufacture near net shaped large bulk eutectic ceramics for applications at elevated temperatures.
