Low-Temperature Sintering of AlN Ceramics by Sm₂O₃-Y₂O₃-CaO Sintering Additives Formed via Decomposition of Nitrate Solutions

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• 作者：Jun Zhan ; Ye Cao ; Hao Zhang ; Jun Guo…
• 关键词：AlN ; liquid ; phase sintering ; microstructure ; property ; sintering additive
• 刊名：Journal of Materials Engineering and Performance
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：26
• 期：1
• 页码：453-459
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Characterization and Evaluation of Materials; Tribology, Corrosion and Coatings; Quality Control, Reliability, Safety and Risk; Engineering Design;
• 出版者：Springer US
• ISSN：1544-1024
• 卷排序：26

文摘

The Sm, Y and Ca anhydrous nitrates were mixed with the AlN powder in ethanol and then decomposed into the Sm₂O₃-Y₂O₃-CaO sintering additives via calcining. Low-temperature sintering of the AlN ceramics was carried out at temperature range from 1675 to 1750 °C. Effects of the composition and adding amount of the sintering additives on the phases, microstructures and properties of the AlN ceramics were investigated. During sintering the AlN ceramics, main secondary phases of CaYAl₃O₇ and CaSmAl₃O₇ form. The relative density, bending strength and thermal conductivity of the AlN ceramics increase with the increase in the rare-earth oxides in them. The thermal conductivity of the sintered AlN ceramics is also greatly affected by the distribution of the secondary phases. As sintered at 1750 °C, the AlN ceramics by adding the sintering additives of 2 wt.% Sm₂O₃, 2 wt.% Y₂O₃ and 1 wt.% CaO formed via decomposition of their nitrates is fully dense and have the optimal bending strength and thermal conductivity of 402.1 MPa and 153.7 W/(m K), respectively.