Rapid solidification and fracture behavior of ternary metastable eutectic Al2O3/YAG/YSZ in situ composite ceramic

被引:24
作者
Su, Haijun [1 ]
Zhang, Jun [1 ]
Yu, Jianzheng [1 ]
Liu, Lin [1 ]
Fu, Hengzhi [1 ]
机构
[1] Northwestern Polytech Univ, State Key Lab Solidificat Proc, Xian 710072, Peoples R China
来源
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING | 2011年 / 528卷 / 4-5期
基金
中国国家自然科学基金;
关键词
Oxide eutectics; Fracture toughness; Laser zone-remelting; Al2O3/YAG/ZrO2; In situ composite ceramics; Rapid solidification; HIGH-TEMPERATURE STRENGTH; MECHANICAL-PROPERTIES; THERMAL-STABILITY; MICROSTRUCTURE; GROWTH; DEFORMATION; SYSTEM;
D O I
10.1016/j.msea.2010.11.046
中图分类号
TB3 [工程材料学];
学科分类号
0805 ; 080502 ;
摘要
Directionally solidified oxide ceramic eutectic in situ composites are promising candidate materials for high-temperature structural applications in oxidizing environments. The rapid solidification characteristics of ternary metastable eutectic composition of Al2O3/YAG/YSZ in situ composite ceramics grown by laser zone-remelting technique are investigated. The fracture toughness and crack propagation behavior of the as-solidified composites are examined by the Vickers indentation technique. The metastable eutectic Al2O3/YAG/YSZ ceramic consists of Al2O3, YAG and YSZ phases, showing a typical ultra-fine irregular lamellar microstructure morphology with eutectic spacing as fine as 0.5 mu m. Moreover, the ternary eutectic microstructures with coupled growth characteristics are also formed at the off-eutectic composition, effectively enlarging the eutectic growth range. The mean fracture toughness of the metastable eutectic Al2O3/YAG/YSZ ceramic is 3.9 +/- 1.0 MPa m(1/2). The addition of ZrO2 which weakens the interface bonding between YAG and Al2O3 phases, crack deflection, branching and microcrack toughening are the predominant toughening mechanisms. (C) 2010 Elsevier B.V. All rights reserved.
引用
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页码:1967 / 1973
页数:7
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