TY - JOUR
T1 - Rapid solidification and fracture behavior of ternary metastable eutectic Al2O3/YAG/YSZ in situ composite ceramic
AU - Su, Haijun
AU - Zhang, Jun
AU - Yu, Jianzheng
AU - Liu, Lin
AU - Fu, Hengzhi
PY - 2011/2/25
Y1 - 2011/2/25
N2 - 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 0.5μm. 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±1.0MPam1/2. 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.
AB - 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 0.5μm. 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±1.0MPam1/2. 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.
KW - Fracture toughness
KW - In situ composite ceramics
KW - Laser zone-remelting
KW - Oxide eutectics
KW - Rapid solidification
UR - http://www.scopus.com/inward/record.url?scp=78650510482&partnerID=8YFLogxK
U2 - 10.1016/j.msea.2010.11.046
DO - 10.1016/j.msea.2010.11.046
M3 - 文章
AN - SCOPUS:78650510482
SN - 0921-5093
VL - 528
SP - 1967
EP - 1973
JO - Materials Science and Engineering: A
JF - Materials Science and Engineering: A
IS - 4-5
ER -