Processing, microstructure, and properties of laser remelted Al_2O_3/Y_3Al_5O_(12)(YAG) eutectic in situ composite  

作　　者：苏海军 张军 刘林 傅恒志 

机构地区：[1]State Key Laboratory of Solidification Processing, Northwestern Polytechnical University

出　　处：《中国有色金属学会会刊：英文版》2007年第6期1259-1264,共6页Transactions of Nonferrous Metals Society of China

基　　金：Project(50102004) supported by the National Natural Science Foundation of China;Project(04G53048) supported by the Aeronautical Science Foundation of China;Project(20040699035) supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China;Project(W018101) supported by the Research Fund of Northwestern Polytechnical University, China;Project supported by the Developing Program for Outstanding Persons in Northwestern Polytechnical University, China

摘　　要：Laser remelting and rapid solidification were performed in preparing the high-performance Al2O3/Y3Al5O12(YAG) eutectic in situ composite. The microstructure characteristic and solidification behavior were studied using scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS), X-ray diffractometry(XRD) and simultaneous thermal analysis(STA). The hardness and fracture toughness were obtained using an indentation technique. The results show that the laser remelted Al2O3/YAG composite has a homogeneous eutectic microstructure without microcrack and pore. The component phases of Al2O3 and YAG are three-dimensionally and continuously reticular connected, and finely coupled without grain boundaries, colonies and amorphous phases between interfaces. The eutectic interspacing is greatly refined with increasing the scanning rate and average is only 1 μm. The synthetically thermal analysis indicates that the eutectic temperature of Al2O3-YAG is 1 824 ℃, well matching the phase diagram of Al2O3-Y2O3 system. The maximum hardness reaches 19.5 GPa and the room fracture toughness is 3.6 MPa·m1/2.Laser remelting and rapid solidification were performed in preparing the high-performance Al2O3/Y3Al5O12（YAG） eutectic in situ composite. The microstructure characteristic and solidification behavior were studied using scanning electron microscopy（SEM）, energy dispersive spectroscopy（EDS）, X-ray diffractometry（XRD） and simultaneous thermal analysis（STA）. The hardness and fracture toughness were obtained using an indentation technique. The results show that the laser remelted Al2O3/YAG composite has a homogeneous eutectic microstructure without microcrack and pore. The component phases of Al2O3 and YAG are three-dimensionally and continuously reticular connected, and finely coupled without grain boundaries, colonies and amorphous phases between interfaces. The eutectic interspacing is greatly refined with increasing the scanning rate and average is only l μm. The synthetically thermal analysis indicates that the eutectic temperature of Al2O3-YAG is 1 824 ℃, well matching the phase diagram of Al2O3-Y2O3 system. The maximum hardness reaches 19.5 GPa and the room fracture toughness is 3.6 MPa.m^1/2.

关 键 词：Al2O3/Y3Al35O12 共晶 复合材料 激光再熔化 微观结构 

分 类 号：TB33[一般工业技术—材料科学与工程]