The super high strength aluminum alloy ingots with 100 mm in diameter were cast by the process of low-frequency electromagnetic horizontal continuous casting (LFEHC) and the effect of electromagnetic field on the as-c...The super high strength aluminum alloy ingots with 100 mm in diameter were cast by the process of low-frequency electromagnetic horizontal continuous casting (LFEHC) and the effect of electromagnetic field on the as-cast microstructure was studied. Results show that microstructure of the sample prepared by the LFEHC process was greatly refined. Microstructures at the border and the center of the ingots were fine, uniform and rosette-shaped. Electromagnetic frequency plays a key role in microstructure refining. Fine and uniform microstructures can be obtained with optimal electromagnetic frequency. In this experiment, under a frequency of 30 Hz the microstructure was the finest and the most uniform.展开更多
Here,we report the effect of an 8 T magnetic field on the microstructure and properties of a reetangular Bi_2Sr_2CaCu2Ox/AgMg(Bi2212/AgMg) conductor with low aspect ratio.The magnetic field was applied during split me...Here,we report the effect of an 8 T magnetic field on the microstructure and properties of a reetangular Bi_2Sr_2CaCu2Ox/AgMg(Bi2212/AgMg) conductor with low aspect ratio.The magnetic field was applied during split melt process with the field direction perpendicular and parallel to the wide surface of the conductors.After heat treatment, the conductors were electrically characterized using four-point critical current measurements as a function of magnetic field and magnetic field orientation relative to the conductor.The superconducting transition and magnetization hysteresis were measured using a SQUID magnetometer.The microstructure was characterized using scanning electron microscopy. It was found that the presence of magnetic field during split melt processing enhances the electrical transport and magnetic behavior.The magnetic field increases the Bi2212 grains alignment and long range texture within filaments and bridges between filaments by textured growth of Bi2212 phase.展开更多
基金National "863" project (NO.2001AA332030) of China
文摘The super high strength aluminum alloy ingots with 100 mm in diameter were cast by the process of low-frequency electromagnetic horizontal continuous casting (LFEHC) and the effect of electromagnetic field on the as-cast microstructure was studied. Results show that microstructure of the sample prepared by the LFEHC process was greatly refined. Microstructures at the border and the center of the ingots were fine, uniform and rosette-shaped. Electromagnetic frequency plays a key role in microstructure refining. Fine and uniform microstructures can be obtained with optimal electromagnetic frequency. In this experiment, under a frequency of 30 Hz the microstructure was the finest and the most uniform.
基金Item Sponsored by the National Institute of Health of U.S.A.and Natural Science Foundation of China[No.50401006]Natural Science Foundation of Liaoning of China[No.20041015]
文摘Here,we report the effect of an 8 T magnetic field on the microstructure and properties of a reetangular Bi_2Sr_2CaCu2Ox/AgMg(Bi2212/AgMg) conductor with low aspect ratio.The magnetic field was applied during split melt process with the field direction perpendicular and parallel to the wide surface of the conductors.After heat treatment, the conductors were electrically characterized using four-point critical current measurements as a function of magnetic field and magnetic field orientation relative to the conductor.The superconducting transition and magnetization hysteresis were measured using a SQUID magnetometer.The microstructure was characterized using scanning electron microscopy. It was found that the presence of magnetic field during split melt processing enhances the electrical transport and magnetic behavior.The magnetic field increases the Bi2212 grains alignment and long range texture within filaments and bridges between filaments by textured growth of Bi2212 phase.
