The grain refinement of superalloy IN718 under the action of low voltage pulsed magnetic field was investigated. The experimental results show that fine equiaxed grains are acquired under the action of low voltage pul...The grain refinement of superalloy IN718 under the action of low voltage pulsed magnetic field was investigated. The experimental results show that fine equiaxed grains are acquired under the action of low voltage pulsed magnetic field. The refinement effect of the pulsed magnetic field is affected by the melt cooling rate and superheating. The decrease of cooling rate and superheating enhance the refinement effect of the low voltage pulsed magnetic field. The magnetic force and the melt flow during solidification are modeled and simulated to reveal the grain refinement mechanism. It is considered that the melt convection caused by the pulsed magnetic field, as well as cooling rate and superheating contributes to the refinement of solidified grains.展开更多
Zero field cooled (ZFC) and field cooled (FC) DC magnetization and AC susceptibility of sintered SrRuO 3 were measured over the magnetic ordering temperature. The peak in susceptibility against temperature shifts ...Zero field cooled (ZFC) and field cooled (FC) DC magnetization and AC susceptibility of sintered SrRuO 3 were measured over the magnetic ordering temperature. The peak in susceptibility against temperature shifts to lower temperature when the bias field increases. As the field still increases, the peak breaks into two peaks. One peak still shifts to lower temperature; the other shifts to higher temperature. Zero bias field susceptibility was measured at different frequencies. The peak value decreases as the increase of frequency, but it does not shift to higher temperature as reported previously. The results show that SrRuO 3 is not spin glass, but ferromagnet.展开更多
基金Project(2010CB631205)supported by the National Basic Research Program of ChinaProject(51034012)supported by the National Natural Science Foundation of China
文摘The grain refinement of superalloy IN718 under the action of low voltage pulsed magnetic field was investigated. The experimental results show that fine equiaxed grains are acquired under the action of low voltage pulsed magnetic field. The refinement effect of the pulsed magnetic field is affected by the melt cooling rate and superheating. The decrease of cooling rate and superheating enhance the refinement effect of the low voltage pulsed magnetic field. The magnetic force and the melt flow during solidification are modeled and simulated to reveal the grain refinement mechanism. It is considered that the melt convection caused by the pulsed magnetic field, as well as cooling rate and superheating contributes to the refinement of solidified grains.
文摘Zero field cooled (ZFC) and field cooled (FC) DC magnetization and AC susceptibility of sintered SrRuO 3 were measured over the magnetic ordering temperature. The peak in susceptibility against temperature shifts to lower temperature when the bias field increases. As the field still increases, the peak breaks into two peaks. One peak still shifts to lower temperature; the other shifts to higher temperature. Zero bias field susceptibility was measured at different frequencies. The peak value decreases as the increase of frequency, but it does not shift to higher temperature as reported previously. The results show that SrRuO 3 is not spin glass, but ferromagnet.
