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研究了纵向磁场对Al-40%Cu(质量分数)过共晶合金定向凝固显微组织的影响.结果表明,在温度梯度G_L=42.6K/cm,生长速率R=2μm/s,施加弱磁场时,Al_2Cu初生相由规则小平面状逐渐变得不规则,并趋向于非小平面方式生长,热电磁对流效应在不同尺度下影响界面前沿溶质分布及各相生长温度,微观尺度下影响初生相形貌,宏观尺度下改变糊状区长度,引起宏观偏析;施加较强磁场后,初生相呈现不规则胞状组织并紧密定向排列,这一现象主要归因于内生热电Lorentz力及磁晶各向异性.
The effects of longitudinal magnetic field on the microstructure of Al-40% Cu hypereutectic alloy were investigated. The results show that under the condition of temperature gradient G_L = 42.6K / cm, growth rate R = 2μm / s, , The Al 2 Cu primary phase gradually becomes irregular by regular facets and tends to grow in a non-faceted manner. The thermo-electromagnetic convection effects the solute distribution and the growth temperature of each phase at different scales, and affects the primary phase at the microscopic scale Morphology and macroscopic scale change the length of the mushy zone, causing macro-segregation; the application of a strong magnetic field, the initial phase of irregular cellular organization and closely aligned arrangement, a phenomenon mainly due to Lorentz force and magnetocaloric To the opposite sex.