Modeling of Orientation and Alignment of Primary Al_3Ni Crystal in Al-Ni Alloy by Imposing a High Magnetic Field

Regarding Al_3Ni crystal as a rigid ellipsoid,a model describing the orientation and alignment of a primary paramagnetic Al_3Ni crystal in Al- Ni alloy solidification under a high magnetic field is developed.The model is based on rigid body rotation dynamics model as well as the magnetic dipole model,respectively.It describes the rotational motion of a magnetic anisotropic crystal around its centroid and around one endpoint of its crystal axis.The orientation time and the orientation characteristics with the intensity of magnetic field,the aspect ratio of the crystal and the effective viscosity of the melt,as well as the crystal growth,are deeply discussed for single grain.Furthermore,the interaction between two crystals during the alignment in high magnetic field are analyzed based on the magnetic dipole model,in which the final state of the grain is dependent on the attractive interaction force between two neighboring grains and the magnetization force acting on each grain.The prediction shows fitness with the experimental and theoretical results in literature.