摘要
The nucleation and growth behaviors of primary Al phase in two hypoeutectic binary alloys of A1-20.8%Cu and Al-3%Ni in high static magnetic fields were investigated with aid of differential thermal analysis(DTA).The DTA curves indicated that the nucleation temperature of primary crystals in two alloys decreased with increase of the magnetic field intensity and their nucleation was retarded in the magnetic field.The dendrite morphology showed that primary dendrites grew from disorderly without the magnetic field to regularly with the field.The retardation of nucleation of primary Al crystals was mainly caused by increase of interracial free energy.The change in dendrite morphology could be attributed to suppression of melt flows in the magnetic field.
The nucleation and growth behaviors of primary Al phase in two hypoeutectic binary alloys of A1-20.8%Cu and Al-3%Ni in high static magnetic fields were investigated with aid of differential thermal analysis(DTA).The DTA curves indicated that the nucleation temperature of primary crystals in two alloys decreased with increase of the magnetic field intensity and their nucleation was retarded in the magnetic field.The dendrite morphology showed that primary dendrites grew from disorderly without the magnetic field to regularly with the field.The retardation of nucleation of primary Al crystals was mainly caused by increase of interracial free energy.The change in dendrite morphology could be attributed to suppression of melt flows in the magnetic field.
基金
Item Sponsored by China Postdoctoral Science Foundation (Grant No.20110490712)
Major State Basic Research Development Program (Grant No.2011CB610404)
Projects of International Cooperation and Exchanges NSFC (Grant No.50911130365)
Natural Science Foundation of China (Grant No.51001068)
