(上海交通大学 材料科学与工程学院, 上海 200030)
摘 要: 研究了在远高于居里点的高温凝固过程中磁场对TbFey和TbxDy1-xFey(x=0.3, y=1.9~2.0)合金取向的影响。 结果表明： 对凝固速率、 熔体温度和材料成分的控制是在磁场中获得沿易轴取向所应考虑的； 在高于100 mT的静磁场中， 直径为16 mm的TbFe1.9和Tb0.3Dy0.7Fe1.9样品被加热至略高于熔点的温度；当冷却速率低于50 ℃/h时， 可以获得［111］的择优取向； 但随着合金中Fe含量的增加， 合金中的RFe3相将出现， 过多的RFe3相将在包晶反应结束后仍然留在固液相中， 从而影响晶体的取向； 当Fe含量y≥2时， TbFey和TbxDy1-xFey在磁场中的慢冷条件下很难获得［111］择优取向的织构。
关键字: R-Fe合金； RFe3相; 凝固; 冷却速率; 易轴; 磁场
（School of Materials Science and Engineering,
Shanghai Jiao Tong University, Shanghai 200030, China）
Abstract: The effect of magnetic field on the orientation of TbFey and TbxDy1-xFey(x=0.3, y=1.9-2.0) alloy during the solidification course at high temperature far above Curie point was studied. The results show that the control of solidification rate, melt temperature and chemical composition is necessary for achieving crystal alignment with orientation along the easy magnetic axis in a magnetic field. In a static magnetic field of above 100 mT, TbFe1.9 and Tb0.3Dy0.7Fe1.9 alloy were heated to the temperature of slightly above their melting point, and then solidified at cooling rate of below 50 ℃/h， the［111］ orientation would be dominant in samples. However, with increasing the content of Fe in alloy from 1.93, RFe3 phases would precipitate in alloy, excessive RFe3 phases would still exist in liquid-solid phase after peritectic reaction, then degrade the orientation degree in sample. It is difficult to obtain the preferred orientation of ［111］ direction for TbFey and TbxDy1-xFey alloy by slow cooling in magnetic field at Fe content y≥2 in alloy.
Key words: R-Fe alloy; RFe3 phase; solidification; cooling rate; easy magnetic axis; magnetic field
