速凝成晶-粘结法制备稀土磁致伸缩材料TbDyFe的研究

Rare Earth Magnetostrictive Materials Prepared by Strip-Casting and Bonding Technology

采用速凝成晶技术,制备了具有〈112〉和〈110〉择优取向的Tb0.27Dy0.73Fe1.95速凝片。研究发现,速凝片的择优取向和显微组织与冷却速度密切相关。随着冷却速度的增加,其择优取向从〈112〉向〈110〉变化,显微组织由枝状晶向胞枝晶转变。研究了由速凝片制备的稀土粘结磁致伸缩样品的性能。结果表明,当粉末粒度≤（100-^150）μm时材料性能较好,具有〈112〉择优取向的样品性能高于〈110〉择优取向的样品,磁场取向成型有利于材料性能的改善。获得了性能良好的粘结磁致伸缩材料,在238.8 kA.m-1时磁致伸缩系数达到740×10^-6。

The flakes of Tbo.27 Dyo.73 Fel.95 with 〈 112〉 and 〈 110〉 preferred orientations were prepared by strip-casting technology. It was found that preferred orientations and microstructure of flakes were closely related to cooling velocities. The preferred orientations of Tbo.27Dyo.73Fe1.95 strip-casting flakes transformed from 〈 1 12 〉 to 〈 1 10 〉 with the cooling velocities increasing, and the microstructures changed from dendrite crystal to cellar and dendrite crystal. The properties of the magnetostrictive materials made from the flakes were studied. The results showed that the properties of the sample were better when the gran-ularity did not exceed 100 - 150μm, the properties of the sample with 〈 112 〉 orientation was better than that with 〈 110〉 orientation. Compacting with a magnetic field was beneficial to the material properties. The bonded magnetostrictive material with high performance was obtained. Its magnetostrictive coeffi- cient was 740 ×10^-6 at a magnetic field of 238.8 kA.m-1.