Al替代Fe对<110>取向Tb-Dy-Fe合金显微组织、磁致伸缩性能和力学性能的影响

Effects of substituting Al for Fe on microstructure,magnetostriction and mechanical properties of <110> oriented Tb-Dy-Fe alloy

采用区熔定向凝固方法制备<110>取向的Tb0.3Dy0.7(Fe1 xAlx)2(x=0,0.05,0.10,0.15)超磁致伸缩合金,研究不同含量Al原子替代Fe原子对于合金微观组织、磁致伸缩性能和力学性能的影响。结果表明:Al原子替代不改变定向凝固样品形成的<110>轴向择优取向,合金依然保持MgCu2型立方Laves相和部分稀土相结构。随着Al含量的增加,黑色RE(FeAl)2相和白色富稀土RE(Al)相的析出数量、尺寸及分布发生变化。微量Al原子(x≤0.05)替代可以显著提高材料低磁场下的动态响应及饱和磁致伸缩系数,随着Al含量进一步提高,合金系饱和磁致伸缩系数降低。Tb0.3Dy0.7(Fe1 xAlx)2(x=0,0.05,0.10,0.15)合金的压缩强度随着Al原子含量增加而增加,合金发生解理断裂。当Al替代量x≤0.1时,合金具有良好的综合性能。

The 〈110〉 oriented Tbo.3Dyo.7（Fe1-xA1x）2（x=0, 0.05, 0.10, 0.15） alloy was prepared by the method of zone-melting directional solidification. The effects of substituting AI for Fe on the mierostructure, magnetostriction and mechanical properties were systemically investigated. The results show that the primary phase of Tbo.3Dyo.7（Fe1-xA1x）2 alloy were MgCu2-type cubic Laves phase structure and some RE phase, and the A1 substitution doesn＇t change the axial preferred orientation. With the increase of A1 content, there are some RE（FeAI）2 phase and RE（M） phase precipitated from the REFe2 matrix, and the quantity, size and distribution of the second phase vary with AI content increasing. The magnetization and magnetostriction measurements show that a small amount of A1 substitution （x~〈0.05） is beneficial to a decrease in the magneto crystalline anisotropy, and the saturation magnetostriction and dynamic response in low magnetic field increase drastically. With the increase of A1 content, the saturation magnetostriction decreases distinctly, while the compressive strength increases. The fracture of the Tbo.3Dyo.y（Fe1-xA1x）2 alloy is cleavage fracture. The alloy with A1 substitution range from 0 to 0.1 has optimal performances.