Abstract Tb-Dy-Fe alloy has been regarded as a giant magnetostrictive material and used in applications such as actuators and sensors. However, the brittleness of Laves phase in Tb-Dy-Fe alloy, resulting in the fracture failure during machining operations and the cracking failure for the material in service, significantly decreases its engineering design and applications. This study aims to investigate the effect of restructuring the grain boundary phases of Tb-Dy-Fe alloy by diffusing low-melting-point alloys. The low-melting-point Dy–Cu alloys were diffused into Tb0.3Dy0.7Fe1.95 alloy ingot by different heat-treatments. The microstructure, magnetostrictive properties, fracture behavior and bending strength were studied systematically. The ductile (Dy,Tb)Cu phase has been produced to substitute for RE-rich phase in grain boundary. The results indicated that magnetostriction remained at a high value (1021–1448 ppm) after diffusion. However, the mechanical property improved significantly, which was attributed to massively formed ductile (Dy,Tb)Cu phase in grain boundary. Compared with the non-diffused alloy with bending strength of 43–48 MPa, the bending strength of Tb0.3Dy0.7Fe1.95 alloy with diffusing DyCu alloy at 1000 °C increased to 74 MPa, and the best bending strength of Tb0.3Dy0.7Fe1.95 alloy with diffusing DyCu2 alloy at 1000 °C increased to 115 MPa.

中文翻译：

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通过扩散Dy-Cu合金在超磁致伸缩Tb-Dy-Fe合金的晶界处引入(Dy,Tb)Cu相提高抗弯强度

摘要 Tb-Dy-Fe合金被认为是一种巨磁致伸缩材料，用于执行器和传感器等应用。然而，Tb-Dy-Fe 合金中 Laves 相的脆性，导致加工操作过程中的断裂失效和使用中材料的开裂失效，显着降低了其工程设计和应用。本研究旨在研究通过扩散低熔点合金来重构 Tb-Dy-Fe 合金晶界相的效果。通过不同的热处理将低熔点 Dy-Cu 合金扩散到 Tb0.3Dy0.7Fe1.95 合金锭中。系统地研究了显微结构、磁致伸缩性能、断裂行为和弯曲强度。已产生韧性 (Dy,Tb)Cu 相以替代晶界中的富稀土相。结果表明，扩散后磁致伸缩保持在高值（1021-1448 ppm）。然而，机械性能显着提高，这归因于在晶界处大量形成的延性 (Dy,Tb)Cu 相。与抗弯强度为43-48 MPa的非扩散合金相比，含扩散DyCu合金的Tb0.3Dy0.7Fe1.95合金在1000℃时的抗弯强度提高到74 MPa，最佳抗弯强度为Tb0.3Dy0 .7Fe1.95 合金与扩散 DyCu2 合金在 1000 °C 下增加到 115 MPa。