Magnetostriction, composition and microstructure of Tb_0.29(Dy_1-xPr_x)_0.71Fe_1.97 alloys with heat treatment

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• 作者：Shaoqiang ZHANG ; Maocai ZHANG ; Yi QIAO ; Minxia LIU ; Hongcheng WANG ; Yongzhao XU
• 关键词：TbDyPrFe alloys ; heat treatment ; magnetostriction ; microstructure ; rare earths
• 刊名：Journal of Rare Earths
• 出版年：2013
• 出版时间：June, 2013
• 年：2013
• 卷：31
• 期：6
• 页码：577-581
• 全文大小：1049 K

文摘

Tb_0.29(Dy_1-xPr_x)_0.71Fe_1.97 (x=0, 0.1, 0.2 and 0.3) alloys prepared by the directional solidification method were treated at 1073, 1123, 1173, 1223 and 1273 K for 4 h for homogenization, respectively. The magnetostriction, micro-morphology and composition distribution were studied by the standard resistance strain gauge technique, optical microscopy and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS). The results indicated that heat treatment could make the microstructure of alloys homogeneous effectively and improve the magnetostriction significantly. The optimum temperature was 1223 K. Compared to the as-cast ones, the increase amplitudes of magnetostriction of the corresponding samples were 39.5 % , 64.9 % , 95.3 % and 50.8 % when x=0, 0.1, 0.2 and 0.3, respectively at the compressive stress of 2 MPa and a magnetic field of 80 kA/m. The compressive stress could also improve the magnetostriction. However, further Pr element addition and over high heat treatment temperature would lead to the excessive decomposition of PrFe₂ and destroy the homogeneity, resulting in the decline of magnetostriction of alloys.