熔体快淬与高能球磨法相结合制备TbCu7型单相Sm-Fe-Zr-Nb合金

Fabrication of TbCu-type Single Phase Sm-Fe-Zr-Nb Alloys by Melt-Spinning Combined with High-Energy Ball Milling

研究了Sm-Fe-Zr-Nb合金粉末在高能球磨过程中获得完全非晶态的相变过程。采用X射线衍射、扫描电镜和高分辨率透射电镜分析了研磨时间对Sm-Fe-Zr-Nb合金粉末的相组成及形貌的影响。结果表明:球磨2.5 h左右可得到完整的非晶态微观结构,球磨3 h以上,非晶态基体中析出尺寸约5 nm的α-Fe相,短程有序原子团数量增加。对球磨2.5 h后的非晶合金进行晶化处理后,得到了微观组织均匀的TbCu7型单相合金,等轴晶尺寸约30 nm。该微观组织调控对改善氮化后的磁性能起关键作用。

The complete amorphous phase transformation of Sm-Fe-Zr-Nb alloy powders during high-energy ball milling process was investigated. The effects of milling time on the phase transformation and morphology of the Sm-Fe-Zr-Nb alloy powders were analyzed by X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy. The result shows that complete amorphous microstructure is obtained after milling for about 2.5 h, and α-Fe phase(-5 nm) is precipitated from the amorphous matrix when the milling time is over 3 h. The number of short-range ordered structure increases. The uniform microstructure and the TbCu7-type single phase are obtained by crystallizing the amorphous precursors milled for 2.5 h. The size of equiaxed grain is -30 nm. This kind of micro-regulation plays a key role in improving the magnetic properties after nitriding.