机械力驱动下Nd16Fe76B8合金氢化-歧化反应机理研究

Study on the Mechanism of Mechanically Activated Hydrogenation-Disproportionation of Nd16Fe76B8 Alloys

摘要:

对机械力驱动下Nd16Fe76B8合金的氢化-歧化反应机理进行了研究。通过测量球磨过程中合金的吸氢量变化，揭示了其氢化-歧化反应动力学特征。采用X射线衍射（XRD）、透射电镜（TEM）、扫描电镜（SEM）等方法，研究了球磨过程中合金的组织演变。结果表明：在球磨的最初阶段，合金只发生氢化反应，生成NdH2.7与Nd2Fe14BHy相，此后随着球磨时间的延长，氢化态合金粉末在机械球磨的作用下被激活至高能状态，并逐渐发生歧化，最终得到晶粒尺寸约10 nm的NdH2.7、Fe2B、α-Fe的纳米歧化组织.

Abstract:

The mechanism of mechanically activated hydrogenation-disproportionation reaction of Nd16Fe76B8 alloy was investigated. The aspects of the kinetics for the mechanically activated hydrogenation-disproportionation were studied by measuring the hydrogen absorption of the alloy during milling, and the phase and microstructure change was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM), respectively. The results show that, firstly, the Nd-rich phase and Nd2Fe14B matrix phase in the Nd16Fe76B8 alloy is hydrogenated into NdH2.7 and Nd2Fe14BHy. After that, the alloy powder is activated by further milling in hydrogen, and then disproportionated into α-Fe, NdH2.7 and Fe2B phases, with a grain size of about 10 nm.