Crystallization behavior of melt-spun NdFeB permanent magnets

来源期刊：中国有色金属学报(英文版)2002年第4期

论文作者：徐晖 倪建森 朱明原 周邦新 董远达 肖学山

文章页码：720 - 722

Key words：nanocomposite magnet；crystallization behavior；activation energy

Abstract: The crystallization behavior of melt-spun Nd_8.5Fe₇₈Co₅Cu₁Nb₁B_6.5 ribbons was investigated using dynamic differential scanning calorimetry (DSC) and X-ray diffractometry (XRD). It was found that the as-spun ribbons crystallize in two steps: at first the Nd₃Fe₆₂B₁₄+α-Fe phases are formed and subsequently Nd₃Fe₆₂B₁₄ transformed to Nd₂Fe₁₄B and α-Fe upon heating above 680℃. The effective activation energy of two crystallization peaks are 332.0kJ/mol and 470.5kJ/mol, respectively. As the wheel speed increases, the magnetic properties of the magnet change obviously. When the wheel speed is 18m/s, the best magnetic properties of the magnet was obtained after the sample was annealed at 690℃ for 8min: B_r=0.74T, _iH_c=421.7kA/m, (BH)_max=64.5kJ/m³.