Microstructure and magnetic properties of hot-deformed anisotropic Nd–Fe–B magnets prepared from amorphous precursors with different crystallization proportions
来源期刊：Rare Metals2017年第4期
论文作者：Wei Zhao Ying Liu Jun Li Ren-Quan Wang Yu-Chong Qiu
文章页码：268 - 276
摘 要：Anisotropic magnets were obtained by hot deformation with the partial crystallized precursor prepared via spark-plasma sintering（SPS）. Amorphous powders with the nominal composition of Nd28.72FebalCo5.66Ga0.59B0.92（wt%） were used as the starting material. The results show that the amorphous powders would suffer varying degrees of crystallization even below the crystallization point during the SPS process under high pressure.And the pre-crystallized grains in precursors have great impacts on the microstructure and magnetic properties of the hot-deformed magnets. The final obtained anisotropic magnets exhibit homogeneous microstructure consisting of well-aligned and platelet-shaped Nd2Fe14B grains without abnormal growth. It can be found that a reasonable proportion of pre-crystallized gains could promote the preferential orientation in the magnet, leading to the achievement of optimal magnetic properties among the magnets with identical composition and best magnetic performance is achieved in the magnet hot deformed from the 490 °C high-pressure hot-pressed precursor.
Wei Zhao1，Ying Liu1，Jun Li1,2，Ren-Quan Wang1，Yu-Chong Qiu1
1. School of Materials Science and Engineering, Sichuan University2. Key Laboratory of Advanced Special Material and Technology,Ministry of Education
摘 要：Anisotropic magnets were obtained by hot deformation with the partial crystallized precursor prepared via spark-plasma sintering（SPS）. Amorphous powders with the nominal composition of Nd28.72FebalCo5.66Ga0.59B0.92（wt%） were used as the starting material. The results show that the amorphous powders would suffer varying degrees of crystallization even below the crystallization point during the SPS process under high pressure.And the pre-crystallized grains in precursors have great impacts on the microstructure and magnetic properties of the hot-deformed magnets. The final obtained anisotropic magnets exhibit homogeneous microstructure consisting of well-aligned and platelet-shaped Nd2Fe14B grains without abnormal growth. It can be found that a reasonable proportion of pre-crystallized gains could promote the preferential orientation in the magnet, leading to the achievement of optimal magnetic properties among the magnets with identical composition and best magnetic performance is achieved in the magnet hot deformed from the 490 °C high-pressure hot-pressed precursor.
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