未经均匀化热处理的纯三元及含Zr,Ga元素的SC合金铸片经优化的HDDR工艺处理都可以制备各向异性Nd Fe B磁粉.这表明:元素的添加及SC铸片是否进行了均匀化热处理都不是HDDR磁粉各向异性形成的必要条件.磁粉各向异性形成的关键因素在于HDD...未经均匀化热处理的纯三元及含Zr,Ga元素的SC合金铸片经优化的HDDR工艺处理都可以制备各向异性Nd Fe B磁粉.这表明:元素的添加及SC铸片是否进行了均匀化热处理都不是HDDR磁粉各向异性形成的必要条件.磁粉各向异性形成的关键因素在于HDDR工艺的调节,即适当地加快歧化反应过程,减缓脱氢再结合过程以及控制脱氢再结合时的合适氢气压强均有利于磁粉各向异性的形成.本文将为制备低成本高各向异性磁粉提供重要的指导.展开更多
Effects of the wheel speeds v and disproportionation time during the SC-HDDR process on the properties of Nd-Fe-B magnetic powders are investigated.It is found that the remanence Br,coercivity Hcj and energy products(...Effects of the wheel speeds v and disproportionation time during the SC-HDDR process on the properties of Nd-Fe-B magnetic powders are investigated.It is found that the remanence Br,coercivity Hcj and energy products(BH)max of magnetic powders all first increase to the maximum at v=3 m/s,and then decrease with enhancing v.This is attributed to the fact that the SC alloy flakes prepared by the wheel speed of 3 m/s display the optimized microstructure.This optimized SC alloy flakes without homogenizing treatment which carried out a short duration disproportionation treatment can prepare the evidently anisotropic powders.With prolonging disproportionation time,the alignment degree of anisotropy of magnetic powders gradually decreases.This is due to the fact that a short duration disproportionation reaction is beneficial to the disproportionated microstructure displaying the lamella crystals,and the lamella disproportionated microstructure is helpful to the formation of anisotropy.Our results confirm that the anisotropic HDDR Nd-Fe-B magnetic powders prepared directly from the SC alloy flakes without homogenizing treatment can be obtained.展开更多
基金Project(2012AA030311)supported by the National High-tech Research and Development Program of ChinaProject(51421001)supported by the National Natural Science Foundation of ChinaProject(106112015CDJXY130002)supported by the Fundamental Research Funds for the Central Universities,China
文摘未经均匀化热处理的纯三元及含Zr,Ga元素的SC合金铸片经优化的HDDR工艺处理都可以制备各向异性Nd Fe B磁粉.这表明:元素的添加及SC铸片是否进行了均匀化热处理都不是HDDR磁粉各向异性形成的必要条件.磁粉各向异性形成的关键因素在于HDDR工艺的调节,即适当地加快歧化反应过程,减缓脱氢再结合过程以及控制脱氢再结合时的合适氢气压强均有利于磁粉各向异性的形成.本文将为制备低成本高各向异性磁粉提供重要的指导.
基金supported by the National Natural Science Foundation of China (Grant Nos 50671055 and 50801043)
文摘Effects of the wheel speeds v and disproportionation time during the SC-HDDR process on the properties of Nd-Fe-B magnetic powders are investigated.It is found that the remanence Br,coercivity Hcj and energy products(BH)max of magnetic powders all first increase to the maximum at v=3 m/s,and then decrease with enhancing v.This is attributed to the fact that the SC alloy flakes prepared by the wheel speed of 3 m/s display the optimized microstructure.This optimized SC alloy flakes without homogenizing treatment which carried out a short duration disproportionation treatment can prepare the evidently anisotropic powders.With prolonging disproportionation time,the alignment degree of anisotropy of magnetic powders gradually decreases.This is due to the fact that a short duration disproportionation reaction is beneficial to the disproportionated microstructure displaying the lamella crystals,and the lamella disproportionated microstructure is helpful to the formation of anisotropy.Our results confirm that the anisotropic HDDR Nd-Fe-B magnetic powders prepared directly from the SC alloy flakes without homogenizing treatment can be obtained.
