利用示差扫描量热法,X射线衍射法、振动样品磁强计和扫描电镜研究了热处理对硬磁性非晶合金Nd58Fe20Al10Co10B2磁学性能的影响。研究表明,随着热处理温度的升高,非晶基体中的团簇的数量不断减少以及晶化过程中析出的晶体相或亚稳相对... 利用示差扫描量热法,X射线衍射法、振动样品磁强计和扫描电镜研究了热处理对硬磁性非晶合金Nd58Fe20Al10Co10B2磁学性能的影响。研究表明,随着热处理温度的升高,非晶基体中的团簇的数量不断减少以及晶化过程中析出的晶体相或亚稳相对磁畴的钉扎作用的破坏,使矫顽力、剩余磁化强度、饱和磁化强度都逐渐降低。大量晶化后,Nd Fe、Nd Fe (Al、Co)团簇之间耦合作用的消失是硬磁性消失的主要原因。展开更多
The influence of Zr addition on the microstructure and magnetic properties of nanocomposite Nd_(10.5)Fe_(78-x)Co_5Zr_xB_(6.5) (x=0～5) alloys was investigated. It was found that the intrinsic coercivity could be signi...The influence of Zr addition on the microstructure and magnetic properties of nanocomposite Nd_(10.5)Fe_(78-x)Co_5Zr_xB_(6.5) (x=0～5) alloys was investigated. It was found that the intrinsic coercivity could be significantly improved by the addition of 2% (atom fraction) Zr. The presence of small amount of amorphous phase is responsible for the low intrinsic coercivity for Zr-free alloy. The small amount addition of Zr may suppress the growth of grains of α-Fe and Nd_2Fe_(14)B phases. The more homogeneous microstructure with an average grain size of 20 nm can be obtained for Nd_(10.5)Fe_(76)Co_5Zr_2B_(6.5) alloy.展开更多
The Nd_(60)Fe_(20)Al_8Co_(10)B_2 alloy was prepared by suction casting of the molten alloy into a copper mold under argon atmosphere. The micro-structural and magnetic property changes in the Nd_(60)Fe_(20)Al_8Co_(10)...The Nd_(60)Fe_(20)Al_8Co_(10)B_2 alloy was prepared by suction casting of the molten alloy into a copper mold under argon atmosphere. The micro-structural and magnetic property changes in the Nd_(60)Fe_(20)Al_8Co_(10)B_2 alloy during crystallization were investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscope (SEM) and the vibrating sample magnetometer (VSM). The precipitation and Nd-rich and Fe-rich phases have no significant effect on the intrinsic coercitity for Nd_(60)Fe_(20)Al_8Co_(10)B_2 alloy annealed below 723 K. However, the growth of Fe-rich phase decreases the saturate magnetization and remanence of the alloy. The hard magnetic behavior is disappeared when the alloy is fully crystallized.展开更多
文摘 利用示差扫描量热法,X射线衍射法、振动样品磁强计和扫描电镜研究了热处理对硬磁性非晶合金Nd58Fe20Al10Co10B2磁学性能的影响。研究表明,随着热处理温度的升高,非晶基体中的团簇的数量不断减少以及晶化过程中析出的晶体相或亚稳相对磁畴的钉扎作用的破坏,使矫顽力、剩余磁化强度、饱和磁化强度都逐渐降低。大量晶化后,Nd Fe、Nd Fe (Al、Co)团簇之间耦合作用的消失是硬磁性消失的主要原因。
基金Project supported by the National Advanced Technology Research and Development Committee of China (2002AA302602 2) and the Shanghai Municipal Developing Foundation of Science & Technology for Special Item of"Qimingxing"(03QF14018)
文摘The influence of Zr addition on the microstructure and magnetic properties of nanocomposite Nd_(10.5)Fe_(78-x)Co_5Zr_xB_(6.5) (x=0～5) alloys was investigated. It was found that the intrinsic coercivity could be significantly improved by the addition of 2% (atom fraction) Zr. The presence of small amount of amorphous phase is responsible for the low intrinsic coercivity for Zr-free alloy. The small amount addition of Zr may suppress the growth of grains of α-Fe and Nd_2Fe_(14)B phases. The more homogeneous microstructure with an average grain size of 20 nm can be obtained for Nd_(10.5)Fe_(76)Co_5Zr_2B_(6.5) alloy.
文摘The Nd_(60)Fe_(20)Al_8Co_(10)B_2 alloy was prepared by suction casting of the molten alloy into a copper mold under argon atmosphere. The micro-structural and magnetic property changes in the Nd_(60)Fe_(20)Al_8Co_(10)B_2 alloy during crystallization were investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscope (SEM) and the vibrating sample magnetometer (VSM). The precipitation and Nd-rich and Fe-rich phases have no significant effect on the intrinsic coercitity for Nd_(60)Fe_(20)Al_8Co_(10)B_2 alloy annealed below 723 K. However, the growth of Fe-rich phase decreases the saturate magnetization and remanence of the alloy. The hard magnetic behavior is disappeared when the alloy is fully crystallized.
