Synthesis of Fe–Co–Nd–B Amorphous Alloys with Glass Transition and their Crystallization-Induced Hard Magnetic Properties

Hard magnetic properties of Fe–Co–Nd–Dy–B nanocrystalline alloys containing residual amorphous phase

“…9 Considering that the maximum B concentration in the meltspun Fe-B binary alloys is about 25 at%, 10 the simultaneous addition of Co and Nd is concluded to be very effective for the extension of the glass formation range to the B-rich side. Figure 1 shows the DSC curve of the Fe 67 Co 9.5 Nd 3 Dy 0.5 B 20 alloy.…”

“…The B-rich Fe-Nd-B amorphous alloys have some advantage points as compared with the Fe-rich Fe-Nd-B amorphous alloys. 3,8,9 These are ͑1͒ lower Nd contents, ͑2͒ higher glass-forming ability, ͑3͒ lower melting points, and ͑4͒ appearance of glass transition and supercooled liquid region prior to crystallization. If we can find an optimum annealing condition leading to a finer mixed structure containing the remaining amorphous phase in the B-rich Fe-Nd-B amorphous alloys, the resulting mixed structure alloys are expected to exhibit improved hard magnetic properties.…”

Bulk nanocomposite permanent magnets produced by crystallization of Fe66.5Co10Pr3.5B20 bulk glassy alloy

“…11 More recently, we have searched for a new glassy alloy in the ͑Fe,Co͒-͑Nd,Pr,Dy͒-B system where a large ⌬T x exceeding 40 K and high T g /T 1 above 0.56 are obtained. [12][13][14][15] The large ⌬T x and high T g /T 1 indicate that a high GFA may be obtained in this alloy system. Furthermore, good hard magnetic properties are also obtained after heat treatment of the glassy alloys, when a nanocomposite structure, consisting of hard magnetic Nd 2 Fe 14 B (Pr 2 Fe 14 B) and soft magnetic Fe 3 B and ␣-Fe phases, is obtained.…”

“…Furthermore, good hard magnetic properties are also obtained after heat treatment of the glassy alloys, when a nanocomposite structure, consisting of hard magnetic Nd 2 Fe 14 B (Pr 2 Fe 14 B) and soft magnetic Fe 3 B and ␣-Fe phases, is obtained. [12][13][14][15] Therefore, a nanocomposite permanent magnet in a bulk form is expected to be obtained after heat treatment of the resulting bulk glassy alloy. This article presents the results of a study of the glass-forming ability, the thermal stability of the supercooled liquid, the crystallized structure, and the magnetic properties for a glassy Fe 66.5 Co 10 Pr 3.5 B 20 alloy prepared by copper mold casting.…”

Consolidation of Fe-Co-Nd-Dy-B Glassy Powders by Spark-Plasma Sintering and Magnetic Properties of the Consolidated Alloys

“…[24][25][26] Recently, it has been found that some rapidly solidified Fe-Co-Nd-B alloys have a large supercooled liquid region and good hard magnetic properties after crystallization. 27) Further improvements in thermal stability and hard magnetic properties have been achieved by addition of a small amount of Dy.…”