Glass forming ability of Fe–Co–Zr–Nd–B alloys and bulk permanent magnets derived from amorphous precursor

Study of microstructure and correlative magnetic property in bulk Fe61Nd10B25Nb4 permanent magnet

“…The other has microstructure with the mainly hard magnetic (Nd,Pr) 2 Fe 14 B phase resulting in a relatively high value of coercivity [8,12]. Compared with the previous studies [1][2][3][4][5][6][7][8][9][10][11][12][13], the highest value of coercivity, 1191 kA/m, is obtained from the Fe 61 Nd 10 B 25 Nb 4 sample annealed at 943 K for 20 min in this work. However, the remanence, 0.42 T, is not impressive in comparison with 1.19 T in the Fe 67 Co 9.4 Nd 3.1 Dy 0.5 B 20 magnet reported by Zhang [1].…”

“…It is shown that mainly two types of fully dense bulk Fe-based permanent magnets have been successfully obtained so far by a devitrification annealing process of rods, sheets and tubes or by directly quenching process [1][2][3][4][5][6][7][8][9][10][11][12][13]. One is the (Fe 3 B, ␣-Fe)/Nd 2 Fe 14 B nanocomposite permanent magnet consisting of the soft magnetic Fe 3 B or ␣-Fe phase, hard magnetic Nd 2 Fe 14 B and non-magnetic phases [1][2][3][4][5][6][7][9][10][11]13]. The other has microstructure with the mainly hard magnetic (Nd,Pr) 2 Fe 14 B phase resulting in a relatively high value of coercivity [8,12].…”

“…Compared with a traditional way to prepare Nd-Fe-B permanent magnets including melt spinning or mechanical milling process, the fully dense magnets have obvious advantages, such as low cost, casting in precise dimensions easily and avoiding the polymer dilution of magnetic phase. Hence, Zhang's work [1] paves a promising way for the bulk permanent magnet prepared by a simple process of copper mold casting and subsequent heat treatment, which stimulates further investigations of microstructure and magnetic properties in other bulk Fe-based alloy systems [2][3][4][5][6][7][8][9][10][11][12][13]. For example, the fully dense bulk (Fe,Co)-Zr-(Pr,Dy)-B or (Fe,Co)-Zr-(Nd,Y)-B permanent magnets with the shapes of rods, sheets or tubes were obtained by a devitrification annealing process [5][6][7][9][10][11].…”

Effects of Cr addition on glass-forming ability and mechanical properties of Cu–Zr–Al bulk metallic glass

“…Since the first synthesis of metallic glass in the Au-Si system by a rapid quenching technique in 1960 [1], much effort has been done in developing bulk metallic glasses (BMGs) [2][3][4][5][6][7][8][9]. Among the BMGs synthesized so far, Cu-based BMGs have been considered to be a potential structural material because of their high glass-forming ability (GFA), wide supercooled liquid region, excellent mechanical strength and relatively low price [10][11][12][13].…”

Fe64B22.8Nd6.6Y3.9Nb2.7 bulk nanocomposite magnets with improved size and magnetic properties

“…It was pointed out that Y is effective in improving the GFA, stabilizing the amorphous phase, reducing the oxides during melting or heat treatment, especially in low-purity alloys. 9 Tan et al 10 developed Nd 5 Y 4 Fe 68 Zr 2 B 21 bulk sheet specimens with relatively larger size of 0.8 Â 10 Â 50 mm 3 , which after crystallization at 690°C exhibit permanent magnetic properties with j H c 5 382 kA/m and (BH) max 5 42.9 kJ/m 3 . However, some challenges still remain in the improvement of GFA and magnetic properties of (Nd,Pr)-Fe-B-Y alloy system.…”