BORON-BASED AMORPHOUS ALLOYS AND PREPARATION METHOD THEREOF

Abstract

Boron-based amorphous alloys and a preparation method thereof is provided. The composition formula of the alloys is B.sub.aCo.sub.bRE.sub.cX1.sub.dX2.sub.eX3.sub.f, wherein RE is any one or more of La, Ce, Pr, Nd, Sm, Gd, Dy, Er and Y; X1 is any one or more of C, Si and Al; X2 is any one or two of Fe and Ni; X3 is any one or more of Zr, Nb, Mo, Hf, Ta and W; and a, b, c, d, e and f respectively represent atomic percent of each corresponding element in the formula, where: 45≤a≤55, 25≤b≤40, 10≤c≤20, 0≤d≤10, 45≤a+d≤55, 0≤e≤20, 25≤b+e≤40, 0≤f≤3, 10≤c+f≤20 and a+b+c+d+e+f=100. The preparation method of the boron-based amorphous alloy comprises: preparing master alloy ingots using an arc furnace or an induction melting furnace; and then obtaining amorphous ribbons with different thicknesses by a single copper roller melt-spinning equipment.

Claims

1. Boron-based amorphous alloys, wherein the composition formula of the alloys is B.sub.aCo.sub.bRE.sub.cX1.sub.dX2.sub.eX3.sub.f, where RE is any one or more of La, Ce, Pr, Nd, Sm, Gd, Dy, Er, and Y; X1 is any one or more of C, Si, and Al; X2 is any one or two of Fe and Ni; and X3 is any one or more of Zr, Nb, Mo, Hf, Ta and W; and a, b, c, d, e, and f respectively represent atomic percent of each corresponding element in the formula, where 45≤a≤55, 25≤b≤40, 10≤c≤20, 0≤d≤10, 45≤a+d≤55, 0≤e≤20, 25≤b+e≤40, 0≤f≤3, 10≤c+f≤20, and a+b+c+d+e+f=100; the preparation method for the boron-based amorphous alloys comprising: (1) material mixing weighing and mixing raw materials including B, C, Si, Al, Co, Fe, Ni, La, Ce, Pr, Nd, Sm, Gd, Dy, Er, Y, Zr, Nb, Mo, Hf, Ta and W with purity higher than 99% according to the nominal composition of the alloy; considering that some rare earth elements are volatile and burnt in the melting process, adding extra 5 wt. % of volatile rare earth elements in this step; (2) preparation of master alloy ingot placing the weighed mixture in step (1) into a water-cooled copper mold of a non-consumable arc furnace; melting the mixture under an argon or nitrogen atmosphere to obtain a master alloy ingot; repeatedly melting the alloy for four times to ensure chemical homogeneity; or putting the mixture in a crucible of an induction furnace, and melting the mixture under the argon or nitrogen atmosphere to obtain the master alloy ingot with chemical homogeneity; (3) preparation of amorphous ribbon crushing the master alloy ingot, putting them into a quartz tube, and the preparing amorphous ribbon using a single copper roller melt-spinning technique, i.e., under the argon or nitrogen atmosphere, heating the master alloy ingot to a molten state through induction smelting; then spraying the melt by high pressure gas onto a copper roller rotating at high speed; and melt-spinning at a linear velocity for the copper roller surface of 20-40 m/s to obtain an amorphous alloy ribbon with a width of 1.5 mm and a thickness of 25-40 μm.

2. (canceled)

Description

DESCRIPTION OF DRAWINGS

[0021] To more clearly describe the technical solutions in the embodiments of the present invention or in prior art, the drawings required to be used in the description of the embodiments or the prior art will be simply presented below. Apparently, the drawings in the following description are merely some embodiments of the present invention, and for those ordinary skilled in the art, other drawings can also be obtained according to these drawings without contributing creative labor.

[0022] FIG. 1 shows an X-ray diffraction pattern of a B.sub.50Co.sub.40Sm.sub.10 amorphous alloy ribbon with a thickness of 35 μm and a width of 1.5 mm prepared by a single copper roller melt-spinning equipment.

[0023] FIG. 2 shows a high-resolution transmission electron microscope image and a selected area electron diffraction pattern of a B.sub.50Co.sub.40Sm.sub.10 amorphous alloy ribbon with a thickness of 35 μm and a width of 1.5 mm prepared by a single copper roller melt-spinning equipment.

[0024] FIG. 3 shows a differential scanning calorimetric curve of a B.sub.50Co.sub.40Sm.sub.10 amorphous alloy ribbon.

DETAILED DESCRIPTION

[0025] It should be explained that if there is no conflict, the embodiments in the present invention and the features in the embodiments can be mutually combined. The present invention will be described in detail below by reference to the drawings and in conjunction with the embodiments.

[0026] To make a purpose, a technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and fully described below in combination with the drawings in the embodiments of the present invention. Apparently, the described embodiments are merely part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative, and shall not be intended to limit the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by those ordinary skilled in the art without contributing creative labor will belong to the protection scope of the present invention.

[0027] The following non-limiting embodiments may enable those ordinary skilled in the art to fully understand the present invention, but do not limit the present invention in any way.

[0028] The test methods described in the following embodiments are conventional methods unless otherwise specified; and the reagents and materials are commercially available unless otherwise specified.

[0029] The present invention provides a kind of B-based amorphous alloys with the composition formula of B.sub.aCo.sub.bRE.sub.cX1.sub.dX2.sub.eX3.sub.f, where RE is any one or more of La, Ce, Pr, Nd, Sin, Gd, Dy, Er, and Y; X1 is any one or more of C, Si, and Al; X2 is any one or two of Fe and Ni; and X3 is any one or more of Zr, Nb, Mo, Hf, Ta and W; and a, b, c, d, e, and f respectively represent atomic percent of each corresponding element in the formula, where 45≤a≤55, 25≤b≤40, 10≤c≤20, 0≤d≤10, 45≤a+d≤55, 0≤e≤20, 25≤b+e≤40, 0≤f≤3, 10≤c+f≤20, and a+b+c+d+e+f=100.

[0030] Further, the B-based amorphous alloys provided by the present invention possess high thermal stability, high hardness, high resistivity and strong AFA, and the amorphous alloy ribbons with critical thickness of not less than 25 μm can be prepared by a single copper roller melt-spinning equipment.

[0031] Further, the B-based amorphous alloys provided by the present invention have the following characteristics:

[0032] Onset temperature of crystallization is 707-820° C.;

[0033] Vickers hardness (H.sub.v) is 1362-1582; Room-temperature resistivity is 2.56-4.28 μΩm.

[0034] The present invention further provides a preparation method of the B-based amorphous alloys, comprising the following steps:

[0035] (1) Material Mixing

[0036] Weighing and mixing raw materials including B, C, Si, Al, Co, Fe, Ni, La, Ce, Pr, Nd, Sin, Gd, Dy, Er, Y, Zr, Nb, Mo, Hf, Ta and W with purity higher than 99% according to the nominal composition of the alloy; considering that some rare earth elements are volatile and burnt in the melting process, adding extra 5 wt. % of volatile rare earth elements in this step.

[0037] (2) Preparation of Master Alloy Ingot

[0038] Placing the weighed mixture in step (1) into a water-cooled copper mold of a non-consumable arc furnace; melting the mixture under an argon or nitrogen atmosphere to obtain a master alloy ingot; repeatedly melting the alloy for four times to ensure chemical homogeneity; or putting the mixture in a crucible of an induction furnace, and melting the mixture under the argon or nitrogen atmosphere to obtain the master alloy ingot with chemical homogeneity;

[0039] (3) Preparation of Amorphous Ribbon

[0040] Crushing the master alloy ingot, putting them into a quartz tube, and the preparing amorphous ribbon using a single copper roller melt-spinning technique, i.e., under the argon or nitrogen atmosphere, heating the master alloy ingot to a molten state through induction smelting; then spraying the melt by high pressure gas onto a copper roller rotating at high speed; and melt-spinning at a linear velocity for the copper roller surface of 20-40 m/s to obtain an amorphous alloy ribbon with a width of 1.5 mm and a thickness of 25-40 μm

Embodiment 1: B.SUB.50.Co.SUB.40.Sm.SUB.10

[0041] Step I: Material Mixing

[0042] Raw materials including B, Co, and Sin with the purity of higher than 99 wt. % are weighed and mixed according to the nominal composition; considering that Sin is volatile and burnt, adding extra 5 wt. % of Sin;

[0043] Step II: Preparation of Master Alloy Ingot

[0044] The weighed raw materials are mixed and then put in a water-cooled copper hearth of a non-consumable arc furnace, and repeatedly melted for four times under an Ar atmosphere to obtain a master alloy ingot with homogeneous chemical composition;

[0045] Step III: Preparation of Amorphous Ribbon

[0046] The master alloy ingot is crushed and then put in a quartz tube with a nozzle diameter of about 0.5 mm, heated to a molten state through induction melting under the Ar atmosphere. The alloy melt is sprayed by a high pressure difference onto a copper roller rotating at a surface linear velocity of 30 m/s to obtain an amorphous alloy ribbon with a width of 1.5 mm and a thickness of 35 μm;

[0047] Step IV: Structural Characterization of Melt-spun Alloy Ribbon

[0048] X-ray diffraction (XRD) (Cu Kα) and transmission electron microscope (TEM) are used to detect the structure of the melt-spun alloy ribbon. As shown in FIG. 1, the XRD pattern demonstrates that the melt-spun alloy ribbon has a completely amorphous structure. As shown in FIG. 2, no lattice fringe appears in the high-resolution TEM and the selected area electron diffraction (SAED) pattern presents an halo characteristic, which further confirm the fully amorphous structure;

[0049] Step V: Properties Testing of Melt-spun Alloy Ribbon

[0050] A differential scanning calorimeter (DSC) is used to evaluate the thermal properties of the alloy. FIG. 3 shows the DSC curve of the melt-spun alloy ribbon. It is determined that the onset temperature of crystallization (T.sub.x) is 756° C. A microhardness tester with a load of 100 gf and dwell period of 10 s is adopted to test the Vickers hardness (H.sub.v), and a four-probe method is used to test the room-temperature resistivity (ρ). The H.sub.v of the melt-spun alloy ribbon is 1518, and the p is 3.76 μΩm. Detailed data are listed in Table 1.

Embodiment 2: B.SUB.50.Co.SUB.35.Sm.SUB.15

[0051] Step I is the same as embodiment 1.

[0052] Step II: Melting the weighed raw materials with an induction melting furnace under the Ar atmosphere to prepare the master alloy ingot with uniform composition.

[0053] Steps III, IV and V are the same as embodiment 1. The amorphous alloy ribbon with a thickness of 35 μm is finally prepared. The T.sub.x, H.sub.v and ρ are listed in Table 1.

Embodiment 3: B.SUB.55.Co.SUB.30.Sm.SUB.15

[0054] The steps are basically the same as embodiment 1 in addition to changing the Ar atmosphere to a nitrogen atmosphere.

[0055] The amorphous alloy ribbon with a thickness of 30 pin is finally prepared. The T.sub.x, H.sub.v and ρ are listed in Table 1.

Embodiment 4: B.SUB.45.Co.SUB.40.Sm.SUB.15

[0056] The steps are the same as embodiment 1.

[0057] The amorphous alloy ribbon with a thickness of 35 pin is finally prepared. The T.sub.x, H.sub.v and ρ are listed in Table 1.

Embodiment 5: B.SUB.55.Co.SUB.25.Sm.SUB.20

[0058] The steps are the same as embodiment 1.

[0059] The amorphous alloy ribbon with a thickness of 30 pin is finally prepared. The T.sub.x, H.sub.v and ρ are listed in Table 1.

Embodiment 6: B.SUB.45.C.SUB.5.Co.SUB.40.Sm.SUB.10

[0060] Step I: Raw materials including B, C, Co, and Sin with the purity of higher than 99 wt. % are weighed and mixed according to the nominal composition; Steps II, III, IV and V are the same as embodiment 1.

[0061] The amorphous alloy ribbon with a thickness of 30 pin is finally prepared. The T.sub.x, H.sub.v and ρ are listed in Table 1.

Embodiment 7: B.SUB.45.Si.SUB.5.Co.SUB.40.Sm.SUB.10

[0062] Step I: Raw materials including B, Si, Co, and Sin with the purity of higher than 99 wt. % are weighed and mixed according to the nominal composition;

[0063] Steps II, III, IV and V are the same as embodiment 1.

[0064] The amorphous alloy ribbon with a thickness of 40 μm is finally prepared. The T.sub.x, H.sub.v and ρ are listed in Table 1.

Embodiment 8: B.SUB.45.Al.SUB.5.Co.SUB.40.Sm.SUB.10

[0065] Step I: Raw materials including B, Al, Co, and Sin with the purity of higher than 99 wt. % are weighed and mixed according to the nominal composition;

[0066] Steps II, III, IV and V are the same as embodiment 1.

[0067] The amorphous alloy ribbon with a thickness of 30 μm is finally prepared. The T.sub.x, H.sub.v and ρ are listed in Table 1.

Embodiment 9: B.SUB.45.C.SUB.5.Si.SUB.5.Co.SUB.35.Sm.SUB.10

[0068] Step I: Raw materials including B, C, Si, Co, and Sin with the purity of higher than 99 wt. % are weighed and mixed according to the nominal composition;

[0069] Steps II, III, IV and V are the same as embodiment 1.

[0070] The amorphous alloy ribbon with a thickness of 32 μm is finally prepared. The T.sub.x, H.sub.v and ρ are listed in Table 1.

Embodiment 10: B.SUB.50.Co.SUB.20.Fe.SUB.20.Sm.SUB.10

[0071] Step I: Raw materials including B, Co, Fe, and Sin with the purity of higher than 99 wt. % are weighed and mixed according to the nominal composition;

[0072] Steps II, III, IV and V are the same as embodiment 1.

[0073] The amorphous alloy ribbon with a thickness of 28 μm is finally prepared. The T.sub.x, H.sub.v and ρ are listed in Table 1.

Embodiment 11: B.SUB.50.Co.SUB.30.Ni.SUB.10.Sm.SUB.10

[0074] Step I: Raw materials including B, Co, Ni, and Sin with the purity of higher than 99 wt. % are weighed and mixed according to the nominal composition;

[0075] Steps II, III, IV and V are the same as embodiment 1.

[0076] The amorphous alloy ribbon with a thickness of 32 μm is finally prepared. The T.sub.x, H.sub.v and ρ are listed in Table 1.

Embodiment 12: B.SUB.50.Co.SUB.20.Fe.SUB.10.Ni.SUB.10.Sm.SUB.10

[0077] Step I: Raw materials including B, Co, Fe, Ni, and Sin with the purity of higher than 99 wt. % are weighed and mixed according to the nominal composition;

[0078] Steps II, III, IV and V are the same as embodiment 1.

[0079] The amorphous alloy ribbon with a thickness of 30 μm is finally prepared. The T.sub.x, H.sub.v and ρ are listed in Table 1.

Embodiment 13: B.SUB.50.Co.SUB.40.Er.SUB.10

[0080] Step I: Raw materials including B, Co, and Er with the purity of higher than 99 wt. % are weighed and mixed according to the nominal composition;

[0081] Steps II, III, IV and V are the same as embodiment 1.

[0082] The amorphous alloy ribbon with a thickness of 25 μm is finally prepared. The T.sub.x, H.sub.v and ρ are listed in Table 1.

Embodiment 14: B.SUB.50.Co.SUB.40.Gd.SUB.10

[0083] Step I: Raw materials including B, Co, and Gd with the purity of higher than 99 wt. % are weighed and mixed according to the nominal composition;

[0084] Steps II, III, IV and V are the same as embodiment 1.

[0085] The amorphous alloy ribbon with a thickness of 35 μm is finally prepared. The T.sub.x, H.sub.v and ρ are listed in Table 1.

Embodiment 15: B.SUB.50.Co.SUB.40.La.SUB.10

[0086] Step I: Raw materials including B, Co, and La with the purity of higher than 99 wt. % are weighed and mixed according to the nominal composition;

[0087] Steps II, III, IV and V are the same as embodiment 1.

[0088] The amorphous alloy ribbon with a thickness of 40 μm is finally prepared. The T.sub.x, H.sub.v and ρ are listed in Table 1.

Embodiment 16: B.SUB.50.Co.SUB.40.Y.SUB.10

[0089] Step I: Raw materials including B, Co, and Y with the purity of higher than 99 wt. % are weighed and mixed according to the nominal composition;

[0090] Steps II, III, IV and V are the same as embodiment 1.

[0091] The amorphous alloy ribbon with a thickness of 35 μm is finally prepared. The T.sub.x, H.sub.v and ρ are listed in Table 1.

Embodiment 17: B.SUB.50.Co.SUB.40.Sm.SUB.5.La.SUB.5

[0092] Step I: Raw materials including B, Co, Sin, and La with the purity of higher than 99 wt. % are weighed and mixed according to the nominal composition;

[0093] Steps II, III, IV and V are the same as embodiment 1.

[0094] The amorphous alloy ribbon with a thickness of 35 μm is finally prepared. The T.sub.x, H.sub.v and ρ are listed in Table 1.

Embodiment 18: B.SUB.55.Co.SUB.30.Sm.SUB.5.Er.SUB.5.La.SUB.5

[0095] Step I: Raw materials including B, Co, Sin, Er and La with the purity of higher than 99 wt. % are weighed and mixed according to the nominal composition;

[0096] Steps II, III, IV and V are the same as embodiment 1.

[0097] The amorphous alloy ribbon with a thickness of 30 μm is finally prepared. The T.sub.x, H.sub.v and ρ are listed in Table 1.

Embodiment 19: B.SUB.50.Co.SUB.40.La.SUB.7.Nb.SUB.3

[0098] Step I: Raw materials including B, Co, La and Nb with the purity of higher than 99 wt. % are weighed and mixed according to the nominal composition;

[0099] Steps II, III, IV and V are the same as embodiment 1.

[0100] The amorphous alloy ribbon with a thickness of 28 μm is finally prepared. The T.sub.x, H.sub.v and ρ are listed in Table 1.

Embodiment 20: B.SUB.50.Co.SUB.40.Sm.SUB.8.Ta.SUB.2

[0101] Step I: Raw materials including B, Co, Sin and Ta with the purity of higher than 99 wt. % are weighed and mixed according to the nominal composition;

[0102] Steps II, III, IV and V are the same as embodiment 1.

[0103] The amorphous alloy ribbon with a thickness of 30 μm is finally prepared. The T.sub.x, H.sub.v and ρ are listed in Table 1.

Embodiment 21: B.SUB.50.Co.SUB.40.Sm.SUB.7.Zr.SUB.3

[0104] Step I: Raw materials including B, Co, Sin and Zr with the purity of higher than 99 wt. % are weighed and mixed according to the nominal composition;

[0105] Steps II, III, IV and V are the same as embodiment 1.

[0106] The amorphous alloy ribbon with a thickness of 32 μm is finally prepared. The T.sub.x, H.sub.v and ρ are listed in Table 1.

Embodiment 22: B.SUB.50.Co.SUB.40.Gd.SUB.9.W.SUB.1

[0107] Step I: Raw materials including B, Co, Gd and W with the purity of higher than 99 wt. % are weighed and mixed according to the nominal composition;

[0108] Steps II, III, IV and V are the same as embodiment 1.

[0109] The amorphous alloy ribbon with a thickness of 35 μm is finally prepared. The T.sub.x, H.sub.v and ρ are listed in Table 1.

Embodiment 23: B.SUB.50.Co.SUB.40.Gd.SUB.8.Mo.SUB.2

[0110] Step I: Raw materials including B, Co, Gd and Mo with the purity of higher than 99 wt. % are weighed and mixed according to the nominal composition;

[0111] Steps II, III, IV and V are the same as embodiment 1.

[0112] The amorphous alloy ribbon with a thickness of 30 μm is finally prepared. The T.sub.x, H.sub.v and ρ are listed in Table 1.

Embodiment 24: B.SUB.50.Co.SUB.20.Fe.SUB.10.Ni.SUB.10.Sm.SUB.7.Hf.SUB.3

[0113] Step I: Raw materials including B, Co, Fe, Ni, Sin and Hf with the purity of higher than 99 wt. % are weighed and mixed according to the nominal composition;

[0114] Steps II, III, IV and V are the same as embodiment 1.

[0115] The amorphous alloy ribbon with a thickness of 30 μm is finally prepared. The T.sub.x, H.sub.v and ρ are listed in Table 1.

Comparison Example 1: Co.SUB.65.Sm.SUB.10.B.SUB.25

[0116] A low-B-content Co.sub.65Sm.sub.10B.sub.25 alloy in the same Co—Sm—B system is selected for comparison. An amorphous alloy ribbon with a thickness of 30 μm is prepared and tested by the methods similar to those in embodiment 1. The T.sub.x, H.sub.v and ρ are listed in Table 1. It can be seen that the B-based amorphous alloys with high B contents have higher thermal stability, hardness and resistivity than the Comparison example 1.

Comparison Example 2: Fe.SUB.78.Si.SUB.9.B.SUB.13

Comparison Example 3: Co.SUB.70.3.Fe.SUB.4.7.Si.SUB.15.B.SUB.10

Comparison Example 4: Cu.SUB.50.Zr.SUB.45.Al.SUB.5

[0117] The above three alloys are respectively selected from Fe-based soft magnetic amorphous ribbon Fe.sub.78Si.sub.9B.sub.13 with an industrial number of 1K101, Co-based amorphous alloy Co.sub.70.3Fe.sub.4.7Si.sub.15B.sub.10 with high permeability and Cu—Zr-based bulk amorphous alloy Cu.sub.50Zr.sub.45Al.sub.5 with high stability of the supercooled liquid. The T.sub.x, H.sub.v and ρ are listed in Table 1. It can be seen that the T.sub.x, H.sub.v and ρ values of the Comparison examples 2-4 are much lower than those of the B-based amorphous alloys provided in the present invention.

Comparison Example 5: Si.SUB.50.Al.SUB.26.Fe.SUB.10.Ni.SUB.7.Cr.SUB.7

Comparison Example 6: Si.SUB.55.Al.SUB.20.Fe.SUB.10.Cr.SUB.5.Ni.SUB.5.Zr.SUB.5

[0118] The above two amorphous alloys are selected from the reference [D. V. Louzguine et al, Materials Transactions, JIM 38 (1997) 1095]. The T.sub.x, H.sub.v and ρ are listed in Table 1. It can be seen that, except that the ρ value of the two alloys is higher than that of the B-based amorphous alloy of the present invention, the T.sub.x and H.sub.v values are much lower than those of the B-based amorphous alloy of the present invention.

TABLE-US-00001 TABLE 1 Alloy compositions and corresponding onset temperature of crystallization (T.sub.x), Vickers hardness (H.sub.v) and room-temperature resistivity (ρ) of embodiments of the present invention and comparison examples. Alloy Composition T.sub.x ρ (at. %) (° C.) H.sub.v (μΩ .Math. m) Embodiment 1 B.sub.50Co.sub.40Sm.sub.10 756 1518 3.76 Embodiment 2 B.sub.50Co.sub.35Sm.sub.15 707 1454 3.02 Embodiment 3 B.sub.55Co.sub.30Sm.sub.15 742 1508 3.43 Embodiment 4 B.sub.45Co.sub.40Sm.sub.15 708 1362 2.56 Embodiment 5 B.sub.55Co.sub.25Sm.sub.20 724 1440 2.99 Embodiment 6 B.sub.45C.sub.5Co.sub.40Sm.sub.10 764 1532 3.81 Embodiment 7 B.sub.45Si.sub.5Co.sub.40Sm.sub.10 738 1481 4.02 Embodiment 8 B.sub.45Al.sub.5Co.sub.40Sm.sub.10 723 1414 2.62 Embodiment 9 B.sub.45C.sub.5Si.sub.5Co.sub.35Sm.sub.10 785 1547 4.15 Embodiment 10 B.sub.50Co.sub.20Fe.sub.20Sm.sub.10 820 1460 3.56 Embodiment 11 B.sub.50Co.sub.30Ni.sub.10Sm.sub.10 765 1487 3.78 Embodiment 12 B.sub.50Co.sub.20Fe.sub.10Ni.sub.10Sm.sub.10 771 1468 3.81 Embodiment 13 B.sub.50Co.sub.40Er.sub.10 753 1523 3.14 Embodiment 14 B.sub.50Co.sub.40Gd.sub.10 756 1516 4.28 Embodiment 15 B.sub.50Co.sub.40La.sub.10 758 1501 3.25 Embodiment 16 B.sub.50Co.sub.40Y.sub.10 754 1520 3.55 Embodiment 17 B.sub.50Co.sub.40Sm.sub.5La.sub.5 735 1500 3.62 Embodiment 18 B.sub.55Co.sub.30Sm.sub.5Er.sub.5La.sub.5 749 1530 3.42 Embodiment 19 B.sub.50Co.sub.40La.sub.7Nb.sub.3 782 1570 3.82 Embodiment 20 B.sub.50Co.sub.40Sm.sub.8Ta.sub.2 780 1583 3.78 Embodiment 21 B.sub.50Co.sub.40Sm.sub.7Zr.sub.3 774 1564 3.82 Embodiment 22 B.sub.50Co.sub.40Gd.sub.9W.sub.1 769 1542 4.13 Embodiment 23 B.sub.50Co.sub.40Gd.sub.8Mo.sub.2 772 1570 3.99 Embodiment 24 B.sub.50Co.sub.40Fe.sub.10Ni.sub.10Sm.sub.7Hf.sub.3 787 1502 3.65 Comparison Co.sub.65Sm.sub.10B.sub.25 635 1084 1.76 example 1 Comparison Fe.sub.78Si.sub.9B.sub.13 497 900 1.37 example 2 Comparison Co.sub.70.3Fe.sub.4.7Si.sub.15B.sub.10 490 860 1.34 example 3 Comparison Cu.sub.50Zr.sub.45Al.sub.5 500 546 2.00 example 4 Comparison Si.sub.50Al.sub.26Fe.sub.10Ni.sub.7Cr.sub.7 438 926 11.70 example 5 Comparison Si.sub.55Al.sub.20Fe.sub.10Cr.sub.5Ni.sub.5Zr.sub.5 427 935 12.30 example 6

[0119] Finally, it should be noted that the above embodiments are only used for describing the technical solution of the present invention rather than limiting the present invention. Although the present invention is described in detail by referring to the above embodiments, those ordinary skilled in the art should understand that: the technical solution recorded in each of the above embodiments can be still amended, or part or all of technical features therein can be replaced equivalently; The amendments or replacements do not enable the essence of the corresponding technical solution to depart from the scope of the technical solution of various embodiments of the present invention.