JP4742268B2 - High-strength Co-based metallic glass alloy with excellent workability - Google Patents

Description

The present invention is a Co having both good workability and high strength and high glass forming ability.
Relates to a metallic glass alloy.

A metal glass alloy is a metal having a structure in which atomic arrangement is random, and has various excellent characteristics resulting from the specificity of the atomic arrangement. For example, it has features such as low Young's modulus, high strength, and high corrosion resistance. Also, since conventional amorphous alloys have low glass forming ability, 10 ⁵ K /
The molten metal must be solidified at a high cooling rate of not less than sec. Therefore, the shape that can be produced is limited to a ribbon shape, a thin wire shape, or a powder shape having a thickness of several tens of μm.

However, metallic glass alloys can be made into bulk metallic glass alloys with a thickness of several tens of millimeters by solidifying the molten metal at a slow cooling rate due to its high glass forming ability. Alloys can be made. For this reason, development of products using the excellent characteristics of metallic glass alloys has been actively conducted in recent years. Such bulk metallic glass alloys are Mg-based, lanthanoid (Ln) -based, Zr-based, (Fe, Co) -based, Pd-Cu.
There are various alloys such as Ti-based alloys or Ti-based alloys, among which (Fe, Co) -based metallic glass alloys have not only good soft magnetic properties but also high strength and mechanical structure. Application to parts is planned.

The present inventors have made various developments so far to use (Fe, Co) -based metallic glass alloys as high-strength materials. For example, regarding the high-strength (Fe, Co) -based metallic glass alloy, the inventors have previously described that the temperature width of the supercooled liquid region is 60 K or more, and the formula (Fe _1-a-
b Co _a Ni _b) in _{100-xyz M x B y T} z [ wherein, M represents, Zr, Nb, Ta, Hf , Mo, W
, Cr are elements composed of one or more of T, and T is Ru, Rh, Pd, Os,
One or more elements of Ir, Pt, Al, Si, Ge, C, P, and 0
≦ a ≦ 0.29, 0 ≦ b ≦ 0.43, 5 atomic% ≦ x ≦ 15 atomic%, 17 atomic% ≦ y ≦ 22
A high-hardness metallic glass alloy was invented and applied for a patent (Patent Document 1).

Further, the Fe—Co—B—Si—Nb-based metallic glass alloy was found to be an alloy having both high strength and high glass forming ability, and a patent application was filed for an invention related to the alloy (Patent Document 2).
). On the other hand, Fe—Y—Mn—Mo of an alloy with improved glass forming ability of the alloy described in Patent Document 1.
An invention relating to a metallic glass alloy composed of -Cr-C-B has been made by a person other than the present inventor and has been applied for a patent (Patent Document 3). The difference between the alloys described in Patent Documents 1 and 3 is only the presence or absence of Y addition. In Patent Document 3, the glass forming ability is increased by the addition of Y, and the diameter is 12 by mold casting.
It is described that a cast material of a metal glass alloy of mm can be produced.

Further, Non-Patent Document 1 discloses that a cast material of a metal glass alloy having a diameter of 12 mm can be produced by die casting even in an Fe—Y—Mo—Cr—C—B-based alloy. As an alloy system in which a rare earth metal is added as in the composition of the alloy described in Patent Document 3, the present inventors have prepared a metal glass alloy powder containing Fe as a main component and 2 to 15 atomic% of a rare earth metal added. A patent application has been filed for an invention relating to a sintered body (Patent Document 4).

Moreover, as an alloy close to the alloy described in Patent Document 4, Non-Patent Document 2 discloses that a metal glass alloy cast material having a diameter of 1.2 mm can be produced by a die casting method.

Furthermore, the metallic glass alloy has a feature that the viscosity of the material is drastically reduced due to glass transition caused by heating, and plastic flow processing can be performed, and the material processing is easy. The processing method is disclosed in Patent Documents 5 and 6.

Since the metallic glass alloy is liable to cause plastic flow as the viscosity decreases, heating the glass transition temperature or higher to lower the viscosity of the material facilitates processing. However, if the heating is continued beyond the glass transition temperature, the metallic glass alloy becomes brittle due to crystallization and has a problem that it cannot be put into practical use. Therefore, when processing the material, it is necessary to raise it to a temperature higher than the glass transition temperature within the range where it does not crystallize, and the glass transition temperature of the metal glass alloy (
The temperature range from Tg) to the crystallization start temperature (Tx), that is, the temperature range of the supercooled liquid region (hereinafter referred to as “ΔTx”) (ΔTx = Tx−Tg) is wide so that the viscous flow processing is performed. It becomes important in carrying out. Therefore, in recent years, metallic glass alloys having a wide ΔTx have attracted much attention.

Japanese Patent Laid-Open No. 10-265917 JP 2005-256038 A WO2005017223 JP 11-71645 A JP-A-6-93395 JP 2005-201789 A V. Ponnambalam, S. J. Poonand G.J. Shiflet; “Fe-based bulk metallic glasses with diameter thickness larger than one centimeter”, J. Mater. Res. 19 (2004), 1320-1323 Itoi T and Inoue A; “Thermal stability and soft magnetic properties of Co-Fe-M-B (M = Nb, Zr) amorphous alloys with large supercooled liquid region”, Mater. Trans., JIM 41 (2000), 1256-1262

Unlike ordinary crystalline metals, metallic glass alloys are mostly alloys that do not exhibit plastic elongation in tensile tests. Even in compositions that exhibit plastic elongation, they exhibit only about 2% or 3% elongation, and are ductile under uniaxial stress. There are very few. For this reason, it is difficult to perform plastic working such as rolling or forging as in the case of ordinary crystalline metal. In addition, metallic glass alloys are stronger than ordinary metals, with a maximum of 5
There are even alloys reaching 000 MPa, and it cannot be said that the machinability is better than that of steel. However, the metallic glass alloy has a feature that the viscosity of the material rapidly decreases above the glass transition temperature. By utilizing this, various processing (viscous fluid processing) in the supercooled liquid region can be performed, By using viscous flow, the material can be excellent in workability.

In addition, even with ordinary crystalline metal, it is necessary to perform machining by a special method in order to perform fine processing of several tens of nanometers, and the special processing must be performed individually. The processed product was very expensive. However, in the case of a metallic glass alloy, the surface shape can be transferred even with a die having a fine surface processed to several tens of nanometers by viscous flow processing. By transferring, a nanometer level processed product can be easily produced. That is, it can be said that the metallic glass alloy is easily processed at the nano level and has high workability.

As described above, the metallic glass alloy can be easily processed in various ways by using viscous flow, but there is a quality in terms of its workability. In general, when ΔTx of a metallic glass alloy is narrow,
Even if the temperature of the supercooled liquid region is maintained, crystallization occurs in a short time. When the metal glass alloy is crystallized, it is no longer a supercooled liquid, so that viscous flow processing cannot be performed. Moreover, the site | part processed before crystallization is also embrittled by the precipitated crystal | crystallization, and becomes impractical. Thus, in order to improve the workability of the metallic glass alloy, ΔTx needs to be wide.

From the viewpoint of ΔTx and glass forming ability in order to obtain a metallic glass alloy having high workability by viscous flow, for example, in the metallic glass alloy disclosed in Patent Document 1,
The example describes that ΔTx is 88K in the composition of Fe ₅₆ Co ₇ Ni ₇ Zr ₈ Ta ₂ B ₂₀ , and ΔTx is wide. However, an alloy that is described as being capable of producing a metal glass alloy bar with a diameter of 5 mm in which no precipitation of the crystalline phase is observed has a composition of Fe ₆₁ Co ₇ Zr ₁₀ Mo ₅ W ₂ B _15. ΔTx of 64K is not an alloy having both high glass forming ability and wide ΔTx.

Also in Patent Document 2, a metallic glass alloy having ΔTx of 60K is described in the examples. However, in a composition that can produce a metal glass alloy bar with a diameter of 5 mm, ΔT
Since x is only 55K, it could not be said to be an alloy having a high glass forming ability and a wide ΔTx.

Patent Document 3 describes that a metal glass alloy bar having a diameter of 12 mm can be produced, and it can be said that the glass forming ability is the highest among Fe-based metal glass alloys. However, when ΔTx is read from the DSC described in Patent Document 3, ΔTx is only 40K. Furthermore, Non-Patent Document 1 is the same author as the inventor of Patent Document 3, and Non-Patent Document 1 includes a photograph of the appearance of a metal glass alloy bar having the same composition as Patent Document 3. The appearance photograph shows that the upper part of the cast material is broken and it can be judged from the photograph that the material is brittle.

Non-Patent Document 2 describes a Co-based metallic glass alloy having a Co ₄₀ Fe ₂₂ Nb ₆ Zr ₂ B ₃₀ composition in which ΔTx reaches 98K, but a metallic glass alloy rod having a diameter of 1.5 mm by a die casting method. Only a material could be obtained, and it could not be said that the alloy had a wide ΔTx and a high glass forming ability. As described above, a metallic glass alloy that combines a high glass forming ability and a wide ΔTx with a (Co, Fe) -based metallic glass alloy and has excellent mechanical properties has not been found.

As a result of searching for various alloy compositions and combinations of elements for the purpose of solving the above-mentioned problems, the present inventors have found that a specific element of a lanthanoid series in a Co— (Cr, Mo) —CB series alloy. A wide ΔTx, good mechanical properties, and high glass-forming ability 3
The inventors have found that an alloy having various characteristics can be obtained, and have completed the present invention.

That is, the present invention _{is, (Co 1-x Fe x} ) 100-abcd M a C b B c L d ( although, M is, Mo, C
One or two selected from r, L is one or more elements selected from Y, Dy, Ho, Er, Tm, and Yb. Further, 0 ≦ x ≦ 0.7, a, b, c, d are atomic%, 22 ≦ a ≦ 35, 6 ≦ b ≦ 20, 1 ≦ c ≦ 11, 10 ≦ b + c ≦ 26, 0 .5 ≦ d
≦ 4 and is) Ri Do a composition represented by the temperature range of the supercooled liquid region (ΔTx = Tx-Tg;
However, Tx is the crystallization start temperature and Tg is the glass transition temperature) at 50K or more at room temperature.
The Co-based metallic glass alloy has a compressive strength of 4000 MPa or more.

The metallic glass alloy of the present invention is produced by a copper mold casting method, and the volume fraction of the glass phase is 10
It is possible to produce a rod having a maximum glass diameter of about 14 mm having a high glass forming ability capable of obtaining a rod having a diameter of 6 mm or more, which is 0%, and a volume fraction of the glass phase being 100%. Co
This greatly exceeds the level of glass forming ability achieved with the metallic glass. Therefore, according to the present invention, a bulk alloy material having a wall thickness larger than about 1 mm can be provided.
It is also easy to provide a ribbon or thin wire having a thickness or diameter of about 0 μm to 1 mm.

Further, the Co-based metallic glass alloy of the present invention is suitable as a material for machine parts manufactured by viscous flow processing.

Since the Co-based metallic glass alloy of the present invention has ΔTx of 50K or more, it is easy to perform viscous flow processing. In addition, it has an excellent glass forming ability that can easily produce a plate or bar material having a thickness of 1 mm or more in diameter or a diameter of 1 mm or more by a die casting method, and can produce an alloy of a glass phase single phase even at a maximum of 14 mm. ing.

Co-based metallic glass alloys of the present invention have the formula _{(Co 1-x Fe x)} 100-abcd M a C b B c L d ( although, M is one or two kinds selected Mo, from Cr, L Are Y, Dy, Ho, Er, Tm,
One or more elements selected from Yb. Also, 0 ≦ x ≦ 0.7, a, b, c, d are
Atomic%, 22 ≦ a ≦ 35, 6 ≦ b ≦ 20, 1 ≦ c ≦ 11, 10 ≦ b + c ≦
26, 0.5 ≦ d ≦ 4).

In the present invention, the substitution concentration of Fe with respect to Co represented by x in (Co _1-x Fe _x ) in the formula is 0 or more and 0.7 or less. An alloy having a low Fe content has a wide ΔTx and excellent workability, but the glass forming ability tends to be high in a composition having a high Fe content. If the substitution concentration of Fe with respect to Co exceeds 0.7, ΔTx is less than 50K and it cannot be said that the alloy is excellent in workability.
From the viewpoint of ΔTx, the value of x is preferably 0.5 or less, more preferably 0.2 or less.

Further, one or two elements selected from Mo and Cr shown in M _a in the formula, 22 atomic% or more and less 35 atomic%, preferably, 25 atomic% or more, at 33 atomic% or less is there.
More preferably, it is composed of two kinds of Mo and Cr, and Cr is 13 atomic% to 17 atomic% and Mo is 12 atomic% to 16 atomic%. When one or two elements selected from Mo and Cr are less than 22 atomic% or more than 35 atomic%, the glass forming ability is drastically lowered, so that the alloy having such a composition is subjected to various manufacturing processes. I can't do that.

Further, C (carbon) in the formula is 6 atom% or more and 20 atom% or less, preferably 10 atom% or more and 17 atom% or less. Further, B (boron) is 1 atom% or more and 11 atom% or less, preferably 3 atom% or more and 9 atom% or less. The total content of C and B is 10 atomic% or more and 26 atomic% or less, preferably 15 atomic% or more and 23 atomic%.
Is less than. If C and B are contained in an amount greater than the alloy composition range of the present invention, they are brittle and cannot be put to practical use.

Further, when C and B are less than the alloy composition range of the present invention, the glass forming ability is lowered, so that it cannot be used for various processes, and ΔTx is lowered, so that viscous flow processing becomes difficult. . In addition, when one or two elements selected from C and B exceed 26 atomic%, the metal glass alloy itself tends to be brittle even if it is produced by a production process with a low cooling rate. .

One or more elements selected from Y, Dy, Ho, Er, Tm, and Yb represented by L _d in the formula are essential elements for enhancing the glass forming ability. Its content is 0.5 atomic% or more,
It is 4 atomic% or less, preferably 1 atomic% or more and 3 atomic% or less. Furthermore, from the viewpoint of glass forming ability, preferably, one or more elements selected from Y, Er, and Tm are 1 atomic% or more and 3 atomic% or less. Lanthanoid elements include Y, La, Ce, Nd and the like. However, since La, Ce, Nd and the like hardly increase the glass forming ability, the contained lanthanoid elements include Y, Dy, Ho, Er, and the like. It must be selected from the element group of Tm, Yb. When one or more elements selected from Y, Dy, Ho, Er, Tm, and Yb are less than 0.5 atomic% or more than 4 atomic%, the glass forming ability is lowered and crystals are precipitated, so that the alloy is brittle. And cannot be put to practical use.

In the alloy of the present invention, ΔTx is 50K or more, preferably 60K or more, more preferably 80K or more. ΔTx is the temperature between the temperature at which the alloy is heated at a heating rate of 40 K / min and the endothermic reaction accompanying the glass transition starts (Tg) and the temperature at which the exothermic reaction occurs due to crystallization (Tx). Difference (Tx−Tg). When partially crystallized by heat treatment or the like, ΔTx becomes narrow and it becomes difficult to heat the material and perform plastic flow processing.
In the present invention, ΔTx is defined as 50K or more. The maximum ΔTx is about 90K.

Further, the alloy of the present invention is characterized by a compressive strength of 4000 MPa or more. According to the production process in which a glass phase is obtained, a compressive strength of 4000 MPa or more is usually exhibited within the alloy composition range of the present invention. However, when a metal glass alloy in which elements selected from C and B exceed 23 at.% In total is subjected to heat treatment, the material may become brittle and may not exceed 4000 MPa. The alloy of the present invention is also characterized by high strength, and the strength is 4000MP.
Limited to a or more. This compressive strength is about 4200 MPa at the maximum.

The alloy of the present invention must have a glass phase. The amount of the glass phase (volume fraction)
Is preferably 80% or more, and more preferably 90% or more. If it is less than 80%, the alloy tends to become brittle rapidly. The amount of the above glass phase is measured with a differential scanning calorimeter and compared with the crystallization heat value of a metal glass alloy produced at a high cooling rate of 10 ⁵ K / s or more such as a ribbon material. This makes it easy to measure.

In the present invention, the glass phase indicates a state in which a sharp peak due to the crystal phase does not exist in the profile measured by the X-ray diffraction method, and only a broad peak of the glass phase exists.

Although the alloy containing the constituent element of the metallic glass alloy of the present invention has been disclosed in Patent Document 3 and Patent Document 4 so far, the alloy described in Patent Document 3 is different from the alloy of the present invention regarding the glass forming ability. Although it is about the same, ΔTx is 40K or less, so even if a metallic glass alloy cast material is produced, viscous fluid processing is difficult. In addition, Fe—Cr—Mo— mainly composed of Fe
C-B-Y alloys cannot be used as structural parts because they are brittle.

On the other hand, Patent Document 4 only describes the case where Nd is used as the rare earth metal in the examples, and no examples of other rare earth elements are disclosed, and the glass forming ability is not disclosed at all. Not. Further, the alloy composition described in Patent Document 4 has a B (boron) content greatly deviating from the alloy composition of the present invention, has a low glass forming ability, and cannot be put into practical use as a bulk-like structural component. The present invention has been repeatedly improved based on the alloy disclosed in Patent Document 1, has a composition with a large Co content ratio with a Fe: Co ratio, and has a wide ΔTx. Among rare earth metals, Y, Dy, Ho, Er are particularly preferred. , Tm, and Yb are based on the discovery that the glass forming ability is drastically improved, which is different from the alloys disclosed in Patent Documents 1, 3, and 4.

The metallic glass alloy of the present invention can be produced by various known methods in addition to the copper mold casting method. A thin plate material can be produced by a single roll method or a twin roll method. Moreover, if it is a fine member, an injection molding method can be used. If it is a thin wire shape, it can be produced by a spinning solution spinning method or a groove quenching method. It is also possible to use a method of quenching in water after melting in a crucible made of quartz glass or the like. Furthermore, it is also possible to solidify and form the metal glass alloy powder by a method such as a gas atomizing method. Regardless of which method is used, the metallic glass alloy of the present invention can be subjected to secondary processing utilizing viscous flow and can be easily solidified and formed into powder.

[Examples 1 to 15, Comparative Examples 1 and 2]
Predetermined proportions of pure substances were mixed in an Ar gas atmosphere, and a mother alloy was produced by arc melting.
Next, a rod-shaped sample was prepared by an injection casting method using a copper mold, and a phase of the cross section of the prepared sample was identified by an X-ray diffraction method.

FIG. 3 shows a schematic configuration of an apparatus used for producing an alloy sample having a diameter of 2 to 16 mm by a copper mold casting method as viewed from the side. After making a mother alloy and filling it into a quartz tube 3 having a small hole (hole diameter of 0.5 to 4 mm) at the tip, the quartz tube 3 was placed immediately above a copper mold 6 provided with a vertical hole 5 as a casting space. Thereafter, the mother alloy was heated and melted by the high frequency generating coil 4. Next, the molten metal 1 in the quartz tube 3 is ejected from the small hole 2 of the quartz tube 3 by pressurization of argon gas (0.1 to 1.0 Kg / cm ² ), injected into the hole of the copper mold 6 and left as it is. The sample was solidified to obtain a rod-shaped sample.

Table 1 shows the composition of the prepared sample and the result of the critical diameter at which the glass phase is obtained. The critical diameter is
The phase of the cast material of each diameter was identified by an X-ray diffraction method, and the maximum diameter at which a volume fraction of the glass phase was 100% was determined as the critical diameter. Further, in the phase identification, as in the X-ray figure of the bar material of Example 1 shown in FIG. 1, a sample having no sharp peak resulting from the crystal and having only a broad peak is determined as the glass phase, A sample having a sharp peak resulting from the crystal was judged as a crystal.

Moreover, the sample which consists of a glass phase also measured the glass transition temperature and the crystallization temperature. Glass transition temperature and crystallization temperature were measured using a differential scanning calorimeter (TAC DSC2910).
Measurements were made at a heating rate of 40 K / min. In addition, as the DSC measurement result of Example 1 shown in FIG. 2, the onset temperature at which an endothermic reaction due to glass transition occurs is defined as the glass transition temperature, and the onset temperature at which an exothermic reaction due to crystallization occurs is crystallized. It was temperature.

As shown in Table 1, all the alloys of the present invention exhibit a critical diameter of 6 mm or more. In Examples 5 and 6, the maximum length is 14 mm. The diameter of the rod-shaped sample corresponds to the diameter of the vertical hole provided as a casting space in the mold, and the cooling rate decreases as this diameter increases, so the alloy of the present invention has a lower cooling rate than the conventional alloy It can be seen that a glass phase can be obtained. That is, it can be said that the glass forming ability is high. However, as shown in Comparative Examples 1 and 2, an alloy that deviates from the alloy composition range of the present invention cannot be put to practical use because the alloy cannot be obtained with a diameter of 2 mm and the alloy becomes brittle. Further, since the alloy of the present invention has a wide ΔTx of 50K or more, it is possible to perform viscous flow processing utilizing glass transition.
[Example 16, comparative examples 3 and 4]

A bar (Example 16) having a diameter of 2 mm made of a glass phase having the composition shown in Table 2 was produced in the same manner as in Example 1 by a die casting method. Similarly, bar materials of Comparative Examples 3 and 4 were produced. Thermomechanical measurements were performed on the quality of the viscous flow processing using the glass transition of these bars. These bars were cut out and used as test pieces having a diameter of 2 mm and a length of 4 mm. In the thermomechanical measurement, the test was performed at a heating rate of 10 K / min and a compressive load of 0.64 MPa, and the change amount was compared with the change amount that changes in length due to the viscosity decrease accompanying the glass transition as the change amount per time.

The mechanical properties of the alloy of the present invention were also measured. The test piece was prepared by producing a cast rod having a composition shown in Table 2 having a diameter of 2 mm and a length of 50 mm by a die casting method, and cutting it to a length of 4 mm. The compression test was performed by an Instron universal testing machine at a strain rate of 5 × 10 ⁻⁴ at room temperature, and the stress at break was measured as the compressive strength. Table 2 shows the results.

Since the alloy of the present invention has a wide ΔTx, it can be processed at a temperature higher than the glass transition temperature (Tg) by 50K or more. For this reason, as shown in Example 16 of Table 2, the decrease in the viscosity becomes significant, and deformation occurs even with a small stress of 0.64 MPa. The deformation speed shows a value equivalent to that of Comparative Example 4 in which viscous flow processing can be performed with a metallic glass alloy.

On the other hand, as shown in Comparative Example 3, an alloy having a narrow ΔTx has a maximum deformation rate that is one order of magnitude slower than that of the alloy of the present invention, and cannot be practically processed. Further, a Zr-based alloy having a wide ΔTx can obtain a processing speed equivalent to that of the alloy of the present invention, but the strength at room temperature is about 2000 MPa, which is only ½ of the strength of the metal glass alloy of the present invention. Less than.

[Example 17]
A ribbon material of a metal glass alloy having a thickness of 0.1 mm having the composition of Example 1 was produced by a single roll liquid quenching method. While pressing a die having a plurality of triangular grooves with a depth of 0.25 μm and a width of 1 μm at a pressure of 10 MPa on this ribbon material, the temperature was raised to 900 K in an argon atmosphere, held for 10 minutes, and then rapidly cooled. It was. Next, the state of the pressed ribbon material surface was observed with a cone focal microscope. Ribbon material surface transfers the surface of the mold, depth 0.5
It had a triangular groove with a width of 1 μm and a good transferability.

The Co-based metallic glass alloy of the present invention has good workability and high strength, and has a high glass forming ability capable of producing a single-phase metallic glass alloy rod having a maximum diameter of 14 mm by a copper mold casting method. Therefore, various precision parts can be produced. Further, the alloy of the present invention is 4
Since it has a compressive strength of 000 MPa or more, it can provide various mechanical parts that require high strength and parts that require wear resistance. In particular, as a part that requires precision and wear resistance,
The Co-based metallic glass alloy of the present invention can be suitably used as a mold for precision small parts having complicated shapes such as micro gears and bearings and precision resin parts.

2 is an X-ray diffraction pattern of a cross section of the bar sample of Example 1. FIG. 3 is a graph showing DSC measurement results of a bar sample of Example 1. FIG. It is a schematic side view of the apparatus used for producing the alloy sample of an Example and a comparative example.

Claims (3)

_{(Co 1-x Fe x)} 100-abcd M a C b B c L d ( although, M is one or two kinds selected Mo, from Cr, L is Y, Dy, Ho, Er, Tm And one or more elements selected from Yb, 0 ≦ x ≦ 0.7, a, b, c and d are each in atomic percent, and 22 ≦ a ≦ 35.
, 6 ≦ b ≦ 20,1 ≦ c ≦ 11,10 ≦ b + c ≦ 26,0.5 ≦ d ≦ a 4) Ri Do a composition represented by the temperature range of the supercooled liquid region (ΔTx = Tx-Tg Where Tx is a crystal
Start temperature, Tg is glass transition temperature) is 50K or more, and compressive strength at room temperature is 4000
Co-based metallic glass alloy, wherein the Ru der than MPa. It is a plate or bar with a thickness or diameter of 1 mm to 14 mm, and the volume fraction of the glass phase is 100%.
The Co-based metallic glass alloy according to claim 1, wherein The material for machine parts which consists of Co type metal glass alloy of Claim 1 , and is manufactured by viscous fluid processing.

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