CN1219905C - Copper base lump non-crystalline alloy - Google Patents

Abstract

The invention relates to a copper-based bulk amorphous alloy, the copper-based amorphous alloy contains an amorphous phase with a volume percentage of at least 50%, and the structural formula of the amorphous alloy is Cu _a -R' _b -R" _c - R _d , where a, b, c, and d are the atomic percentages of the corresponding elements, 45<a<66, 5<b<25, 5≤c≤20, 0≤d<30, and a+b+c+d = 100, R' is Zr and/or Hf, R" is Ti or Nb, R is at least one selected from Fe, Ni, Y, Be, Al, Sn, Si and other elements; the copper-based bulk amorphous The size of the alloy is large, the hardness is high, the thermal stability is good, the ability to form amorphous is good, and the raw material purity of each component element required is low, so it is more suitable for industrial use.

Description

Cu-based bulk amorphous alloy

technical field

The invention relates to an amorphous alloy material, in particular to a copper-based bulk amorphous alloy.

Background technique

Amorphous alloys are usually formed by cooling molten metal alloys below the glass transition temperature and solidifying before nucleation and crystallization. Normally metals and alloys crystallize to form crystals when cooled from a liquid state. However, it has been found that certain metals and alloys will maintain their liquid structure during solidification and inhibit crystallization when the cooling rate is fast enough. This cooling rate usually needs to reach the order of 10 ⁴ -10 ⁶ K/s. In order to achieve such a high cooling rate, the molten metal or alloy can only be sprayed onto a conductive substrate that conducts heat very well, so that an amorphous alloy is formed, but the size is very small. Previously obtained amorphous alloy materials were thin strips obtained by spraying molten metal or alloy onto a high-speed rotating copper roll, or flakes and powders obtained by casting into a cold substrate. Recently, amorphous alloys have been found that have a stronger ability to inhibit crystallization, so that lower cooling rates can be used to inhibit crystallization. If crystallization can be suppressed at very low cooling rates, larger size amorphous alloys can be produced.

As early as 1960, Duwez prepared AuSi-based amorphous strips by copper roll quenching method (Document 1, W.Klement, R.H.Wilens, and Duwez, Nature, 1960, vol.187, pp869-70). Subsequently, amorphous alloys containing metalloid elements (such as Si, C, B, Ge, P), especially iron-based alloys, have been extensively studied.

However, due to the poor amorphous formation ability of most alloys, the cooling rate higher than 10 ⁶ K/s is required for rapid cooling, so the prepared amorphous alloys can only be low-dimensional materials in size, such as thin strips. , filaments, fine powder. Mechanical alloying has also been a method of preparing amorphous powder. Many alloys can be transformed into amorphous by high-energy ball milling, and then the amorphous powder can be compacted into an amorphous block in the supercooled liquid phase region. However, the bulk metallic glass prepared by this method has poor density and is easily mixed with other impurities. Therefore, obtaining bulk amorphous alloys has been the goal pursued by scientists for decades.

Until 1989, Japan's Inoue et al. found that MgCuY and LaAlNi alloys have high amorphous forming ability (document 3, A.Inoue, T.Zhang, and T.Masumoto, Mater.Trans., JIM, 1989, Vol .30, pp965-72), millimeter-scale amorphous alloys can be prepared by copper mold casting, which is the first discovery of a millimeter-scale amorphous alloy-forming system that does not contain precious metals. Since 1993, the United States and Japan have successively developed zirconium-based amorphous alloys, such as Zr ₄₁ Ti ₁₄ Cu ₁₂ Ni ₁₀ Be ₂₃ , Zr ₆₅ Al _7.5 Ni ₁₀ Cul _7.5 , etc., and copper-based bulk amorphous alloys (Document 4, A.Peker and WLJohnson, Appl.Phys.Lett., 1993, Vol.63, PP2342-44 and literature 5, A.Inoue, W.Zhang, T.Zhang and K.Kurosaka, Actamater.2001, vol.49, pp2645-2652). Zirconium-based amorphous will soon be used in golf head panels, other precision optical instrument components, corrosion-resistant vessels, bullets or armor-piercing projectile cores.

In addition, the study found that the bulk amorphous alloy has superplastic deformation ability in the supercooled liquid phase region, thus providing the possibility for the forming and processing of the alloy.

Copper-based bulk amorphous alloy has good mechanical properties, tensile and compressive strengths above 2000Mpa, and good elasticity. At present, the preparation of copper-based bulk metallic glasses discovered by Americans and Japanese requires a very high level of technology, requiring ultra-high-purity alloys, generally higher than 99.999% (document 5, C.T.Liu, L.Heatherly, D.S.Easton, C.A. Carmicheal, J.H. Schneibel, C.H. Chen, J.L. Wright, M.H. Yoo, J.A. Horton, and A. Inoue, Metallurgical and Materials Transaction A, 1998, Vol 29A, pp1811-1820). Moreover, the size of the copper-based bulk metallic glass made by the Japanese is not large, and can only be made into a rod-shaped copper-based amorphous alloy with a diameter of 3-4 mm.

Generally, the composition of the amorphous alloy contains at least one early transition group metal element or one late transition group metal element and beryllium. Ternary alloys containing beryllium usually have good amorphous-forming ability. However, quaternary alloys containing at least three transition group metal elements have a lower critical cooling rate to avoid crystallization, and thus have better amorphous formation ability. Nonetheless, amorphous alloys with better glass-forming ability are found in multicomponent alloys, particularly alloys containing at least two early transition group metal elements and at least two late transition group metal elements.

Typically, an additional 5% to 10% of any transition group metal element added to the amorphous alloy is acceptable and still form an amorphous alloy. In addition, amorphous alloys are allowed to contain a small amount of impurities, such as a small amount of oxygen may be dissolved in amorphous alloys without significant crystallization. It may also contain other incidental elements, such as germanium, phosphorus, carbon, nitrogen, but the total amount of impurities should be less than 5% (atomic percentage).

Curve a and curve b in Fig. 1 are the crystallization curves of two known amorphous alloys; the melting point T _m and the glass transition temperature T _g are indicated in the figure, and the front end of the curve represents the crystallization required for a given crystal volume ratio shortest time. In order to obtain a disordered solid material, the alloy must be cooled from above the melting point through the glass transition without crystallization, that is, the alloy cannot intersect the crystallization curve when cooled from the melting point through the glass transition temperature. The crystallization curve a represents the crystallization behavior of the earliest obtained amorphous alloy, and its cooling rate exceeds 10 ⁵ K/s, usually in the order of 10 ⁶ K/s. The crystallization curve b is the crystallization curve of the amorphous alloy developed later, and the cooling rate required to form the amorphous alloy has been reduced by 1 or 2, or even 3 orders of magnitude, about 10 ³ K/s.

Being able to form amorphous alloys is only the first step in obtaining bulk amorphous alloys. What people want is amorphous alloys with large three-dimensional dimensions and their machinable parts. For bulk amorphous alloys to be processable and maintain their integrity, the alloy is required to be deformable. Amorphous alloys can only undergo uniform deformation under applied pressure around or above the glass transition temperature. Furthermore, crystallization also usually occurs rapidly in this temperature range. Therefore, as shown in Figure 1, each time the formed amorphous alloy is reheated above the glass transition temperature, there is a very narrow temperature region where crystallization does not occur before the amorphous alloy crystallizes.

Figure 2 is a graph of the logarithmic relationship between temperature and viscosity of known amorphous alloys as subcooled liquids between melting point and glass transition temperature. At the glass transition temperature, the viscosity of the alloy is on the order of 10 ¹² poise. In addition, the liquid alloy may have a viscosity of less than 1 poise (the viscosity of water at room temperature is about one hundredth of a poise). It can be seen from Figure 2 that when the amorphous alloy is heated, the viscosity of the amorphous alloy decreases gradually with the increase of temperature in the low temperature region, and then changes rapidly above the glass transition temperature. For every 5°C increase in temperature, the viscosity decreases by an order of magnitude. It is desirable to reduce the viscosity of amorphous alloys to 10 ⁵ Poise so that they can be deformed with less force, which means that amorphous samples should be heated above the glass transition temperature. Processing times for amorphous alloys should be on the order of seconds or longer to allow sufficient time to heat, manipulate, process and cool the alloy before appreciable crystallization occurs. Therefore, for amorphous alloys with good formability, one would expect the crystallization curve to shift to the right, ie to longer times.

The ability of an amorphous alloy to resist crystallization is related to the cooling rate required for the alloy to cool from the molten state to form an amorphous state. This is an indication of the stability of the disordered phase during processing of amorphous alloys above the glass transition temperature. We expect the cooling rate to inhibit crystallization to be from 10 ³ K per second to 1 K per second or less. When the critical cooling rate is reduced, a longer processing time can be obtained before crystallization occurs, that is, such an amorphous alloy can be processed above the glass transition temperature without crystallization, making it suitable for for industrial use.

Therefore, amorphous alloy materials with lower cooling rate, better amorphous formation ability, large size and high strength will be more suitable for industrial use.

Contents of the invention

The object of the present invention is to obtain an amorphous alloy material more suitable for industrial use, thereby providing a copper-based bulk amorphous alloy.

The purpose of the present invention can be achieved through the following measures:

A copper-based bulk amorphous alloy, which contains an amorphous phase with a volume percentage of at least 50%, and the structural formula of the amorphous alloy is: Cu _a -R' _b -R" _c -R _d , wherein a, b, c, d are the atomic percentages of the corresponding elements, 45<a<66, 5<b≤30, 5≤c≤20, 0≤d<30, and a+b+c+d=100, R ' is Zr and/or Hf, R" is Ti or Nb, and R is selected from at least one element of Fe, Ni, Y, Be, Al, Sn, and Si.

The amorphous alloy also contains 5%-10% of any transition group metal element.

The amorphous alloy also contains impurities with a total atomic percentage of less than 5%.

The impurity includes at least one of oxygen, germanium, phosphorus, carbon and nitrogen.

The raw material purity of each constituent element of the amorphous alloy is 99%-99.999%.

Compared with the prior art, the present invention has the following advantages:

The copper-based bulk amorphous alloy provided by the invention has large size, high strength, good thermal stability, good amorphous forming ability, low requirement for raw material purity of each component element required, and is more suitable for industrial use.

Description of drawings

Fig. 1 is the crystallization curve of known two kinds of amorphous alloys and the amorphous alloy of the present invention;

Fig. 2 is the logarithmic relationship figure of temperature and viscosity of known amorphous alloy supercooled liquid between fusing point and glass transition temperature;

Fig. 3 is the X-ray diffraction figure of the amorphous alloy of embodiment 1 of the present invention;

Fig. 4 is the X-ray diffraction figure of the amorphous alloy of embodiment 2-6 of the present invention;

Fig. 5 is the X-ray diffraction figure of the amorphous alloy of embodiment 7 and 8 of the present invention;

Fig. 6 is the differential thermal analysis curve of the amorphous alloy of embodiment 3, 4 and 5 of the present invention;

Graphic description:

a - the crystallization curve of the earliest amorphous alloy;

b- the crystallization curve of the amorphous alloy developed in the later period;

C-crystallization curve of the amorphous alloy of the present invention;

1-Amorphous alloy Cu _58.8 Zr _29.4 Ti _9.8 Y ₂ ; 2-Amorphous alloy Cu ₆₀ Zr ₂₅ Hf ₅ Ti ₁₀ ;

3-Amorphous alloy Cu ₆₀ Zr ₂₀ Hf ₁₀ Ti ₁₀ ; 4-Amorphous alloy Cu ₆₀ Zr ₁₅ Hf ₁₅ Ti ₁₀ ;

5-Amorphous alloy Cu ₆₀ Zr ₁₀ Hf ₂₀ Ti ₁₀ ; 6-Amorphous alloy Cu ₆₀ Zr ₅ Hf ₂₅ Ti ₁₀ ;

7-amorphous alloy Cu ₆₀ Zr ₃₀ Ti ₁₀ ; 8-amorphous alloy Cu ₄₇ Ti ₃₄ Zr ₁₁ Ni ₈ .

Detailed ways

The present invention can adopt domestically produced electrolytic copper, and use the known preparation method of amorphous alloy to obtain the copper-based amorphous alloy material of the present invention.

Curve c in Fig. 1 is the crystallization curve of the amorphous alloy of the present invention, the required cooling rate is further greatly reduced, and the cooling rate does not exceed 10 ² K per second. The uniform alloy melt is cooled at a cooling rate of 1-100K/s or lower, and the size of the prepared material is not less than 1 mm in each dimension. Such a cooling rate can be realized by various existing technologies for the preparation of amorphous alloys: for example, the casting method can be used to cast the alloy into a water-cooled copper mold to obtain plates, rods, and strips with a size of 1 to 8 mm or larger Or mesh parts; the water quenching method can be used to perform water cooling and quenching in a quartz container to obtain rod-shaped samples with a size of 8 mm or larger; the vacuum suction casting method can also be used to suck the alloy into a copper mold to obtain large-sized samples.

The proportion of amorphous phase in amorphous alloy can be analyzed and estimated by differential thermal analysis or transmission electron microscope TEM.

The amorphous phase in amorphous alloys can be verified by many well-known methods. The X-ray diffraction pattern of a completely amorphous alloy shows a broad diffuse scattering peak. Fig. 3 to Fig. 5 are the X-ray diffraction analysis figures of the amorphous alloy of the present invention, find out from the figure, do not observe any crystallization peak in the effective resolution of X-ray diffractometer, illustrate that the prepared alloy is amorphous crystal alloy. When the amorphous alloy contains a crystalline phase, a relatively sharp Bragg diffraction peak representing the crystalline phase will be observed.

Table 1 Example Glass transition temperature T _g (K) Crystallization temperature T _X (K) Melting point T _m (K) The width of the supercooled liquid phase region ΔT(K) Yield strength (Mpa) Tensile strength (Mpa) 1 714 763 1057 49 2030 2100 3 712 763 1067 51 - 2190 7 706 751 1175 45 2010 2160 8 705 742 1058 37 - 2000 9 712 760 1085 38 - 2450 10 708 753 1081 45 - 1920 11 718 766 1140 48 - 2050

Table 1 is the performance of the copper-based amorphous alloy of the present invention. These alloys are larger than 1 mm in diameter and are completely amorphous. Through differential thermal analysis DSC, the properties of amorphous alloys are obtained, including glass transition temperature T _g expressed in absolute temperature, crystallization temperature T _X , melting point T _m , width ΔT of supercooled liquid phase region; and obtained through mechanical tests corresponding strength. Since the measurement of the sample is carried out in an argon atmosphere, and the commercial argon gas used usually contains some oxygen, the surface of the sample will be somewhat oxidized after heating during the measurement. The crystallization temperature is higher when the surface of the sample being tested is so clean that uniform nucleation occurs rather than heterogeneous nucleation. The crystallization temperature of the actual samples is therefore higher than that obtained after the surface of the samples was oxidized in these tests. The supercooled liquid region width is the difference between the crystallization temperature and the glass transition temperature obtained in the differential thermal analysis measurement. Generally, a wider supercooled liquid region indicates that the amorphous alloy has a lower critical cooling rate, that is, the amorphous alloy has a longer processing time above the glass transition temperature.

Example 1:

The preparation of this example adopts the known water quenching method: Cu, Zr, Ti, Y and other elements with a purity of 99.5% are arced in an argon atmosphere adsorbed by titanium according to the required atomic ratio of the formula Cu _58.8 Zr _29.4 Ti _9.8 Y ₂ Melting, mixing evenly, and cooling to obtain master alloy ingots. These ingots are crushed and put into quartz glass tubes, vacuum pumped to 10 ^-3 Pa and packaged, heated in a furnace to 1050°C for 10 minutes to remelt the ingots, and then water quenched to obtain Cu _58.8 with uniform composition. Zr _29.4 Ti _9.8 Y ₂ A 5 mm diameter round rod of bulk amorphous alloy 1. The amorphous alloy contains impurities: oxygen and nitrogen in a total of about 1 atomic percent. It can be seen from the X-ray diffraction pattern in FIG. 3 that all of the amorphous alloy 1 is an amorphous phase and no crystallized phase. It can be seen from Table 1 that the melting point _Tm of this alloy 1 is 1057K, the crystallization temperature _Tx is 763K, and the glass transition temperature _Tg is 714K. The tensile strength is 2100Mpa.

Embodiment 2-6:

The examples in this series were prepared by known casting methods. Taking Example 3 as an example below to illustrate the preparation of amorphous alloys by casting method: Cu, Zr, Hf, Ti with a purity of 99.9% are arced in an argon atmosphere adsorbed by titanium according to the proportion of Cu ₆₀ Zr ₂₀ Hf ₁₀ Ti ₁₀ Melting, mixing evenly, and cooling to obtain master alloy ingots. Then the master alloy ingot is broken and melted in a high-frequency induction furnace. The vacuum degree of the vacuum chamber of the high-frequency induction furnace is 10 ^-1 Pa. After melting, argon is blown into a water-cooled copper mold to obtain Cu ₆₀ Zr ₂₀ Hf ₁₀ Ti ₁₀ bulk amorphous alloy 3. The X-ray diffraction pattern of the amorphous alloy is shown in Fig. 4, which shows that all of the amorphous alloy 3 is an amorphous phase and no crystallized phase. In the amorphous alloy 3, germanium, phosphorus and carbon are reduced to a total of about 2 percent by atomic percent. This alloy 3 is obtained by replacing part of Zr with metal element hafnium in Cu ₆₀ Zr ₃₀ Ti ₁₀ alloy. The addition of a small amount of metal element hafnium improves the amorphous forming ability of the alloy and makes the alloy have higher and better manufacturability. The differential thermal analysis curve of the amorphous alloy 3 is shown in FIG. 6 . As can be seen from Table 1, the glass transition temperature of this amorphous alloy 3 is 712K, and the width of its supercooled liquid phase region is 51K, indicating that its thermal stability and amorphous forming ability are better than the bulk amorphous alloy prepared in Example 1. good. In addition, Cu ₆₀ Zr ₂₅ Hf ₅ Ti ₁₀ copper-based bulk amorphous alloy 2; Cu ₆₀ Zr ₁₅ Hf ₁₅ Ti ₁₀ copper-based bulk amorphous alloy 4; Cu ₆₀ Zr ₁₀ Hf ₂₀ Ti ₁₀ copper-based bulk amorphous alloy 5; Cu ₆₀ Zr ₅ Hf ₂₅ Ti ₁₀ copper-based bulk amorphous alloy 6; it can be seen from Figure 4 that there is no crystallized phase in amorphous alloys 4 and 5, and the amorphous The differential thermal curves of alloys 4 and 5 are shown in Figure 6; a small amount of crystallized phase exists in amorphous alloys 2 and 6.

Embodiment 7:

This embodiment adopts the known vacuum suction casting method: Cu, Zr, and Ti with a purity of 99% are arc-melted in an argon atmosphere adsorbed by titanium according to the atomic ratio of the chemical formula Cu ₆₀ Zr ₃₀ Ti ₁₀ , and mixed uniformly. The electric arc furnace has a suction casting device, and then the alloy is sucked into the copper mold to obtain the glass transition temperature T _g and the initial crystallization temperature T _x . It can be seen from Table 1 that the amorphous alloy 7 is characterized by a high melting point T _m 1175K and a crystallization temperature T _x 751K, so the thermal stability is very good and the applicable temperature is very high. The glass transition temperature of the amorphous alloy 7 is 706K, and the width of the supercooled liquid phase region of this alloy is 45K, indicating that its ability to form amorphous is very good. The tensile strength is 2160Mpa.

Embodiment 8:

Cu, Zr, Ti, and Ni with a purity of 99.99% are prepared according to the chemical formula of Cu ₄₇ Ti ₃₄ Zr ₁₁ N ₈ , and the method of Example 1 is used to prepare a bulk amorphous with the composition Cu ₄₇ Ti ₃₄ Zr ₁₁ Ni ₈ Alloy 8, which has the highest content of titanium, has less zirconium and other more expensive alloying elements, and is less expensive. FIG. 5 shows that the amorphous alloy 8 also has no crystallized phase. It can be seen from Table 1 that the glass transition temperature of the amorphous alloy 8 is 705K, the crystallization temperature is 742K, and the melting point is 1058K. The maximum diameter of the sample can reach 4 mm, and at the same time, it has high strength.

Embodiment 9:

Cu, Zr, Be, and Ti with a purity of 99.999% are prepared according to the ratio of the chemical formula of Cu ₅₄ Zr ₂₇ Ti ₉ Be ₁₀ , and the method of Example 1 is used to prepare a bulk amorphous alloy with a composition of Cu ₅₄ Zr ₂₇ Ti ₉ Be ₁₀ . This alloy is obtained by adding a small amount of metal element beryllium to Cu ₆₀ Zr ₃₀ Ti ₁₀ alloy. The addition of a small amount of metal element beryllium improves the amorphous forming ability of the alloy and makes the alloy have higher and better manufacturability. The sample diameter of the amorphous alloy is up to 5 mm, and all of them are amorphous, and its X-ray diffraction pattern is similar to that in Figure 5. It can be seen from Table 1 that the glass transition temperature of the amorphous alloy 9 is 712K, and the width of the supercooled liquid phase region is 48K. In this example, the method of increasing small atoms is used to improve the formation ability of the amorphous. In addition, a sample with a diameter of 8 mm can be prepared, containing at least 50 percent of the amorphous phase by volume.

Example 10:

A bulk amorphous alloy with a composition of Cu ₄₇ Ti ₃₁ Zr ₁₁ Ni ₈ Sn ₃ was prepared by using the method in Example 3. This alloy is obtained by replacing titanium element with a small amount of metal element tin in Cu ₄₇ Ti ₃₄ Zr ₁₁ Ni ₈ alloy. The addition of a small amount of metal element tin improves the amorphous forming ability of the alloy and makes the alloy have higher and better manufacturability. It can be seen from Table 1 that the glass transition temperature of this amorphous alloy is 708K, and its supercooled liquid zone width is wider than that of Cu ₄₇ Ti ₃₄ Zr ₁₁ Ni ₈ amorphous alloy 8, indicating its thermal stability and amorphous forming ability It is better than the bulk amorphous alloy prepared in Example 4. A completely amorphous sample with a diameter of 5 mm can be prepared, and its X-ray diffraction pattern is similar to that in Figure 5. Amorphous samples with a volume percentage of more than 50% and a diameter of 8 mm can also be prepared.

Example 11: An amorphous alloy Cu ₆₀ Hf ₂₅ Ti ₁₅ with a diameter of 3 mm was prepared by the method of Example 7. It can be seen from Table 1 that the melting point T _m of the amorphous alloy is 1140K, and the crystallization temperature T _x is 766K , the glass transition temperature is 718K. The tensile strength is 2050Mpa.

Example 12: The method of Example 1 was used to prepare an amorphous alloy Cu ₆₀ Zr ₁₅ Nb ₅ Hf ₁₀ Ti ₁₀ with a diameter of 3 mm.

Example 13: An amorphous alloy Cu ₆₀ Zr ₂₈ Ti ₁₀ Fe ₂ with a diameter of 1-3 mm was prepared by the method of Example 3, wherein the volume percentage of the amorphous phase was greater than 90%;

Example 14: An amorphous alloy Cu ₆₀ Zr ₂₅ Ti ₁₀ Al ₅ with a diameter of 1-3 mm was prepared by the method of Example 7, wherein the volume percentage of the amorphous phase was greater than 90%; and

Example 15: Using the method of Example 1, an amorphous alloy Cu ₄₇ Ti ₃₁ Zr ₁₁ Ni ₈ Sn ₁ Si ₂ with a diameter of 1-3 mm was prepared, wherein the volume percentage of the amorphous phase was greater than 90%.

The X-ray diffraction patterns of Examples 11-15 are all similar to FIG. 5 .

As shown by the above examples, the material of the present invention contains at least 50% by volume of an amorphous phase. The amorphous alloy provided by the present invention has high strength, and its value is mostly or exceeds 2000GPa, as can be seen from Table 1, the crystallization temperature of the alloy exceeds 730K, and the glass transition temperature exceeds 700K, which shows that they have better thermal stability sex. The amorphous alloys provided by the invention all have a critical cooling rate of 10-100 K/s without crystallization, and have a rather wide supercooled liquid phase region, indicating that they all have good amorphous forming ability. By using the three preparation methods described in the present invention, the amorphous material on the order of millimeters can be obtained, and the maximum size can reach 8 millimeters.

Claims (1)

1, a kind of copper base large amorphous alloy comprises volume percent and is at least 50% amorphous phase in this non-crystaline amorphous metal, the structural formula of this non-crystaline amorphous metal is: Cu _a-R ' _b-R " _c-R _d, wherein a, b, c, d are the atomic percent of respective element, 54≤a≤60,15≤b≤30,5≤c≤10,2≤d≤10, and a+b+c+d=100, R ' is Zr or/and Hf, R " and be Ti or Nb, R is Y or Be.

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