Re-based high-temperature amorphous alloy and preparation method thereof

Abstract

The invention belongs to the technical field of amorphous alloys, and particularly discloses a Re-based high-temperature amorphous alloy and a preparation method thereof.The Re-based high-temperature amorphous alloy is a quaternary amorphous alloy with the molecular formula of ReaCobTacBd, and a + b + c + d = 100; the glass transition temperature of the Re-based high-temperature amorphous alloy ranges from 1000 K to 1100 K; and the width of a supercooled liquid phase region is 80-110K. According to the Re-based high-temperature amorphous alloy and the preparation method thereof, a novel high-temperature amorphous system is researched and explored through the preparation method, and then the application field of the high-temperature amorphous alloy can be effectively widened.

Description

Technical Field

[0001] The present invention belongs to the technical field of amorphous alloys, and in particular relates to a Re-based high-temperature amorphous alloy and a preparation method thereof. Background Art

[0002] Amorphous alloys have high strength, high hardness and high wear resistance due to their unique amorphous structure. However, the amorphous structure is a metastable structure, which may crystallize due to temperature, irradiation and other reasons during service, thus losing its excellent performance. Therefore, the service temperature of amorphous alloys must be lower than the glass transition temperature. The glass transition temperature of amorphous alloys reported so far is usually below 873K, which greatly limits the application field of amorphous alloys. The development of high-temperature amorphous systems with higher glass transition temperatures has become a hot spot and difficulty in the current research on amorphous alloys.

[0003] Therefore, the art needs to develop a Re-based high-temperature amorphous alloy and a preparation method thereof to study and explore new high-temperature amorphous systems, thereby effectively broadening the application field of high-temperature amorphous alloys. Summary of the invention

[0004] The purpose of the present invention is to provide a Re-based high-temperature amorphous alloy. By using the preparation method, a new high-temperature amorphous system can be studied and explored, thereby effectively broadening the application field of the high-temperature amorphous alloy.

[0005] To achieve the above object, the present invention provides a Re-based high temperature amorphous alloy, wherein the Re-based high temperature amorphous alloy has a molecular formula of Re a Co b Ta c B d , wherein a+b+c+d=100 is a quaternary amorphous alloy;

[0006] The glass transition temperature of the Re-based high-temperature amorphous alloy is 1000K-1100K; the width of the supercooled liquid phase region is 80-110K.

[0007] Preferably, the critical diameter of the Re-based high-temperature amorphous alloy is 3-4 mm, the average nanoindentation hardness is 20-25 GPa, the compressive strength is 6-6.7 GPa, and the oxidation resistance is greater than 1200K.

[0008] A method for preparing a Re-based high-temperature amorphous alloy comprises the following steps:

[0009] Step S1: Based on the high vibration entropy of the intermetallic compound Co2B and the Co-Ta eutectic component Co 86.2 Ta 13.8 and Re-B eutectic composition Re 55 B 45Combination, Re-based amorphous alloy Re 27 Co 44 7B 22 ;

[0010] Step S2: Re-based amorphous alloy Re 27 Co 44 7B 22 , increase the content of Re, Ta, and B, reduce the content of Co, and directly obtain a series of Re by arc melting and copper mold suction casting. a Co b Ta c B d , a quaternary amorphous alloy wherein a+b+c+d=100.

[0011] Preferably, step S2 specifically comprises:

[0012] Step S21, increasing the contents of Re, Ta, and B, and reducing the content of Co, for the Re-based amorphous alloy Re 27 Co 44 7B 22 Mixing the ingredients to obtain a Re-Co-Ta-B quaternary amorphous alloy raw material;

[0013] Step S22, repeatedly melting the prepared Re-Co-Ta-B quaternary amorphous alloy raw material in a WK type non-consumable vacuum arc furnace to obtain a master alloy ingot with uniform composition;

[0014] Step S23, in a WK type non-consumable vacuum arc furnace, placing a master alloy ingot with uniform composition into a copper crucible, and heating it to a molten state;

[0015] Step S24: Under the action of pressure difference, the molten alloy is quickly sucked into a copper mold with a suction hole of 3-4 mm in size, and quickly cooled to room temperature to form an amorphous rod, that is, Re a Co b Ta c B d , a quaternary amorphous alloy wherein a+b+c+d=100.

[0016] Preferably, step S22 specifically includes:

[0017] Step S221: vacuumize the equipment until the vacuum degree reaches 4×10 -3 -5×10 -3 Pa, high-purity argon is filled until the pressure in the furnace chamber of the WK type non-consumable vacuum arc furnace is 0.4×10 5 -0.5×10 5 Pa;

[0018] Step S222, under the protection of high-purity argon, the prepared Re-Co-Ta-B quaternary amorphous alloy raw materials are melted in sequence, firstly melting the titanium balls for 20-30 seconds to absorb the oxygen in the cavity, after melting once, waiting for the sample to cool to room temperature, and turning the sample over;

[0019] Step S223, repeat step S222, and smelt each sample 4-5 times to obtain a master alloy ingot with uniform composition.

[0020] Preferably, the operating conditions and steps of step S23 are the same as those of step S22, including vacuuming, melting titanium balls to absorb oxygen, and melting samples.

[0021] The present invention adopts the above-mentioned Re-based high-temperature amorphous alloy and its preparation method, and the beneficial effects are as follows:

[0022] (1) The present invention relates to a Re-based quaternary high-temperature amorphous alloy with high strength, high hardness and high oxidation resistance and a preparation method thereof, which is designed based on vibration entropy for a high-temperature amorphous alloy system; Re and Ta elements with the second and fourth melting points are mainly selected, and B elements that are easy to form covalent bonds and Co elements that have a certain negative mixing heat with B and Ta are added to obtain Re a Co b Ta c B d A quaternary alloy of (a+b+c+d=100);

[0023] (2) The present invention is based on the high vibration entropy of the intermetallic compound Co2B in the Co-B phase diagram and the Co-Ta eutectic component Co 86.2 Ta 13.8 and Re-B eutectic composition Re 55 B 45 A new type of Re-based amorphous alloy Re 27 Co 44 7B 22 Then, a certain amount of Ta, Re, and B are used to replace Co, thereby obtaining a series of Re-Co-Ta-B amorphous alloy compositions, and Re is directly obtained by arc melting and copper mold suction casting. a Co b Ta c B d A quaternary alloy of (a+b+c+d=100);

[0024] (3) The nanoindentation hardness of the Re-based bulk amorphous alloy prepared by the present invention exceeds 20 GPa, and the optimal component Re 29 Co 38 9B 24 The nanoindentation hardness is as high as 24.56GPa, the compressive strength is 6.7GPa, and the oxidation resistance exceeds 1200K;

[0025] (4) The present invention uses the preparation method to study and explore new high-temperature amorphous systems, thereby effectively broadening the application field of high-temperature amorphous alloys.

[0026] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 3mm and 4mm suction casting samples of Re0, Re1, Re2, Re3, and Re4 prepared by an embodiment of the present invention of a Re-based high-temperature amorphous alloy and a preparation method thereof;

[0028] Figure 2 The performance test diagrams of Re0, Re1, Re2, Re3 and Re4 prepared by an embodiment of a Re-based high-temperature amorphous alloy and a preparation method thereof of the present invention; wherein (a) is an X-ray diffraction (XRD) diagram; (b) is a differential scanning calorimetry (DSC) curve diagram;

[0029] Figure 3 The uniaxial compression stress-strain curves of Re0, Re1, Re2, Re3, and Re4 amorphous alloy samples with a diameter of 2 mm by suction casting according to an embodiment of a Re-based high-temperature amorphous alloy and a preparation method thereof of the present invention;

[0030] Figure 4 Thermogravimetric TG curves of Re0, Re1, Re2, Re3 and Re4 prepared by a Re-based high-temperature amorphous alloy and a preparation method thereof according to the present invention;

[0031] Figure 5 This is a nanoindentation hardness diagram of Re0, Re1, Re2, Re3, and Re4 prepared according to an embodiment of the Re-based high-temperature amorphous alloy and its preparation method in the present invention. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0033] Unless otherwise defined, technical or scientific terms used in the present invention shall have the common meanings understood by one having ordinary skills in the field to which the present invention belongs.

[0034] Example

[0035] A method for preparing a Re-based high-temperature amorphous alloy comprises the following steps:

[0036] Step S1: Based on the high vibration entropy of the intermetallic compound Co2B and the Co-Ta eutectic component Co 86.2 Ta 13.8and Re-B eutectic composition Re 55 B 45 Combination, Re-based amorphous alloy Re 27 Co 44 7B 22 ;

[0037] Step S2: using Re and Ta single-substance raw materials with a purity of more than 99.95%, and CoB master alloy, respectively according to Re 27+x Co 44-3x Ta 7+x B 22+x , where x=0, 1, 2, 3, 4, and these alloys are named according to the content of x, namely Re0, Re1, Re2, Re3, and Re4. The precision used for weighing is 1×10 -4 The upper and lower error range of the balance is kept at 4×10 -4 Within g.

[0038] The melting equipment used is the WK type non-consumable vacuum arc furnace of Beijing Wuke Optoelectronics. The prepared quaternary amorphous alloy raw materials and titanium balls are placed in the melting crucible respectively. Before melting the alloy, the equipment is evacuated and the vacuum degree reaches 5×10 -3 Pa, high-purity argon gas is filled into the arc furnace until the pressure in the furnace chamber reaches 0.5×10 5 Pa. The raw materials were melted in sequence under the protection of argon. The titanium ball was first melted for 30 seconds to absorb the oxygen in the cavity. After one melting, the sample was cooled to room temperature, turned over, and the above process was repeated. Each sample was melted 4-5 times to ensure that Re0, Re1, Re2, Re3, and Re4 master alloy ingots with uniform composition could be obtained.

[0039] In a WK type non-consumable vacuum arc furnace, the master alloy ingots with uniform composition are placed in copper crucibles respectively. Before melting the alloy, the equipment is evacuated until the vacuum degree reaches 5×10 -3 Pa, high-purity argon gas is filled into the arc furnace until the pressure in the furnace chamber reaches 0.5×10 5 Pa. The raw materials were melted in sequence under the protection of argon gas. The titanium ball was first melted for 30 seconds to absorb the oxygen in the cavity. After one melting, the sample was cooled to room temperature, and the sample was turned over and the above process was repeated. Each sample was melted 4-5 times and heated to a molten state.

[0040] When the fluidity of the alloy liquid is relatively high, the suction valve is pressed to disconnect the arc. Under the action of the pressure difference, the molten alloy is quickly sucked into the copper molds with suction holes of 3mm and 4mm in size, and quickly cooled to room temperature to form amorphous rods, that is, 3mm and 4mm quaternary amorphous alloy rods of Re0, Re1, Re2, Re3, and Re4 are obtained. Figure 1 shown.

[0041] The quaternary amorphous alloy rods prepared in the example were subjected to performance testing.

[0042] (1) The microstructure of the prepared Re0, Re1, Re2, Re3, and Re4 quaternary bulk amorphous alloys was detected using an X-ray diffractometer. The test samples were cut from suction-cast rods using a water-cooled diamond slow saw. The analysis was performed using a Japanese Rigaku D / max-2500PC X-ray diffractometer, using a Cu-Kα target, a scanning speed of 4° / min, a current of 200mA, a voltage of 40kV, and a test range (2θ) of 20°-80°.

[0043] like Figure 2 As shown in (a), the DSC curves of all alloys are diffuse peaks, indicating their amorphous structures, and their maximum critical formation size is 4 mm.

[0044] (2) The glass transition temperature T of the prepared Re0, Re1, Re2, Re3, and Re4 quaternary amorphous alloy bulks was analyzed using differential scanning calorimetry (DSC). g , Crystallization start temperature T x The differential scanning calorimeter used for the analysis is a NETZSCH DSC404F3 differential scanning calorimeter, an alumina crucible is used as the crucible, the temperature range is from room temperature to 1673K, and the scanning speed is 20° / min.

[0045] During the measurement process, empty plates must be placed at two locations first, the program must be set, and the heat flow curve must be used as the baseline. The sample measurement procedure must then be consistent with the baseline measurement procedure. After the test is complete, the heat flow curve can be obtained using the corresponding software.

[0046] like Figure 2 As shown in (b), all curves show an increase in specific heat followed by heat release, indicating that the glass transition is followed by crystallization. From Table 1, it can be found that T g The highest value reaches 1113K, ΔT x The maximum is over 100K.

[0047] Table 1 Characteristic temperature, critical size and fracture strength of Re0, Re1, Re2, Re3 and Re4 amorphous alloys

[0048] <![CDATA[T g / K]]> <![CDATA[T x / K]]> <![CDATA[ΔT x / K]]> <![CDATA[D c / mm]]> <![CDATA[σ y / GPa]]> Re0 1009.5 1112 102.5 4 6703 Re1 1043 1130 87 4 6438 Re2 1063.6 1147.8 84.2 4 6741 Re3 1094.1 1171.7 77.6 4 6101 Re4 1113 1189.1 76.1 3 6390

[0049] (3) The antioxidant capacity of the prepared Re0, Re1, Re2, Re3, and Re4 quaternary amorphous alloy blocks was analyzed using a thermogravimetric analyzer TG. The differential scanning calorimeter used for the analysis was a Netzsch DSC404F5 differential scanning calorimeter. The crucible was an alumina crucible. The temperature range was from room temperature to 1473K. The scanning speed was 20° / min and the atmosphere was synthetic air. During the measurement process, empty plates were placed at two locations, the program was set, the mass was weighed, and the thermogravimetric curve was used as the baseline. The program for measuring the sample was then kept consistent with the program for measuring the baseline. After the test was completed, the thermogravimetric curve could be obtained using the corresponding software;

[0050] like Figure 4 As shown, the alloy has no obvious weight increase before 1243K, indicating its high oxidation resistance.

[0051] (4) The hardness of the prepared Re0, Re1, Re2, Re3, and Re4 quaternary bulk amorphous alloys was tested using a Nano Indenter G200X nanoindenter produced by KLA, USA. Before the test, the sample was cold mounted, and the sample surface was ground and mechanically polished to a mirror surface using a balanced grinding table. During the grinding process, the upper and lower surfaces of the sample must always remain parallel.

[0052] like Figure 5 As shown, the nanoindentation hardness of the alloys exceeds 20 GPa, which shows ultra-high hardness.

[0053] (5) A universal testing machine Instron-5982 was used to perform uniaxial compression tests on amorphous alloy samples to test their mechanical properties. A water-cooled diamond abrasive slow saw was used to cut a sample with an aspect ratio of 2:1 from a 2 mm diameter suction-cast amorphous rod for uniaxial compression tests. The strain rate was set to 5 × 10 -4 s -1 To ensure the reliability of the data, the compression test of each component of the amorphous alloy sample was repeated 5 times, and the compression data was averaged. The stress-strain curve of the compression test, such as Figure 3 The results show that all samples exhibit ultra-high strength, with a maximum compressive strength of up to 6.7 GPa, making them a group of high-strength bulk amorphous alloys.

[0054] Therefore, the present invention adopts the above-mentioned Re-based high-temperature amorphous alloy and its preparation method, and uses the preparation method to study and explore new high-temperature amorphous systems, thereby effectively broadening the application field of high-temperature amorphous alloys.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A Re-based high-temperature amorphous alloy, characterized in that: Re-based high temperature amorphous alloys are a Co b Ta c B d , wherein a+b+c+d=100 is a quaternary amorphous alloy; The glass transition temperature of the Re-based high-temperature amorphous alloy is 1000K-1100K; the width of the supercooled liquid phase region is 80-110K.

2. The Re-based high-temperature amorphous alloy according to claim 1, characterized in that: The critical diameter of the Re-based high-temperature amorphous alloy is 3-4 mm, the average nanoindentation hardness is 20-25 GPa, the compressive strength is 6-6.7 GPa, and the oxidation resistance is greater than 1200K.

3. A method for preparing a Re-based high-temperature amorphous alloy as claimed in any one of claims 1 to 2, characterized in that: The following steps are involved: Step S1: Based on the high vibration entropy of the intermetallic compound Co2B and the Co-Ta eutectic component Co 86.2 Ta 13.8 and Re-B eutectic composition Re 55 B 45 Combination, Re-based amorphous alloy Re 27 Co 44 7B 22 ; Step S2: Re-based amorphous alloy Re 27 Co 44 7B 22 , increase the content of Re, Ta, and B, reduce the content of Co, and directly obtain a series of Re by arc melting and copper mold suction casting. a Co b Ta c B d , a quaternary amorphous alloy wherein a+b+c+d=100.

4. The method for preparing a Re-based high-temperature amorphous alloy according to claim 3, characterized in that: Step S2 specifically includes: Step S21, increasing the contents of Re, Ta, and B, and reducing the content of Co, for the Re-based amorphous alloy Re 27 Co 44 7B 22 Mixing the ingredients to obtain a Re-Co-Ta-B quaternary amorphous alloy raw material; Step S22, repeatedly melting the prepared Re-Co-Ta-B quaternary amorphous alloy raw material in a WK type non-consumable vacuum arc furnace to obtain a master alloy ingot with uniform composition; Step S23, in a WK type non-consumable vacuum arc furnace, placing a master alloy ingot with uniform composition into a copper crucible, and heating it to a molten state; Step S24: Under the action of pressure difference, the molten alloy is quickly sucked into a copper mold with a suction hole of 3-4 mm in size, and quickly cooled to room temperature to form an amorphous rod, that is, Re a Co b Ta c B d , a quaternary amorphous alloy wherein a+b+c+d=100.

5. The method for preparing a Re-based high-temperature amorphous alloy according to claim 4, characterized in that: Step S22 specifically includes: Step S221: vacuumize the equipment until the vacuum degree reaches 4×10 -3 -5×10 -3 Pa, high-purity argon is filled until the pressure in the furnace chamber of the WK type non-consumable vacuum arc furnace is 0.4×10 5 -0.5×10 5 Pa; Step S222, under the protection of high-purity argon, the prepared Re-Co-Ta-B quaternary amorphous alloy raw materials are melted in sequence, firstly melting the titanium balls for 20-30 seconds to absorb the oxygen in the cavity, after melting once, waiting for the sample to cool to room temperature, and turning the sample over; Step S223, repeat step S222, and smelt each sample 4-5 times to obtain a master alloy ingot with uniform composition.

6. The method for preparing a Re-based high-temperature amorphous alloy according to claim 5, characterized in that: The operating conditions and steps of step S23 are the same as those of step S22, including vacuuming, melting the titanium ball to absorb oxygen, and melting the sample.

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