Cu-Zr-Se series metallic glass and preparation method thereof

Abstract

The invention discloses Cu-Zr-Se series metallic glass and a preparation method thereof, and belongs to the technical field of metallic glass materials, the chemical components of alloy raw materials are expressed by atomic percent as CuaZrbSec, the value range of a is 40-60, the value range of b is 40-60, the value range of c is 0.1-10, and a + b + c = 100. The preparation method comprises the following steps: alloying Cu and Se through an induction melting method to obtain an intermediate alloy Cu2Se; cu, Zr and Cu2Se are alloyed through a vacuum arc melting method, and the Cu-Zr-Se series metal glass with high glass forming ability and good plasticity and toughness is formed.

Description

Technical Field

[0001] The present invention belongs to the technical field of metallic glass materials, and particularly relates to a Cu-Zr-Se series metallic glass and a preparation method thereof. Background Art

[0002] Metallic glass, also known as amorphous alloy, is an amorphous substance formed by the disordered packing of atoms. The microstructure of amorphous alloy is similar to that of liquid metal, showing the characteristics of long-range disorder and short-range order in structure, and not containing crystal structure characteristics such as point defects, line defects, and grain boundaries. It has characteristics such as high strength, high hardness, high corrosion resistance, and excellent soft magnetic properties. These characteristics make it promising for engineering applications in fields such as ultra-precision molds, micro-mechanics, high-grade sports equipment, cutting tools, and magnetic components. However, the limited glass-forming ability and poor plasticity and toughness of amorphous alloys have long restricted their wide application in many fields. Summary of the Invention

[0003] Aiming at the problems of the limited glass-forming ability and poor plasticity and toughness of the above-mentioned metallic glass, the present invention provides a Cu-Zr-Se series metallic glass and a preparation method thereof. By induction melting, Cu and Se are alloyed to obtain an intermediate alloy Cu2Se. By vacuum arc melting, Cu, Zr, and Cu2Se are alloyed to form a Cu-Zr-Se series metallic glass with high glass-forming ability and good plasticity and toughness.

[0004] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0005] The present invention provides a Cu-Zr-Se series metallic glass. The chemical composition of the metallic glass is expressed in atomic percentage as Cu a Zr b Se c ,

[0006] wherein, the value range of a is: 40 - 60, the value range of b is: 40 - 60, the value range of c is: 0.1 - 10, and a + b + c = 100.

[0007] In some embodiments, the value range of c is: 0.5 - 4.

[0008] In some embodiments, the value of c is 0.5 - 2.

[0009] The present invention also provides a preparation method of a Cu-Zr-Se series metallic glass, comprising the following steps:

[0010] S1. Pretreatment: Grind the Cu, Zr, Se alloy raw materials to remove the surface oxide layer, ultrasonically clean the ground alloy raw materials with absolute ethanol, weigh them using a precision electronic balance, and proportion the alloy raw materials according to the nominal composition of the alloy;

[0011] S2. Preparation of intermediate alloy Cu2Se: Put the Cu and Se alloy raw materials into a melting furnace for melting to obtain the intermediate alloy Cu2Se;

[0012] S3. Melting of metallic glass: Put the intermediate alloy Cu2Se and the alloy raw materials into the melting furnace in turn according to the increasing melting points of the metals, carry out alloy melting under a protective atmosphere, turn over the ingot after cooling and carry out repeated melting 4 - 6 times to obtain an alloy melt;

[0013] S4. Preparation of metallic glass: Inject the alloy melt into a copper mold for rapid cooling to obtain bulk metallic glass. Place the bulk metallic glass in a melt spinning machine, heat and melt the alloy ingot under a protective atmosphere, apply pressure to make the melt spray out from the quartz tube orifice, and cool it by a rapidly rotating copper roller to obtain the Cu - Zr - Se series metallic glass.

[0014] In some embodiments, in step S2, the atomic ratio of Cu to Se in the Cu and Se alloy raw materials is 2:1.

[0015] In some embodiments, in step S1 and step S2, the melting furnace is an induction melting furnace.

[0016] In some embodiments, in steps S3 and S4, the protective atmosphere is argon.

[0017] In some embodiments, in step S3, before alloy melting, arc is initiated to melt a titanium ingot to consume the residual oxygen.

[0018] In some embodiments, in step S3, the smelting furnace is a vacuum arc melting furnace.

[0019] In some embodiments, the Cu - Zr - Se series metallic glass is a metallic glass ribbon.

[0020] The beneficial effects achieved by the present invention are as follows:

[0021] By alloying with multiple elements of Cu, Zr, Se and regulating the composition of the amorphous alloy, a Cu - Zr - Se series metallic glass with high glass - forming ability, good thermal stability and excellent plastic toughness is obtained. It is measured that the critical casting size of the metallic glass prepared by the present invention is 2 mm, the width of the super - cooled liquid region can reach 61 K, the yield strength can reach 1.62 GPa, the compressive strength can reach 1.83 GPa, and the compressive plasticity can reach 6.6%.

[0022] Among them, the addition of a small amount of selenium element expands the width of the supercooled liquid region of the CuZr-based bulk metallic glass, thereby enhancing the glass-forming ability and thermal stability of the alloy. At the same time, it promotes the close packing of atoms and the formation of a large number of shear bands on the side surface, so that the plastic toughness can be improved while maintaining the high strength of the CuZr-based bulk metallic glass. Excessive addition of selenium will change the crystallization sequence and promote the formation of the Cu 10 Zr7 phase. At the same time, first alloy Cu and Se by induction melting method to obtain the intermediate alloy Cu2Se, and then alloy Cu, Zr, and Cu2Se by vacuum arc melting method to prepare a metallic glass with high glass-forming ability and good plastic toughness. Brief Description of the Drawings

[0023] Figure 1 Schematic diagram of the melting of the intermediate alloy Cu2Se in the embodiment of the present invention;

[0024] Figure 2 X-ray diffraction patterns of the metallic glass strips of Examples 1-5 and Comparative Example 1;

[0025] Figure 3 X-ray diffraction patterns of the bulk metallic glasses of Examples 1-5 and Comparative Example 1;

[0026] Figure 4 X-ray diffraction patterns of the bulk metallic glasses of Example 4 and Comparative Example 1;

[0027] Figure 5 Transmission electron microscope image of the bulk metallic glass of Example 1;

[0028] Figure 6 Measurement result diagram of the low-temperature region of the heat flow change curve of the bulk metallic glasses of Examples 1-5 and Comparative Example 1;

[0029] Figure 7 Measurement result diagram of the high-temperature region of the heat flow change curve of the bulk metallic glasses of Examples 1-5 and Comparative Example 1;

[0030] Figure 8 Compression curve of the bulk metallic glass prepared in Example 1;

[0031] Figure 9 Scanning electron microscope image of the side surface of the fractured sample of the bulk metallic glass prepared in Example 1;

[0032] Figure 10 Scanning electron microscope image of the fracture surface of the bulk metallic glass prepared in Example 1.

[0033] The accompanying drawings are used to provide a further understanding of the present invention and form a part of the description. They are used in conjunction with the embodiments of the present invention to explain the present invention and do not constitute a limitation to the present invention. Detailed Description of the Invention

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0035] The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present invention. In addition, the present invention provides examples of various specific processes and materials, but those skilled in the art can be aware of the application of other processes and / or the use of other materials.

[0036] In the research field of metallic glasses, microalloying is considered an effective method to improve the glass-forming ability and mechanical properties of metallic glasses. At present, it has been found that adding a small amount of sulfur can promote the glass-forming ability of metallic glasses. It has been found that by adding Se, the glass-forming ability of metallic glasses can be further improved.

[0037] In a first aspect of the present invention, a Cu-Zr-Se-based metallic glass is provided. The chemical composition of the alloy raw materials is expressed in atomic percentages as Cu a Zr b Se c ,

[0038] wherein, the value range of a is: 40 - 60, the value range of b is: 40 - 60, the value range of c is: 0.1 - 10, and a + b + c = 100.

[0039] The addition of a small amount of selenium element expands the width of the supercooled liquid region of the CuZr-based bulk metallic glass, thereby improving the glass-forming ability and thermal stability of the alloy. At the same time, it promotes the close packing of atoms and the formation of a large number of shear bands on the side surface, so that the plastic toughness of the CuZr-based bulk metallic glass can be improved while maintaining its high strength; at the same time, through experiments, it was surprisingly found that adding an appropriate amount of selenium (atomic percentage content exceeding 0.1 - 10) would change the phase formation sequence of the alloy. As the Se content further increases, the Cu 10 Zr7 phase begins to appear, indicating that Se has a stabilizing effect on the Cu 10 Zr7 phase.

[0040] Moreover, the addition of an appropriate amount of Se atoms results in a large atomic size mismatch and a negative mixing enthalpy between Se and other BMG components. Further, the covalent interaction caused by Se improves the glass-forming ability. Meanwhile, in terms of thermal stability, mainly due to the too large difference in Se atomic size, the close packing of atoms is promoted, improving the thermal stability of the alloy, Cu a Zr b Se c The excellent plasticity and toughness of the bulk metallic glass are attributed to a large number of shear bands on the side surface. Therefore, Cu a Zr b Se c The bulk metallic glass has high glass-forming ability, good thermal stability, and excellent plasticity and toughness.

[0041] In addition, by defining the value range of a as: 40 - 60, the value range of b as: 40 - 60, and the value range of c as: 0.1 - 10, the metallic glass can have better amorphous formation ability.

[0042] In some embodiments, the value range of c is: 0.5 - 4. When the value range of c is: 0.5 - 4, the metallic glass has better amorphous formation ability, as well as good strength and plasticity and toughness of the metallic glass.

[0043] In some embodiments, the value of c is 0.5 - 2. Experiments show that when the value of c is 0.5 - 2, the crystallization phases of the metallic glass are mainly B2-CuZr phase and cubic CuZr phase. At this time, the metal has better glass-forming ability, good thermal stability, and excellent plasticity and toughness.

[0044] The second aspect of the present invention provides a preparation method of a Cu-Zr-Se-based metallic glass, comprising the following steps:

[0045] S1. Pretreatment: Grind the Cu, Zr, and Se alloy raw materials to remove the surface oxide layer, ultrasonically clean the ground alloy raw materials with absolute ethanol, weigh them using a precision electronic balance, and proportion the alloy raw materials according to the nominal composition of the alloy;

[0046] S2. Preparation of intermediate alloy Cu2Se: Place the Cu and Se alloy raw materials in an induction melting furnace for heating and melting to obtain the intermediate alloy Cu2Se;

[0047] S3. Melting of the metallic glass: Place the intermediate alloy Cu2Se and the alloy raw materials into the melting furnace in ascending order of the melting points of the metals. Under a protective atmosphere, carry out alloy melting, and after cooling, turn over the ingot and carry out repeated melting 4 - 6 times to obtain an alloy melt;

[0048] S4. Preparation of metallic glass: Inject the alloy melt into a copper mold for rapid cooling to obtain bulk metallic glass. Place the bulk metallic glass in a melt spinning machine. Under a protective atmosphere, heat and melt the alloy ingot, and apply pressure to make the melt spray out from the quartz tube orifice and cool by a rapidly rotating copper roller to obtain the Cu-Zr-Se series metallic glass.

[0049] Refer to Figure 1 , Figure 1 is a schematic diagram of the melting of the intermediate alloy Cu2Se. By first preparing the intermediate alloy Cu2Se, the uniformity of element distribution can be improved, the uniformity and performance stability of the alloy can be enhanced. At the same time, it can avoid the burning loss or volatilization of Se with a low melting point during the melting process; placing the alloy raw materials in the melting furnace in ascending order of the melting points of the metals can avoid the volatilization of low melting point elements and thus cause quality loss; repeatedly melting multiple times (such as 4 - 6 times) can ensure the uniformity of the alloy composition.

[0050] In some embodiments, in step S1, the purity of the alloy raw materials is not less than 99.95%. High-purity alloy raw materials contribute to more precisely controlling the composition of the alloy, and avoid adding impurities to reduce the performance of the alloy.

[0051] In some embodiments, in step S1, the precision of the ratio is controlled within 0.002. By improving the precision of the alloy ratio, the stability of the alloy performance can be ensured.

[0052] In some embodiments, in step S2, the atomic ratio of Cu and Se in the Cu and Se alloy raw materials is 2:1. The chemical formula of Cu2Se indicates that each molecule contains 2 Cu atoms and 1 Se atom. Therefore, when preparing the Cu2Se alloy, it is necessary to ensure that the atomic ratio of Cu and Se conforms to this chemical composition, that is, Cu:Se = 2:1, ensuring that the chemical composition of the alloy is close to the ideal state of Cu2Se.

[0053] In some embodiments, in step S2, the melting furnace is an induction melting furnace. The induction melting furnace realizes heating by means of electromagnetic induction heating plus heat transfer. It has a fast heating speed, can heat the material to the expected depth and temperature in a very short time, and has less heat loss and high heating efficiency. Therefore, it is suitable for preparing the Cu2Se intermediate alloy.

[0054] In some embodiments, in steps S3 and S4, the protective atmosphere is argon. As an inert gas, argon has very stable chemical properties and is not easily chemically reacted with other substances. Therefore, it can prevent the metal from oxidizing at high temperatures.

[0055] In some embodiments, in step S3, before alloy melting, the furnace chamber is cleaned with argon. To ensure a high vacuum degree and prevent alloy oxidation, it is necessary to clean the furnace chamber with argon at least three times before alloy melting.

[0056] In some embodiments, in step S3, before alloy melting, an arc is struck to melt the titanium ingot to consume the residual oxygen. Although the melting furnace has been vacuum-treated before alloy melting, there may still be a certain amount of residual oxygen. Melting the titanium ingot by striking an arc can consume the residual oxygen in the melting furnace and create a relatively oxygen-free environment for subsequent metal melting.

[0057] In some embodiments, in step S3, the smelting furnace is a vacuum arc melting furnace. The vacuum arc melting furnace is suitable for melting high-melting-point metals and can more precisely control the melting process, thus facilitating the melting of metallic glasses.

[0058] In some embodiments, the Cu-Zr-Se-based metallic glass is a metallic glass ribbon. The metallic glass ribbon can have higher strength than bulk metallic glass without sacrificing plasticity. Therefore, the bulk metallic glass is fabricated into a metallic glass ribbon.

[0059] The present invention will be further described by way of specific embodiments below.

[0060] The experimental methods in the following embodiments are all conventional methods unless otherwise specified; the test materials used in the following embodiments are all obtained from commercial channels unless otherwise specified.

[0061] Example 1

[0062] A Cu-Zr-Se-based metallic glass, the chemical composition of the alloy raw materials is in atomic percentage, and the expression is Cu 49.75 Zr 49.75 Se 0.5 .

[0063] The preparation method of the Cu-Zr-Se-based metallic glass includes the following steps:

[0064] S1. Grind the Cu, Zr, and Se alloy raw materials to remove the surface oxide layer, and ultrasonically clean the ground raw materials with absolute ethanol. All alloy raw materials are selected as raw materials with a purity of 99.95%. After calculating the corresponding weights of each element raw material according to the atomic ratio Cu:Se = 2:1, use a precision electronic balance to weigh the raw materials, and control the accuracy within 0.002;

[0065] S2. Place the Cu and Se alloy raw materials in a quartz tube and heat and melt them through an induction melting furnace to obtain an intermediate alloy Cu2Se;

[0066] S3. Place the master alloy Cu2Se and alloy raw materials into the melting furnace in ascending order of the melting points of the metals. Clean the furnace cavity three times with argon gas. Under an argon atmosphere, conduct alloy melting. After cooling, turn over the ingot and conduct repeated melting 6 times to obtain an alloy melt;

[0067] S4. Preparation of metallic glass: Inject the alloy melt into a copper mold for rapid cooling to obtain bulk metallic glass. Place the bulk metallic glass in a melt spinning machine. Under an argon atmosphere, heat and melt the alloy ingot, and apply pressure to make the melt spray out from the quartz tube orifice and cool by a rapidly rotating copper roller to obtain Cu-Zr-Se series metallic glass.

[0068] Example 2

[0069] A Cu-Zr-Se series metallic glass, the chemical composition of the alloy raw materials is in atomic percentage, and the expression is Cu 49.5 Zr 49.5 Se1.

[0070] The preparation method of the Cu-Zr-Se series metallic glass is the same as that of Example 1.

[0071] Example 3

[0072] A Cu-Zr-Se series metallic glass, the chemical composition of the alloy raw materials is in atomic percentage, and the expression is Cu 49 Zr 49 Se2.

[0073] The preparation method of the Cu-Zr-Se series metallic glass is the same as that of Example 1.

[0074] Example 4

[0075] A Cu-Zr-Se series metallic glass, the chemical composition of the alloy raw materials is in atomic percentage, and the expression is Cu 48.5 Zr 48.5 Se3.

[0076] The preparation method of the Cu-Zr-Se series metallic glass is the same as that of Example 1.

[0077] Example 5

[0078] A Cu-Zr-Se series metallic glass, the chemical composition of the alloy raw materials is in atomic percentage, and the expression is Cu 48 Zr 48 Se4.

[0079] The preparation method of the Cu-Zr-Se series metallic glass is the same as that of Example 1.

[0080] Comparative Example 1

[0081] A metallic glass, which is different from that of Example 1 in that Se is not added. The chemical composition of the alloy raw materials is in atomic percentage, and the expression is Cu 50 Zr 50 .

[0082] Crystal structure characterization:

[0083] Characterize the crystal structures of the metallic glass strips and bulk metallic glasses prepared in Examples 1-5 and Comparative Example 1.

[0084] Figure 2 is the X-ray diffraction pattern of the metallic glass strips of Examples 1-5 and Comparative Example 1, indicating that the metallic glass strips are all amorphous structures.

[0085] Figure 3 and Figure 4 is the X-ray diffraction pattern of the bulk metallic glasses of Examples 1-5 and Comparative Example 1, indicating that the crystallization phases of Se0, Se1, and Se2 are mainly the B2-CuZr phase and the cubic CuZr phase. With the further increase of the Se content, the Cu 10 Zr7 phase begins to appear, indicating that Se has a stabilizing effect on the Cu 10 Zr7 phase.

[0086] Figure 5 is the high-resolution transmission electron microscopy image of the bulk metallic glass of Example 1. The critical casting size is 2 mm. By selecting the electron diffraction pattern, it can be determined that the alloy is in a glassy state.

[0087] Overall Figures 2 to 5 viewed, the metallic glasses prepared in Examples 1-5 have high glass-forming ability.

[0088] Thermal stability and crystallization behavior characterization:

[0089] Characterize the thermal stability and crystallization behavior of the bulk metallic glasses prepared in Examples 1-5 and Comparative Example 1.

[0090] Figure 6 is the measurement result diagram of the low-temperature region of the heat flow change curve of the bulk metallic glasses of Examples 1-5 and Comparative Example 1, reflecting that the glass transition temperature and the crystallization onset temperature of the (Cu 50 Zr 50 ) 99.5 Se 0.5 bulk metallic glasses are both increased, which are 681 K and 739 K respectively, and the width of the supercooled liquid region is also improved to a certain extent, which are 58 K respectively, and the enthalpy change value is 17.9 J / g.

[0091] Figure 7It is a measurement result graph of the high-temperature region of the heat flow change curve of the bulk metallic glasses in Examples 1-5 and Comparative Example 1, which reflects that the reduced glass transition temperature is increased to 0.557. In addition, it can be observed that the alloy has superheat behavior in the high-temperature region, which may be caused by the melting of oxide and sulfide phases.

[0092] Overall Figure 6 and Figure 7 judging from it, the metallic glasses prepared in Examples 1-5 have good thermal stability.

[0093] Mechanical tests and fracture sample characterization:

[0094] Mechanical tests were carried out on the bulk metallic glass prepared in Example 1 and the fracture samples were characterized. The compression test was completed on an MTS-CMT5205 universal mechanical testing machine, and the strain rate was 1×10 -4 s -1， The compression sample was a round rod sample with a diameter of 2 mm and a height of 4 mm.

[0095] Figure 8 It is the compression curve of the bulk metallic glass prepared in Example 1. It is measured that its yield strength can reach 1.62 GPa, the compressive strength can reach 1.83 GPa, it has a high hardness, and the compression plasticity can reach 6.6%, showing high plastic toughness.

[0096] Figure 9 It is the scanning electron microscope image of the side surface of the fracture sample of the bulk metallic glass prepared in Example 1. Among them, the fracture angle is 45°, and there are abundant shear bands on the side surface, further indicating that the alloy has good plastic toughness.

[0097] Figure 10 It is the scanning electron microscope image of the fracture surface of the bulk metallic glass prepared in Example 1. A large number of vein-like networks can be observed, which also confirms the high plastic toughness of the alloy.

[0098] Overall Figure 8 、 Figure 9 and Figure 10 judging from it, the metallic glass of Example 1 has good strength, hardness and plastic toughness, and has excellent mechanical properties.

[0099] The above are only the preferred embodiments of the present invention and do not impose any formal limitations on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the relevant art can make some changes or modifications to equivalent embodiments within the scope of the technical solution of the present invention by using the disclosed technical content. However, as long as it does not depart from the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A Cu-Zr-Se metallic glass, characterized in that: The chemical composition of the metallic glass is expressed in atomic percentage as Cu a Zr b Se c , Among them, the value range of a is: 40-60, the value range of b is: 40-60, the value range of c is: 0.1-10, and a+b+c=100.

2. The Cu-Zr-Se metallic glass according to claim 1, characterized in that: The value range of c is: 0.5-4.

3. The Cu-Zr-Se based metallic glass according to claim 1, characterized in that: The value of c is 0.5-2.

4. The method for preparing the Cu-Zr-Se metallic glass according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1. Pretreatment: Grind the Cu, Zr, and Se alloy raw materials to remove the surface oxide layer, ultrasonically clean the polished alloy raw materials with anhydrous ethanol, weigh them with a precision electronic balance, and proportion the alloy raw materials according to the nominal composition of the alloy; S2. Preparation of master alloy Cu2Se: taking Cu and Se alloy raw materials and putting them into a smelting furnace for smelting to obtain master alloy Cu2Se; S3. Melting of metallic glass: placing the master alloy Cu2Se and alloy raw materials into a melting furnace in order from low to high melting points of the metals, melting the alloy under a protective atmosphere, and after cooling, turning the ingot over and repeatedly melting for 4-6 times to obtain an alloy melt; S4. Preparation of metallic glass: The alloy melt is injected into a copper mold and rapidly cooled to obtain bulk metallic glass. The bulk metallic glass is placed in a belt spinning machine. Under a protective atmosphere, the alloy ingot is heated and melted, and pressurized to eject the melt from a quartz tube. The melt is cooled by a high-speed rotating copper rod to obtain Cu-Zr-Se metallic glass.

5. The preparation method according to claim 3, characterized in that: In step S2, the atomic ratio of Cu to Se in the Cu and Se alloy raw material is 2:

1.

6. The preparation method according to claim 3, characterized in that: In step S2, the smelting furnace is an induction smelting furnace.

7. The preparation method according to claim 3, characterized in that: In steps S3 and S4, the protective atmosphere is argon.

8. The preparation method according to claim 3, characterized in that: In step S3, before alloy smelting, an arc is struck to melt the titanium ingot to consume residual oxygen.

9. The preparation method according to claim 3, characterized in that: In step S3, the smelting furnace is a vacuum arc melting furnace.

10. The preparation method according to claim 3, characterized in that: The Cu-Zr-Se metallic glass is a metallic glass strip.

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