Lightweight high-strength multi-principal-element intermetallic compound as well as preparation method and application thereof

Abstract

The invention discloses a light high-strength multi-principal-element intermetallic compound and a preparation method and application thereof.The intermetallic compound comprises Ti, Nb, V and Al, according to the atomic percent being 100%, the intermetallic compound comprises 45%-60% of Ti, 15%-20% of Nb, 15%-25% of V and 15%-25% of Al, and the atomic percent of V is equal to that of Al. The multi-principal-element intermetallic compound prepared by the invention has lower density, higher strength and hardness and certain plasticity, and is expected to have important application (such as high-temperature blades, supersonic aircrafts and the like) in the extreme environment fields such as advanced weaponry and aerospace engines.

Description

[0001] This application claims priority to a prior application entitled “A Lightweight, High-Strength, High-Entropy Intermetallic Compound and Its Preparation Method and Application” filed with the State Intellectual Property Office of China on September 27, 2023 with patent application number 2023112633748. The entire text of the prior application is incorporated into this application by reference. Technical Field

[0002] The present invention belongs to the field of metal materials, and relates to an intermetallic compound and a preparation method and application thereof, and specifically relates to a lightweight, high-strength, multi-principal-element intermetallic compound and a preparation method and application thereof. Background Art

[0003] With the continuous improvement of science and technology and the increasing demand for high-performance metal materials in domestic economic construction, traditional single-principal alloys can no longer meet people's demand for material performance. Multi-principal alloys break through the limitations of traditional alloy composition. By adjusting the arrangement, combination and content of multiple components, they greatly expand the design range of metal material composition, reflecting excellent performance different from traditional alloys. Due to their unique physical, chemical and mechanical properties, multi-principal alloys are expected to play an important role in major engineering fields such as national defense, aviation, aerospace, ocean, nuclear energy, medical care, and new energy, especially in extreme environments such as high temperature, high pressure, and high strain rate. It has great application prospects.

[0004] Lightweight intermetallic compounds are important structural materials with high specific strength and low energy consumption. They are also key materials in high-end weapons and equipment and energy conservation and emission reduction projects. They are of great significance for promoting the upgrading of major equipment and achieving the dual carbon goals. Ti-based intermetallic compounds have become an important type of lightweight high-temperature structural materials due to their low density, high specific strength and specific modulus, good oxidation resistance and excellent fatigue resistance. They have important applications in military and civilian industrial fields such as aerospace industry, weapons and equipment, and automobiles. However, with the continuous improvement of scientific and technological levels, higher requirements are placed on the service temperature range and comprehensive mechanical properties of high-temperature materials. Therefore, it is necessary to develop a new type of intermetallic compound with low density and high strength that can adapt to the service performance requirements and oxidation resistance of extreme environments such as high temperature, high pressure and high strain rate to replace some high-temperature alloys and ceramic components. Summary of the invention

[0005] In order to improve the above-mentioned technical problems, the present invention provides a multi-principal element intermetallic compound, which has the advantages of light weight, high strength, high entropy, etc., and is expected to have important applications under extreme environmental conditions in the fields of weapons and equipment (especially advanced weapons and equipment) and aerospace engines (such as for high-temperature blades, supersonic aircraft, etc.).

[0006] Specifically, the present invention provides the following technical solutions:

[0007] A multi-principal intermetallic compound comprises Ti, Nb, V and Al, and based on 100% atomic percentage, comprises 45-60% Ti, 15-20% Nb, 15-25% V and 15-25% Al, wherein the atomic percentages of V and Al are equal.

[0008] According to an embodiment of the present invention, the atomic ratio of Ti to Nb is 3.

[0009] According to an embodiment of the present invention, the multi-principal intermetallic compound comprises 45-54% Ti, 15-18% Nb, 15-20% V, and 15-20% Al, based on 100% atomic percentage, wherein the atomic percentages of V and Al are equal. Preferably, the atomic ratio of Ti to Nb is 3.

[0010] According to an embodiment of the present invention, the multi-principal intermetallic compound may further include Zr. Specifically, the atomic percentage of Zr is 0 to 5%, preferably 2 to 4%.

[0011] According to an embodiment of the present invention, the multi-principal intermetallic compound is composed of Ti, Nb, V and Al. Further, based on 100% by atomic percentage, Ti is 45-60%, Nb is 15-20%, V is 15-25%, and Al is 15-25%, wherein the atomic percentages of V and Al are equal. Specifically, the atomic ratio of Ti to Nb is 3.

[0012] According to an embodiment of the present invention, the multi-principal intermetallic compound is composed of Ti, Nb, V, Al and Zr. Further, based on 100% by atomic percentage, Ti is 45-60%, Nb is 15-20%, V is 15-25%, Al is 15-25%, and Zr is 0-5%, wherein the atomic percentages of V and Al are equal. Specifically, the atomic ratio of Ti to Nb is 3.

[0013] According to an embodiment of the present invention, the atomic percentage of Ti is, for example, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, or 54%.

[0014] According to an embodiment of the present invention, the atomic percentage of Nb is, for example, 15%, 16%, 17%, or 18%.

[0015] According to an embodiment of the present invention, the atomic percentage of V is, for example, 15%, 16%, 17%, 18%, 19%, or 20%.

[0016] According to an embodiment of the present invention, the atomic percentage of Al is, for example, 15%, 16%, 17%, 18%, 19%, or 20%.

[0017] According to an embodiment of the present invention, the atomic percentage of Zr is, for example, 2%, 2.5%, 3%, 3.5%, or 4%.

[0018] According to an embodiment of the present invention, the multi-principal intermetallic compound is composed of a single intermetallic compound phase. Specifically, the intermetallic compound is composed of a single B2 phase intermetallic compound. Also specifically, the crystal structure of the intermetallic compound is an ordered body-centered cubic.

[0019] According to an embodiment of the present invention, the Vickers hardness of the multi-principal-element intermetallic compound is 4.0 to 6.0 GPa.

[0020] According to an embodiment of the present invention, the density of the multi-principal metal compound is 5.0 to 5.6×10 3 kg.m -3 .

[0021] According to an embodiment of the present invention, the yield strength of the multi-principal-element intermetallic compound is 770-1100 MPa.

[0022] According to an embodiment of the present invention, the multi-principal intermetallic compound is subjected to a relatively low strain rate (e.g., at 10 -4 ~10 -2 s -1 Under the condition of strain rate), the elongation can reach 6% and the cross-sectional shrinkage can reach 18%, for example, the cross-sectional shrinkage is 6 to 18%.

[0023] According to the embodiment of the present invention, the multi-principal-element intermetallic compound has a uniform structure, and each element is evenly distributed, without any segregation phenomenon at the grain boundary.

[0024] The present invention also provides a method for preparing the above-mentioned multi-principal-element intermetallic compound, the method comprising:

[0025] Ti, Nb, V, Al and Zr which may or may not be added are mixed according to the above atomic percentages and vacuum arc melting is adopted to prepare a multi-principal-element intermetallic compound.

[0026] According to an embodiment of the present invention, Ti, Nb, V and Al are all high purity metals.

[0027] According to an embodiment of the present invention, Zr is a high purity metal.

[0028] According to an embodiment of the present invention, the smelting is carried out in a vacuum arc furnace.

[0029] According to an embodiment of the present invention, the smelting pressure is 0.5-1 atmosphere.

[0030] According to an embodiment of the present invention, the smelting heating current is 100-300A, preferably 150-250A, and the heating voltage is 10-30V, preferably 15-25V.

[0031] According to an embodiment of the present invention, the heating temperature of the smelting is 3000-3500K.

[0032] According to an embodiment of the present invention, the smelting time is 5-30 min, preferably 5-15 min, depending on the total mass of the sample.

[0033] According to an embodiment of the present invention, the method is carried out under an inert atmosphere, such as a nitrogen atmosphere or an argon atmosphere.

[0034] In the present invention, the smelting needs to be repeated 3-5 times to ensure that the elements in the sample are fully mixed and evenly distributed. Preferably, the sample mass during smelting is 10-300g, the heating time each time is 5-15 minutes, and the alloy liquid state is maintained for no less than 5-8 minutes.

[0035] As an exemplary technical solution of the present invention, the preparation method of the multi-principal metal compound comprises the following steps:

[0036] a) mixing high purity metals Ti, Nb, V and Al in the above atomic percentage ratio;

[0037] b) placing the metals mixed in the above proportions in a vacuum arc furnace and evacuating the furnace by a front-stage mechanical pump and a molecular pump (e.g., evacuating the furnace to 1.0×10 -3 After the pressure reaches 1 Pa, backfill with high-purity argon (for example, to one atmosphere), repeat the above-mentioned process of evacuating and backfilling with argon at least once (for example, once, twice, three times or more);

[0038] c) performing high-temperature arc melting in a protective atmosphere of high-purity argon gas, and after the smelted product is naturally cooled (e.g., a button-shaped product), turning the obtained product over, and repeating the high-temperature arc melting process at least 3 times (e.g., 3 to 5 times) to obtain the multi-principal element intermetallic compound.

[0039] In step c) of the present invention, the high temperature arc melting process is repeated in order to ensure that the elements in the product are fully mixed and their distribution is uniform.

[0040] According to an embodiment of the present invention, the multi-principal intermetallic compound prepared by the method is composed of a single B2 phase intermetallic compound, and the crystal structure belongs to an ordered body-centered cubic. The microhardness is 4.0 to 6.0 GPa. More specifically, the density of the multi-principal intermetallic compound is 5.0 to 5.6×10 3 kg.m -3 .

[0041] The present invention also provides the application of the above-mentioned multi-principal metal intermetallic compounds in the fields of weapon equipment (especially advanced weapon equipment) and aerospace engines, such as high-temperature blades, supersonic aircraft, etc.

[0042] Beneficial effects achieved by the present invention:

[0043] The present invention provides a multi-principal intermetallic compound having properties such as light weight and high strength; specifically, the present invention provides a multi-principal intermetallic compound mainly composed of B2 phase, which has low density, high strength and hardness, and certain plasticity, and is expected to have important applications in extreme environment fields such as weapons and equipment (especially advanced weapons and equipment) and aerospace engines (such as for high-temperature blades, supersonic aircraft, etc.).

[0044] In addition, the present invention also provides a method for preparing the multi-principal metal compound. Specifically, the present invention adopts a vacuum arc furnace under the protective atmosphere of high-purity argon to mix Ti, Nb, V and Al, optionally adding 0-5% Zr, according to proportions, and then directly melts at high temperature to obtain the multi-principal metal compound. The method is simple in process, and the multi-principal metal compound prepared has the above-mentioned advantages.

[0045] Furthermore, the present invention can further improve the strength of the alloy by 10-20% by adding a proper amount of Zr element to the multi-principal metal compound, but it is not conducive to improving the plasticity. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 is the XRD pattern of the intermetallic compound in Example 1;

[0047] Figure 2 is the organization diagram of the intermetallic compound in Example 1;

[0048] Figure 3 1 and 2 are the compressive stress-strain curves (a) and the tensile stress-strain curves (b) of the intermetallic compound in Example 1. DETAILED DESCRIPTION

[0049] The technical scheme of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary descriptions and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope that the present invention is intended to protect.

[0050] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0051] Example 1

[0052] The TiNbVAl intermetallic compound of this embodiment is prepared by a preparation method comprising the following steps:

[0053] a) mixing high-purity metals Ti, Nb, V and Al in a ratio of atomic percentage (specifically, Ti: 48%, Nb: 16%, V: 18%, Al: 18%) to prepare a metal sample with a total mass of 30 g;

[0054] b) placing the metals mixed in the above proportions in a vacuum arc furnace and evacuating the furnace to a vacuum of 10 -3 After Pa, high-purity argon gas is backfilled to one atmosphere, and the above vacuuming and backfilling argon gas process is repeated 1 to 2 times;

[0055] c) High-temperature arc melting is performed under the protective atmosphere of high-purity argon gas. The specific parameter settings are as follows: atmosphere pressure is 0.5 atmospheres, heating current is 150A, heating voltage is 15V, minimum heating temperature is 3000K, liquid retention time is 5 minutes, and button samples are obtained after the samples are naturally cooled. The obtained samples are turned over and the high-temperature arc melting process is repeated 3 to 5 times to ensure that the elements inside the samples are fully mixed and their distribution is uniform.

[0056] The multi-principal alloy prepared in Example 1 is composed of a single B2 phase intermetallic compound phase, and the XRD analysis diagram of its phase composition is as follows: Figure 1 The solidification structure is coarse single-phase dendrites, such as Figure 2 shown. Figure 3 1 is a compressive stress-strain curve (a) and a tensile stress-strain curve (b) of the intermetallic compound in Example 1. Figure 3 As shown, in 10 -4 ~10 -2 s -1 Under the strain rate condition, the static yield strength is 750-950MPa, the tensile strength is 700-780MPa, the elongation is 1-6%, and the cross-sectional shrinkage is 6-18%.

[0057] The density of the multi-principal alloy is 5.50-5.55×10 3 kg.m -3 , Vickers hardness is 4.5GPa.

[0058] Example 2

[0059] The TiNbVAlZr intermetallic compound of this embodiment is prepared by a preparation method comprising the following steps:

[0060] a) mixing high-purity metals Ti, Nb, V, Al and Zr in a ratio of atomic percentage (specifically, Ti: 45%, Nb: 15%, V: 18%, Al: 18%, Zr: 4%) to prepare a metal sample with a total mass of 100 g;

[0061] b) placing the metals mixed in the above proportions in a vacuum arc furnace and evacuating the furnace to a vacuum of 10 -3 After Pa, high-purity argon gas is backfilled to one atmosphere, and the above vacuuming and backfilling argon gas process is repeated 1 to 2 times;

[0062] c) High-temperature arc melting was performed under a protective atmosphere of high-purity argon gas. The specific parameters were as follows: atmosphere pressure was 0.5 atm, heating current was 200 A, heating voltage was 20 V, maximum heating temperature was 3300 K, liquid retention time was 8 minutes, and button samples were obtained after the samples were naturally cooled. The obtained samples were turned over and the high-temperature arc melting process was repeated 3 to 5 times to ensure that the elements inside the samples were fully mixed and their distribution was uniform.

[0063] The microstructure characteristics of the multi-principal component alloy prepared in Example 2 are similar to those in Example 1, and the hardness and strength thereof are both improved by 10-20%, the Vickers hardness is about 5.2 GPa, and the static yield strength is 900-1100 MPa.

[0064] The density of the multi-principal alloy is 5.55-5.60×10 3 kg.m -3 .

[0065] The above is an exemplary description of the embodiments of the present invention. However, the protection scope of the present invention is not limited to the above embodiments. Any modification, equivalent substitution, improvement, etc. made by those skilled in the art within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A multi-principal intermetallic compound, characterized in that: The multi-principal intermetallic compound includes Ti, Nb, V and Al, and based on 100% atomic percentage, includes 45-60% Ti, 15-20% Nb, 15-25% V, and 15-25% Al, wherein the atomic percentages of V and Al are equal.

2. The multi-principal intermetallic compound according to claim 1, characterized in that: The atomic ratio of Ti to Nb is 3.

3. The multi-principal intermetallic compound according to claim 1, characterized in that: The multi-principal intermetallic compound further includes Zr; Preferably, the atomic percentage of Zr is 0-5%.

4. The multi-principal intermetallic compound according to claim 1, characterized in that: The multi-principal intermetallic compound is composed of Ti, Nb, V and Al; based on 100% atomic percentage, Ti is 45-60%, Nb is 15-20%, V is 15-25%, and Al is 15-25%, wherein the atomic percentages of V and Al are equal; Preferably, the atomic ratio of Ti to Nb is 3.

5. The multi-principal intermetallic compound according to claim 3, characterized in that: The multi-principal intermetallic compound is composed of Ti, Nb, V, Al and Zr; based on 100% atomic percentage, Ti is 45-60%, Nb is 15-20%, V is 15-25%, Al is 15-25%, and Zr is 0-5%, wherein the atomic percentages of V and Al are equal; Preferably, the atomic ratio of Ti to Nb is 3.

6. The multi-principal intermetallic compound according to any one of claims 1 to 5, characterized in that: The multi-principal intermetallic compound is composed of a single intermetallic compound phase; Preferably, the multi-principal intermetallic compound consists of a single B2 phase intermetallic compound; Preferably, the crystal structure of the multi-principal-element intermetallic compound is an ordered body-centered cubic structure.

7. The multi-principal intermetallic compound according to any one of claims 1 to 6, characterized in that: The intermetallic compound has at least one of the properties: 1) Vickers hardness is 4.0~6.0GPa; 2) Density is 5.0~5.6×10 3 kg.m -3 ; 3) Yield strength is 770~1100MPa; 4) In 10 -4 ~10 -2 s -1 Under the condition of strain rate, the elongation can reach 6% and the section shrinkage can reach 18%.

8. The method for preparing a multi-principal-element intermetallic compound according to any one of claims 1 to 7, characterized in that: The method comprises: Ti, Nb, V, Al and Zr which may or may not be added are mixed according to the above atomic percentages and vacuum arc melting is adopted to prepare a multi-principal-element intermetallic compound.

9. The method according to claim 8, characterized in that The smelting pressure is 0.5-1 atmosphere; Preferably, the smelting heating current is 100-300A, and the heating voltage is 10-30V. Preferably, the heating temperature of the smelting is 3000-3500K; Preferably, the smelting time is 5-30 min.

10. Application of the multi-principal-element intermetallic compound according to any one of claims 1 to 7 in the field of weapon equipment and aerospace engines, for example, in high-temperature blades or supersonic aircraft.

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