High-strength high-energetic high-entropy alloy reactive structural material and preparation method thereof

Abstract

The application discloses a high-strength high-energetic high-entropy alloy reaction structural material and a preparation method thereof, wherein the material comprises at least two of Ti, Zr, V, Nb and Ta elements. The high-entropy alloy reaction structural material provided by the application realizes the single-phase solid solution structure of Ti, Zr, V, Nb and Ta elements by special element composition and special proportioning relationship, especially introduces the V element, presents the characteristics of high activity and high strength and plasticity, and the density of the alloy is significantly higher than that of the existing reaction structural material. Due to the design of the active element, the high-entropy alloy reaction structural material has the characteristics of high strength, high activity and high density.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of alloy materials, in particular to a high-strength high-energy high-entropy alloy reaction structural material and a preparation method thereof. BACKGROUND

[0002] Reaction structural materials are materials that have certain mechanical properties and can induce high-energy chemical reactions between material components or between components and environmental media under certain conditions to release heat. Reaction structural materials have the characteristics of structural and energy integration. At normal temperature and pressure, they are inert. Under extreme conditions such as impact loading, high temperature and high pressure, reaction structural materials are activated, triggering chemical reactions between component groups or between component groups and environmental media.

[0003] Traditional reaction structural materials can be mainly divided into three types: metal-fluoropolymer, metal-oxide, and metal-metal. Metal-fluoropolymer is a composite material composed of metal components and fluoropolymer, which has the characteristics of high energy density. However, due to the low strength of polymer materials, metal-fluoropolymer reaction structural materials often have low structural strength (less than 100 MPa), making it difficult to directly meet the actual engineering application. Metal-oxide has the problems of low reaction rate, low actual heat release, and insufficient reaction process in the application process. Metal-metal reaction structural materials are composed of high-activity metals and metal or metalloid elements, and the reaction products are often intermetallic compounds. However, the mechanical properties, density, and compactness of metal active composites have been difficult to effectively solve in practical application.

[0004] Therefore, the traditional reaction structural materials have the disadvantage of low strength, which has not been solved and cannot meet the needs of existing engineering.

[0005] Multi-principal element high-entropy alloy is a new type of metal material developed in recent years, which can be designed and controlled in performance. It overturns the traditional alloy design idea of single metal element, and is a solid solution alloy formed by melting multiple elements according to equal atomic or near atomic ratio.

[0006] The design concept of high-entropy alloy realizes the "free design" and combination of alloy components at the atomic level. Combined with the adjustment of preparation and heat treatment process, solid solution materials with excellent comprehensive performance can be obtained. Through the optimization of main elements, the characteristics of high strength, high energy, and high density required by reaction structural materials can be met.

[0007] Although theoretically, high strength, high energy, high density high-entropy alloy reaction structure materials can be designed by the design concept of high-entropy alloy, at present, there is no report of high-entropy alloy reaction structure materials with the above-mentioned related properties. Mainly because the existing high-entropy alloy has not been studied in the related field, and no material with related properties has appeared, so high strength, high energy, high density high-entropy alloy reaction structure materials are still blank at present. SUMMARY

[0008] The purpose of the present application is to provide a high strength high energy high-entropy alloy reaction structure material and a preparation method thereof, so as to solve the technical problems that the high-entropy alloy materials produced in the prior art cannot simultaneously meet the characteristics of high strength, high energy and high density.

[0009] To solve the above technical problems, the present application specifically provides the following technical solutions:

[0010] In the first aspect of the present application, a high strength high energy high-entropy alloy reaction structure material is provided, which comprises at least two of Ti, Zr, V, Nb and Ta elements.

[0011] Further, the general formula of the high-entropy alloy is TiZrVNbTa, and the content of each element is as follows in terms of atomic percentage:

[0012] Ti: 0%-25%;

[0013] Zr: 0%-25%;

[0014] V: 0%-15%;

[0015] Nb: 0%-25%;

[0016] Ta: 20%-45%.

[0017] Further, the general formula of the high-entropy alloy is TiZrVNbTa, and the content of each element is as follows in terms of atomic percentage:

[0018] Ti: 15%-25%;

[0019] Zr: 15%-25%;

[0020] V: 0%-10%;

[0021] Nb: 15%-25%;

[0022] Ta: 30%-40%.

[0023] In the second aspect of the present application, a preparation method of a high strength high energy high-entropy alloy reaction structure material is provided, comprising the following steps:

[0024] Ingredients: clean Ti element particles, Zr element particles, V element particles, Nb element particles and Ta element particles are proportioned according to atomic content;

[0025] Melting: the above ingredients are sent to a magnetic suspension induction melting furnace and melted in a vacuum environment;

[0026] Hot isostatic pressing: the as-cast alloy prepared after melting is subjected to hot isostatic pressing treatment to obtain a high-entropy alloy reaction structure material.

[0027] Further, the purity of the Ti element particles is 99.9%, the purity of the Zr element particles is 99.95%, the purity of the V element particles is 99.9%, the purity of the Nb element particles is 99.95%, and the purity of the Ta element particles is 99.95%;

[0028] Wherein, the above metal particles are clean raw materials without oxide skin.

[0029] Further, the elements contained in the above metal particles are as follows according to atomic percentage content:

[0030] Ti: 15%-25%;

[0031] Zr: 15%-25%;

[0032] V: 0%-10%;

[0033] Nb: 15%-25%;

[0034] Ta: 30%-40%.

[0035] Further, when alloy melting is performed, the raw materials are sequentially fed in the following feeding order:

[0036] First, Ti and Zr elements are synthesized into TiZr intermediate alloy, and Nb and Ta elements are synthesized into NbTa intermediate alloy;

[0037] Then, the TiZr intermediate alloy, the NbTa intermediate alloy and a small amount of V element are melted to form a single-phase solid solution structure.

[0038] Further, the above melting step is specifically: 10 -3 Pa vacuum environment, melting 4-6 times, each time the melting temperature is 2200-2300℃, and each time the melting time is 15-20 minutes, and after the alloy composition is uniform, pouring into a mold, and naturally cooling under vacuum protection environment.

[0039] Further, the hot isostatic pressing step is performed in a vacuum or inert gas protection atmosphere, and the temperature of the hot isostatic pressing is 1150-1250℃, and the holding time is 4-6h.

[0040] Further, the hot isostatic pressing pressure is 180-200 MPa, the pressure holding time is 4-6 hours, and the cooling speed is 50℃ / min.

[0041] Compared with the prior art, the present application has the following beneficial effects:

[0042] 1. The high-entropy alloy reaction structure material provided by the present application realizes single-phase solid solution structure of Ti, Zr, V, Nb and Ta elements by special element composition and special proportioning relationship, especially by introducing V element and regulating the content of V element, and presents high activity and high strength and plasticity characteristics.

[0043] 2. The high-entropy alloy preparation method provided by the present application fully combines the particularity of the contained elements of the high-entropy alloy and the particularity of the atomic content of each element, adopts a special feeding sequence, generates TiZr intermediate alloy and NbTa intermediate alloy respectively first, then smelts them with a small amount of V element to form a single-phase solid solution structure, and performs hot isostatic pressing treatment, so that the alloy is a single-phase BCC structure under specific smelting conditions and isostatic pressing treatment conditions, has high strength and high energy release characteristics under impact loading conditions, and has uniform internal organizational structure and excellent room temperature static and dynamic compression strength and plasticity. BRIEF DESCRIPTION OF DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only exemplary, and for those skilled in the art, other drawings can be obtained from the provided drawings without creative labor.

[0045] Figure 1 The high-entropy alloy ingot of the present application is shown in the figure;

[0046] Figure 2 The energy release overpressure diagram of the high-entropy alloy of the first embodiment of the present application is shown in the figure;

[0047] Figure 3 The static and dynamic mechanical property diagram of the first embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0048] With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of the present application.

[0049] The conventional reaction structure material has the defect of low strength, and has been unable to be solved, and cannot meet the needs of the existing engineering.

[0050] Although theoretically, high-entropy alloy reaction structure materials with high strength, high energy content and high density can be designed by the design concept of high-entropy alloy, at present, high-entropy alloy reaction structure materials with the above-mentioned properties have not been reported. The main reason is that the existing high-entropy alloy has not been studied in the related field, and no material with the related properties has appeared, so high-entropy alloy reaction structure materials with high strength, high energy content and high density are still blank at present.

[0051] The difficulty of designing high-entropy alloy reaction structure materials with high strength, high energy content and high density by the design concept of high-entropy alloy lies in how to design the composition of elements in the high-entropy alloy, and how to design the atomic ratio of each element on the basis of the element composition, so that the high-entropy alloy can have high strength, high energy content and high density at the same time.

[0052] As shown in Figure 1 The present application provides a high-strength high-energy high-entropy alloy reaction structure material, which comprises at least two of Ti, Zr, V, Nb and Ta elements.

[0053] The general formula of the high-entropy alloy is TiZrVNbTa, and the content of each element is as follows in terms of atomic percentage:

[0054] Ti: 0%-25%;

[0055] Zr: 0%-25%;

[0056] V: 0%-15%;

[0057] Nb: 0%-25%;

[0058] Ta: 20%-45%.

[0059] The general formula of the high-entropy alloy is TiZrVNbTa, and the content of each element is as follows in terms of atomic percentage:

[0060] Ti: 15%-25%;

[0061] Zr: 15%-25%;

[0062] V: 0%-10%;

[0063] Nb: 15%-25%;

[0064] Ta: 30%-40%.

[0065] High strength requires reasonable V content control, low V content, low strength, however, when the V content is higher, it is easy to appear brittle intermetallic compound phase, so that the overall material is brittle, difficult to practical engineering application. Therefore, the ratio between V content and other elements is the key and difficulty of controlling the strength of the alloy.

[0066] Ta content is controlled between 30%-40% to ensure the high density characteristics of the material, while avoiding the significant reduction of material activity caused by too high Ta content. The near-atomic ratio design of Zr, Ti and Nb effectively improves the material mixing entropy, so that the material can exhibit single-phase solid solution characteristics.

[0067] The atomic radius of the alloy composition elements is small, which is beneficial to realize single-phase solid solution structure and avoid the material being brittle. In addition, the addition of appropriate amount of V (within 10%) can significantly improve the strength of the material, realizing the characteristics of high strength and high activity. At the same time, it avoids the formation of brittle intermetallic compound and Laves phase, so that the high-entropy alloy reaction structure material has good plasticity.

[0068] The main function of appropriate amount of V element is to improve the strength of the material, while avoiding the formation of brittle intermetallic compound phase.

[0069] After designing the composition and ratio of internal elements of high-entropy alloy, how to produce high-strength, high-energy, high-density high-entropy alloy reaction structure material becomes the next technical difficulty.

[0070] In order to solve this problem, a preparation method of high-strength, high-energy, high-entropy alloy reaction structure material is provided below, comprising the following steps:

[0071] Batching: clean Ti element particles, Zr element particles, V element particles, Nb element particles and Ta element particles are batched according to the atomic content ratio;

[0072] Melting: the above-mentioned batch is sent to a magnetic suspension induction melting furnace and melted in a vacuum environment;

[0073] Hot isostatic pressing: the as-cast alloy prepared after melting is subjected to hot isostatic pressing treatment to obtain a high-entropy alloy reaction structure material.

[0074] In the preparation method, the magnetic levitation melting can ensure the clean characteristics of the melting and avoid the pollution of impurity elements. In order to avoid the pollution of impurity elements, further, the purity of the Ti element particles is 99.9%, the purity of the Zr element particles is 99.95%, the purity of the V element particles is 99.9%, the purity of the Nb element particles is 99.95%, and the purity of the Ta element particles is 99.95%.

[0075] The above metal particles are all clean raw materials with oxide removed.

[0076] The above metal particles contain the following elements according to atomic percentage:

[0077] Ti: 15%-25%;

[0078] Zr: 15%-25%;

[0079] V: 0%-10%;

[0080] Nb: 15%-25%;

[0081] Ta: 30%-40%.

[0082] After the ratio between the elements is determined, in addition, the feeding sequence needs to be controlled during the melting process. If the raw materials are added in random sequence, brittle intermetallic compounds will appear, it is difficult to form a solid solution structure, and the generated alloy cannot meet the requirements. Therefore, in the preparation method, the addition sequence of the raw materials is particularly important.

[0083] Here, when the alloy is melted, the raw materials are fed in the following feeding sequence:

[0084] First, the Ti and Zr elements are synthesized into TiZr intermediate alloy, and the Nb and Ta elements are synthesized into NbTa intermediate alloy.

[0085] Then, the TiZr intermediate alloy and the NbTa intermediate alloy are melted with a small amount of V element to form a single-phase solid solution structure.

[0086] The feeding sequence needs to be controlled during the melting process to avoid the formation of intermetallic compounds.

[0087] The key and difficulty of the preparation method is to first generate TiZr intermediate alloy and NbTa intermediate alloy, and then melt with a small amount of V element to form a single-phase solid solution structure.

[0088] The above melting step is specifically: under the condition of 10 -3 Pa vacuum environment, melting 4-6 times, each time the melting temperature is 2200-2300℃, and each time the melting time is 15-20 minutes. After the alloy composition is uniform, pour into a mold and naturally cool under vacuum protection environment.

[0089] The hot isostatic pressing step is performed in a vacuum or inert gas protective atmosphere, the temperature of the hot isostatic pressing is 1150-1250℃, and the holding time is 4-6h.

[0090] The pressure of the hot isostatic pressing is 180-200MPa, the holding time is 4-6h, and the cooling speed is 50℃ / min.

[0091] The melting point of the material is about 2100℃, in the method, the hot isostatic pressing temperature is controlled near 0.5Tm, too low temperature is difficult to eliminate the as-cast defects, and too high temperature may cause overburning, damaging the initial structure of the material.

[0092] The as-cast alloy is first naturally cooled, and then hot isostatic pressing is performed, the hot isostatic pressing mainly functions to homogenize the as-cast alloy and eliminate the as-cast element segregation.

[0093] The following is further illustrated in combination with specific embodiments:

[0094] Embodiment 1:

[0095] 1) Alloy composition (in terms of atomic percentage): Ti: 20%, Zr: 20%, V: 5%, Nb: 15%, Ta: 40%.

[0096] 2) Preparation method:

[0097] Batching: clean Ti element particles, Zr element particles, V element particles, Nb element particles and Ta element particles after removing the oxide skin are batched according to the above atomic percentage;

[0098] Melting: the above batched materials are sent to a magnetic suspension induction melting furnace, and melted 4 times under a vacuum environment of 10 -3 Pa, each time the melting temperature is 2200℃, and each time the melting time is 15 minutes, and after the alloy composition is uniform, poured into a 100mm diameter mold, and naturally cooled under vacuum protection;

[0099] When the alloy is melted, the raw materials are fed in the following feeding order: first, Ti and Zr elements are synthesized into TiZr intermediate alloy, and Nb and Ta elements are synthesized into NbTa intermediate alloy; then, the TiZr intermediate alloy and the NbTa intermediate alloy are melted with a small amount of V element to form a single-phase solid solution structure.

[0100] Hot isostatic pressing: the as-cast alloy prepared after melting is placed in a hot isostatic pressing device with inert gas protection, the pressure is set to 180MPa, the holding time is 4 hours, the temperature is set to 1200℃, the holding time is 4 hours, and the cooling speed is 50℃ / min, to obtain a high-entropy alloy reaction structure material, and the alloy ingot appearance is as shown in Figure 1As shown.

[0101] Test method: the density adopts the Archimedes drainage method.

[0102] According to GB / T23370-2009 and GB / T8167-2008, the alloy prepared above is subjected to room temperature quasi-static compression and dynamic compression, and the critical failure stress of static and dynamic deformation is tested.

[0103] The test results are shown in the following table:

[0104] Performance Example 1 Density (g / cm 3 ) 10.5 Quasi-static compressive ultimate stress (MPa) 1750 Quasi-static compressive ultimate strain at break (%) 25 Dynamic compressive ultimate stress (MPa) 2760 Dynamic compressive ultimate strain at break (%) 20

[0105] From the above table analysis, the following conclusions can be drawn:

[0106] The examples show that the high-entropy alloy provided by the application has a density of 10.0-11 g / cm 3 , the quasi-static compression strength of the material is greater than 1600 MPa, the dynamic compression strength is greater than 2500 MPa, the internal structure is uniform, and the material has excellent room temperature static and dynamic compression strength and plasticity.

[0107] The energy release overpressure value of the high-entropy alloy reaction structure material provided by the application can reach 0.5 MPa under the impact loading of a ballistic gun at 1300 m / s on a 27L closed tank body.

[0108] The above examples are only exemplary embodiments of the application and are not used to limit the application, and the protection scope of the application is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements to the application within the spirit and protection scope of the application, and such modifications or equivalent replacements should also be considered to fall within the protection scope of the application.

Claims

1. A high-strength, high-energy, high-entropy alloy reactive structural material, characterized in that, The alloy includes Ti, Zr, V, Nb and Ta elements. The general formula of the high-entropy alloy is TiZrVNbTa. During alloy smelting, the raw materials are fed in the following order: first, Ti and Zr elements are synthesized into TiZr master alloy, and Nb and Ta elements are synthesized into NbTa master alloy. Then, the TiZr master alloy, NbTa master alloy and a small amount of V element are smelted to form a single-phase solid solution structure. In terms of atomic percentage, the content of each element is not 0%, and the total content is 100%. The content of each element is as follows: Ti: 0%-25%; Zr：0%-25%； V：0%-15%； Nb: 0%-25%; Ta: 40%-45%.

2. The high-strength, high-energy, high-entropy alloy reactive structural material according to claim 1, characterized in that, The general formula of the high-entropy alloy is TiZrVNbTa, and the contents of each element, in atomic percentage, are as follows: Ti: 15%-25%; Zr：15%-25%； V：0%-10%； Nb: 15%-25%; Ta: 40%.

3. A method for preparing a high-strength, high-energy, high-entropy alloy reactive structural material as described in claim 1, characterized in that, Includes the following steps: Ingredients: Clean Ti, Zr, V, Nb and Ta particles are mixed according to their atomic content ratio; Smelting: The above ingredients are fed into a magnetic levitation induction melting furnace and smelted in a vacuum environment. The raw materials are fed in the following order: Ti and Zr elements are first synthesized into TiZr master alloy, Nb and Ta elements are synthesized into NbTa master alloy, and then TiZr master alloy, NbTa master alloy and a small amount of V element are smelted to form a single-phase solid solution structure. Hot isostatic pressing: The cast alloy prepared after melting is subjected to hot isostatic pressing to obtain a high-entropy alloy reaction structure material.

4. The preparation method according to claim 3, characterized in that, The purity of the Ti element particles is 99.9%, the purity of the Zr element particles is 99.95%, the purity of the V element particles is 99.9%, the purity of the Nb element particles is 99.95%, and the purity of the Ta element particles is 99.95%. The aforementioned elemental particles are all clean raw materials with oxide scale removed.

5. The preparation method according to claim 4, characterized in that, The elements contained in the above-mentioned elemental particles, calculated as atomic percentages, are as follows: Ti: 15%-25%; Zr：15%-25%； V：0%-10%； Nb: 15%-25%; Ta: 40%-45%.

6. The preparation method according to claim 3, characterized in that, The above smelting steps are specifically as follows: at 10 -3 Melt the alloy 4-6 times under vacuum, with each melting temperature between 2200℃ and 2300℃ and each melting time between 15-20 minutes. After the alloy composition is uniform, pour it into the mold and let it cool naturally under vacuum protection.

7. The preparation method according to claim 6, characterized in that, The hot isostatic pressing step is carried out in a vacuum or inert gas protected atmosphere, and the hot isostatic pressing temperature is 1150-1250℃, with a holding time of 4-6 hours.

8. The preparation method according to claim 7, characterized in that, The hot isostatic pressing pressure is 180-200 MPa, the holding time is 4-6 hours, and the cooling rate is 50℃ / min.

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