CN114703393A

CN114703393A - High-strength Ti-Zr-Ta alloy and preparation method and application thereof

Info

Publication number: CN114703393A
Application number: CN202210257427.4A
Authority: CN
Inventors: 李顺; 唐宇; 白书欣; 刘泽人; 张周然; 朱利安; 叶益聪; 王震; 牛顿
Original assignee: National University of Defense Technology
Current assignee: National University of Defense Technology
Priority date: 2022-03-16
Filing date: 2022-03-16
Publication date: 2022-07-05

Abstract

The invention discloses a high-strength Ti-Zr-Ta alloy and a preparation method and application thereof. The preparation method provided by the invention adopts a powder metallurgy method, overcomes the defects that the traditional smelting and casting method is difficult to form in a large size, easy to produce shrinkage cavities and the like, avoids the subsequent heat treatment process required by casting, and can realize the near-net forming of large-size components through the design of a forming die. Meanwhile, powder metallurgy can inhibit component segregation, dendrite formation and multiphase precipitation of the alloy, and a block alloy material with a uniform phase structure is formed, so that the performance of the alloy can be better ensured. The Ti-Zr-Ta alloy prepared by the method has uniform structure and good mechanical property, and the tensile strength of the alloy can reach more than 1000 MPa.

Description

High-strength Ti-Zr-Ta alloy and preparation method and application thereof

Technical Field

The invention relates to the technical field of metal materials, in particular to a high-strength Ti-Zr-Ta alloy and a preparation method and application thereof.

Background

The energetic structural material has the characteristic of structural energy integration, and can replace inert parts such as fragments, liner and shell structures of the traditional warhead. Compared with the traditional inert material, the damage element formed by the energetic structural material can induce high-energy chemical reactions among material components and between the components and oxygen in the environment after acting with a target, so that an explosion-like phenomenon is generated, a large amount of heat is released, high-temperature and high-pressure action is generated in the target, and the damage effect is greatly improved.

The metal type energetic structural material consists of metal or metalloid elements with high combustion heat value. Refractory metal elements such as Ti, Zr, Ta, Nb, Hf and the like are the first choice of the high-strength metal type energetic structure material due to the characteristics of high density, high combustion heat value and the like. The energy-containing structural material composed of refractory metal elements such as Ti, Zr, Ta and the like is mainly formed by a smelting and casting method at present due to the fact that the melting points of all the components are generally high, and early-stage research shows that the prepared Ti-Zr-Ta alloy has good energy release characteristics. However, because the melting points of different refractory metal elements are very different, the large-size forming is difficult by a smelting and casting method, and the defects of segregation, shrinkage cavity and the like are easy to generate.

Disclosure of Invention

The invention provides a high-strength Ti-Zr-Ta alloy and a preparation method and application thereof, which are used for overcoming the defects that a casting forming method in the prior art is difficult to form in large size and is easy to form segregation, shrinkage cavity and the like.

In order to realize the aim, the invention provides a preparation method of a high-strength Ti-Zr-Ta alloy, which comprises the following steps:

s1: designing components of a Ti-Zr-Ta alloy, weighing raw material Ti, raw material Zr and raw material Ta according to the designed components of the Ti-Zr-Ta alloy, uniformly mixing, and smelting to obtain an alloy ingot;

s2: carrying out sand blasting treatment and acid washing on the surface of the alloy cast ingot in sequence;

s3: placing the alloy ingot subjected to surface treatment in a hydrogenation furnace, and carrying out hydrogenation treatment at the temperature of 600-900 ℃ and the hydrogen pressure of 0.1-0.3 MPa for 1-5 h;

s4: carrying out physical coarse crushing on the alloy ingot after hydrogenation treatment, and then ball-milling into powder with a particle size of less than 100 meshes;

s5: carrying out dehydrogenation treatment on the ball-milled powder in a vacuum environment at the temperature of 500-700 ℃ for 2-6 h to obtain Ti-Zr-Ta alloy powder;

s6: and carrying out hot-pressing sintering treatment or hot isostatic pressing sintering treatment on the dehydrogenated Ti-Zr-Ta alloy powder at the temperature of 1000-1400 ℃ and the pressure of 30-150 MPa for 1-4 h to obtain the Ti-Zr-Ta alloy.

In order to achieve the purpose, the invention also provides a high-strength Ti-Zr-Ta alloy prepared by the preparation method.

In order to achieve the purpose, the invention also provides application of the high-strength Ti-Zr-Ta alloy, and the Ti-Zr-Ta alloy prepared by the preparation method or the Ti-Zr-Ta alloy is used in fragments, liner and shell structures of warheads.

Compared with the prior art, the invention has the beneficial effects that:

the preparation method of the high-strength Ti-Zr-Ta alloy comprises the steps of smelting raw materials into alloy ingots, performing surface treatment, hydrotreating, crushing, dehydrogenating, sintering and the like. And (3) carrying out sand blasting treatment on the surface of the alloy ingot to remove mechanical processing traces such as oil stains, impurities and the like on the surface of the alloy ingot, and carrying out acid washing to remove an oxide film on the surface of the ingot. The hydrogen element is dissolved into alloy crystal lattice by means of adsorption and inward diffusion of hydrogen element on the alloy surface, so that various hydrides are formed to expand the alloy volume and the alloy is crushed under the action of internal stress. The diameter of an alloy block after hydrogenation crushing is generally in a millimeter level, the particle size is required to be reduced to a micron level through physical coarse crushing, the particle size is reduced to be below 100 meshes in a ball milling mode, the particle size distribution is more concentrated, the particle size is further reduced, and the subsequent dehydrogenation treatment is more sufficient through increasing the specific surface area of the alloy. The dehydrogenation treatment is to generate hydride decomposition in a high-temperature vacuum environment, and hydrogen elements are diffused to the surface of the alloy through defects such as vacancies, grain boundaries and the like, and finally form hydrogen molecules to be dissipated. And finally, carrying out hot-pressing sintering or hot isostatic pressing sintering treatment, and carrying out compact molding on the powder under the action of high temperature and high pressure to finally obtain the Ti-Zr-Ta large-size bulk alloy. The preparation method provided by the invention adopts a powder metallurgy method, overcomes the defects that the traditional smelting and casting method is difficult to form in large size, easy to produce shrinkage cavity and the like, avoids the subsequent heat treatment process required by casting, and can realize near-net forming of large-size components through the design of a forming die. Meanwhile, powder metallurgy can inhibit component segregation, dendrite formation and multiphase precipitation of the alloy, and a block alloy material with a uniform phase structure is formed, so that the performance of the alloy can be better ensured. The Ti-Zr-Ta alloy prepared by the method has uniform structure and good mechanical property, and the tensile strength of the alloy can reach more than 1000 MPa.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a photograph of a Ti-Zr-Ta alloy powder obtained in step S5 of example 1;

FIG. 2 is an XRD pattern of the Ti-Zr-Ta alloy powder obtained in step S5 of example 1;

FIG. 3 is an SEM photograph of the Ti-Zr-Ta alloy obtained in step S6 of example 1;

FIG. 4 is a tensile stress-strain curve of the Ti-Zr-Ta alloy obtained in step S6 in example 1.

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In addition, the technical solutions in the embodiments of the present invention may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination of technical solutions should not be considered to exist, and is not within the protection scope of the present invention.

The drugs/reagents used are all commercially available without specific mention.

The invention provides a preparation method of a high-strength Ti-Zr-Ta alloy, which comprises the following steps:

s1: designing components of the Ti-Zr-Ta alloy, weighing raw material Ti, raw material Zr and raw material Ta according to the designed components of the Ti-Zr-Ta alloy, uniformly mixing, and smelting to obtain an alloy ingot.

Preferably, the composition of the Ti-Zr-Ta alloy is: the molar fraction of Ti is 45-75%, the molar fraction of Zr is 15-40%, and the balance is Ta. The alloy in the composition range has a single-phase structure, high mechanical strength and good energy release effect.

Preferably, the purities of the raw material Ti, the raw material Zr and the raw material Ta are all more than 99.5 wt%. The purity of the raw materials is controlled to ensure that the final product contains less impurities and has excellent performance.

After the alloy is prepared, oil stains on the surface of the alloy raw material are removed in a solvent soaking mode.

Because the alloy has high melting point, the Ti-Zr-Ta alloy cast ingot is preferably prepared by adopting a suspension smelting mode, and the alloy cast ingot needs to be repeatedly smelted for more than 5 times for 30-60min each time in order to ensure the uniform components of the casting.

S2: and carrying out sand blasting treatment and acid washing on the surface of the alloy cast ingot in sequence.

And (4) pickling to remove the oxide film on the surface of the alloy ingot.

Preferably, the acid washing is specifically:

hydrofluoric acid with the concentration of 0.1-5% or HF and HNO with the mass ratio of 1:1 are utilized₃The mixed solution is subjected to acid washing for 2-5 minutes. The pickling time is strictly controlled to prevent excessive corrosion.

And taking out the acid-washed surface after the acid-washing, sequentially washing the surface with water and alcohol, and drying the surface in a 60 ℃ drying oven.

S3: and (3) placing the alloy ingot subjected to surface treatment in a hydrogenation furnace, and carrying out hydrogenation treatment at the temperature of 600-900 ℃ and the hydrogen pressure of 0.1-0.3 MPa for 1-5 h.

The hydrogen pressure is kept constant in the hydrogenation process, so that the hydrogenation rate is kept at a relatively stable level, and the situation that the pressure is increased sharply due to temperature rise and expansion to threaten equipment and environmental safety is avoided. When the alloy absorbs hydrogen to cause pressure reduction or gas expansion by heating, gas is charged and discharged in time.

S4: and carrying out physical coarse crushing on the alloy ingot after the hydrogenation treatment, and then ball-milling the alloy ingot into powder with the particle size of less than 100 meshes.

Preferably, the physical coarse crushing is specifically:

the alloy ingot after the hydrogenation treatment was physically coarsely crushed by a vibratory ball mill, and the crushed powder was sieved with a 32-mesh sieve, and the coarse particles were returned to step S3.

Preferably, the ball milling is specifically:

putting the alloy after physical coarse crushing into a ball milling tank, adding grinding balls according to the mass ratio of the grinding balls to the alloy (2:1) - (10:1), and sealing the ball milling tank;

ball milling is carried out for 0.5-2 h at the rotating speed of 200-250 r/min under the inert atmosphere.

Preferably, the grinding balls are at least one of cemented carbide balls and stainless steel balls. The grinding balls are made of metal materials with high strength, so that the raw materials can be sufficiently ball-milled, and the raw materials cannot be polluted due to damage in the ball-milling process due to low strength.

Preferably, the grinding balls comprise grinding balls with different particle sizes, and the mass ratio of the grinding balls with different particle sizes is different, so that the ball milling efficiency is improved.

Preferably, the ball milling is performed in a batch ball milling mode, specifically, each ball milling is performed for 5min, the ball milling is suspended for 5min, and then the ball milling is performed for 5min in a reverse direction. The intermittent ball milling mode is adopted to avoid the generation of overhigh heat due to continuous ball milling.

S5: and (3) carrying out dehydrogenation treatment on the ball-milled powder in a vacuum environment at the temperature of 500-700 ℃ for 2-6 h to obtain Ti-Zr-Ta alloy powder.

The invention also provides a high-strength Ti-Zr-Ta alloy prepared by the preparation method.

The invention also provides application of the high-strength Ti-Zr-Ta alloy, and the Ti-Zr-Ta alloy prepared by the preparation method or the Ti-Zr-Ta alloy is applied to fragments, liner and shell structures of warheads and the like.

Example 1

This example provides a Ti-Zr-Ta alloy having a Ti content of 70%, a Zr content of 20%, and the balance Ta. The tensile strength of the alloy is 1176MPa, and the elongation is 2.7%.

The embodiment also provides a preparation method of the Ti-Zr-Ta gold, which includes:

s1: designing components of the Ti-Zr-Ta alloy, weighing raw material Ti, raw material Zr and raw material Ta according to the designed components of the Ti-Zr-Ta alloy, uniformly mixing, and carrying out arc melting to obtain an alloy ingot.

The composition of the Ti-Zr-Ta alloy, i.e., Ti content 70%, Zr content 20%, and the balance Ta.

S2: the surface of the alloy ingot was subjected to sand blasting, and then acid pickling with hydrofluoric acid having a solubility of 0.1% was performed to remove an oxide film on the surface of the ingot.

S3: and (3) placing the alloy ingot subjected to surface treatment in a hydrogenation furnace, and carrying out hydrogenation treatment at the temperature of 900 ℃ and the hydrogen pressure of 0.2MPa for 5 h.

S4: the alloy ingot after hydrogenation treatment is subjected to physical coarse crushing, and is further crushed into powder with the particle size of less than 100 meshes by a planetary ball mill.

S5: and (3) carrying out dehydrogenation treatment on the ball-milled powder in a vacuum environment at the temperature of 700 ℃ for 6 hours to obtain Ti-Zr-Ta alloy powder.

S6: and carrying out hot isostatic pressing sintering treatment on the Ti-Zr-Ta alloy powder obtained after dehydrogenation at the temperature of 1300 ℃ and under the pressure of 50MPa for 4h to obtain the Ti-Zr-Ta alloy.

The SEM (scanning electron microscope) photograph and XRD (X-ray diffraction) pattern of the alloy powder prepared in this example are shown in fig. 1 and 2. FIG. 3 is an SEM (scanning Electron microscope) photograph of a Ti-Zr-Ta alloy obtained after sintering. As can be seen from fig. 1, the alloy powder is in an irregular block shape with clear edges and corners, and belongs to a typical crushing appearance, and the particle size of the powder is concentrated, which indicates that the subsequent physical coarse crushing and ball milling are sufficient. As can be seen from FIG. 2, the dehydrogenated powder had a single BCC structure, consistent with the bulk alloy, indicating adequate dehydrogenation and no residual hydrogenation products. As can be seen from fig. 3, no voids were evident after sintering, and the densification was complete. FIG. 4 is a tensile stress-strain curve of the Ti-Zr-Ta alloy, which has a tensile strength of 1176MPa, an elongation of 2.7%, a high material strength and a moderate plasticity, and can meet the requirements of bearing and damaging in use.

Example 2

This example provides a Ti-Zr-Ta alloy having 53% Ti, 27% Zr, and the balance Ta. The tensile strength of the alloy is 1287MPa, and the elongation is 7.1%.

The composition of the Ti-Zr-Ta alloy, i.e., 53% Ti, 27% Zr, and the balance Ta.

S2: the surface of the alloy ingot was subjected to sand blasting, and then acid cleaning with hydrofluoric acid having a solubility of 5% was performed to remove the oxide film on the surface of the ingot.

S3: and (3) placing the alloy ingot subjected to surface treatment in a hydrogenation furnace, and carrying out hydrogenation treatment at the temperature of 850 ℃ and the hydrogen pressure of 0.3MPa for 5 h.

S5: and carrying out dehydrogenation treatment on the ball-milled powder in a vacuum environment at the temperature of 650 ℃ for 4 hours to obtain Ti-Zr-Ta alloy powder.

S6: and carrying out hot isostatic pressing sintering treatment on the Ti-Zr-Ta alloy powder obtained after dehydrogenation at the temperature of 1100 ℃ and under the pressure of 150MPa for 3h to obtain the Ti-Zr-Ta alloy.

The tensile strength of the Ti-Zr-Ta alloy prepared by the embodiment is 1287MPa, and the elongation is 7.1%.

Example 3

The composition of the Ti-Zr-Ta alloy, i.e., 75% Ti, 15% Zr, and the balance Ta.

S2: the surface of the alloy ingot was subjected to sand blasting, and then acid pickling with hydrofluoric acid having a solubility of 2% was performed to remove the oxide film on the surface of the ingot.

S3: and (3) placing the alloy ingot subjected to surface treatment in a hydrogenation furnace, and carrying out hydrogenation treatment at the temperature of 600 ℃ and the hydrogen pressure of 0.2MPa for 1 h.

S5: and (3) carrying out dehydrogenation treatment on the ball-milled powder in a vacuum environment at the temperature of 500 ℃ for 2h to obtain Ti-Zr-Ta alloy powder.

S6: and carrying out hot isostatic pressing sintering treatment on the Ti-Zr-Ta alloy powder obtained after dehydrogenation at the temperature of 1000 ℃ and the pressure of 30MPa for 1h to obtain the Ti-Zr-Ta alloy.

The tensile strength of the Ti-Zr-Ta alloy prepared by the embodiment is 1187MPa, and the elongation is 3.5%.

Example 4

The composition of the Ti-Zr-Ta alloy, i.e. 45% of Ti, 40% of Zr and the balance Ta.

S2: the surface of the alloy ingot was subjected to sand blasting, and then acid cleaning with hydrofluoric acid having a solubility of 3% was performed to remove the oxide film on the surface of the ingot.

S3: and (3) placing the alloy ingot subjected to surface treatment in a hydrogenation furnace, and carrying out hydrogenation treatment at the temperature of 700 ℃ and the hydrogen pressure of 0.15MPa for 2.5 h.

S5: and (3) carrying out dehydrogenation treatment on the ball-milled powder in a vacuum environment at the temperature of 600 ℃ for 5 hours to obtain Ti-Zr-Ta alloy powder.

S6: and carrying out hot isostatic pressing sintering treatment on the Ti-Zr-Ta alloy powder obtained after dehydrogenation at the temperature of 1400 ℃ and the pressure of 100MPa for 1.5h to obtain the Ti-Zr-Ta alloy.

The tensile strength of the Ti-Zr-Ta alloy prepared by the embodiment is 1230MPa, and the elongation is 6.5%.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A preparation method of a high-strength Ti-Zr-Ta alloy is characterized by comprising the following steps:

s4: carrying out physical coarse crushing on the alloy ingot after hydrogenation treatment, and then ball-milling the alloy ingot into powder with the particle size of less than 100 meshes;

s6: and carrying out hot pressing sintering treatment or hot isostatic pressing sintering treatment on the dehydrogenated Ti-Zr-Ta alloy powder at the temperature of 1000-1400 ℃ and the pressure of 30-150 MPa for 1-4 h to obtain the Ti-Zr-Ta alloy.

2. The production method according to claim 1, wherein in step S1, the composition of the Ti-Zr-Ta alloy is: the molar fraction of Ti is 45-75%, the molar fraction of Zr is 15-40%, and the balance is Ta.

3. The method of claim 1, wherein the purities of the raw material Ti, the raw material Zr, and the raw material Ta are each more than 99.5 wt% in step S1.

4. The method according to claim 1, wherein in step S2, the acid washing is specifically:

hydrofluoric acid with the concentration of 0.1-5% or HF and HNO with the mass ratio of 1:1 are utilized₃The mixed solution is subjected to acid washing for 2-5 minutes.

5. The method according to claim 1, wherein in step S4, the physical coarse crushing is specifically:

6. The preparation method according to claim 1, wherein in step S4, the ball milling is specifically:

7. The method of claim 6, wherein the grinding balls are at least one of cemented carbide balls and stainless steel balls.

8. The preparation method of claim 6, wherein the ball milling is performed by intermittent ball milling, specifically, each ball milling is performed for 5min, the ball milling is suspended for 5min, and then the ball milling is performed in a reverse direction for 5 min.

9. A high-strength Ti-Zr-Ta alloy which is prepared by the preparation method of any one of claims 1 to 8.

10. The application of the high-strength Ti-Zr-Ta alloy is characterized in that the Ti-Zr-Ta alloy prepared by the preparation method in any one of claims 1 to 8 or the Ti-Zr-Ta alloy in claim 9 is used in fragments, liners and shell structures of warheads.