Titanium-based composite material, method for preparing the same and use thereof

Abstract

The application discloses a titanium-based composite material and a preparation method and application thereof, and the titanium-based composite material is composed of Ti 70wt%-90wt%, W 10wt%-30wt%, and inevitable impurities in the rest; wherein, the W particles are dispersedly distributed on the Ti matrix and a Ti / W gradient diffusion zone exists. The ductile W particles replace the ceramic particles, which can achieve the effect of hardening and will not cause the plasticity of the material to be greatly reduced; the Ti / W gradient diffusion zone can accommodate more dislocations to coordinate deformation in the plastic deformation process, so that the plasticity of the material is further improved. The process flow of the application is very short, and the rapid preparation of the high-performance titanium-based composite material can be realized, and the problems of long process flow and great processing difficulty of the traditional titanium-based composite material are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of alloys, in particular to a titanium-based composite material and a preparation method and application thereof. BACKGROUND

[0002] Titanium alloy has low density, excellent corrosion resistance and high specific strength, and is widely used in aerospace, marine engineering, rail transportation and other fields. Titanium-based composite material is obtained by adding second phase particles in the titanium alloy matrix to achieve the effect of strengthening and hardening, so as to improve its wear resistance. The second phase particles added in the traditional titanium-based composite material are mainly ceramic particles such as TiC, TiB and Al2O3. Although the addition of these ceramic particles can improve the strength and hardness of titanium alloy (the strength can reach 1000 MPa, and the hardness can reach 50HRC), it will also cause a significant reduction in the plasticity of the material (the plasticity is less than 5%), which seriously affects the processing performance and subsequent service effect of the material. Therefore, it is of great significance to develop titanium-based composite material with high hardness and high plasticity to promote its application in the field of wear and corrosion resistance.

[0003] Researchers have developed a non-continuous network structure titanium-based composite material preparation technology, which controls the network distribution of ceramic particles in the titanium alloy matrix to improve the strength and plasticity. However, this technology has a long process flow in controlling the network structure, and the processing performance of the material is still poor. Some scholars have also developed a titanium-based composite material with heterogeneous pellet structure, which controls the pellet distribution of ceramic particles in the titanium alloy matrix to improve the strength and plasticity. This technology has good strengthening effect, but it needs to go through complex processes such as self-consumption smelting, rotating electrode atomization and hot isostatic pressing, so the production cost of the material is high. In the subsequent improvement, researchers proposed to replace ceramic particles with W particles as the reinforcing phase of titanium-based composite material to reduce the problem of large difference in physical properties between the reinforcing phase and the titanium matrix, so that the reinforcing phase and the interface have certain plastic deformation capacity, thereby improving the plasticity of the titanium-based composite material. This technology has a certain effect on improving the plasticity of titanium-based composite material, but it does not solve the problems of uniform dispersion of W particles and interface control between the matrix and the particles, resulting in low overall plasticity of the material. In general, there is no report on low-cost, short-process high-hardness high-plasticity titanium-based composite material preparation technology in China at present. SUMMARY

[0004] The present application aims to solve at least one of the above-mentioned technical problems in the prior art. To this end, the purpose of the present application is to provide a titanium-based composite material and a preparation method and application thereof.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows:

[0006] In a first aspect, the present invention provides a titanium-based composite material comprising 70wt%–90wt% Ti, 10wt%–30wt% W, and the balance being unavoidable impurities; wherein W particles are dispersed in a Ti matrix, and a Ti / W gradient diffusion region exists at the interface between the two, and the distribution density N of the W particles is [not specified]. w At least 1×10 5 pcs / mm 3 The width L of the Ti / W gradient diffusion region Ti / W The size ranges from 3μm to 20μm.

[0007] In this invention, compared to traditional titanium-based composite materials, tough W particles are used instead of ceramic particles. These W particles are dispersed within the Ti matrix, achieving a hardening effect without significantly reducing the material's plasticity. Furthermore, the presence of the Ti / W gradient diffusion region allows the material to accommodate more dislocations during plastic deformation to coordinate the deformation, further improving the composite material's plasticity. Agglomeration of W particles or an excessively narrow or wide Ti / W gradient diffusion region can both lead to a decrease in the composite material's plasticity.

[0008] In some embodiments of the present invention, the size D of the W particle is... w Within 10 μm; preferably within 8 μm.

[0009] In some embodiments of the present invention, the distribution density N of the W particles is... w At least 1.1 × 10 5 pcs / mm 3 At least 1.3 × 10 5 pcs / mm 3 At least 1.4 × 10 5 pcs / mm 3 At least 1.5 × 10 5 pcs / mm 3 At least 1.6 × 10 5 pcs / mm 3 At least 1.7 × 10 5 pcs / mm 3 At least 1.8 × 10 5 pcs / mm 3 At least 1.9 × 10 5 pcs / mm 3 At least 2.0 × 10 5 pcs / mm 3 At least 2.1 × 10 5 pcs / mm 3 wait.

[0010] In some embodiments of the present application, the content of W element in the Ti / W gradient diffusion zone increases gradually from the Ti substrate to the W particles, and the concentration of W element gradually increases from about 5% to about 95%; preferably, the concentration of W element gradually increases from about 8% to about 92%; preferably, the concentration of W element gradually increases from about 10% to about 90%; wherein, “about” means “within ± 2%”.

[0011] In some embodiments of the present application, the test method for the width of the Ti / W gradient diffusion zone is scanning electron microscope image statistics; preferably, the test method is specifically as follows: under the backscattering shooting mode of the scanning electron microscope, 50 W particles are randomly selected, EDS (Energy Dispersive Spectrometer, Energy Dispersive Spectrometer of Field Emission Scanning Electron Microscope) line scanning test is performed from the Ti substrate to the center of the W particle, the region with W element content of about 10% to about 90% is taken as the Ti / W gradient diffusion zone, and the width of the region is measured as the width of the Ti / W gradient diffusion zone.

[0012] In some embodiments of the present application, the distribution density N w of the W particles is tested by the scanning electron microscope image statistics method; preferably, the test method is specifically as follows: under the backscattering shooting mode of the scanning electron microscope, 50 microscopic images with a field range of 200 μm×200 μm are randomly taken, the number of W particles in the images is counted, and the average number is taken as n, and the distribution density is converted by the formula N w =125n 3 / 2 .

[0013] In some embodiments of the present application, the hardness of the titanium-based composite material is at least 50 HRC and / or the tensile elongation is at least 18%; preferably, the hardness of the titanium-based composite material is at least 51 HRC and / or the tensile elongation is at least 18%; preferably, the hardness of the titanium-based composite material is at least 52 HRC and / or the tensile elongation is at least 18%; preferably, the hardness of the titanium-based composite material is at least 60 HRC and / or the tensile elongation is at least 20%; preferably, the hardness of the titanium-based composite material is at least 65 HRC and / or the tensile elongation is at least 30%, etc.

[0014] In a second aspect of the present application, a preparation method of the titanium-based composite material is provided, which comprises the following steps:

[0015] The Ti powder and the W powder are mixed by ultrasonic resonance in proportion to obtain a mixture, and the mixture is hot-pressed and sintered under a vacuum atmosphere to obtain the titanium-based composite material.

[0016] In the present application, the Ti powder and the W powder are uniformly mixed by ultrasonic resonance, because the density of the Ti powder and the W powder is very different, and the conventional V-shaped mixing, three-dimensional mixing, ball milling mixing and other powder mixing methods are difficult to uniformly mix the Ti powder and the W powder; and the mixture is hot-pressed and sintered under vacuum, which is beneficial to the diffusion of the W particles, so that the W particles are dispersed and distributed and form a Ti / W gradient diffusion zone.

[0017] In some embodiments of the present application, the resonance frequency of the ultrasonic resonance mixing is 55Hz-65Hz; and / or, the mixing acceleration is 30g-60g; and / or, the mixing time is 1min-10min. Preferably, the mixing time is 3min-8min; preferably, the mixing time is 3min-5min.

[0018] In some embodiments of the present application, the hot-pressing sintering is rapid hot-pressing sintering.

[0019] In some embodiments of the present application, the temperature of the hot-pressing sintering is 1350℃-1500℃; the heating rate is 50℃ / min-100℃ / min; preferably, the temperature of the hot-pressing sintering is 1400℃-1450℃; the heating rate is 80℃ / min-100℃ / min.

[0020] In some embodiments of the present application, the pressure of the hot-pressing sintering is 20MPa-40MPa, and the holding time is 10min-30min.

[0021] In some embodiments of the present application, the vacuum degree of the vacuum is within 1Pa, such as 0.8Pa, 0.5Pa, 0.3Pa, etc.

[0022] In the preparation method of the titanium-based composite material of the present application, the temperature, the heating rate, the pressure and the holding time of the hot-pressing sintering are limited, which is beneficial to forming a structure with small grains and obvious gradient, so that the W particles are dispersed and distributed and form a Ti / W gradient diffusion zone, thereby improving the hardness and plasticity of the material. If the sintering temperature is too low, the diffusion of the W particles is not conducive, and the Ti / W gradient diffusion zone cannot be formed; if the temperature is too high or the holding time is too long, the grains of the Ti matrix will be excessively coarse, resulting in a decrease in the strength and hardness of the material. However, the preparation method of the titanium-based composite material of the present application is not limited to the above hot-pressing sintering, but can also be other sintering methods, as long as the W particles are dispersed and distributed (the distribution density N w of the W particles is at least 1×10 5 mm 3 ) and a Ti / W gradient diffusion zone (the width L Ti / W is 3μm-20μm) is formed.

[0023] In some embodiments of the present application, the average particle size of the Ti powder is 50-180 μm; preferably 50-100 μm.

[0024] In some embodiments of the present application, the Ti powder is a hydrogenated dehydrogenated powder, which is less expensive.

[0025] In some embodiments of the present application, the particle size of the W particles is 1-15 μm; preferably 2-8 μm.

[0026] In a third aspect of the present application, a wear-resistant metal material is provided, which comprises the titanium-based composite material.

[0027] The present application has the following advantages.

[0028] (1) The present application provides a titanium-based composite material with high hardness and high plasticity gradient structure, which does not contain Mo, Ta, Cr, Nb, V and other expensive alloy elements, and has simple component ratio, thereby effectively reducing the cost of raw materials.

[0029] (2) The present application provides a titanium-based composite material with high hardness and high plasticity gradient structure, which has a microstructure of Ti matrix, W particles and Ti / W gradient diffusion zone. Compared with the traditional titanium-based composite material, the gradient structure titanium-based composite material of the present application has comparable hardness (about 50 HRC) and significantly improved plasticity (from about 5% to about 20%). The principle mainly lies in that, on the one hand, the use of ductile W particles instead of ceramic particles can achieve the effect of increasing hardness without causing a significant decrease in material plasticity; on the other hand, the Ti / W gradient diffusion zone can accommodate more dislocations to coordinate deformation during plastic deformation, thereby further improving the plasticity of the material.

[0030] (3) The process flow of the present application is very short, which can realize the rapid preparation of high-performance titanium-based composite materials, and solves the problems of long process flow and difficult processing of traditional titanium-based composite materials. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 FIG. 1 is a structural schematic diagram of the titanium-based composite material of the present application.

[0032] Figure 2 FIG. 2 is an SEM diagram of the titanium-based composite material of Example 1 and Comparative Examples 1-3 of the present application.

[0033] Figure 3 FIG. 3 is a W element content change trend of the Ti / W gradient diffusion zone in the titanium-based composite material of Example 1 of the present application.

[0034] Figure 4 FIG. 4 is a tensile property diagram of the titanium-based composite material of Example 1 and Comparative Example 1 of the present application.

[0035] Figure 5 This is a diagram showing the width of a Ti / W gradient diffusion region in the titanium-based composite material of Example 2 of the present invention. Detailed Implementation

[0036] The present invention will be further described in detail below through specific embodiments. Unless otherwise specified, the raw materials, reagents, or apparatus used in the embodiments and comparative examples are all available from conventional commercial sources or can be obtained by existing technical methods. Unless otherwise specified, the test or experimental methods are conventional methods in the art.

[0037] In the following examples or comparative examples, the test method for the width of the Ti / W gradient diffusion region is the statistical method of scanning electron microscopy images, specifically as follows: Figure 1 As shown, in the backscatter imaging mode of scanning electron microscope, 50 W particles were randomly selected and EDS line scan was performed along the Ti matrix to the center of the W particles. The region with W element content of ~10% to ~90% was taken as the Ti / W gradient diffusion region, and the width of this region was measured as the width of the Ti / W gradient diffusion region.

[0038] Distribution density of W particles N w The testing method was a scanning electron microscope (SEM) image statistical method. Specifically, 50 microscopic images with a field of view of 200 μm × 200 μm were randomly captured in the backscatter imaging mode of the SEM. The number of W particles in the images was counted, and the average number was taken as n. The result was calculated using the formula N. w =125n 3 / 2 Convert to distribution density.

[0039] In the following examples or comparative examples, the material mechanics testing standards are as follows:

[0040] Tensile strength: GB / T 228.1-2010 Metallic materials, tensile testing—Part 1: Test method at room temperature;

[0041] Tensile elongation: GB / T 228.1-2010 Metallic materials, tensile testing—Part 1: Test method at room temperature;

[0042] Hardness: GB / T 230.1-2018 Metallic materials Rockwell hardness test - Part 1: Test method.

[0043] Example 1

[0044] This embodiment provides a titanium-based composite material with the following composition: Ti: 80%, W: 20%; its preparation process is as follows:

[0045] (1) Weigh out Ti powder (D) according to the above composition. 50 =50μm) and W powder (D 50The metal powders are placed in a powder mixing tank and ultrasonic resonance mixed on an acoustic resonance mixer at a resonance frequency of 60 Hz, a mixing acceleration of 30 g, and a powder mixing time of 5 min to obtain a mixed and uniform composite powder.

[0046] (2) The composite powder is loaded into a graphite mold for rapid hot-press sintering at a heating rate of 100°C / min, a sintering temperature of 1400°C, a pressure of 30 MPa, and a holding time of 10 min to obtain a high-hardness and high-plasticity gradient structure titanium-based composite material.

[0047] The microstructure of the obtained composite material is analyzed by scanning electron microscopy, and the SEM image is shown in Figure 2 The microstructure is composed of a Ti matrix, W particles, and a Ti / W gradient diffusion zone, the W particles are uniformly distributed, and the Ti / W gradient diffusion zone is obvious. The size D w of the W particles is less than 10 μm, the particle distribution density N w is 1.3 x 10 5 particles / mm 3 , and the width L Ti / W of the Ti / W gradient diffusion zone is in the range of 3 μm to 12 μm. The W element content of the Ti / W gradient diffusion zone is analyzed by line scanning, and the results are shown in Figure 3 The W element concentration gradually increases from about 10% to about 90% from the Ti matrix to the W particles.

[0048] The tensile property curve is measured and shown in Figure 4 The tensile strength of the composite material is 1025 MPa, the elongation is 21%, and the hardness of the composite material is 51.3 HRC. The high-hardness and high-plasticity gradient structure titanium-based composite material obtained in this embodiment has excellent hardness and plasticity.

[0049] Example 2

[0050] This embodiment provides a titanium-based composite material with a composition of Ti: 70%, W: 30%, and a specific process as follows:

[0051] (1) Ti powder (D 50 = 90 μm) and W powder (D 50 = 8 μm) are weighed according to the above composition, the metal powders are placed in a powder mixing tank, and ultrasonic resonance mixed on an acoustic resonance mixer at a resonance frequency of 65 Hz, a mixing acceleration of 50 g, and a powder mixing time of 3 min to obtain a mixed and uniform composite powder.

[0052] (2) The composite powder is put into a graphite mold to perform rapid hot-press sintering, the heating rate is 80°C / min, the sintering temperature is 1450°C, the pressure is 30 MPa, and the holding time is 20 min, to obtain the high-hardness and high-plasticity gradient structure titanium-based composite material.

[0053] The W particle size D of the composite material obtained in the example is less than 10 μm, the particle distribution density N is 1.4 x 1010 / mm2, and the Ti / W gradient diffusion zone width L is in the range of 5 μm to 18 μm. w w 5 3 Ti / W Figure 5 The W particle size D of the composite material obtained in the example is less than 10 μm, the particle distribution density N is 1.4 x 1010 / mm2, and the Ti / W gradient diffusion zone width L is in the range of 5 μm to 18 μm. Ti / W The tensile strength of the composite material is 1108 MPa, the elongation is 19%, and the hardness is 52.4 HRC. The high-hardness and high-plasticity gradient structure titanium-based composite material obtained in the example has excellent hardness and plasticity.

[0054] Example 3

[0055] The example provides a titanium-based composite material, which has the following components: Ti: 90%, and W: 10%, and the specific process is as follows:

[0056] (1) Ti powder (D 50 = 50 μm) and W powder (D 50 = 3 μm) are weighed according to the above components, the metal powder is put into a powder mixing tank, and ultrasonic resonance mixing is performed on an acoustic resonance mixer, the resonance frequency is 65 Hz, the mixing acceleration is 50 g, and the powder mixing time is 3 min, to obtain uniformly mixed composite powder.

[0057] (2) The composite powder is put into a graphite mold to perform rapid hot-press sintering, the heating rate is 100°C / min, the sintering temperature is 1400°C, the pressure is 30 MPa, and the holding time is 15 min, to obtain the high-hardness and high-plasticity gradient structure titanium-based composite material.

[0058] The W particle size D of the composite material obtained in the example is less than 10 μm, the particle distribution density N is 1.4 x 1010 / mm2, and the Ti / W gradient diffusion zone width L is in the range of 5 μm to 18 μm. w w 5 3 Ti / W The tensile strength of the composite material is 1108 MPa, the elongation is 19%, and the hardness is 52.4 HRC. The high-hardness and high-plasticity gradient structure titanium-based composite material obtained in the example has excellent hardness and plasticity.

[0059] Comparative Example 1​​​​​​​​​

[0060] A titanium-based composite material was prepared in this comparative example. The specific process is as follows:

[0061] Titanium-based composite materials were prepared according to the steps of Example 1. The sintering temperature in step (2) was adjusted to 1200℃, while other parameters remained unchanged, and titanium-based composite materials were obtained.

[0062] The microstructure of the composite material was analyzed by scanning electron microscopy, and the SEM images are shown below. Figure 1 As shown, its microstructure consists of a Ti matrix and W particles. The W particles are uniformly distributed, but no obvious Ti / W gradient diffusion region is formed. The width L of the Ti / W interface diffusion region is... Ti / W Its micrometer size ranges from only 0.5 μm to 2 μm. The measured tensile property curves are as follows: Figure 4 As shown, the composite material has a tensile strength of 895 MPa, an elongation of 13%, and a hardness of 48.9 HRC. It can be seen that when the sintering temperature is too low, it is not conducive to the diffusion of W, and a significant Ti / W gradient diffusion zone cannot be formed, resulting in a significant reduction in the plasticity of the composite material.

[0063] Comparative Example 2

[0064] A titanium-based composite material was prepared in this comparative example. The specific process is as follows:

[0065] Titanium-based composite materials were prepared according to the steps of Example 1. The sintering temperature in step (2) was adjusted to 1500℃ and the holding and pressure time was 2h. Other parameters remained unchanged, and titanium-based composite materials were obtained.

[0066] The microstructure of the composite material was analyzed by scanning electron microscopy, and the SEM images are shown below. Figure 1 As shown, its microstructure is a single-phase structure, with W powder completely diffused into the Ti matrix, without forming W particle structures or a Ti / W gradient diffusion region. Figure 4 As shown, the tensile strength of the composite material was measured to be 1252 MPa, the elongation was 7%, and the hardness was 53.3 HRC. It can be seen that when the sintering temperature is too high and the holding time is too long, the W element will diffuse entirely into the Ti matrix, resulting in the loss of the composite material structure and a significant reduction in the material's plasticity.

[0067] Comparative Example 3

[0068] A titanium-based composite material was prepared in this comparative example. The specific process is as follows:

[0069] Titanium-based composite materials were prepared according to the steps of Example 2, with the ultrasonic vibration mixing in step (1) adjusted to ordinary V-shaped mixing (without acoustic resonance), and the mixing time set to 5 hours. All other parameters remained unchanged, and the titanium-based composite materials were obtained.

[0070] The microstructure of the prepared composite material was analyzed by scanning electron microscopy, and the SEM image is shown in Figure 1 The microstructure is composed of Ti matrix, W particles and Ti / W gradient diffusion zone, but the W particles are not dispersed, and a large number of agglomerates are formed. The size D w of the W particle agglomerates reaches 40 μm, and the particle distribution density N w is only 8×10 3 / mm 3 .As shown in Figure 4 , the tensile strength of the composite material is 952 MPa, the elongation is 8%, and the hardness of the composite material is 47.7 HRC. It can be seen that it is difficult to uniformly mix the W powder and the Ti powder by the conventional powder mixing method, the microstructure of the material is very uneven, the W particles are seriously agglomerated, and the plasticity of the composite material is significantly reduced. The main reason is that the conventional mixing method is to turn the powder up and down to achieve uniform mixing effect, but due to the large difference in density between the W powder and the Ti powder, the W powder is easy to sink to the bottom during the turning process, which makes it difficult to mix uniformly. In order to uniformly mix the W powder and the Ti powder, the ultrasonic resonance effect in the acoustic resonance mixer is used to avoid the influence of density, and other mixing methods that can uniformly mix the W powder and the Ti powder are also within the protection scope of the present application.

[0071] The above embodiments are the preferred embodiments of the present application, but the embodiments of the present application are not limited by the above embodiments, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the present application are equivalent replacement methods, which are all included in the protection scope of the present application.

Claims

1. A titanium-based composite material, characterized by: Ti 70wt%-90wt%, W 10wt%-30wt%, the rest being inevitable impurities; wherein, W particles are dispersedly distributed in the Ti matrix, and there is a Ti / W gradient diffusion zone at the interface of the two, the distribution density of the W particles N w at least 1x10 5 3 ; the width of the Ti / W gradient diffusion zone L Ti / W is 3-20μm; the size of the W particles D w is within 10μm.​ 2. The titanium-based composite of claim 1, wherein: The content of W element in the Ti / W gradient diffusion zone increases from the Ti base to the W particle direction, and the concentration of W element gradually increases from 5% to 95%.

3. The titanium-based composite of claim 1, wherein: The hardness of the titanium-based composite material is at least 50HRC and / or the tensile elongation is at least 18%.

4. A method of producing a titanium-based composite material as claimed in any one of claims 1 to 3, characterized in that: The method comprises the following steps: The Ti powder and the W powder are mixed by ultrasonic resonance in proportion to obtain a mixture, and the mixture is hot-pressed and sintered in a vacuum atmosphere to obtain the titanium-based composite material. The temperature of the hot-pressing sintering is 1350-1450°C.

5. The method of producing a titanium-based composite material according to claim 4, characterized by: The resonance frequency of the ultrasonic resonance mixing is 55-65Hz; and / or, the mixing acceleration is 30-60g; and / or, the mixing time is 1-10min.

6. The method of making a titanium matrix composite of claim 4, wherein: The heating rate of the hot-pressing sintering is 50-100°C / min.

7. The method of making a titanium matrix composite of claim 4, wherein: The pressure of the hot-pressing sintering is 20-40MPa, and the holding time is 10-30min.

8. The method of making a titanium matrix composite of claim 4, wherein: The average particle size of the Ti powder is 50-180μm; and / or, the particle size of the W particle is 1-15μm. 9.A wear-resistant metal material comprising the titanium-based composite material according to any one of claims 1-3.

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