Composite material with high density, high strength and excellent dynamic mechanical properties and preparation method thereof
By designing and preparing a high-density tungsten matrix and a high-entropy alloy composite phase, a composite material with high density, high strength and excellent dynamic mechanical properties was prepared, which solved the problem of the lack of self-sharpening properties in traditional tungsten alloys and is suitable for armor-piercing projectile core materials.
Patent Information
- Application Number
- CN202512020024.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-30
- Publication Date
- 2026-04-17
AI Technical Summary
Traditional tungsten alloy core materials lack self-sharpening properties during high-speed penetration, leading to projectile passivation. Existing new composite materials still suffer from insufficient plasticity and stringent manufacturing processes, making it difficult to achieve synergistic optimization of high density, high strength, and excellent dynamic mechanical properties.
Wx･(FeaNibCrcVdAle)y composite material was prepared by designing a high-density tungsten matrix and a high-entropy alloy composite phase through vacuum suspension melting, vacuum atomization and hot pressing sintering processes. The Ni/Al content was controlled to form a nano-L12 phase, which promoted the self-sharpening of the adiabatic shear band. The density was improved by combining ball milling and liquid phase sintering.
A composite material with high density (nearly 15 g/cm3), high strength (compressive strength above 2.3 GPa) and excellent dynamic mechanical properties was prepared, which solved the problem of projectile passivation and is suitable for armor-piercing projectile core materials.
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Figure CN121874583A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of composite material technology, specifically relating to a composite material with high density, high strength and excellent dynamic mechanical properties and its preparation method. Background Technology
[0002] Armor-piercing projectiles, as core anti-armor weapons in modern military equipment, directly determine their combat effectiveness through their penetration performance. The projectile core, as a key component of an armor-piercing projectile, must possess high density, high strength, and excellent dynamic mechanical properties. Traditional projectile core materials are mainly tungsten-based alloys (such as W-Ni-Fe systems), with a theoretical density reaching 17-18 g / cm³. 3 However, during high-speed penetration, traditional tungsten alloys suffer from insufficient sensitivity to thermal shear bands, leading to blunting of the projectile (the head of the armor-piercing projectile becomes mushroom-shaped), which significantly reduces the penetration depth and aspect ratio. This phenomenon is known in academia as the "lack of self-sharpening" bottleneck.
[0003] To overcome the limitation of insufficient self-sharpening properties, researchers have successively developed novel projectile core composite materials such as W / CuZn composites and W-based amorphous composite systems. However, these materials still suffer from problems such as insufficient plasticity, stringent preparation processes, and the formation of brittle intermetallic compounds, which restrict their engineering applications. Therefore, achieving synergistic optimization of self-sharpening and plasticity in the intrinsic properties of materials has become the core objective of armor-piercing projectile core material design.
[0004] The dynamic mechanical behavior of armor-piercing projectile core materials, especially their high strain rate response, is crucial. Recent studies have shown that high-entropy alloys exhibit significant advantages under dynamic loading. For example, Al... 0.1 CrFeCoNi alloys exhibit high strain rate sensitivity and a twin-dominated deformation mechanism during deformation; TiHfZrTaNb alloys form numerous localized shear bands under dynamic loading. These characteristics indicate that high-entropy alloys have the potential to be ideal composites for tungsten-based materials.
[0005] Therefore, we aim to propose a tungsten-based / high-entropy alloy composite material system. By combining high-density tungsten with high-dynamic-strength high-entropy alloy through composite design, and by adjusting the composition and optimizing the process, we can successfully prepare a composite projectile core material with high density, high strength and excellent dynamic mechanical properties, thus solving the problem of projectile passivation during penetration. Summary of the Invention
[0006] The technical problem to be solved by this invention is to address the shortcomings of the prior art by providing a composite material that combines high density, high strength, and excellent dynamic mechanical properties. The composite material of this invention uses high-density tungsten as the matrix component and a high-entropy alloy component with ultra-high dynamic strength and excellent strain localization capability as the composite phase, thus obtaining a composite material with high density, high strength, and excellent dynamic mechanical properties. As a projectile core material, it exhibits better self-sharpening properties during high-speed penetration, solving the problem of projectile passivation during the penetration process.
[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a composite material with high density, high strength and excellent dynamic mechanical properties, characterized in that the chemical formula of the composite material is W x ･(Fe a Ni b Cr c V d Al e ) y Where x corresponds to the mass percentage of W, satisfying 70 ≤ x ≤ 90, and y corresponds to Fe. a Ni b Cr c V d Al e The mass percentages satisfy 10≤y≤30, and the mass ratios of Fe, Ni, Cr, V, and Al are a: b: c: d: e = 15~30: 45~60: 10~18: 2~9: 5~6.
[0008] The aforementioned composite material possessing high density, high strength, and excellent dynamic mechanical properties is characterized in that the chemical formula of the composite material is W. 85 ･(Fe 22 Ni 58 Cr 12 V3Al5) 15 .
[0009] Meanwhile, this invention also discloses a method for preparing the composite material with high density, high strength and excellent dynamic mechanical properties as described above, characterized in that the method includes the following steps: Step 1: Select iron, nickel, chromium, vanadium and aluminum metal raw materials according to the nominal composition of the target product composite material, weigh them, then prepare alloy ingots using vacuum suspension melting process, and then prepare spherical alloy powder using vacuum atomization process. After sieving through a sieve, obtain high-entropy alloy spherical powder with suitable particle size. Step 2: Weigh the high-entropy alloy spherical powder and tungsten powder obtained in Step 1, put them into a ball mill jar containing tungsten carbide grinding balls and seal it. Then put the whole thing into a high-energy ball mill for ball milling and mixing to obtain a mixed powder. Step 3: Transfer the mixed powder obtained in Step 2 into a graphite mold, and place the whole mixture in a hot pressing sintering furnace for hot pressing sintering to obtain a tungsten-based / high-entropy alloy composite material.
[0010] The above-described preparation method is characterized in that, in step one, the vacuum suspension melting process controls the vacuum level within the melting chamber to be no higher than 1×10⁻⁶. -3 Pa, and component homogenization is achieved through five tumbling melting processes; the vacuum degree in the vacuum atomization process control system is not higher than 1×10⁻⁶. -3 The atomization temperature is 1400℃~1600℃, and a gradient power of 10kW~25W is used to maintain the melt temperature for 60min~100min. After sieving, high-entropy alloy spherical powder with a particle size of 25μm~53μm is obtained. This invention ensures the compositional uniformity of high-entropy alloy spherical powder by optimizing the melting parameters and atomization process.
[0011] The above preparation method is characterized in that, in step two, the high-entropy alloy spherical powder accounts for 10% to 30% by mass fraction, and the tungsten powder accounts for 70% to 90%.
[0012] The above-described preparation method is characterized in that, during the ball milling and mixing in step two, the total mass ratio of tungsten carbide grinding balls to powder is 2-5:1, and the diameters of the tungsten carbide grinding balls include 10 mm, 8 mm, and 5 mm, corresponding to a grinding ball mass ratio of 4:1:5. The ball milling speed is 250 r / min to 400 r / min, and the ball milling time is 3 h to 6 h. This invention, by coordinating the mass ratio of tungsten carbide grinding balls to powder, the grinding ball size, and the ball milling process parameters, ensures thorough mixing of high-entropy alloy spherical powder and tungsten powder.
[0013] The above preparation method is characterized in that the inner diameter of the graphite mold in step three is 50 mm, and the hot pressing sintering process is as follows: under vacuum conditions, the temperature is first raised to 1000°C at a heating rate of 10°C / min, and then raised to 1200°C~1400°C at a heating rate of 6°C / min and held for 120 min~240 min, with a sintering pressure of 40 MPa~50 MPa.
[0014] Compared with the prior art, the present invention has the following advantages: 1. This invention proposes for the first time the concept of designing a composite material using "high-density tungsten + high-entropy alloy". High-density tungsten is selected as the matrix component, and a high-entropy alloy FeNiCrVAl system with ultra-high dynamic strength and excellent strain localization capability is selected as the composite phase. The matrix tungsten has high density and can provide high kinetic energy during high-speed penetration. For the high-entropy alloy composite phase, by controlling the Ni mass content to 45%~60% and the Ni / Al content ratio to about 5, a large number of nano-L12 phases are induced to form, thereby inducing the adiabatic shear band to achieve a self-sharpening effect. Furthermore, by adjusting the composition ratio of tungsten and high-entropy alloy, a composite material with high density, high strength and excellent dynamic mechanical properties is obtained, which breaks through the bottleneck of the lack of self-sharpening in traditional tungsten alloys and realizes its self-sharpening characteristics as a core material during high-speed penetration, thus solving the problem of projectile passivation during penetration.
[0015] 2. This invention achieves a dense composite of high-entropy alloy spherical powder and tungsten powder by adjusting the ratio of high-entropy alloy spherical powder to tungsten powder, combined with ball milling and hot pressing sintering processes. The high-entropy alloy spherical powder and tungsten powder exhibit good wettability and solubility. The solid solubility of tungsten in the high-entropy alloy is 4 at%~5 at%, and the contact angle between the two is 34.5°~39.5° at 1100℃~1500℃. This good wettability promotes the densification process of tungsten and high-entropy alloy materials during liquid-phase sintering, increasing the density of the tungsten-based / high-entropy alloy composite material. Therefore, by controlling the temperature of the hot pressing sintering process, liquid-phase sintering is ensured, guaranteeing the high density of the composite material, thus preparing a tungsten-based / high-entropy alloy composite material with good performance, suitable as a core material for armor-piercing projectiles.
[0016] 3. The tungsten-based / high-entropy alloy composite material prepared by this invention has excellent performance indicators, with an actual measured density of nearly 15 g / cm³. 3 The density can reach over 98%, the compressive strength is close to 2.3 GPa, and the maximum compressive strain exceeds 20%, and it reaches 4770 s. -1 The dynamic yield strength at the strain rate is higher than 1.5 GPa.
[0017] 4. The preparation process of the present invention is simple to operate, the material composition is highly controllable, the molding effect is good, and the material density is high. It can further guide hot isostatic pressing technology, so as to facilitate its large-scale promotion and application in the future.
[0018] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0019] Figure 1 The image shows the XRD pattern of the tungsten-based / high-entropy alloy composite material prepared in Example 1 of this invention.
[0020] Figure 2 This is a SEM image of the tungsten-based / high-entropy alloy composite material prepared in Example 1 of the present invention.
[0021] Figure 3 The image shows the compressive stress-strain curve of the tungsten-based / high-entropy alloy composite material prepared in Example 1 of this invention.
[0022] Figure 4 The image shows the dynamic compressive true stress-strain curve of the tungsten-based / high-entropy alloy composite material prepared in Example 1 of this invention. Detailed Implementation
[0023] Example 1 The chemical formula of the composite material in this embodiment is W. 85 ･(Fe 22 Ni 58 Cr 12 V3Al5) 15 .
[0024] The method for preparing the composite material in this embodiment includes the following steps: Step 1: Based on the nominal composition of the target product composite material, according to Fe... 22 Ni 58 Cr 12 V3Al5 alloys were prepared by weighing and proportioning iron, nickel, chromium, vanadium, and aluminum metals, each with a purity greater than 99.7%, and then using a vacuum suspension melting process to produce 3kg alloy ingots. The vacuum level in the melting chamber was controlled at 1×10⁻⁶. -3 Pa, and the composition is homogenized through five tumbling melting processes, and then spherical alloy powder is prepared by vacuum atomization process, controlling the vacuum degree in the system to be 1×10 -3 Pa, and the atomization temperature is 1500℃, and the melt is held at 20kW gradient power for 60min. After sieving, high-entropy alloy spherical powder with a particle size of 25μm~53μm is obtained. Step 2: Weigh 30g of high-entropy alloy spherical powder with a particle size of 25μm~53μm obtained in Step 1 and 170g of spherical tungsten powder with a particle size of 1μm~3μm, and put them into a ball milling jar containing 600g of tungsten carbide grinding balls and seal it. Then, put the whole thing into a high-energy ball mill for ball milling and mixing. The diameter of the tungsten carbide grinding balls includes 10mm, 8mm and 5mm, and the corresponding mass ratio of grinding balls is 4:1:5. The ball milling speed is 360r / min and the ball milling time is 6h to obtain mixed powder. Step 3: Transfer the mixed powder obtained in Step 2 into a graphite mold with an inner diameter of 50 mm, and place the whole thing in a hot pressing sintering furnace for hot pressing sintering. Under vacuum conditions, first heat up to 1000℃ at a heating rate of 10℃ / min, then heat up to 1300℃ at a heating rate of 6℃ / min and hold for 180 min. After reaching the sintering temperature, control the sintering pressure to 45 MPa.
[0025] Figure 1 The image shows the XRD pattern of the tungsten-based / high-entropy alloy composite material prepared in this embodiment. Figure 1 As can be seen from the data, the phase composition of the tungsten-based / high-entropy alloy composite material after hot pressing and sintering is mainly FCC phase, and the diffraction peaks shift to the left due to the doping of high-entropy alloy powder.
[0026] Figure 2 The image shows a SEM image of the tungsten-based / high-entropy alloy composite material prepared in this embodiment. Figure 2 As can be seen, tungsten powder and high-entropy alloy powder can form the equiaxed crystal structure observed after sintering based on the principle of liquid phase sintering. The grain size is about 45 micrometers, and there are dispersed alumina second phase particles of 1μm~3μm.
[0027] Figure 3 The image shows the compressive stress-strain curve of the tungsten-based / high-entropy alloy composite material prepared in this embodiment. Figure 3 As can be seen, this tungsten-based / high-entropy alloy composite material has excellent work hardening ability and high compressive strength, with a compressive yield strength of 962 MPa and a compressive strength close to 2.3 GPa, and a compressive strain of over 20%.
[0028] Figure 4 This is a dynamic compressive true stress-strain curve of the tungsten-based / high-entropy alloy composite material prepared in this embodiment. Figure 4 As can be seen from this, the tungsten-based / high-entropy alloy composite material exhibits performance at 4770 s. -1 The compressive yield strength at the strain rate is higher than 1.5 GPa.
[0029] The measured density of the tungsten-based / high-entropy alloy composite material prepared in this embodiment was 14.8 g / cm³. 3 The density reached 97.8%.
[0030] Example 2 The chemical formula of the composite material in this embodiment is W. 90 ･(Fe 30 Ni 45 Cr 18 V2Al5) 10 .
[0031] The method for preparing the composite material in this embodiment includes the following steps: Step 1: Based on the nominal composition of the target product composite material, according to Fe... 30 Ni 45 Cr 18 V2Al5 alloys were prepared by weighing and proportioning iron, nickel, chromium, vanadium, and aluminum metals, each with a purity greater than 99.7%, and then using a vacuum suspension melting process to produce 3kg alloy ingots. The vacuum level in the melting chamber was controlled at 1×10⁻⁶. -3 Pa, and the composition is homogenized through five tumbling melting processes, and then spherical alloy powder is prepared by vacuum atomization process, controlling the vacuum degree in the system to be 1×10 -3 Pa, and the atomization temperature is 1600℃, and the melt is held at 10kW gradient power for 80min. After sieving, high-entropy alloy spherical powder with a particle size of 25μm~53μm is obtained. Step 2: Weigh 20g of high-entropy alloy spherical powder with a particle size of 25μm~53μm obtained in Step 1 and 180g of spherical tungsten powder with a particle size of 1μm~3μm, and put them into a ball milling jar containing 1000g of tungsten carbide grinding balls and seal it. Then, put the whole thing into a high-energy ball mill for ball milling and mixing. The diameter of the tungsten carbide grinding balls includes 10mm, 8mm and 5mm, and the corresponding mass ratio of grinding balls is 4:1:5. The ball milling speed is 400r / min and the ball milling time is 3h to obtain mixed powder. Step 3: Transfer the mixed powder obtained in Step 2 into a graphite mold with an inner diameter of 50 mm, and place the whole thing in a hot pressing sintering furnace for hot pressing sintering. Under vacuum conditions, first heat up to 1000℃ at a heating rate of 10℃ / min, then heat up to 1400℃ at a heating rate of 6℃ / min and hold for 240 min. After reaching the sintering temperature, control the sintering pressure to 50 MPa.
[0032] The measured density of the tungsten-based / high-entropy alloy composite material prepared in this embodiment was 16.5 g / cm³. 3 The density reaches 98.0%, the room temperature compressive yield strength is 1028 MPa, the compressive strength is 2.5 GPa, the compressive strain is 14%, and the compressive strain is close to 4500 s. -1 The compressive yield strength at the strain rate is 1.7 GPa.
[0033] Example 3 The chemical formula of the composite material in this embodiment is W. 70 ･(Fe 15 Ni 60 Cr 10 V9Al6) 30 .
[0034] The method for preparing the composite material in this embodiment includes the following steps: Step 1: Based on the nominal composition of the target product composite material, according to Fe... 15 Ni 60 Cr 10 V9Al6 alloys were prepared by weighing and proportioning iron, nickel, chromium, vanadium, and aluminum metals, each with a purity greater than 99.7%, and then using a vacuum suspension melting process to produce 3kg alloy ingots. The vacuum level in the melting chamber was controlled at 1×10⁻⁶. -3 Pa, and the composition is homogenized through five tumbling melting processes, and then spherical alloy powder is prepared by vacuum atomization process, controlling the vacuum degree in the system to be 1×10 -3 Pa, and the atomization temperature is 1400℃, and the melt is held at 25kW gradient power for 100min. After sieving, high-entropy alloy spherical powder with a particle size of 25μm~53μm is obtained. Step 2: Weigh 60g of high-entropy alloy spherical powder with a particle size of 25μm~53μm obtained in Step 1 and 140g of spherical tungsten powder with a particle size of 1μm~3μm, and put them into a ball milling jar containing 400g of tungsten carbide grinding balls and seal it. Then, put the whole thing into a high-energy ball mill for ball milling and mixing. The diameter of the tungsten carbide grinding balls includes 10mm, 8mm and 5mm, and the corresponding mass ratio of grinding balls is 4:1:5. The ball milling speed is 250r / min and the ball milling time is 5h to obtain mixed powder. Step 3: Transfer the mixed powder obtained in Step 2 into a graphite mold with an inner diameter of 50 mm, and place the whole thing in a hot pressing sintering furnace for hot pressing sintering. Under vacuum conditions, first heat up to 1000℃ at a heating rate of 10℃ / min, then heat up to 1200℃ at a heating rate of 6℃ / min and hold for 120 min. After reaching the sintering temperature, control the sintering pressure to 40 MPa.
[0035] The measured density of the tungsten-based / high-entropy alloy composite material prepared in this embodiment was 12.1 g / cm³. 3 The density reaches 97.1%, the room temperature compressive yield strength is 870 MPa, the compressive strength is 2.1 GPa, the compressive strain is 22%, and the compressive strain is close to 4800 s. -1 The compressive yield strength at the strain rate is 1.3 GPa.
[0036] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the inventive essence shall still fall within the protection scope of the present invention.
Claims
1. A composite material possessing high density, high strength, and excellent dynamic mechanical properties, characterized in that, The chemical formula of the composite material is W x ･(Fe a Ni b Cr c V d Al e ) y Where x corresponds to the mass percentage of W, satisfying 70 ≤ x ≤ 90, and y corresponds to Fe a Ni b Cr c V d Al e The mass percentages satisfy 10≤y≤30, and the mass ratios of Fe, Ni, Cr, V, and Al are a: b: c: d: e = 15~30: 45~60: 10~18: 2~9: 5~6.
2. The composite material with high density, high strength, and excellent dynamic mechanical properties according to claim 1, characterized in that, The chemical formula of the composite material is W 85 ･(Fe 22 Ni 58 Cr 12 V3Al5) 15 .
3. A method for preparing a composite material with high density, high strength, and excellent dynamic mechanical properties as described in claim 1 or 2, characterized in that, The method includes the following steps: Step 1: Select iron, nickel, chromium, vanadium and aluminum metal raw materials according to the nominal composition of the target product composite material, weigh them, then prepare alloy ingots using vacuum suspension melting process, and then prepare spherical alloy powder using vacuum atomization process. After sieving through a sieve, obtain high-entropy alloy spherical powder with suitable particle size. Step 2: Weigh the high-entropy alloy spherical powder and tungsten powder obtained in Step 1, put them into a ball mill jar containing tungsten carbide grinding balls and seal it. Then put the whole thing into a high-energy ball mill for ball milling and mixing to obtain a mixed powder. Step 3: Transfer the mixed powder obtained in Step 2 into a graphite mold, and place the whole mixture in a hot pressing sintering furnace for hot pressing sintering to obtain a tungsten-based / high-entropy alloy composite material.
4. The preparation method according to claim 3, characterized in that, The vacuum suspension melting process described in step one controls the vacuum level in the melting chamber to be no higher than 1×10⁻⁶. -3 Pa, and component homogenization is achieved through five tumbling melting processes; the vacuum degree in the vacuum atomization process control system is not higher than 1×10⁻⁶. -3 Pa, and the atomization temperature is 1400℃~1600℃, and the melt is held at a gradient power of 10kW~25W for 60min~100min. After sieving, high-entropy alloy spherical powder with a particle size of 25μm~53μm is obtained.
5. The preparation method according to claim 3, characterized in that, In step two, the high-entropy alloy spherical powder accounts for 10%~30% by mass fraction, and the tungsten powder accounts for 70%~90%.
6. The preparation method according to claim 3, characterized in that, In step two, during ball milling and mixing, the total mass ratio of tungsten carbide grinding balls to powder is 2-5:1, and the diameter of the tungsten carbide grinding balls includes 10mm, 8mm and 5mm, with a corresponding grinding ball mass ratio of 4:1:
5. The ball milling speed is 250r / min-400r / min, and the ball milling time is 3h-6h.
7. The preparation method according to claim 3, characterized in that, The inner diameter of the graphite mold mentioned in step three is 50mm. The hot pressing sintering process is as follows: under vacuum conditions, the temperature is first raised to 1000℃ at a heating rate of 10℃ / min, and then raised to 1200℃~1400℃ at a heating rate of 6℃ / min and held for 120min~240min. The sintering pressure is 40MPa~50MPa.