A particulate-reinforced aluminum matrix composite and a method for making the same

Abstract

The present application belongs to the technical field of aluminum-based material preparation, and particularly relates to a kind of particle reinforced aluminum matrix composite material and its preparation method.The preparation method comprises the following steps: providing aluminum melt with a temperature of 750-950 DEG C;adding additives to the aluminum melt, and the mass ratio of the additives to the aluminum melt is 0.1-30:99.9-70;wherein, the composition of the additives meets the following conditions:i, comprising at least one solid block that has not been powderized;and, ii, in at least one solid block, the liquidus temperature of at least one solid block is > 950 DEG C;continue smelting at 750-950 DEG C to obtain a particle reinforced aluminum matrix composite material.The present application solves the technical problems of high raw material cost and difficulty in effectively improving the volume fraction and distribution uniformity of the reinforcing phase caused by the need for powderization treatment of the reinforcing phase additives due to the melting point difference in the existing liquid phase method, has the advantages of short dissolution process and simple process, and has significant economic benefits.

Description

Technical Field

[0001] This invention belongs to the field of aluminum-based material preparation technology, specifically relating to a particle-reinforced aluminum-based composite material and its preparation method. Background Technology

[0002] Aluminum alloys, due to their excellent properties such as lightweight, corrosion resistance, and ease of processing, are indispensable key structural materials in aerospace, automotive manufacturing, and other fields. However, their inherent insufficient high-temperature strength and stability limit their application in more demanding working conditions. To overcome this bottleneck, introducing high-melting-point, high-performance ceramics, intermetallic compound particles (such as carbides, nitrides, and borides), and high-entropy alloys into the aluminum matrix to prepare aluminum-based composite materials has become an important technological development direction.

[0003] Currently, the mainstream technical routes for achieving this type of high-melting-point reinforcing phase composite with aluminum matrix and their inherent drawbacks are as follows: 1. Solid-state methods such as powder metallurgy: This method involves mixing, pressing, and sintering high-melting-point reinforcing phase powder with aluminum powder. Although it can suppress interfacial reactions, the process is lengthy and complex, involving high-energy ball milling and long-term sintering, resulting in high costs and the easy introduction of impurities and porosity, making it difficult to achieve low-cost, high-efficiency fabrication of large-size components.

[0004] 2. Selective laser melting and other liquid-solid composite methods: This method uses a high-energy beam to locally melt aluminum-based powder and combine it with reinforcement. Although it offers flexible forming capabilities, it generally suffers from problems such as high porosity of the formed parts, high equipment and raw material costs, and limited forming dimensions, making it difficult to meet the needs of large-scale industrial production.

[0005] 3. Liquid-phase methods such as smelting: This method shows significant potential in preparing high-density materials, adapting to continuous industrial production, and controlling overall costs. However, it faces a fundamental physical contradiction: aluminum has a relatively low melting point (approximately 660℃), while the ideal reinforcing phase typically has an extremely high melting point (e.g., TiC, TiB2, high-entropy alloys, etc., typically above 1500℃). This significant difference in melting points makes it extremely difficult for high-melting-point reinforcing phase materials to dissolve and disperse uniformly in molten aluminum.

[0006] To overcome the kinetic barrier caused by this melting point difference, existing liquid-phase methods almost invariably resort to a "powdering" strategy when introducing high-melting-point reinforcing phases. This involves first preparing the reinforcing material into micron- or even nano-sized powders to significantly increase its specific surface area and promote its dissolution in the aluminum melt. For example, several Chinese patent documents, including publication numbers CN114807712A and CN105478724A, explicitly state the need for pre-preparation or the direct use of high-entropy alloy powders as raw materials. Furthermore, for ceramic reinforcing phases such as carbides and borides, the direct use of commercial powders is an industry practice.

[0007] However, this "powdering" approach itself has brought new and more severe industry bottlenecks: Extremely high powder production cost: For many high-performance metal reinforcing phases (such as high-entropy alloys and refractory metals), the powder production process (using plasma rotating electrode atomization, mechanical alloying, etc.) is complex and energy-intensive, leading to a sharp increase in raw material costs; Poor processability and safety: High specific surface area active powders are easily oxidized and hygroscopic, and have stringent requirements for storage, transportation and handling, which increases process complexity and safety risks; The abundance and performance of the reinforcing phase are limited: Due to the solubility limit, floating / sinking and agglomeration tendency of powder in the melt, the volume fraction (abundance) and distribution uniformity of the reinforcing phase in the final composite material are difficult to control effectively, which restricts the ultimate improvement of material performance.

[0008] In summary, existing technologies are caught in a dilemma: if the traditional liquid phase method is used, the high cost of powder raw materials and the complex powder processing procedures must be endured; if powder production is to be avoided, there is a lack of direct methods to effectively process high-melting-point bulk alloys in molten aluminum.

[0009] Therefore, developing a novel technology that fundamentally avoids the powder-making process, directly utilizes high-melting-point blocky or coarse-particle raw materials, and achieves their efficient dissolution and composite in molten aluminum is of urgent practical significance and enormous industrial value for promoting the low-cost, large-scale industrial application of high-performance aluminum-based composite materials. This invention was completed against this backdrop. Summary of the Invention

[0010] This invention provides a particle-reinforced aluminum matrix composite material and its preparation method, which solves the technical problems of high powdering process cost, complex raw material processing and easy oxidation caused by the large melting point difference between the high melting point reinforcing phase and the aluminum melt in the existing liquid phase method, as well as the difficulty in effectively improving the volume fraction and distribution uniformity of the reinforcing phase in the final composite material. It has the advantages of short dissolution process and simple process, and significant economic benefits.

[0011] To address the aforementioned technical problems, this invention provides a novel method for preparing particle-reinforced aluminum matrix composites. It abandons the traditional "powdering" pretreatment step, directly adding at least one solid block without pre-crushing or atomization treatment and with a melting point higher than the aluminum melt temperature to molten aluminum at 750–950°C as a reinforcing phase material. The mixture is then smelted at 750–950°C to obtain a particle-reinforced aluminum matrix composite, successfully achieving the effective dissolution and composite of high-melting-point solid blocks in molten aluminum.

[0012] A method for preparing a particle-reinforced aluminum matrix composite material includes the following steps: (a) Provide molten aluminum at a temperature of 750–950°C; (b) Adding an additive for forming a reinforcing phase to the aluminum melt, wherein the mass ratio of the additive to the aluminum melt is 0.1–30:99.9–70; wherein the composition of the additive satisfies the following conditions: i. Contains at least one solid block that has not undergone powdering treatment; and ii. In at least one solid block, there exists a liquidus temperature > 950°C; (c) Continue melting at 750–950°C to dissolve and disperse the additive in the aluminum melt to obtain a particle-reinforced aluminum-based composite material.

[0013] In one specific embodiment of the present invention, the solid block is any one or a combination of any of the following: ingot, ingot, and mechanically divided block of ingot or ingot.

[0014] In one specific embodiment of the present invention, the volume of the solid block is > 0.1 cm³. 3 Preferably, the volume of the solid block is > 0.5 cm³. 3 .

[0015] In one specific embodiment of the present invention, the additive is a TC4 alloy, a TiVNb alloy, or a TiVNb-N alloy.

[0016] In one specific embodiment of the present invention, the TiVNb alloy or TiVNb-N alloy contains Ti, V and Nb elements in equal atomic ratios.

[0017] In one specific embodiment of the present invention, the TiVNb alloy block contains Ti, V and Nb in equal atomic ratios.

[0018] In one specific embodiment of the present invention, the dissolution is the complete dissolution of the additive within at least 45 minutes.

[0019] In one specific embodiment of the present invention, the dissolution refers to the complete dissolution of the additive within 45 to 180 minutes.

[0020] In one specific embodiment of the present invention, the purity of aluminum in the aluminum melt is ≥99.99%.

[0021] In one specific embodiment of the present invention, the mass ratio of the alloy or metallic solid to the aluminum melt is 3-20:97-80.

[0022] The particle-reinforced aluminum matrix composite material was prepared according to the above preparation method.

[0023] In this invention, dissolution specifically refers to the process by which a solid mass is gradually broken down into small particles in a high-temperature molten aluminum, and then mixed and homogenized in the aluminum through diffusion and convection.

[0024] The beneficial effects of this invention are: 1. The method of the present invention directly dissolves high-melting-point, blocky additives in molten aluminum at 750-950℃. By utilizing the aluminum-induced phase boundary number density, diffusion dissolution channels are increased, realizing the low-temperature rapid dissolution of blocky refractory high-entropy alloys, improving the efficiency of aluminum-based composite materials, reducing the manufacturing cost of aluminum-based composite materials, and simplifying the preparation process of aluminum-based composite materials. 2. The method of the present invention can be applied to the dissolution of refractory alloys, high-entropy alloys or refractory high-entropy alloys with a liquidus temperature difference of up to 1000°C from 950°C, and to prepare alloy particle-reinforced aluminum matrix composite materials. 3. The method of the present invention provides a new approach and solution for the composite preparation of aluminum-based composite materials with high content of reinforcing phase. Attached Figure Description

[0025] Figure 1 The image shows the SEM morphology and EDS elemental distribution of the aluminum-based composite material in Example 3 of this invention. Figure 2 These are the dissolution kinetics fitting curves for Examples 2-4 of the present invention; Detailed Implementation

[0026] A method for preparing a particle-reinforced aluminum matrix composite material includes the following steps: (a) Provide molten aluminum at a temperature of 750–950°C; (b) Adding an additive for forming a reinforcing phase to the aluminum melt, wherein the mass ratio of the additive to the aluminum melt is 0.1–30:99.9–70; wherein the composition of the additive satisfies the following conditions: i. Contains at least one solid block that has not undergone powdering treatment; and ii. In at least one solid block, there exists a liquidus temperature > 950°C; (c) Continue melting at 750–950°C to dissolve and disperse the additive in the aluminum melt to obtain a particle-reinforced aluminum-based composite material.

[0027] In some instances, the solid block is any one or a combination of any combination of ingots, blocks, and mechanically divided blocks of ingots or blocks.

[0028] It should be noted that an ingot is a disc-shaped, square-shaped, or other shaped casting obtained by cooling an alloy melt used to form a reinforcing phase. It is added to the aluminum melt as an additive to obtain an alloy particle-reinforced aluminum matrix composite material. An ingot is a disc-shaped, square-shaped, or other shaped casting obtained by separating and cooling an alloy melt used to form a reinforcing phase. A segmented block is a block with irregular or regular shapes that is separated from a larger ingot or casting part by sawing, wire cutting, machining, etc. It can also be formed by dividing a single ingot or ingot by sawing, wire cutting, machining, etc. However, the number of times a single ingot or ingot is divided should be controlled below 10 times, otherwise the manufacturing cost of the segmented block will increase.

[0029] In some instances, the volume of the solid mass is >0.1 cm³. 3 Preferably, the volume of the solid block is > 0.5 cm³. 3 .

[0030] In some instances, the additive is a TC4 alloy, a TiVNb alloy, or a TiVNb-N alloy.

[0031] In some instances, the TiVNb alloy or TiVNb-N alloy contains Ti, V, and Nb elements in equal atomic ratios.

[0032] In some instances, the dissolution refers to the complete dissolution of the additive within at least 45 minutes.

[0033] In some instances, the dissolution refers to the complete dissolution of the additive within 45 to 180 minutes.

[0034] It should be noted that if the volume of the solid block is large during the dissolution process, resulting in the solid block not being completely dissolved within 45-180 minutes, the undissolved solid can be separated from the melt by slag removal, but this will not meet the design requirements for the abundance of the target reinforcing phase.

[0035] In some instances, the purity of aluminum in the aluminum melt is ≥99.99%.

[0036] It should be noted that the aluminum melt can also be an aluminum alloy, but it can melt at 750–950°C and does not experience significant volatilization loss at 750–950°C.

[0037] In some instances, the mass ratio of the additive to the molten aluminum is 3–20:97–80; preferably, the mass ratio is 3:97.

[0038] The particle-reinforced aluminum matrix composite material prepared according to the aforementioned preparation method has reinforcing phase particles that precipitate during the cooling process after melting. Due to the high melting point of the reinforcing phase, it preferentially forms a solid before aluminum. During the cooling process, attention should be paid to the cooling rate; otherwise, the reinforcing phase particles may float or sink due to the influence of relative density, affecting the stability of the particle-reinforced aluminum matrix composite material's properties.

[0039] The method of the present invention will be described below with reference to specific embodiments.

[0040] Example 1

[0041] The method in this embodiment includes: 1. According to the atomic ratio of titanium, vanadium, and niobium, take elemental titanium, elemental vanadium, elemental niobium, and niobium nitride particles, and repeatedly melt them 4 times in a vacuum arc melting furnace to obtain a TiVNb-1.5N alloy ingot with uniform structure. 2. Take 140.27g of 99.99% pure aluminum into a graphite crucible and heat it to 850℃ to completely melt the aluminum into an aluminum melt; then add the above-mentioned TiVNb-1.5N alloy block with a mass of 4.33g, and continue to hold at 850℃ for 80min until it is completely dissolved. After cooling, a high-entropy alloy particle-reinforced aluminum matrix composite material is obtained.

[0042] Example 2

[0043] The method in this embodiment includes: 1. According to the atomic ratio of titanium, vanadium, and niobium, take elemental titanium, elemental vanadium, and elemental niobium, and repeatedly melt them 4 times in a vacuum electric arc melting furnace to obtain a TiVNb alloy block with uniform structure and equal atomic ratio. 2. Take 113.81g of 99.99% pure aluminum into a graphite crucible and heat it to 750℃ to completely melt the aluminum into an aluminum melt; then, add the above-mentioned TiVNb alloy block with a volume of 0.550cm³. 3 The mass was 3.52g. It was completely dissolved when it was kept at 750℃ for 180min. After cooling, a high-entropy alloy particle-reinforced aluminum matrix composite material was obtained.

[0044] Example 3

[0045] The method in this embodiment includes: 1. According to the atomic ratio of titanium, vanadium, and niobium, take elemental titanium, elemental vanadium, and elemental niobium, and repeatedly melt them 4 times in a vacuum electric arc melting furnace to obtain a TiVNb alloy block with uniform structure and equal atomic ratio. 2. Take 115.75g of 99.99% pure aluminum in a graphite crucible and heat it to 850℃ to completely melt the aluminum into an aluminum melt; then, add the above-mentioned TiVNb alloy block, the volume of a single TiVNb alloy block with atomic ratio of 0.559cm³.3 The sample weighed 3.58g and was completely dissolved after being kept at 850℃ for 80 minutes. After cooling, a high-entropy alloy particle-reinforced aluminum matrix composite material was obtained.

[0046] The morphology and elemental distribution of the aluminum-based composite material obtained in this embodiment were analyzed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS), as shown in the attached figure. Figure 1 As shown; where a is the SEM morphology of the aluminum-based composite material, and b is the surface distribution diagram of Al, Ti, V and Nb elements.

[0047] From the appendix Figure 1 As can be seen, the aluminum-based composite material in this embodiment is composed of 96.7 wt% Al, 1.2 wt% Ti, 1.1 wt% V and 1.1 wt% Nb. The TiVNb alloy has been completely dissolved in the aluminum matrix, and the TiVNb alloy is dispersed in particulate form. This indicates that the bulk high-entropy alloy can be dissolved in the aluminum matrix by the method of this invention and form a high content of reinforcing phase, which is beneficial to improving the mechanical properties and comprehensive properties of the aluminum-based material.

[0048] Example 4

[0049] The method in this embodiment includes: 1. According to the atomic ratio of titanium, vanadium, and niobium, take elemental titanium, elemental vanadium, and elemental niobium, and repeatedly melt them 4 times in a vacuum electric arc melting furnace to obtain a TiVNb alloy block with uniform structure and equal atomic ratio. 2. Take 114.46 g of 99.99% pure aluminum in a graphite crucible and heat it to 950℃ to completely melt the aluminum into an aluminum melt; then, add the above-mentioned TiVNb alloy block, the volume of a single TiVNb alloy block with atomic ratio of 0.552 cm³. 3 The sample weighed 3.54g and was completely dissolved after being kept at 950℃ for 45 minutes. After cooling, a high-entropy alloy particle-reinforced aluminum matrix composite material was obtained.

[0050] Example 5

[0051] The method in this embodiment includes: 1. According to the atomic ratio of titanium, vanadium, and niobium, elemental titanium, elemental vanadium, and elemental niobium are taken and repeatedly melted in a vacuum arc melting furnace four times. The mixture is then separated and cast to obtain four TiVNb alloy blocks with uniform structure and equal atomic ratio. 2. Take 102.80g of 99.99% pure aluminum into a graphite crucible and heat it to 850℃ to completely melt the aluminum into an aluminum melt; then, add the above-mentioned TiVNb alloy block, with a single equiatomic TiVNb alloy block having a volume of approximately 0.6cm³. 3The total weight was 15.36g. It was completely dissolved when kept at 850℃ for 45min. After cooling, a high-entropy alloy particle-reinforced aluminum matrix composite material was obtained.

[0052] Dissolution kinetics of TiVNb high-entropy alloys in aluminum melt at 750–950 °C in Examples 2-4: Based on the experimental schemes of Examples 2-4, the dissolution kinetics fitting curves of TiVNb alloy blocks with equal atomic ratios in aluminum melt were obtained using Origin software, providing a reference for subsequent process optimization.

[0053] The solution kinetics fitting curve obtained from Origin software is shown in the attached figure. Figure 2 As shown; the equation of the curve is: ; Where y represents the dissolution temperature in °C; and x represents the dissolution rate of the TiVNb alloy block in cm⁻¹. 3 / h; e represents the natural exponential function, approximately equal to 2.71828.

Claims

1. A method for preparing a particle-reinforced aluminum matrix composite material, characterized in that, Includes the following steps: (a) Provide molten aluminum at a temperature of 750–950°C; (b) Adding an additive for forming a reinforcing phase to the aluminum melt, wherein the mass ratio of the additive to the aluminum melt is 0.1–30:99.9–70; wherein the composition of the additive satisfies the following conditions: i. Contains at least one solid block that has not undergone powdering treatment; and ii. In at least one solid block, there exists a liquidus temperature > 950°C; (c) Continue melting at 750–950°C to dissolve and disperse the additive in the aluminum melt to obtain a particle-reinforced aluminum-based composite material.

2. The preparation method according to claim 1, characterized in that: The solid block is any one or any combination of several of the following: ingot, block, and mechanically divided block of ingot or block.

3. The preparation method according to claim 1, characterized in that: The volume of the solid block is > 0.1 cm³. 3 Preferably, the volume of the solid block is > 0.5 cm³. 3 .

4. The preparation method according to claim 3, characterized in that: The additive is TC4 alloy, TiVNb alloy, or TiVNb-N alloy.

5. The preparation method according to claim 4, characterized in that: The TiVNb alloy or TiVNb-N alloy contains Ti, V, and Nb elements in equal atomic ratios.

6. The preparation method according to claim 1, characterized in that: The dissolution refers to the complete dissolution of the additive within at least 45 minutes.

7. The preparation method according to claim 6, characterized in that: The dissolution refers to the complete dissolution of the additive within 45 to 180 minutes.

8. The preparation method according to claim 1, characterized in that: The purity of aluminum in the aluminum melt is ≥99.99%.

9. The preparation method according to claim 1, characterized in that: The mass ratio of the additive to the molten aluminum is 3-20:97-80.

10. The particle-reinforced aluminum matrix composite material prepared by the preparation method according to any one of claims 1-9.

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