High-strength corrosion-resistant lightweight Al-Mg alloy material and preparation process thereof

Abstract

The invention provides a high-strength corrosion-resistant lightweight Al-Mg alloy material and a preparation process thereof, and the alloy material comprises the following components in percentage by weight: 0.2-0.5 wt% of magnesium, 0.4-0.8 wt% of a group VIII element, and the balance of aluminum. The rotor prepared by adopting the optimized centrifugal aluminum casting process has the advantages of light weight, excellent catalytic performance, good mechanical strength and excellent corrosion resistance, and can be applied to an application scene with the rotating speed higher than 20000 rpm.

Description

Technical Field

[0001] This application relates to the field of motor technology, specifically to a high-strength, corrosion-resistant, lightweight Al-Mg alloy material and its preparation process. Background Technology

[0002] Electric motors are core power components in modern industry, and their performance directly affects the efficiency, size, and weight of the entire system. As the core rotating component of the motor, the rotor's lightweight design is crucial for improving power density and reducing energy consumption. Currently, motor rotors are mainly made of laminated silicon steel sheets or cast iron and cast steel. However, silicon steel rotors suffer from high eddy current losses and low high-frequency efficiency; while cast iron and cast steel rotors have high density, which is not conducive to system lightweighting, and they also experience enormous centrifugal stress at high speeds, placing stringent requirements on material strength.

[0003] To address the aforementioned issues, aluminum alloys, due to their low density and high specific strength, have been introduced as rotor materials. Traditional cast aluminum rotors, such as Al-Si alloys, while achieving lightweight design, still suffer from insufficient corrosion resistance, mechanical strength, and especially high-temperature strength, making it difficult to meet the durability and reliability requirements of ultra-high speed conditions of 20,000 rpm and above. The first technical problem this application aims to solve is how to significantly improve the high-temperature performance and long-term durability of aluminum alloy rotors while maintaining lightweight design, strength, and corrosion resistance.

[0004] With the expansion of electric motor applications, new requirements have been placed on motor components beyond their power transmission function in special scenarios such as chemical engineering, environmental protection, aerospace, new energy vehicles, and high-end equipment. For example, there is a desire for rotor surfaces to possess catalytic functions, enabling simultaneous catalytic reactions of the working medium (such as fluids) during rotation, thereby achieving compactness and multifunctional integration of equipment. However, existing motor rotor technologies mostly focus on optimizing electromagnetic and mechanical properties, and there is still no effective solution that can endow the rotor with excellent surface catalytic activity while ensuring high-intensity, high-speed operation.

[0005] Achieving this "structure-function integration" goal faces significant challenges: if surface coating technology (such as spraying catalytic materials) is used, the coating is prone to peeling off from the substrate under long-term effects of high speed, high temperature, and centrifugal stress, resulting in poor reliability; if overall alloying is used to improve catalytic performance, it often damages the mechanical and processing properties of the substrate material. Therefore, the second technical problem this application aims to solve is how to maintain excellent mechanical properties within the rotor body while endowing it with robust, efficient, and substrate-integrated catalytic functionality. Summary of the Invention

[0006] To address the aforementioned technical problems, this application provides a high-strength, corrosion-resistant, lightweight Al-Mg alloy material and its preparation process, wherein the alloy material, by weight percentage, comprises magnesium: 0.2-0.5 wt%, Group VIII elements: 0.4-0.8 wt%, and the remainder being aluminum. Furthermore, Group VIII elements are one or more of iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, and iridium.

[0007] Furthermore, Group VIII elements include at least iron. Aluminum and iron form Al3Fe, which can improve the strength and hardness of materials. The challenge lies in how to utilize the strengthening effect of iron while minimizing its disadvantages of brittleness and reduced corrosion resistance. This application optimizes the scheme by precisely controlling the content and selecting a suitable casting process.

[0008] Furthermore, the alloy material, by weight percentage, includes magnesium: 0.4-0.5 wt%, iron: 0.4-0.6 wt%, and the remainder being aluminum.

[0009] Excessive iron content can lead to the formation of needle-like or skeletal Al3Fe phases, which are crack initiation sites. In this case, optimizing the magnesium content provides solid solution strengthening, which can balance the influence of iron and compensate for some of the strength loss due to the reduction of iron content. At the same time, some harmful impurities need to be controlled, such as silicon content less than 0.1 wt%, copper content less than 0.1 wt%, and zinc content less than 0.1 wt%.

[0010] Furthermore, in order to control harmful impurities, control can be achieved at the source by selecting high-purity raw materials. The aluminum material is high-purity aluminum with a purity of ≥99%, and the magnesium material is high-purity magnesium with a purity of ≥99%.

[0011] Furthermore, Group VIII elements include at least iron and cobalt. Cobalt forms the Al9Co2 phase with aluminum, exhibiting excellent thermal stability and significantly improving the high-temperature strength and creep resistance of the alloy.

[0012] Furthermore, Group VIII elements include at least iron and nickel. Nickel forms the Al3Ni phase with aluminum, which has good thermal stability and high hardness, providing a significant precipitation strengthening effect and improving the mechanical strength and high-temperature durability of materials.

[0013] Furthermore, Group VIII elements include at least iron, cobalt, and nickel. When iron, cobalt, and nickel coexist, they form a more complex composite phase, which mutually inhibits the coarsening and growth of the other phase, thus obtaining a nanoscale precipitate phase that is finer than that of a single element.

[0014] Preferably, the mass ratio of iron, cobalt, and nickel is 1.5:1:1.

[0015] Preferably, the raw materials used are aluminum-iron, aluminum-cobalt, or aluminum-nickel master alloys to ensure dissolution and homogenization.

[0016] When Group VIII elements contain other components besides iron, the heat treatment steps are as follows: First, hold at 480-500℃ for 4-6 hours to allow the multiple elements to undergo amplitude-modulated decomposition or form enrichment zones in the matrix, preparing for subsequent precipitation while avoiding overheating; then hold at 515-530℃ for 2-4 hours to allow more soluble strengthening elements to dissolve into the matrix; after rapid water quenching, hold at 220-240℃ for 8-12 hours to allow multiple strengthening phases to precipitate in a more stable manner, improving toughness, stress corrosion resistance, and dimensional stability.

[0017] This application provides a preparation process for a high-strength, corrosion-resistant, lightweight Al-Mg alloy material, comprising the following steps: (1) Melt aluminum and materials containing group VIII elements at 710-750℃, and press magnesium into the bottom of the melt. After dissolving, stir evenly, maintain the temperature at 710-730℃ for refining, and let stand to obtain the molten liquid; (2) Preheat the casting mold, then pour the molten liquid into the casting mold for centrifugal casting to obtain the casting; (3) The casting is heat-treated and then cooled to obtain the final product.

[0018] Further, in step (2), the casting mold is preheated to 150-200℃, the pouring temperature of the molten liquid is 680-710℃, the centrifugal speed is 110-130r / min, and the centrifugation time is 30-60s.

[0019] Furthermore, in step (2), the molten liquid is poured into the casting mold and immediately cooled at a cooling rate greater than 100 k / s.

[0020] Furthermore, in step (1), the refining step can use nitrogen or Ar gas for rotary degassing.

[0021] Furthermore, when the group VIII element is iron, the iron material is an Al-Fe master alloy, and step (3) uses T5 heat treatment, with a heat treatment temperature of 170-190℃ and a heat treatment time of 10-14 hours.

[0022] Furthermore, the alloy material obtained in step (3) is then subjected to surface treatment. The steps are as follows: the heat-treated alloy material is subjected to surface cleaning, alkaline activation, dealloying, secondary cleaning, and drying in sequence to obtain the surface-treated alloy material.

[0023] Preferably, the surface cleaning step is: grinding and polishing the alloy material (removing the oxide layer and processing marks to obtain a smooth surface, with a final surface finish Ra of less than 0.1 micrometers, reducing the unevenness of subsequent dealloying depth).

[0024] Preferably, after polishing, ultrasonic cleaning is performed. The alloy material sample is placed in a solvent and ultrasonically cleaned for 10-15 minutes to thoroughly remove surface oil, fingerprints and polishing residue. The solvent can be acetone or ethanol.

[0025] Preferably, the alkaline activation step is as follows: after ultrasonic cleaning, the sample is immersed in a 3-8 wt% sodium hydroxide aqueous solution at 60-70°C for 30-60 seconds, and then rinsed with deionized water to further remove organic contaminants and slightly etch the surface to increase the reactivity.

[0026] Preferably, in the dealloying step, an acidic solution (0.1-0.5M hydrochloric acid aqueous solution or 5-10wt% phosphoric acid aqueous solution) can be used to react at 20-40℃ for 30 seconds to 10 minutes; or an alkaline solution (1-5M sodium hydroxide aqueous solution) can be used to react at 40-60℃ for 1-5 minutes.

[0027] Preferably, stirring is performed during the dealloying step to ensure that the product leaves the reaction interface in a timely manner, allowing fresh solution to come into contact with the metal surface and ensuring uniform reaction.

[0028] Preferably, the secondary cleaning involves rinsing the dealloyed sample with flowing deionized water for at least 5 minutes, and then immersing the sample in anhydrous ethanol or isopropanol for 10 minutes to displace the residual moisture inside the porous structure, effectively preventing the nanoporous structure from collapsing due to capillary forces during subsequent drying.

[0029] Preferably, compressed air or nitrogen is used for drying, and high-temperature drying should be avoided as much as possible to prevent damage to the nanostructure.

[0030] The beneficial effects of this application are as follows: 1. Aluminum has a much lower density than steel. Rotors made from this alloy are more than 60% lighter than traditional steel rotors. This lightweight design reduces the rotor's moment of inertia, increases power density, reduces bearing load, and extends bearing life. Magnesium is incorporated into the aluminum lattice, causing lattice distortion and significantly improving the strength and hardness of the matrix. Too low a magnesium content results in insufficient strengthening, while too high a magnesium content severely impairs ductility and corrosion resistance, increasing the risk of stress corrosion cracking. Group VIII elements have extremely low solubility in aluminum and form fine, hard intermetallic compound particles, such as Al3Fe and Al3Ni. These hard particles effectively hinder dislocation movement, providing a strong strengthening effect and improving the material's stiffness, hardness, and creep resistance.

[0031] 2. The presence of iron in the system can refine the as-cast microstructure. Centrifugal casting of this alloy system can give full play to its advantages. Under the action of centrifugal force, the melt has a strong feeding ability, which can effectively eliminate casting defects such as shrinkage cavities and porosity, and obtain extremely dense castings.

[0032] 3. Group VIII elements are excellent catalysts for many important chemical reactions, such as hydrogenation and oxidation. The alloy composition ensures that these catalytic elements are uniformly distributed in the matrix in a combined state. Through post-processing, the aluminum on the surface is selectively dissolved, while the intermetallic compounds rich in Group VIII elements are retained. A high specific surface area nanoporous catalytic layer is constructed in situ on the surface of the alloy material, so that the rotor has additional surface catalytic activity while performing its core mechanical transmission function.

[0033] 4. The alloy composition of this application, combined with centrifugal casting process, can refine the microstructure, obtain fine grains, increase the nucleation rate, reduce columnar crystal regions, expand equiaxed crystal regions, thereby refining the overall as-cast microstructure, making the distribution of each phase more uniform in density, reducing specific gravity segregation, and refining the precipitated phases.

[0034] 5. Step (2) involves strong cooling of the molten liquid to create an extremely high temperature gradient and a high cooling rate, which can greatly refine the α-Al dendrites and cause the phase formed by group VIII elements and aluminum to change from coarse needle-like shapes to finer Chinese character-like or more diffuse shapes, thereby improving the toughness of the alloy.

[0035] 6. When the group VIII element is iron, combining it with T5 heat treatment avoids the redissolution of the Al3Fe phase or coarsening during slow cooling caused by solution treatment. This can stabilize the as-cast structure, eliminate internal stress, and improve dimensional stability. It can also make the Al3Mg2 phase transformation at the grain boundaries discontinuous and coarsen, thereby significantly improving the alloy's resistance to stress corrosion cracking and improving the alloy's durability. Detailed Implementation

[0036] Unless otherwise specified, the reagents and instruments used in the following examples are all commercially available products.

[0037] Example 1 The rotor alloy material, by weight percentage, includes magnesium: 0.5wt%, iron: 0.4wt%, and the remainder is aluminum.

[0038] The preparation process includes the following steps: (1) Melt aluminum and Al-Fe master alloy at 710°C, and press magnesium into the bottom of the melt to melt. After stirring evenly, the mixture is refined with argon gas by rotating the jet at 710℃ for 15 minutes and then allowed to stand to obtain the molten liquid. (2) Preheat the casting mold to 200°C, then pour the molten liquid at 710°C into the casting mold for centrifugal casting. The centrifugal speed is 130 r / min, and the casting is obtained in 30s. (3) The casting is subjected to T5 heat treatment at a temperature of 170°C for 14 hours and then cooled to obtain the final product.

[0039] Example 2 The rotor alloy material, by weight percentage, includes magnesium: 0.4 wt%, iron: 0.6 wt%, and the remainder is aluminum.

[0040] The preparation process includes the following steps: (1) Melt aluminum and Al-Fe master alloy at 750°C, and press magnesium into the bottom of the melt to melt. After stirring evenly, the mixture is refined with argon gas by rotating and blowing at 730℃ for 20 minutes, and then allowed to stand to obtain the molten liquid. (2) Preheat the casting mold to 150°C, then pour the molten liquid into the casting mold for centrifugal casting. Cool it while pouring, with a cooling rate of 300k / s, so that the casting temperature of the molten liquid reaches 680°C. The centrifugal speed is 110r / min, and the casting is obtained in 60s. (3) Perform T5 heat treatment on the casting. The heat treatment temperature is 190℃ and the heat treatment time is 10 hours. Then cool it to obtain the casting.

[0041] Example 3 The rotor alloy material, by weight percentage, includes magnesium: 0.2wt%, iron: 0.4wt%, cobalt: 0.4wt%, and the remainder is aluminum.

[0042] The preparation process includes the following steps: (1) Melt aluminum, Al-Fe master alloy, and Al-Co master alloy at 730℃, and press magnesium material. After the liquid is dissolved at the bottom of the melt, it is stirred evenly and refined with nitrogen gas by rotating the jet at 720℃ for 10 minutes. The liquid is then allowed to stand to obtain the molten liquid. (2) Preheat the casting mold to 180°C, then pour the molten liquid into the casting mold for centrifugal casting. Cool it while pouring, with a cooling rate of 200k / s, so that the casting temperature of the molten liquid reaches 690°C. The centrifugal speed is 120r / min, and the casting is obtained in 40s. (3) Heat treatment of the casting: first heat treatment at 520℃ for 8 hours, then quench in water at 30℃, and then heat treatment at 180℃ for 15 hours to obtain the casting.

[0043] Example 4 The rotor alloy material, by weight percentage, includes magnesium: 0.2wt%, iron: 0.3wt%, cobalt: 0.2wt%, nickel: 0.2wt%, and the remainder is aluminum.

[0044] The preparation process includes the following steps: (1) The aluminum material, Al-Fe master alloy, Al-Co master alloy, and Al-Ni master alloy were subjected to 720℃ Smelting: Magnesium material is pressed into the bottom of the melt and stirred evenly after melting. Argon gas is sprayed and maintained at 720℃ for 15 minutes for refining. The melt is then allowed to stand to obtain the molten liquid. (2) Preheat the casting mold to 160°C, then pour the molten liquid into the casting mold for centrifugal casting. Cool it while pouring, with a cooling rate of 500k / s, so that the casting temperature of the molten liquid reaches 700°C. The centrifugal speed is 120r / min, and the casting is obtained in 50s. (3) Heat treatment of the casting: first heat treatment at 480℃ for 6 hours, then heat treatment at 520℃ for 10 hours, then quench in water at 20℃, and then heat treatment at 240℃ for 8 hours to obtain the casting.

[0045] Example 5 The following steps are added after steps (1-3) in Example 2: (4) After grinding and polishing the rotor, the rotor sample is placed in acetone and ultrasonically cleaned for 10 minutes. (5) Immerse the rotor sample in a 60°C, 8wt% sodium hydroxide aqueous solution for 30 seconds, then rinse with deionized water. Rinse with water; (6) Immerse the rotor sample in 0.5M hydrochloric acid aqueous solution and react at 40°C for 1 minute. Then take it out and rinse it with deionized water. Then immerse the sample in anhydrous ethanol for 10 minutes and take it out to dry.

[0046] Example 6 The following steps are added after steps (1-3) in Example 3: (4) After grinding and polishing the rotor, the rotor sample is placed in ethanol for ultrasonic cleaning for 12 minutes. (5) Immerse the rotor sample in a 70°C, 3wt% sodium hydroxide aqueous solution for 60 seconds, then rinse with deionized water. Rinse with water; (6) Immerse the rotor sample in a 5wt% phosphoric acid aqueous solution at 20°C for 3 minutes, then rinse with deionized water, immerse the sample in anhydrous ethanol for 10 minutes, and then dry it.

[0047] Example 7 The following steps are added after steps (1-3) in Example 4: (4) After grinding and polishing the rotor, the rotor sample is placed in ethanol for ultrasonic cleaning for 15 minutes. (5) Immerse the rotor sample in a 65°C, 5wt% sodium hydroxide aqueous solution for 40 seconds, then rinse with deionized water. Rinse with water; (6) Immerse the rotor sample in 3M sodium hydroxide aqueous solution at 60°C for 2 minutes, then rinse with deionized water, immerse the sample in isopropanol for 10 minutes, and then dry it.

[0048] Comparative Example 1 The difference compared to Example 2 is that the magnesium content is 0.1 wt%.

[0049] Comparative Example 2 The difference compared to Example 2 is that the magnesium content is 0.6 wt%.

[0050] Comparative Example 3 The difference from Example 2 is that the iron content is 0.3 wt%.

[0051] Comparative Example 4 The difference from Example 2 is that the iron content is 1.0 wt%.

[0052] Characterization: The rotor samples obtained in the above embodiments and comparative examples were characterized as follows: 1. The end faces of the cast aluminum rotors prepared in the above embodiments and comparative examples were sampled for mechanical properties and electrical conductivity tests. The electrical conductivity test specimens met the requirements of GB / T12966-2008 and were tested for electrical conductivity. The mechanical property test specimens met the standard of ASTM E8 and were analyzed for tensile properties. The results are shown in Table 1.

[0053] 2. Corrosion Resistance: The rotor sample was cut into uniformly sized cubes. A 3.5wt% sodium chloride solution was used to simulate seawater or an industrial environment. The cubes were ultrasonically cleaned sequentially with acetone, ethanol, and deionized water, then dried with cold air and left to stand for 24 hours. The initial weight of the cubes was recorded as W0. The cubes were then suspended and immersed in the sodium chloride solution at room temperature for 7 days. After removal, the cubes were gently brushed with a soft brush under deionized water, dried with cold air, and weighed as W1. The corrosion rate was calculated using the formula: Corrosion rate (mm / year) = (k*W2) / (A*T*D), where k is a constant (8.76*10). 4 W2 = W0 - W1 (g), A is the initial surface area of ​​the test block (cm²) 2 T represents the soaking time (h), and D represents the material density (g / cm³). 3 The results are shown in Table 2. The lower the corrosion rate, the better the corrosion resistance.

[0054] 3. Catalytic performance: The rotor sample was cut into uniformly sized cubes. 100 mL of a 20 mg / L methylene blue aqueous solution was placed in a beaker, and the absorbance (A0) at 664 nm was measured using a UV-Vis spectrophotometer. 5 mL of a 0.1 M sodium borohydride aqueous solution was added to the beaker, and the rotor sample was immediately placed inside. The mixture was then magnetically stirred, and samples were taken every 5 minutes to measure the absorbance at 664 nm (A0). t The degradation process lasts for 30 minutes. The degradation rate (%) is calculated as follows: = 100% * (A0 - A)t The results are shown in Table 2. A faster degradation rate indicates better catalytic performance.

[0055] 4. High-speed operation durability: The rotor sample was mounted on the drive shaft of the high-speed test bench. It was initially started at 5000 rpm and allowed to run stably for 10 minutes before vibration monitoring. The speed was then increased by 2000 rpm each time, with stable operation at each speed for 10 minutes followed by vibration monitoring. Finally, the speed was increased to 30000 rpm and maintained for 10 minutes. If the rotor did not experience any damage or deformation, and the vibration amplitude remained within the safe threshold (the effective value of the vibration velocity measured at all speed points did not exceed 4.5 mm / s, and no significant resonance was observed), the output was "pass," indicating that the rotor possessed high-speed operation durability. The results are shown in Table 2.

[0056] Table 1

[0057] As shown in Table 1, compared with Example 2, the higher iron content and cooling rate in Example 2 increased the number of fine dispersed phases, and the higher heat treatment temperature resulted in more complete precipitation, which improved the rotor strength. The introduction of cobalt in Example 3 significantly improved the strength. The use of multi-component composite reinforcement in Example 4 also effectively improved the rotor strength. Data from Examples 5-7 show that, with proper control of the surface treatment process and parameters, the surface treatment has little impact on the mechanical properties of the rotor.

[0058] Comparative Example 1 shows that insufficient magnesium content weakens the solid solution strengthening effect and reduces strength. Comparative Example 2 shows that excessive magnesium content increases the amount of brittle phases at grain boundaries, significantly deteriorates plasticity, and limits strength. Comparative Example 3 shows that insufficient iron content results in fewer dispersed strengthening phases and lower strength. Comparative Example 4 shows that excessive iron content forms coarse and brittle phases, leading to poor toughness and reduced electrical conductivity.

[0059] Table 2

[0060] As shown in Table 2, the high magnesium content in Comparative Example 2 leads to a large amount of anodic phase, and the high iron content in Comparative Example 4 leads to a large amount of cathodic phase, both of which exacerbate electrochemical corrosion. The values ​​from Examples 5-7 show that surface dealloying in this application does not affect the corrosion resistance of the substrate.

[0061] Catalytic activity increases with the increase of the types and total amount of Group VIII elements. Example 4 shows the best bulk catalytic activity. Examples 5-7 show that after dealloying treatment, a nanoporous structure is formed on the surface, the specific surface area increases dramatically, the active sites are fully exposed, and the catalytic performance undergoes a qualitative leap, which is far higher than that of the bulk.

[0062] The rotor obtained in this application has achieved sufficiently high strength and good toughness through composition optimization and process control, and can withstand the huge centrifugal stress brought by more than 20,000 rpm. The strength of Comparative Examples 1 and 3 is too low, and the toughness of Comparative Examples 2 and 4 is too poor. They are very prone to cracking under high-speed impact loads or stress concentration.

[0063] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0064] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A high-strength, corrosion-resistant, lightweight Al-Mg alloy material, characterized in that, By weight percentage, it includes magnesium: 0.2-0.5 wt%, Group VIII elements: 0.4-0.8 wt%, and the remainder is aluminum.

2. The high-strength, corrosion-resistant, lightweight Al-Mg alloy material according to claim 1, characterized in that, Group VIII elements are one or more of the following: iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, and iridium.

3. The high-strength, corrosion-resistant, lightweight Al-Mg alloy material according to claim 1, characterized in that, Group VIII elements contain at least iron.

4. The high-strength, corrosion-resistant, lightweight Al-Mg alloy material according to claim 1, characterized in that, By weight percentage, it includes magnesium: 0.4-0.5 wt%, iron: 0.4-0.6 wt%, and the remainder is aluminum.

5. A preparation process for a high-strength, corrosion-resistant, lightweight Al-Mg alloy material, characterized in that, Includes the following steps: (1) Melt aluminum and materials containing group VIII elements at 710-750℃, and press magnesium into the bottom of the melt. After dissolving, stir evenly, maintain the temperature at 710-730℃ for refining, and let stand to obtain the molten liquid; (2) Preheat the casting mold, then pour the molten liquid into the casting mold for centrifugal casting to obtain the casting; (3) The casting is heat-treated and then cooled to obtain the final product.

6. The preparation process according to claim 5, characterized in that, The aluminum material is high-purity aluminum with a purity of ≥99%, and the magnesium material is high-purity magnesium with a purity of ≥99%.

7. The preparation process according to claim 5, characterized in that, Step (2) Preheat the casting mold to 150-200℃, pour the molten liquid at 680-710℃, centrifuge at 110-130r / min, and centrifuge for 30-60s.

8. The preparation process according to claim 5, characterized in that, Step (2) The molten liquid is poured into the casting mold and cooled immediately at a cooling rate greater than 100k / s.

9. The preparation process according to claim 5, characterized in that, When the element of group VIII is iron, the iron material is an Al-Fe master alloy. In step (3), T5 heat treatment is used. The heat treatment temperature is 170-190℃ and the heat treatment time is 10-14 hours.

10. The preparation process according to claim 5, characterized in that, The alloy material obtained in step (3) is then subjected to surface treatment. The steps are as follows: the heat-treated alloy material is subjected to surface cleaning, alkaline activation, dealloying, secondary cleaning, and drying in sequence to obtain the surface-treated alloy material.

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