A method for preparing a high-performance aluminum matrix composite forging

Abstract

The application provides a preparation method of a high-performance aluminum matrix composite forging, comprising the following steps: high-energy ball milling of aluminum powder and ceramic powder to obtain mixed powder; isostatic pressing of the mixed powder to obtain a preform; preheating of the preform and then forging sintering to obtain the high-performance aluminum matrix composite forging. The application completes the rapid sintering of the ultrafine aluminum matrix composite powder under pressure, the deformation, flow and mold filling process of the metal fluid through sintering forging technology, synchronously realizes the powder sintering and the forging deformation of the sintered body, and finally obtains the aluminum matrix composite forging with high compactness, high mechanical property and high-temperature stable structure.

Description

Technical Field

[0001] This invention belongs to the field of aluminum-based composite materials technology, and particularly relates to a method for preparing high-performance aluminum-based composite material forgings. Background Technology

[0002] With the rapid development of the transportation industry, the lightweight substitution of steel with aluminum-based materials in key components can significantly improve equipment performance and save energy and costs. Particularly in the lightweighting process of passenger cars and trucks, the use of aluminum alloys and aluminum-based composite materials is showing a significant upward trend in parts such as chassis components, wheel hubs, pistons, and brake discs. Ceramic particle-reinforced aluminum-based composite materials possess excellent properties such as high strength, low density, good thermal conductivity, wear resistance, and high temperature resistance, and have broad application prospects in the field of lightweight vehicle structural components.

[0003] Currently, the casting method commonly used to prepare particle-reinforced aluminum matrix composites cannot solve the problems of poor dispersion of ceramic particles in the matrix and low content of reinforcement, while traditional powder metallurgy methods are difficult to obtain products with large size, complex structure, and uniform properties. Therefore, how to obtain aluminum matrix composites with better performance has become a research hotspot in this field. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a method for preparing high-performance aluminum-based composite material forgings. The method provided by this invention has a simple process and the aluminum-based composite material forgings obtained have good performance.

[0005] This invention provides a method for preparing high-performance aluminum-based composite forgings, comprising:

[0006] Aluminum powder and ceramic powder are ball-milled at high energy to obtain a mixed powder;

[0007] The mixed powder is subjected to isostatic pressing to obtain a preform;

[0008] The preform is preheated and then forged and sintered to obtain a high-strength aluminum-based composite material forging.

[0009] In embodiments of the present invention, the ceramic powder may be selected from one or more of SiC, TiC and Al2O3, such as SiC, TiC and Al2O3; the mass ratio of SiC, TiC and Al2O3 may be selected from 1:(0.8-1.2):(0.8-1.2), such as 1:1:1.

[0010] In embodiments of the present invention, the mass content of ceramic powder in the mixed powder can be selected from 15% to 45%, such as 20%, 25%, 30%, 35%, and 40%; the mass content of aluminum powder in the mixed powder can be selected from 55% to 85%, such as 60%, 65%, 70%, 75%, and 80%.

[0011] In embodiments of the present invention, the composition of the mixed powder may be:

[0012] 0–45 wt% SiC;

[0013] 0–45 wt% TiC;

[0014] 0–45 wt% Al2O3;

[0015] The balance is Al.

[0016] In embodiments of the present invention, the mass content of SiC can be selected from 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, and 40%; the mass content of TiC can be selected from 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, and 40%; and the mass content of Al2O3 can be selected from 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, and 40%.

[0017] In embodiments of the present invention, high-energy ball milling can be selected from two-stage ball milling, and the method of high-energy ball milling can include:

[0018] Aluminum powder is subjected to a single-stage ball milling process to obtain ultrafine aluminum powder;

[0019] The ultrafine aluminum powder and ceramic powder were mixed and then subjected to two-stage ball milling to obtain a mixed powder.

[0020] In embodiments of the present invention, the ball-to-material ratio in the primary ball milling process can be selected from (10-14):1, such as 11:1, 12:1, 13:1; the primary ball milling time can be selected from 30-50h, such as 35h, 40h, 45h; an anti-forging agent can be added during the primary ball milling process, which may include ethanol and acetone; the volume ratio of ethanol to acetone can be selected from (16-20):(1-5), such as (17-19):(2-4), 18:3; the ratio of aluminum powder to ethanol can be selected from 1000g:(16-20)mL, such as 1000g:17mL, 1000g:18mL, 1000g:19mL.

[0021] In embodiments of the present invention, the ball-to-material ratio in the secondary ball milling process can be selected from (8-12):1, such as 9:1, 10:1, or 11:1; the secondary ball milling time can be selected from 1-5 hours, such as 2 hours, 3 hours, or 4 hours; an anti-forging agent can be added during the secondary ball milling process, and the anti-forging agent can be selected from ethanol; the ratio of mixed powder to ethanol can be selected from (1200-1800) g: (1-5) mL, such as (1300-1700) g: (2-4) mL, or (1400-1600) g: 3 mL.

[0022] In embodiments of the present invention, the amplitude of the steel ball during high-energy ball milling (such as primary ball milling and secondary ball milling) can be selected from 4 to 6 mm, such as 5 mm; the vibration frequency can be selected from 1450 to 1490 cpm, such as 1460 cpm, 1470 cpm, 1480 cpm; an anti-forging agent can be added during high-energy ball milling, which includes ethanol and / or acetone.

[0023] In embodiments of the present invention, the average grain size of the aluminum powder in the mixed powder can be selected from 170 to 420 nm, such as 200 nm, 250 nm, 300 nm, 350 nm, and 400 nm; the average particle size of the ceramic powder in the mixed powder can be selected from 10 to 100 μm, such as 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, and 90 μm.

[0024] In embodiments of the present invention, isostatic pressing can be selected from cold isostatic pressing, the pressure of isostatic pressing can be selected from 220 to 320 MPa, such as 240 MPa, 270 MPa, or 300 MPa; the isostatic pressing time can be selected from 2 to 4 min, such as 2.5 min, 3 min, or 3.5 min; and the density of the preform can be selected from 75 to 85%, such as 78%, 80%, or 82%.

[0025] In embodiments of the present invention, the preheating temperature can be selected from 580 to 640°C, such as 590°C, 600°C, 610°C, 620°C, and 630°C; the preheating time can be selected from 3 to 7 minutes, such as 4 minutes, 5 minutes, and 6 minutes.

[0026] In embodiments of the present invention, calcination and sintering can be carried out in a forging die; the temperature of the forging die during the forging and sintering process can be selected from 340 to 380°C, such as 350°C, 360°C, or 370°C.

[0027] In embodiments of the present invention, the forging and sintering method may include:

[0028] First, pressurize for one stage, then pressurize for the second stage.

[0029] In the embodiments of the present invention, the temperature during the forging and sintering process can be the same as the temperature of the forging mold described in the above technical solution, which will not be repeated here; the first stage of pressure is the initial forging, and the second stage of pressure is the final forging.

[0030] In embodiments of the present invention, the speed of pressurization can be selected from 0.5 to 0.6 mm / s, such as 0.55 mm / s; the pressure of pressurization can be selected from 100 to 200T, such as 120T, 140T, 150T, 160T, 180T; and the forging ratio of pressurization can be selected from (1.8 to 2.2):1, such as 2:1.

[0031] In an embodiment of the present invention, when the height of the forging obtained by the first stage of pressurization is 45-56% of the height of the preform, a second stage of pressurization is performed, such as 48%, 50%, 52%, and 54%.

[0032] In embodiments of the present invention, the speed of the two-stage pressurization can be selected from 10 to 12 mm / s, such as 11 mm / s; the pressure of the two-stage pressurization can be selected from 400 to 750T, such as 450T, 500T, 550T, 600T, 650T, 700T; and the forging ratio of the two-stage pressurization can be selected from (1.1 to 1.5):1, such as 1.2:1, 1.3:1, 1.4:1.

[0033] In embodiments of the present invention, forging sintering is a process technology that combines powder metallurgy and precision forging. Using metal and its composite material powders as raw materials, it can obtain forging products with uniform internal structure, high dimensional accuracy, and excellent mechanical properties. The forging sintering process combines the advantages of powder metallurgy and forging, and can produce forgings with a density close to the theoretical density, overcoming the disadvantage of low density of ordinary powder metallurgy parts. This results in powder forgings having mechanical properties exceeding those of ordinary forgings, while maintaining the advantages of ordinary powder metallurgy, which involves less and no cutting processes.

[0034] Because the powder metallurgy process of aluminum matrix composites involves severe oxidation, leading to brittleness, research on forging to obtain forgings based on powder metallurgy aluminum matrix composites is relatively limited. Furthermore, the "sintered body + forging" powder forging process involves numerous steps and a complex flow, such as... Figure 1 As shown. Therefore, this invention further optimizes the powder forging process, simplifies the process flow, and improves material properties, which is of great significance and importance for the large-scale application and industrialization of aluminum-based composite materials.

[0035] This invention employs powder forging technology to prepare high-performance aluminum-based composite material forgings. First, clean and highly active ultrafine aluminum-based composite material powder is prepared. Then, rapid sintering and forging deformation of the ultrafine aluminum-based composite material powder are achieved through powder forging technology, such as... Figure 2As shown. This invention employs high-energy ball milling technology to prepare ultrafine, clean, and highly active aluminum-based composite powder by controlling the ball milling process and using process control agents. Due to the action of the process control agents, the activity and cleanliness of the ultrafine aluminum-based composite powder surface are temporarily protected, solving the technical challenges of preparing, storing, and transporting ultrafine, highly active aluminum-based composite powder in an air environment, thus providing the foundation for subsequent rapid sintering and forging deformation. This invention achieves rapid sintering of ultrafine aluminum-based composite powder under pressure and the deformation, flow, and molding process of the metal fluid through forging sintering technology, simultaneously realizing powder sintering and forging deformation of the sintered body. Ultimately, it obtains aluminum-based composite forgings with high density and high mechanical properties, whereas conventional powder forging products must undergo separate, long-term sintering before subsequent forging. Furthermore, the matrix of the aluminum-based composite material prepared by this invention is nanocrystalline pure aluminum, which does not undergo phase transformation under high-temperature service conditions, ensuring matrix strength while avoiding performance degradation caused by phase transformation, exhibiting excellent high-temperature resistance. Attached Figure Description

[0036] Figure 1 This is a process flow diagram for powder forging in the existing technology;

[0037] Figure 2 This is a process flow diagram of sintering and forging in an embodiment of the present invention;

[0038] Figure 3 This is a SEM image of the fracture surface of the forging product prepared in Example 1 of the present invention after a tensile test. Detailed Implementation

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Example 1

[0041] 1000g of aluminum powder was placed in a ball mill jar for primary ball milling at a ball-to-powder ratio of 12:1. 18ml of ethanol and 3ml of acetone were added as anti-forging agents. The steel ball amplitude was 5mm and the vibration frequency was 1470cpm. After mechanical milling for 40 hours, highly active aluminum powder was obtained. The obtained highly active aluminum powder was mixed with 400g of SiC ceramic powder and then subjected to secondary ball milling at a ball-to-powder ratio of 10:1. 3ml of ethanol was added as an anti-forging agent. The steel ball amplitude was 5mm and the vibration frequency was 1470cpm. After mechanical milling for 3 hours, highly active composite material powder was obtained. The average grain size of the aluminum powder in the composite material powder was 350 nm, and the average particle size of the ceramic powder was 55 μm.

[0042] The highly active composite powder was subjected to cold isostatic pressing at a pressure of 270 MPa and a holding time of 3 minutes to obtain a preform.

[0043] The preform is placed in a high-temperature furnace for preheating at a temperature of 610℃ for 5 minutes.

[0044] The billet is removed and placed in a forging mold at 360°C. The preform is then subjected to powder forging and sintering, followed by a first-stage and a second-stage pressing process. The first-stage pressing speed is 0.55 mm / s, the pressure is 150 tons, and the forging ratio is 2:1. When the height of the forging obtained from the first-stage pressing reaches 50% of the height of the preform, the second-stage pressing is performed. The second-stage pressing speed is 11 mm / s, the pressure is 600 tons, and the forging ratio is 1.2:1, thus obtaining the forging product.

[0045] The product prepared in Example 1 of this invention was sampled, polished, and subjected to performance tests. The tensile test was conducted according to GB / T228.1-2010 "Metallic materials - Tensile testing - Part 1: Test method at room temperature", and the hardness test was conducted according to GB231-84 "Metallic materials - Brinell hardness test method". The performance of the forgings obtained is shown in Table 1.

[0046] The microstructure of the forgings prepared in Example 1 was analyzed. Figure 3 The image shows the SEM image of the fracture surface of the aluminum matrix composite forging after tensile testing. It can be seen that the composite material has a dense structure, with the reinforcement encapsulated by the matrix structure and evenly distributed in the matrix. After the specimen fails and fractures, the reinforcement breaks, but the composite interface is well bonded, and the reinforcement plays a good role in load transfer and strengthening.

[0047] Example 2

[0048] 1000g of aluminum powder was placed in a ball mill jar for primary ball milling at a ball-to-powder ratio of 10:1. 16ml of ethanol and 1ml of acetone were added as anti-forging agents. The steel ball amplitude was 4mm and the vibration frequency was 1450cpm. After mechanical milling for 30 hours, highly active aluminum powder was obtained. The obtained highly active aluminum powder was then mixed with 800g of TiC ceramic powder and subjected to secondary ball milling at a ball-to-powder ratio of 8:1. 1ml of ethanol was added as an anti-forging agent. The steel ball amplitude was 4mm and the vibration frequency was 1450cpm. After mechanical milling for 1 hour, highly active composite material powder was obtained. The average grain size of the aluminum powder in the composite powder was 420 nm, and the particle size of the ceramic powder was 100 μm.

[0049] The highly active composite powder was subjected to cold isostatic pressing at a pressure of 220 MPa for 2 minutes to obtain a preform.

[0050] The preform is placed in a high-temperature furnace for preheating at a temperature of 580°C for 3 minutes.

[0051] The billet is removed and placed in a forging mold at 340℃. The preform is subjected to powder forging and sintering, followed by a first stage of pressurization and a second stage of pressurization. The first stage of pressurization has a speed of 0.5 mm / s and a pressure of 100 tons, with a forging ratio of 1.8:1. When the height of the forging reaches 56% of the height of the preform, the second stage of pressurization is carried out at a speed of 10 mm / s and a pressure of 400 tons, with a forging ratio of 1.1:1. The forged product is then obtained.

[0052] The performance of the forging products prepared in Example 2 was tested according to the method in Example 1, and the test results are shown in Table 1.

[0053] Example 3

[0054] 1000g of aluminum powder was placed in a ball mill jar for primary ball milling at a ball-to-powder ratio of 14:1. 20ml of ethanol and 5ml of acetone were added as anti-forging agents. The steel ball amplitude was 6mm and the vibration frequency was 1490cpm. After mechanical grinding for 50 hours, highly active aluminum powder was obtained. The highly active aluminum powder obtained above was mixed with 200g of Al2O3 ceramic powder and then subjected to secondary ball milling at a ball-to-powder ratio of 12:1. After grinding for 5 hours, highly active composite material powder was obtained. The average grain size of aluminum powder in the composite powder was 170 nm, and the average particle size of ceramic powder was 10 μm.

[0055] The highly active powder was subjected to cold isostatic pressing at a pressure of 320 MPa for 4 minutes to obtain a preform.

[0056] The preform is placed in a high-temperature furnace for preheating at a temperature of 640°C for 7 minutes.

[0057] The billet is removed and placed in a forging mold at 380℃. The preform is then subjected to powder forging and sintering, followed by a first-stage and a second-stage pressurization process. The first-stage pressurization has a pressurization rate of 0.6 mm / s, a pressure of 200 tons, and a forging ratio of 2.2:1. When the height of the forging reaches 45% of the preform height, the second-stage pressurization is performed. The second-stage pressurization has a pressurization rate of 12 mm / s, a pressure of 750 tons, and a forging ratio of 1.5:1, thus obtaining the forging product.

[0058] The performance of the forging products prepared in Example 3 was tested according to the method in Example 1, and the test results are shown in Table 1.

[0059] Example 4

[0060] 1000g of aluminum powder was placed in a ball mill jar for primary ball milling at a ball-to-powder ratio of 13:1. 19ml of ethanol and 4ml of acetone were added as anti-forging agents. The steel ball amplitude was 5mm and the vibration frequency was 1470cpm. After mechanical milling for 45 hours, highly active aluminum powder was obtained. The obtained highly active aluminum powder was then mixed with 300g of Al2O3 ceramic powder and subjected to secondary ball milling at a ball-to-powder ratio of 11:1. 4ml of ethanol was added as an anti-forging agent. The steel ball amplitude was 5mm and the vibration frequency was 1470cpm. After mechanical milling for 4 hours, highly active composite material powder was obtained. The average grain size of the aluminum powder in the composite powder was 300 nm, and the average particle size of the ceramic phase was 45 μm.

[0061] The highly active powder was subjected to cold isostatic pressing at a pressure of 300 MPa for 3.5 minutes to obtain a preform.

[0062] The preform is placed in a high-temperature furnace for preheating at a temperature of 620°C for 6 minutes.

[0063] The billet is removed and placed in a forging mold at 370℃. The preform is then subjected to powder forging and sintering, followed by a first-stage and a second-stage pressurization process. The first-stage pressurization speed is 0.55 mm / s, the pressure is 180 tons, and the forging ratio is 2:1. When the height of the forging reaches 50% of the preform height during the first-stage pressurization, the second-stage pressurization is performed at a speed of 11 mm / s, the pressure is 700 tons, and the forging ratio is 1.3:1. The resulting forging product is then obtained.

[0064] The performance of the forging products prepared in Example 4 was tested according to the method in Example 1, and the test results are shown in Table 1.

[0065] Example 5

[0066] 1000g of aluminum powder was placed in a ball mill jar for primary ball milling at a ball-to-powder ratio of 11:1. 17ml of ethanol and 2ml of acetone were added as anti-forging agents. The steel ball amplitude was 5mm, the vibration frequency was 1470cpm, and mechanical milling was carried out for 38 hours to obtain highly active aluminum powder. The obtained highly active aluminum powder was then mixed with 300g of SiC and 200g of Al2O3 ceramic powder and subjected to secondary ball milling. 2ml of ethanol was added as an anti-forging agent. The steel ball amplitude was 5mm, the vibration frequency was 1470cpm, the ball-to-powder ratio was 9:1, and mechanical milling was carried out for 2 hours to obtain highly active composite material powder. The average grain size of the aluminum powder in the composite powder was 400 nm, and the particle size of the ceramic powder was 65 μm.

[0067] The highly active powder was subjected to cold isostatic pressing at a pressure of 240 MPa for 4 minutes to obtain a preform.

[0068] The preform is placed in a high-temperature furnace for preheating at a temperature of 600°C for 4 minutes.

[0069] The billet is removed and placed in a forging mold at 350℃. The preform is then subjected to powder forging and sintering, followed by a first-stage and a second-stage pressurization process. The first-stage pressurization speed is 0.55 mm / s, the pressure is 120 tons, and the forging ratio is 2:1. When the height of the forging reaches 50% of the preform height during the first-stage pressurization, the second-stage pressurization is performed at a speed of 11 mm / s, the pressure is 500 tons, and the forging ratio is 1.2:1. The resulting forging product is then obtained.

[0070] The performance of the forging products prepared in Example 5 was tested according to the method in Example 1, and the test results are shown in Table 1.

[0071] Example 6

[0072] 1000g of aluminum powder and 400g of SiC ceramic powder were placed in a ball mill jar and ball-milled at a ratio of 12:1. 20ml of ethanol and 3ml of acetone were added as anti-forging agents. The amplitude of the steel ball was 5mm and the vibration frequency was 1470cpm. After mechanical grinding for 43 hours, a highly active composite material powder was obtained.

[0073] The highly active powder was subjected to cold isostatic pressing at a pressure of 270 MPa for 3 minutes to obtain a preform.

[0074] The preform is placed in a high-temperature furnace for preheating at a temperature of 610℃ for 5 minutes.

[0075] The billet is removed and placed in a forging mold at 360°C. The preform is then subjected to powder forging and sintering, followed by a first-stage and a second-stage pressurization process. The first-stage pressurization speed is 0.55 mm / s, the pressure is 150 tons, and the forging ratio is 2:1. When the height of the forging reaches 50% of the preform height during the first-stage pressurization, the second-stage pressurization is performed at a speed of 11 mm / s, the pressure is 600 tons, and the forging ratio is 1.2:1, thus obtaining the forged product.

[0076] The performance of the forging products prepared in Example 6 was tested according to the method in Example 1, and the test results are shown in Table 1.

[0077] Example 7

[0078] 1000g of aluminum powder was placed in a ball mill jar for primary ball milling at a ball-to-powder ratio of 13:1. 19ml of ethanol and 4ml of acetone were added as anti-forging agents. The steel ball amplitude was 5mm and the vibration frequency was 1470cpm. After mechanical milling for 45 hours, highly active aluminum powder was obtained. The obtained highly active aluminum powder was mixed with 200g of Al2O3 ceramic powder and then subjected to secondary ball milling at a ball-to-powder ratio of 11:1. 4ml of ethanol was added as anti-forging agent. The steel ball amplitude was 5mm and the vibration frequency was 1470cpm. After mechanical milling for 5 hours, highly active composite material powder was obtained.

[0079] The highly active powder was subjected to cold isostatic pressing at a pressure of 300 MPa for 3.5 minutes to obtain a preform.

[0080] The preform is placed in a high-temperature furnace for preheating at a temperature of 620°C for 6 minutes.

[0081] The billet is removed and placed in a forging mold at 370℃. The preform is then subjected to powder forging and sintering. Only one stage of pressurization is performed, with a pressurization speed of 11 mm / s, a pressure of 700 tons, and a forging ratio of 1.3:1 to obtain the forging product.

[0082] The performance of the forging products prepared in Example 7 was tested according to the method in Example 1, and the test results are shown in Table 1.

[0083] Example 8

[0084] 1000g of aluminum powder was placed in a ball mill jar for primary ball milling at a ball-to-powder ratio of 11:1. 10ml of ethanol and 2ml of acetone were added as anti-forging agents. The steel ball amplitude was 5mm and the vibration frequency was 1470cpm. After mechanical milling for 35 hours, highly active aluminum powder was obtained. The highly active aluminum powder obtained above was mixed with 200g of SiC and 200g of Al2O3 ceramic powder and then subjected to secondary ball milling. 1ml of ethanol was added as anti-forging agent. The steel ball amplitude was 5mm and the vibration frequency was 1470cpm. The ball-to-powder ratio was 9:1. After mechanical milling for 2 hours, highly active composite material powder was obtained.

[0085] The highly active powder was subjected to cold isostatic pressing at a pressure of 250 MPa for 4 minutes to obtain a preform.

[0086] The preform is placed in a high-temperature furnace for preheating at a temperature of 600°C for 3 minutes.

[0087] The billet is removed and placed in a forging mold at 350℃. The preform is then subjected to powder forging and sintering, followed by a first-stage and a second-stage pressurization process. The first-stage pressurization speed is 0.55 mm / s, the pressure is 120 tons, and the forging ratio is 2:1. When the height of the forging reaches 50% of the preform height during the first-stage pressurization, the second-stage pressurization is performed at a speed of 11 mm / s, the pressure is 500 tons, and the forging ratio is 1.2:1. The resulting forging product is then obtained.

[0088] The performance of the forging product prepared in Example 8 was tested according to the method in Example 1, and the test results are shown in Table 1.

[0089] Table 1. Performance test results of the forging products prepared in the examples.

[0090]

[0091] As shown in Table 1, Examples 1-5, by controlling the ball milling parameters, the amount of process control agent added, and the forging and sintering parameters, ultimately obtained aluminum matrix composite forgings with high density, high mechanical properties, and stable high-temperature microstructure. Example 6 did not use two-stage ball milling, Example 7 did not use two-stage pressure for forging and sintering, and Example 8 had an improper amount of control agent added, and the aluminum powder was cold-welded and forged during high-energy ball milling, resulting in coarse aluminum matrix grains in the composite forgings; thus, the products prepared in Examples 6-8 had lower performance.

[0092] This invention replaces the multi-step process in existing powder forging processes with a one-step "forging and sintering" process under pressure, such as... Figure 1 and Figure 2 As shown, compared with the prior art, this invention utilizes a high-energy dry ball milling process. Under the collision action of high-energy grinding media, repeated cold welding and fracture occur between the component powders, resulting in a fine and uniform composite powder of aluminum matrix and ceramic particles. The gaseous molecules of the added process control agent are coated onto the surface of the ultrafine, highly active powder during this process, playing a role in blocking oxygen and protecting surface activity. Then, isostatic pressing is used to pressurize the powder to obtain a uniform green body with a density of about 80%. The green body is then preheated to release the gas coated on the particle surface and re-expose the ultrafine, highly active surface. Finally, the powder particles with highly active surfaces in the green body are rapidly sintered through a rapid sintering and forging process under pressure, achieving effective bonding between particles. Finally, through the deformation, flow and molding process of metal fluid, a forging with a specific shape is formed. The resulting aluminum-based composite material forging has a fine and uniform microstructure, thereby improving the strength and hardness of the forging.

[0093] The preparation method provided by this invention can simultaneously achieve rapid sintering and forging deformation under pressure, eliminating the need for separate powder metallurgy sintering processes, separate forging processes, and subsequent heat treatment processes such as solution treatment and aging, thus achieving high mechanical properties in forgings. Furthermore, the entire preparation process can be carried out in an air atmosphere. It also boasts advantages such as simple process, convenient operation, and fewer steps, making it suitable for the large-scale industrial production of aluminum alloy forgings. This invention utilizes a simple technique to simultaneously complete aluminum-based composite powder metallurgy sintering and forging under pressure, obtaining aluminum-based composite forgings with ultrafine microstructure and high mechanical properties. This invention employs high-energy ball milling technology to prepare micro / nano aluminum-based composite powders; and through in-situ activation sintering and forging technology, obtains highly dense aluminum-based composite forgings, significantly improving their strength. The key to this invention lies in the preparation method of aluminum matrix composite forgings. By using powder forging and sintering technology, the rapid sintering, fluid deformation, flow and molding process of ultrafine aluminum matrix composite powder under pressure is completed, and the powder sintering and sintered body forging deformation are realized simultaneously, ultimately obtaining aluminum matrix composite forgings with high density and high mechanical properties, such as SiC particle-reinforced aluminum matrix composites with ultrafine structure.

[0094] While the invention has been described and illustrated with reference to specific embodiments thereof, such description and illustration are not intended to limit the invention. It will be readily understood by those skilled in the art that various changes may be made to suit particular circumstances, materials, compositions, substances, methods, or processes to the objectives, spirit, and scope of this application without departing from the true spirit and scope of the invention as defined by the appended claims. All such modifications are intended to be within the scope of the appended claims. Although the methods disclosed herein have been described with reference to specific operations performed in a particular order, it should be understood that these operations may be combined, subdivided, or reordered to form equivalent methods without departing from the teachings of the invention. Therefore, unless specifically indicated herein, the order and grouping of operations are not a limitation of this application.

Claims

1. A method for preparing a high-performance aluminum-based composite forging, comprising: Aluminum powder and ceramic powder are ball-milled at high energy to obtain a mixed powder; The mixed powder is subjected to isostatic pressing to obtain a preform; The preform is preheated and then forged and sintered to obtain a high-performance aluminum-based composite material forging. The high-energy ball milling method includes: Aluminum powder is subjected to a single-stage ball milling process to obtain ultrafine aluminum powder; The ultrafine aluminum powder and ceramic powder are mixed and then subjected to two-stage ball milling to obtain a mixed powder; During the first-stage ball milling process, an anti-forging agent is added, which includes ethanol and acetone; the volume ratio of ethanol to acetone is selected from (16~20):(1~5); during the second-stage ball milling process, an anti-forging agent is added, which is selected from ethanol; the ratio of mixed powder to ethanol is selected from (1200~1800) g:(1~5) mL. The forging and sintering process involves a first stage of pressurization followed by a second stage of pressurization. The pressurization speed is selected from 0.5~0.6 mm / s; The speed of the two-stage pressurization is selected from 10~12 mm / s.

2. The preparation method according to claim 1, characterized in that, The mass content of aluminum powder in the mixed powder is selected from 55% to 85%; the mass content of ceramic powder in the mixed powder is selected from 15% to 45%.

3. The preparation method according to claim 1, characterized in that, The ceramic powder is selected from one or more of SiC, TiC and Al2O3.

4. The preparation method according to claim 1, characterized in that, The composition of the mixed powder is: 0~45wt% SiC; 0~45wt% TiC; 0~45wt% Al2O3; The balance is Al.

5. The preparation method according to claim 1, characterized in that, The high-energy ball milling method includes: The primary ball milling time is selected from 30 to 50 hours; The time for the secondary ball milling is selected from 1 to 5 hours.

6. The preparation method according to claim 5, characterized in that, The average grain size of the aluminum powder in the mixed powder is selected from 170~420nm; The average particle size of the ceramic powder in the mixed powder is selected from 10 to 100 micrometers.

7. The preparation method according to claim 1, characterized in that, The isostatic pressing pressure is selected from 220~320MPa; the isostatic pressing time is selected from 2~4min.

8. The preparation method according to claim 1, characterized in that, The preheating temperature is selected from 580~640℃; the preheating time is selected from 3~7 minutes.

9. The preparation method according to claim 1, characterized in that, The forging and sintering are carried out in a forging die, and the temperature of the forging die during the forging and sintering process is selected from 340~380℃.

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