A method of producing metal oxide reinforced aluminum matrix composite material by micro-rolling combined with hot rolling

Abstract

This invention discloses a method for preparing metal oxide reinforced aluminum matrix composites by micro-rolling combined with hot rolling. The method involves first wet micro-rolling of aluminum powder to obtain flake-shaped aluminum powder, and then combining the flake-shaped aluminum powder with MeO2. x MeO was obtained by second wet micro-ball milling of powder. x @Al mixed powder, then MeO x MeO was obtained by mixing and molding Al powders. x / Al raw blank, then MeO x / Al green blank was sintered to obtain MeO x / Al sintered blank, and finally MeO x MeO is obtained by hot rolling Al sintered billets. x The method of this invention, for Al composite materials, enables the dispersed distribution of oxide particles; the prepared MeO x / Al-based composite materials exhibit a room temperature tensile strength exceeding 350 MPa and a tensile strength exceeding 180 MPa at 400℃. This method involves MeO... x The preparation process of Al-based composite materials is short, the manufacturing cost is low, and they are safe and environmentally friendly, making them suitable for large-scale production.

Description

Technical Field

[0001] This invention relates to the field of powder metallurgy technology, and specifically to a method for preparing metal oxide reinforced aluminum matrix composites by micro-rolling combined with hot rolling. Background Technology

[0002] Due to their excellent specific strength, plasticity, corrosion resistance, and ease of processing, aluminum matrix composites are widely used in aerospace, aviation, and marine industries. Most aluminum matrix composites are precipitation-strengthened alloys. These dispersed second phases in the matrix effectively hinder the movement of dislocations and grain boundaries, thereby increasing the alloy's strength. However, the service temperature of these aluminum alloys is limited to below 200℃, mainly because common precipitates in the alloy tend to coarsen above 200℃, significantly reducing their ability to hinder dislocation and grain boundary movement, leading to a sharp decline in strengthening effect. Therefore, there is an urgent need for aluminum matrix materials that maintain high strength and high plasticity and toughness at higher temperatures, making heat-resistant aluminum matrix composites a target of researchers.

[0003] Introducing second-phase reinforcements (such as micro / nano-scale intermetallic compounds, precipitated phases, or ceramic particles) is one of the core strategies for improving the heat resistance of traditional aluminum-based materials, mainly by activating load transfer and Orowan strengthening mechanisms. However, the strengthening effect of these aluminum-based alloys is highly dependent on the uniform dispersion of hard particles in the relatively soft aluminum matrix, i.e., the degree of dispersion. On the one hand, the content of the second-phase reinforcement cannot be too high, as this can easily cause brittle damage to the matrix; on the other hand, the size of the second-phase reinforcement must be small enough to achieve a highly uniform distribution. Otherwise, the effect of second-phase reinforcement on improving the high-temperature performance of aluminum-based materials is limited. Based on this, a large amount of research has focused on how to reduce the content of the second-phase reinforcement, how to reduce the size of the second-phase reinforcement, and how to improve the dispersion uniformity of the second-phase reinforcement. For example, a research team at Shanghai Jiao Tong University proposed an aluminum-based superalloy architecture design strategy based on additive manufacturing technology, and successfully prepared an AlLaScZr alloy using laser powder bed melting technology. This alloy utilizes the eutectic alloying effect of La to form a thermally stable nanoscale Al-La eutectic cellular network, exhibiting excellent high-temperature mechanical properties. Its high-temperature yield strength reaches approximately 250 MPa at 300℃ and remains around 110 MPa at 400℃. Despite these significant performance advantages, this technology still faces unresolved issues: cracks and residual stress are easily generated during the preparation process, and high-temperature performance is highly sensitive to process parameters, requiring further optimization of the heat treatment process to improve performance stability, which undoubtedly increases the complexity of the preparation process. A research team at Tianjin University proposed an "interface replacement" particle dispersion control strategy, using a composite reinforcing phase of few-layer graphite coated with ultrafine MgO particles, successfully preparing a high-performance MgO / Al composite material. This composite material exhibits superior high-temperature load-bearing capacity; even under harsh conditions at 500℃, the tensile strength can still stably reach 200 MPa, far exceeding the high-temperature mechanical properties of traditional aluminum-based composites. However, this technology is still in the laboratory stage and has a long way to go before industrialization. It also faces key bottlenecks: First, the ball milling conditions at nearly -200°C deter many equipment manufacturers, as the requirements for equipment and economic costs are very high; Second, it is difficult to achieve nanoscale dispersion of magnesium oxide in large-scale production processes. Summary of the Invention

[0004] To address the issues of operability, repeatability, scalability, and low cost in existing aluminum-based composite material preparation processes, this invention aims to provide a method for preparing metal oxide-reinforced aluminum-based composite materials using a combination of micro-rolling and hot rolling. This invention obtains extremely thin micro-aluminum sheets through micro-rolling at room temperature, and then embeds nano-oxide particles into these micro-aluminum sheets, thereby obtaining an aluminum-based composite material with an approximately nanoscale oxide dispersion. The preparation method of this invention has advantages such as simple operation, low cost, and wide applicability.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] This invention discloses a method for preparing metal oxide reinforced aluminum matrix composites using micro-rolling combined with hot rolling. The method involves first wet micro-rolling of aluminum powder to obtain flake-shaped aluminum powder, and then combining the flake-shaped aluminum powder with MeO2. x MeO was obtained by second wet micro-ball milling of powder. x @Al mixed powder, then MeO x MeO was obtained by mixing and molding powders with Al. x / Al raw blank, then MeO x / Al green blank was sintered to obtain MeO x / Al sintered blank, and finally MeO x / Al sintered billets are hot-rolled to obtain MeO x / Al composite materials.

[0007] The preparation method of this invention first obtains extremely thin flake aluminum powder through a first wet micro-rolling ball milling process, and then adds nano-sized metal oxide MeO x The powder and flake aluminum powder are subjected to a second wet micro-rolling ball milling process to produce MeO x Powder coating of flake aluminum powder forms MeO x @Al mixed powder, pressed into shape to obtain MeO x Al blank, sintered to obtain MeO x The Al sintered billet is then hot-rolled to eliminate the fine micropores in the sintered billet, thereby obtaining a densified MeO₂. x / Al composite material, MeO obtained in this invention x In the / Al composite material, metal oxides are uniformly dispersed at the nanoscale in the aluminum matrix, thereby achieving the purpose of reinforcing the aluminum matrix.

[0008] In a preferred embodiment, the secondary particle size D of the Al powder is... 50 The particle size of the Al powder is 5~200μm, and the purity is ≥99.9%. Controlling the particle size of the Al powder within this range yields the best performance of the resulting composite material. If the aluminum powder particles are too small, the MeO2... x The powder particles are too large to achieve effective MeO x Aluminum coating; however, aluminum powder particles are too large, although they can make MeO x Coated aluminum powder, but MeO x The powder is difficult to distribute among large aluminum particles, which actually reduces the MeO2 content. x The uniform dispersion effect of particles in aluminum powder.

[0009] In a preferred embodiment, during the first wet micro-rolling ball milling, the rotation speed is controlled at 30~200 r / min, and the time is 10~100h.

[0010] In a preferred embodiment, anhydrous ethanol is used as the milling medium during the first wet micro-rolling ball milling, and the solid-liquid mass ratio of the milling medium to the aluminum powder is 1:2~10.

[0011] In a preferred embodiment, during the first wet micro-rolling ball milling, a round bar with an aspect ratio of 1 to 5 is used as the ball milling tool, and the mass ratio of the ball milling tool to aluminum powder is 10 to 40:1.

[0012] Experiments have shown that only by using the micro-rolling ball milling method of this invention, in conjunction with the ball milling tool of this invention, can the required flake aluminum powder be obtained. Using conventional ball milling methods, or replacing the round bar in this invention with a grinding ball, cannot obtain the flake aluminum powder required by this invention. In addition, if the length-to-diameter ratio of the round bar is too long, it cannot achieve the micro-ball milling effect and cannot obtain flake aluminum; if the length-to-diameter ratio is too small, the ball milling is not in surface contact and cannot obtain flake aluminum.

[0013] In a further preferred embodiment, the material of the ball milling tool is selected from stainless steel and cemented carbide.

[0014] In a further preferred embodiment, during the first wet micro-rolling ball milling, the material of the milling jar is selected from polyurethane and stainless steel.

[0015] In a preferred embodiment, the slurry obtained after the first wet micro-rolling ball milling of aluminum powder is vacuum dried to obtain flake aluminum powder. The vacuum drying adopts a box-type vacuum drying oven with a vacuum degree of -0.1MPa, a temperature of 50~100℃, and a time of 10~40h.

[0016] In a preferred embodiment, the aluminum powder is in the shape of a near-circular sheet with a diameter-to-thickness ratio of 10 to 100 and a thickness of ≤10 μm.

[0017] In a preferred embodiment, the MeO x Powder, with an initial particle size of 5~50nm and a secondary particle size D 50 The particle size is 1~10 μm, and the purity is ≥99.9%. Experiments have shown that MeO can be obtained simply by controlling the secondary particle size of the aluminum powder. x Powder particles coated with aluminum, however MeO x When using powder as a coating layer, its original particle size needs to be controlled to be at the nanoscale to effectively encapsulate aluminum powder particles. However, nanoparticles are prone to agglomeration. During the coating process in a ball mill mixer, MeO2... x Powder particles that are too large are difficult to disperse to obtain nanoscale particles. Therefore, by appropriately controlling their secondary particle size within the range of this invention, it can be ensured that MeO2 is obtained after mixing. x @Al combined powder.

[0018] In a preferred embodiment, the MeO xIn the powder, Me is selected from one of Al, Mg, Si, Zr, Ce, Y, and La, preferably one of Mg, Y, and La.

[0019] In a preferred embodiment, the rotational speed of the second wet micro-rolling ball mill is 30~200 r / min, and the time is 10~100 h.

[0020] In a preferred embodiment, anhydrous ethanol is used as the milling medium during the second wet micro-rolling ball milling, and the solid-liquid mass ratio of the milling medium to the aluminum powder is 1:2~10.

[0021] In a preferred embodiment, during the second wet micro-rolling ball milling, a round bar with an aspect ratio of 1 to 5 is used as the ball milling tool, and the mass ratio of the ball milling tool to aluminum powder is 10 to 40:1.

[0022] In this invention, flake-shaped aluminum powder with the largest possible surface area is first obtained through a first wet micro-rolling ball milling process, and then nano-sized MeO is added to the obtained flake-shaped aluminum powder. x The particles were then subjected to a second round of ball milling, producing MeO2. x The particles are crushed into sheet aluminum, thus forming pinned-coated MeO. x @Al flake powder. Experiments showed that continuing with wet micro-rolling milling or using other mixing methods instead of wet micro-rolling milling would break the flake aluminum, making it impossible to form pinned MeO. x @Al flake powder, on the one hand, reduces the MeO pinning on the surface of the flake aluminum. x Particles, on the other hand, will cause MeO x Poor particle dispersion distribution ultimately reduces MeO2. x Mechanical properties of Al composite materials.

[0023] In a preferred embodiment, the MeO x @Al mixed powder, MeO x The volume fraction of the powder is 0.1-10%, preferably 8-10%.

[0024] In a preferred embodiment, the molding process is dry hydraulic molding, wherein the hydraulic mold is made of either carbon steel or stainless steel.

[0025] In a preferred embodiment, the compression molding pressure is 10~40 MPa and the holding time is 30~300 s.

[0026] In a preferred embodiment, the sintering is performed under vacuum conditions with a vacuum degree ≤1×10⁻⁶. -3The sintering temperature is 500~600℃, and the sintering time is 60~300min. Low-temperature vacuum sintering under these conditions effectively prevents aluminum oxidation. Subsequent hot rolling eliminates the fine micropores in the sintered billet, resulting in a densified MeO₂. x / Al composite materials

[0027] In a preferred embodiment, the hot rolling temperature is 400~600℃, and the hot rolling is performed 2~5 times.

[0028] Further preferred, when the MeO x @Al mixed powder, MeO x The powder volume fraction is 0.1~2%, the number of hot rolling passes is controlled at 2, and the reduction per pass is 32-38%; when the MeO x @Al mixed powder, MeO x When the volume fraction of the powder is greater than 2% and less than or equal to 5%, the number of hot rolling passes is controlled at 3, and the reduction per pass is 21-27%; when the MeO x @Al mixed powder, MeO x When the volume fraction of the powder is greater than 5% and less than or equal to 8%, the number of hot rolling passes is controlled at 4, and the reduction per pass is 18-20%; when the MeO x @Al mixed powder, MeO x When the volume fraction of the powder is greater than 8% and less than or equal to 10%, the number of hot rolling passes should be controlled at 5, and the reduction per pass should be 14-17%.

[0029] In actual operation, a two-roll cold / hot rolling mill is used for hot rolling.

[0030] Compared with the prior art, the advantages of the present invention are as follows:

[0031] (1) Performance advantages: By precisely controlling the powder particle size and metal oxide content, flake aluminum powder is prepared to obtain high-performance aluminum-based composite materials, so that the metal oxide powder can be uniformly dispersed in the aluminum alloy matrix to form nanocrystal nuclei, thereby achieving the purpose of reinforcement; the aluminum-based composite material prepared by the technology of this invention has a tensile strength of more than 350 MPa at room temperature and a tensile strength of more than 180 MPa at 400℃.

[0032] (2) Process advantages: The process of combining sintering and hot rolling is adopted to achieve the densification of powder metallurgy high-temperature alloys. The high-temperature environment can not only reduce the deformation resistance of the high-temperature alloy matrix, but also redistribute the metal oxide particles in the matrix. Combined with the plastic deformation effect of the rolling process, the density of the high-temperature alloy and the uniformity of oxide particle distribution are effectively improved.

[0033] (3) Equipment and economic advantages: The preparation process of this invention is simple and easy to implement, with high operational flexibility. The entire experimental process can be carried out at room temperature, saving the purchase cost of high-value cryogenic equipment and reducing the manufacturing cost of ball milling and mixing under extreme conditions. In addition, the preparation process involved in this invention is applicable to the preparation of different types and thicknesses of powder metallurgy aluminum oxide-based alloys, and has good versatility.

[0034] In summary, this invention utilizes powder metallurgy technology to further improve the properties of aluminum-based alloys by adding metal oxides to prepare flake aluminum powder, effectively reducing the manufacturing process. The related research theories can also be extended to other powder metallurgy materials. The manufacturing process of this invention is simple, easy to operate, and has high feasibility for industrial-scale production.

[0035] 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

[0036] Figure 1 This is a process flow diagram of the present invention;

[0037] Figure 2 SEM image of the original aluminum powder;

[0038] Figure 3 Here is a SEM image of the ball-milled flaky aluminum powder from Example 1;

[0039] Figure 4 For example, 10 vol%-MeO x SEM images of @Al powder at different magnifications; among which Figure 4 (a) in the text is MeO x Granular aluminum powder with pinned coating. Figure 4 (b) in the image is a magnified view of a portion of (a).

[0040] Figure 5 MeO in Example 1 and Comparative Example 5 x Fracture surface SEM of Al-based composite materials Figure 5 (a) in Example 1 refers to MeO. x Fracture surface SEM of Al-based composite materials; Figure 5 (b) in the middle is MeO x Fracture surface SEM of Al-based composite materials.

[0041] Figure 6 For example, 10.0 vol%-MeO x Figure showing the good room temperature and high temperature mechanical properties of Al-based composite materials;

[0042] Figure 7The image shows the SEM image of the ball-milled aluminum powder in Comparative Example 1. Detailed Implementation

[0043] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0044] Example 1

[0045] (1) Aluminum powder with a purity ≥ 99.9% (secondary particle size D) 50 Its size is 20 μm, and its SEM image is as follows: Figure 2 The aluminum powder (as shown) was loaded into a ball mill jar. A 5mm diameter cemented carbide rod (length-to-diameter ratio 2:1) was used, with a mass ratio of cemented carbide rod to aluminum powder of 40:1. The grinding media was high-purity anhydrous ethanol, with a volume ratio of grinding media to powder of 4:1. The ball milling speed was 60 r / min, and the milling time was 20 h. After ball milling, an aluminum slurry was obtained.

[0046] (2) The aluminum paste from step (1) was dried in a vacuum drying oven with a vacuum degree of 0.1 MPa at a drying temperature of 75°C for 20 hours to obtain flake aluminum powder. The SEM image of the powder is shown below. Figure 3 As shown.

[0047] (3) The flake aluminum powder from step (2) and MgO powder with a content of 2.0 vol% (original particle size of 20 nm, secondary particle size of 8 μm) were further mixed by micro-rolling ball milling. A cemented carbide rod with a diameter of 5 mm (length-to-diameter ratio of 2:1) was used, and the mass ratio of the cemented carbide rod to the raw material powder was 40:1. The grinding medium was high-purity anhydrous ethanol, and the volume ratio of the grinding medium to the raw material powder was 4:1. The rolling ball milling speed was 60 r / min, and the milling time was 20 h to obtain a MgO@Al-based composite material with a MgO content of 2.0 vol%. The MgO@Al-based composite material was then loaded into a mold and molded to obtain a preform. The molding pressure was 20 MPa, and the holding time was 30 s.

[0048] (4) The green blank obtained in step (3) is sintered in a vacuum sintering furnace with a vacuum degree of 10. -3 Pa, sintering temperature is 580℃, holding time is 60min.

[0049] (5) The aluminum alloy obtained after sintering in step (4) is hot rolled in a two-roll cold / hot rolling mill at a temperature of 600℃. This rolling process is repeated twice, with each roll being 37% of the original thickness, to obtain the aluminum alloy. The room temperature tensile strength of this Al-based composite material is approximately 215 MPa.

[0050] Example 2

[0051] (1) Aluminum powder with a purity ≥ 99.9% (secondary particle size D)50 The aluminum powder (20 μm) was loaded into a ball mill jar and prepared according to Example 1.

[0052] (2) The obtained flake aluminum powder was mixed with 10.0 vol% MgO powder (original particle size of 20 nm), and the powder SEM image was obtained as follows. Figure 4 As shown, the molding, sintering, and hot rolling operations were then completed according to Example 1. The hot rolling process was repeated five times, with each reduction being 17% of the original thickness, resulting in a MgO@Al-based composite material with a MgO content of 10.0 vol%. The fracture surface SEM is shown below. Figure 5 As shown in (a). Testing revealed that the room temperature tensile strength of this Al-based composite material is approximately 420 MPa, and the tensile strength at 400°C is approximately 200 MPa. Figure 6 As shown.

[0053] Example 3

[0054] (1) Aluminum powder with a purity ≥ 99.9% (secondary particle size D) 50 The aluminum powder (20 μm) was loaded into a ball mill jar and prepared according to Example 1.

[0055] (2) The obtained flake aluminum powder was mixed with Y2O3 powder (original particle size 20 nm) with a content of 10.0 vol%, and the molding, sintering, and hot rolling operations were completed according to Example 2 to obtain Y2O3@Al-based composite material with a Y2O3 content of 10.0 vol%. The room temperature tensile strength of the Al-based composite material was tested to be approximately 387 MPa.

[0056] Example 4

[0057] (1) Aluminum powder with a purity ≥ 99.9% (secondary particle size D) 50 The aluminum powder (20 μm) was loaded into a ball mill jar and prepared according to Example 1.

[0058] (2) The obtained flake aluminum powder was mixed with 10.0 vol% La2O3 powder (original particle size of 20 nm), and the molding, sintering, and hot rolling operations were completed according to Example 2 to obtain a La2O3@Al-based composite material with a La2O3 content of 10.0 vol%. The room temperature tensile strength of the Al-based composite material was tested to be approximately 376 MPa.

[0059] Example 5

[0060] (1) Aluminum powder with a purity ≥ 99.9% (secondary particle size D) 50 The aluminum powder (20 μm) was loaded into a ball mill jar and prepared according to Example 1.

[0061] (2) The obtained flake aluminum powder was mixed with ZrO2 powder (original particle size 20 nm) with a content of 10.0 vol%, and the molding, sintering, and hot rolling operations were completed according to Example 2 to obtain ZrO2@Al-based composite material with a ZrO2 content of 10.0 vol%. The room temperature tensile strength of the Al-based composite material was tested to be approximately 400 MPa.

[0062] Comparative Example 1

[0063] Other conditions were the same as in Example 1, except that sheet aluminum powder was directly loaded into a mold and molded to obtain a preform. The molding pressure was 20 MPa, the holding time was 30 s, and then the preform was sintered in a vacuum sintering furnace at a vacuum degree of 10. -3 The aluminum alloy was sintered at 580℃ for 60 minutes, and then hot-rolled twice on a two-roll cold / hot rolling mill at 600℃ to obtain the final alloy. The room temperature tensile strength of this pure aluminum alloy was measured to be approximately 170 MPa.

[0064] Example 6

[0065] All other conditions are the same as in Example 1, except that the secondary particle size D of the aluminum powder used is different. 50 The thickness is 5 μm, and the room temperature tensile strength of this Al-based composite material is approximately 200 MPa.

[0066] Example 7

[0067] All other conditions are the same as in Example 1, except that the secondary particle size D of the aluminum powder used is different. 50 The thickness is 200 μm. The room temperature tensile strength of this Al-based composite material was tested to be approximately 220 MPa.

[0068] Example 8

[0069] Other conditions were the same as in Example 1, except that aluminum powder with a purity ≥ 99.9% (secondary particle size D) was used. 50 The powder (20 μm thick) was loaded into a ball mill jar using a 5 mm diameter cemented carbide rod (length-to-diameter ratio 4:1) and a ball-to-powder mass ratio of 40:1. The grinding media was high-purity anhydrous ethanol, with a grinding media-to-powder volume ratio of 4:1. The ball milling speed was 60 r / min, and the milling time was 10 h. After milling, a flake-like aluminum slurry was obtained. Testing showed that the room temperature tensile strength of this Al-based composite material was approximately 190 MPa.

[0070] Example 9

[0071] Other conditions were the same as in Example 1, except that aluminum powder with a purity ≥ 99.9% (secondary particle size D) was used. 50The powder (20 μm in diameter) was loaded into a ball mill jar using a 5 mm diameter cemented carbide rod (length-to-diameter ratio 5:1) and a ball-to-powder mass ratio of 40:1. The grinding media was high-purity anhydrous ethanol, with a grinding media-to-powder volume ratio of 4:1. The ball milling speed was 60 r / min, and the milling time was 100 h. After milling, an aluminum slurry was obtained. Testing showed that the room temperature tensile strength of this Al-based composite material was approximately 235 MPa.

[0072] Comparative Example 2

[0073] (1) Aluminum powder with a purity ≥ 99.9% (secondary particle size D) 50 The aluminum powder (20 μm) was loaded into a ball mill jar and prepared according to Example 1.

[0074] (2) The obtained flake aluminum powder was mixed with MgO powder (average particle size 2 μm) with a content of 10 vol%, and the molding, sintering, and hot rolling operations were completed according to Example 2 to obtain MgO@Al based composite material with a MgO content of 10 vol%. Its fracture surface SEM is shown in Figure 1. Figure 5 As shown in (b), the room temperature tensile strength of this Al-based composite material was tested to be approximately 285 MPa.

[0075] Example 10

[0076] (1) Aluminum powder with a purity ≥ 99.9% (secondary particle size D) 50 The powder (20 μm in diameter) was loaded into a ball mill jar, and a 5 mm diameter cemented carbide rod (length-to-diameter ratio 2:1) was used. The ball-to-powder mass ratio was 40:1. The grinding media was high-purity anhydrous ethanol, with a grinding media-to-powder volume ratio of 4:1. The ball milling speed was 60 r / min, and the milling time was 20 h. After ball milling, an aluminum slurry was obtained.

[0077] (2) The obtained aluminum paste was dried and shaped according to Example 1;

[0078] (3) The green blank obtained in step (2) is sintered in a vacuum sintering furnace with a vacuum degree of 10. -3 Pa, sintering temperature is 600℃, holding time is 60min.

[0079] (4) The aluminum-based composite sintered body obtained after sintering in step (3) is hot rolled in a two-roll cold / hot rolling mill in accordance with the method of Example 1 to obtain an aluminum alloy. The room temperature tensile strength of the Al-based composite material is about 225 MPa.

[0080] Example 11

[0081] (1) Example 10 yielded an aluminum-based composite preform;

[0082] (2) The green blank obtained in step (1) is sintered in a vacuum sintering furnace with a vacuum degree of 10. -3 Pa, sintering temperature is 500℃, holding time is 300min.

[0083] (3) The aluminum-based composite sintered body obtained after sintering in step (2) was hot rolled in a two-roll cold / hot rolling mill as described in Example 1 to obtain an aluminum alloy. The room temperature tensile strength of the Al-based composite material was tested to be approximately 219 MPa.

[0084] Comparative Example 3

[0085] (1) Aluminum powder with a purity ≥ 99.9% (secondary particle size D) 50 The aluminum powder (20 μm in diameter) was loaded into a ball mill jar and 10 mm diameter cemented carbide balls were used. The mass ratio of cemented carbide balls to aluminum powder was 40:1. The grinding media was high-purity anhydrous ethanol, with a grinding media to powder volume ratio of 4:1. The ball milling speed was 60 r / min, and the milling time was 20 h. After ball milling, aluminum slurry was obtained.

[0086] (2) The aluminum paste from step (1) was dried in a vacuum drying oven with a vacuum degree of 0.1 MPa at a temperature of 75°C for 20 hours to obtain non-flaky aluminum powder. The powder SEM image is shown below. Figure 7 As shown.

[0087] Then, using the method of Example 1, an Al-based composite material was obtained, and the final Al-based composite material had a room temperature tensile strength of approximately 150 MPa.

[0088] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for preparing metal oxide reinforced aluminum matrix composites by micro-rolling combined with hot rolling, characterized in that: Aluminum powder was subjected to a first wet micro-rolling ball milling to obtain flake aluminum powder. The flake aluminum powder was then mixed with MeO. x MeO was obtained by second wet micro-ball milling of powder. x @Al mixed powder, then MeO x MeO was obtained by mixing and molding Al powders. x / Al raw blank, then MeO x / Al green blank was sintered to obtain MeO x / Al sintered blank, and finally MeO x MeO is obtained by hot rolling Al sintered billets. x / Al composite material.

2. The method for preparing metal oxide reinforced aluminum matrix composites by micro-rolling combined with hot rolling according to claim 1, characterized in that: The secondary particle size D of the Al powder 50 The size ranges from 5 to 200 μm, and the purity is ≥99.9%.

3. The method for preparing metal oxide reinforced aluminum matrix composites by micro-rolling combined with hot rolling according to claim 1, characterized in that: During the first wet micro-rolling ball milling, the rotation speed was controlled at 30~200 r / min, and the time was 10~100h; In the first wet micro-rolling ball milling, anhydrous ethanol was used as the ball milling medium, and the solid-liquid mass ratio of the ball milling medium to the aluminum powder was 1:2~10. In the first wet micro-rolling ball milling, a round bar with a length-to-diameter ratio of 1 to 5 is used as the ball milling tool, and the mass ratio of the ball milling tool to aluminum powder is 10 to 40:

1. The material of the ball milling tool is selected from stainless steel and cemented carbide. During the first wet micro-rolling ball milling, the material of the milling jar is selected from polyurethane and stainless steel.

4. The method for preparing metal oxide reinforced aluminum matrix composites by micro-rolling combined with hot rolling according to claim 1, characterized in that: The slurry obtained after the first wet micro-rolling ball milling of aluminum powder is vacuum dried to obtain flake aluminum powder. The vacuum drying adopts a box-type vacuum drying oven with a vacuum degree of -0.1MPa, a temperature of 50~100℃, and a time of 10~40h. The aluminum powder is in the shape of a near-circular sheet, with a diameter-to-thickness ratio of 10~100 and a thickness of ≤10 μm.

5. The method for preparing metal oxide reinforced aluminum matrix composites by micro-rolling combined with hot rolling according to claim 1, characterized in that: The MeO x Powder, with an initial particle size of 5~50nm and a secondary particle size D 50 The size is 1~10 μm, and the purity is ≥99.9%; the MeO x In the powder, Me is selected from one of Al, Mg, Si, Zr, Ce, Y, and La.

6. The method for preparing metal oxide reinforced aluminum matrix composites by micro-rolling combined with hot rolling according to claim 1, characterized in that: The second wet micro-rolling ball milling process involves a rotation speed of 30-200 r / min and a time of 10-100 h. In the second wet micro-rolling ball milling, anhydrous ethanol was used as the ball milling medium, and the solid-liquid mass ratio of the ball milling medium to the aluminum powder was 1:2~10. In the second wet micro-rolling ball milling, a round bar with a length-to-diameter ratio of 1 to 5 is used as the ball milling tool, and the mass ratio of the ball milling tool to aluminum powder is 10 to 40:

1.

7. The method for preparing metal oxide reinforced aluminum matrix composites by micro-rolling combined with hot rolling according to claim 1, characterized in that: The MeO x @Al mixed powder, MeO x The volume fraction of the powder is 0.1% to 10%.

8. The method for preparing metal oxide reinforced aluminum matrix composites by micro-rolling combined with hot rolling according to claim 1, characterized in that: The compression molding is dry hydraulic molding, and the hydraulic mold in the dry hydraulic molding is made of either carbon steel or stainless steel. The compression molding pressure is 10~40 MPa, and the holding time is 30~300 s.

9. The method for preparing metal oxide reinforced aluminum matrix composites by micro-rolling combined with hot rolling according to claim 1, characterized in that: The sintering is carried out under vacuum conditions with a vacuum degree ≤1×10⁻⁶. -3 Pa, the sintering temperature is 500~600℃, and the sintering time is 60~300min.

10. The method for preparing metal oxide reinforced aluminum matrix composites by micro-rolling combined with hot rolling according to claim 1, characterized in that: The hot rolling temperature is 400~600℃, and the hot rolling is performed 2~5 times.

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