High-toughness aluminum alloy material and preparation method thereof

Abstract

The invention discloses a high-toughness aluminum alloy material, and relates to the technical field of alloys. When the high-toughness aluminum alloy material is prepared, firstly, a TiB-HfC gradient transition layer is deposited on the surface of silicon carbide fiber to obtain a toughening phase, secondly, an AlMgB-TiO nano-composite phase serves as a nano-phase, and finally, the toughening phase, the nano-phase and aluminum alloy powder are mixed and prepared into the aluminum alloy in an interlayer laying mode. The prepared high-toughness aluminum alloy material has good mechanical properties.

Description

Technical Field

[0001] This invention relates to the field of alloys, specifically to a high-toughness aluminum alloy material and its preparation method. Background Technology

[0002] Aluminum alloys, due to their low density, good plasticity, and relatively high specific strength, have become an important lightweight material in the automotive industry, widely used in the manufacture of automotive frame structural components, suspension systems, and more. However, with societal development, users have increasingly higher requirements for lightweight aluminum materials in automobiles, demanding that aluminum materials possess certain strength and good plasticity. However, in actual extrusion processes, aluminum alloys often exhibit low hardness, and their mechanical properties after natural or artificial aging fail to meet standards. When used in load-bearing structures, their strength sometimes cannot meet the design requirements for automotive load strength, potentially leading to structural deformation. Furthermore, the strength properties of traditional high-toughness aluminum alloys need improvement, limiting their wider application. Summary of the Invention

[0003] The purpose of this invention is to provide a high-toughness aluminum alloy material, its preparation method, and its application, so as to solve the problems existing in the prior art.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A method for preparing a high-toughness aluminum alloy material includes the following steps: (1) Preparation of toughening phase: The toughening phase is obtained by forming a TiB2-HfC gradient transition layer on the surface of silicon carbide fiber in three stages; (2) Preparation of nanophase: Al powder, Mg powder and B powder were mixed and heat-treated to obtain AlMgB 14 Ceramic powder; AlMgB 14 The nanophase was obtained by ball milling a mixture of ceramic powder and TiO2 nanoparticles. (3) Mixing: The toughening phase, nano phase and aluminum alloy powder are mixed and ball-milled to obtain mixture A; the nano phase and aluminum alloy powder are mixed to obtain mixture B; (4) Cold pressing: The mixture and aluminum alloy powder are loaded into the mold by interlayer laying method and pressed into a blank; (5) Vacuum hot pressing sintering: The billet is placed in a high temperature resistance furnace, heated to 550-575℃, and held at 45MPa for 120-130min to obtain the alloy precursor; (6) T6 heat treatment: after solution treatment at 515℃ for 2 hours, water quenching and aging at 190℃ for 8 hours, high toughness aluminum alloy material is obtained.

[0005] As an optimization, the preparation method of the toughening phase in step (1) is as follows: after annealing silicon carbide fibers in an Ar atmosphere at 900°C for 30-40 min, the fibers are placed in a chemical vapor deposition reactor and evacuated to 10°C. -3 Pa, Ar gas is introduced for protection, the temperature is raised to 1000℃, and H2 is introduced for 10 min to reduce the surface of silicon carbide fiber; TiB2-HfC gradient transition layer is formed by chemical deposition on the surface of silicon carbide fiber in three stages. First stage of deposition: Temperature 1050℃, pressure 1.0 kPa, time 30 min; Gas composition: TiCl4, 5% B2H6 / H2 mixture, H2, Ar; Second stage of deposition: Temperature 1010℃, pressure 1.2 kPa, time 40 min The gas composition for the first 20 minutes was: TiCl4, 5% B2H6 / H2 mixture, H2, CH4, HfCl4, and Ar; The gas composition for the last 20 minutes was HfCl4, CH4, and H2; Third stage of deposition: Temperature 1150℃, pressure 1.5 kPa, time 30 min; The gas composition at this stage is: HfCl4, CH4, H2, and Ar.

[0006] As an optimization, the preparation method of the nanophase in step (2) is as follows: Al powder, Mg powder and B powder are mixed, heated to 950℃, heat-treated for 1 hour, and then heated to 1200℃ for 4 hours to obtain AlMgB. 14 ceramic powder, AlMgB 14 Ceramic powder, TiO2 nanoparticles, and anhydrous ethanol were added to a planetary ball mill at a ball-to-particle ratio of 10:1. The mixture was ball-milled at 300 rpm for 4 hours and then sintered at 900-1000℃ and 30-40 MPa for 1-2 hours to obtain a nanophase.

[0007] As an optimization, the molar ratio of Al powder, Mg powder, and B powder in step (2) is 1:1:(14-14.5); the particle size of TiO2 is 50 nm, and the amount added is 10%-15% of the total mass of Al powder, Mg powder, and B powder; the amount of anhydrous ethanol added is AlMgB 14 The total mass of ceramic powder and TiO2 nanoparticles is 0.4-0.5 times.

[0008] As an optimization, the preparation method of the mixture A in step (3) is as follows: weigh out the toughening phase 15%-20%, the nano phase 10%-12%, and the aluminum alloy powder 68%-75% by weight percentage; mix the toughening phase, the nano phase, and the aluminum alloy powder evenly, add them to a ball mill and ball mill to obtain the mixture A.

[0009] As an optimization, the preparation method of the mixture B in step (3) is as follows: weigh 5%-10% of nano phase and 90%-95% of aluminum alloy powder by weight percentage; mix the nano phase and aluminum alloy powder evenly, add them to a ball mill for ball milling, and obtain mixture B.

[0010] As an optimization, the ball milling conditions are as follows: ball-to-material ratio of (8-10):1, rotation speed of 150-180 rpm, and ball milling time of 2-3 hours.

[0011] As an optimization, the preparation method of the blank in step (4) is as follows: the mixed powder is loaded into the mold by interlayer laying method, and the powder is laid according to the following steps: a. A 0.5 mm thick layer of pure aluminum alloy powder is laid on the bottom of the mold; b. Lay a 0.3mm thick layer of mixed material A (fiber orientation parallel to the X-axis); c. Lay a 0.1 mm thick layer of mixed material B; d. Lay a 0.3 mm thick layer of mixed material A (fiber orientation parallel to the Y-axis); e. Lay a 0.1 mm thick layer of mixed material B; f. Repeat step be until the mold is full; g. A 0.5 mm thick aluminum alloy powder layer is laid on the top layer; Press the blank by holding the pressure at 600 MPa for 15-20 minutes.

[0012] As an optimization, the silicon carbide fiber in step (1) is a 15-17 μm fiber.

[0013] The present invention also provides a high-toughness aluminum alloy material prepared by any of the methods described above.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention are: The TiB2-HfC gradient transition layer constructed at the fiber interface in this invention can resolve the abrupt change in thermal stress between silicon carbide and metal, and form a dual chemical anchoring of B-Si / Al-O covalent bonds and nano-transition phase at the molecular level, thereby improving the interfacial bonding strength. When the material is subjected to stress, the nanograin boundaries inside the gradient layer induce micro-plastic deformation through lattice slip, forcing macroscopic cracks to bifurcate and passivate when crossing the gradient interface.

[0015] AlMgB 14- The toughening mechanism of TiO2 nanocomposite ceramic phases exhibits multi-level response characteristics: ball milling process in AlMgB 14 In-situ embedded TiO2 nanoislands at grain boundaries form semi-coherent interfaces, becoming energy traps for dislocation motion; AlMgB2 exhibits high hardness under load. 14 The skeleton forces the crack to bypass, while the local shear strain field induced by TiO2 particles activates aluminum lattice distortion, causing the crack tip to continuously consume kinetic energy.

[0016] The interlayered structure constructs a three-dimensional toughened skeleton, with orthogonally arranged silicon carbide fiber layers forming a spatial defense network: the crack is first forced to turn and propagate along the X-axis fiber, and when it penetrates the B layer of the mixture, the nanophase triggers micro-region plastic deformation to form the first energy dissipation barrier; when the crack continues to invade the vertical Y-axis fiber layer, the crack path is again forcibly deflected by 90°; this periodically occurring orthogonal turning structure causes the crack kinetic energy to decay, and the nanophase composite matrix in the B layer of the mixture plays a key pivotal role—both buffering the stress interference of adjacent fiber layers and delaying interface debonding through nanoparticle bridging; while the surface pure aluminum layer contains residual energy through large-scale plastic deformation in the final fracture stage.

[0017] The synergistic effect of the three components forms a full-scale protection system: the gradient layer resolves the stress concentration at the interface and inhibits crack initiation from the source; the nanophase lays up a microscopic barrier network in the matrix to dissipate the kinetic energy of crack propagation; the orthogonal lay-up transforms the linearly propagating crack into a tortuous energy-dissipating path; and the surface pure aluminum finally completes the energy dissipation closed loop, which enables the material to maintain structural integrity under extreme conditions such as ultra-low temperature impact and high cycle fatigue. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] In the following examples and comparative examples, sccm refers to the gas flow rate unit; 5% in the 5% B2H6 / H2 mixture is a volume percentage, meaning the mixture consists of 5% B2H6 and 95% H2; the TiO2 particle size is 50nm; the aluminum alloy powder is AA2024 aluminum alloy powder; the Al powder has a particle size of 200 mesh, the Mg powder has a particle size of 300 mesh, and the B powder has a particle size of 500 mesh.

[0020] Example 1: A high-toughness aluminum alloy material, the preparation method of the material is as follows: (1) Preparation of toughening phase: 15 μm silicon carbide fibers were ultrasonically cleaned and dried with acetone, annealed at 900 °C for 40 min in an Ar atmosphere, and then placed in a chemical vapor deposition reactor and evacuated to 10 °C. -3 Pa, Ar gas was introduced for protection (200 sccm), the temperature was increased to 1000℃ at a rate of 10℃ / min, and H2 (200 sccm) was introduced for reduction for 10 min to activate the surface of silicon carbide fiber; TiB2-HfC gradient transition layer was formed on the surface of silicon carbide fiber by chemical deposition in three stages. First stage of deposition: Temperature 1050℃, pressure 1.0 kPa, time 30 min; Gas composition: TiCl4 (20 sccm carried by Ar carrier gas), 5% B2H6 / H2 mixture (10 sccm), H2 (300 sccm, reducing agent), Ar (170 sccm, dilution gas); Second stage of deposition: Temperature 1010℃, pressure 1.2 kPa, time 40 min The gas composition for the first 20 minutes was: TiCl4 (10 sccm), 5% B2H6 / H2 mixture (5 sccm), H2 (300 sccm, reducing agent), CH4 (15 sccm, carbon source), HfCl4 (10 sccm, evaporator temperature 80℃), and Ar (170 sccm, dilution gas). The gas composition for the last 20 minutes was HfCl4 (flow rate 20 sccm, evaporator temperature 80℃), CH4 (30 sccm, carbon source), and H2 (300 sccm, reducing agent). Third stage of deposition: Temperature 1150℃, pressure 1.5 kPa, time 30 min; The gas composition at this stage is: HfCl4 (15 sccm, evaporator temperature 80℃), CH4 (gas flow rate 30 sccm, carbon source), H2 (300 sccm, reducing agent), and Ar (155 sccm, dilution gas). After deposition, the flow of TiCl4 and B2H6 / H2 mixed gas was stopped. Under a protective atmosphere of H2 (100 sccm) and Ar (200 sccm), the reactor temperature was reduced to 200℃ at a rate of 5℃ / min. (2) Preparation of nanophase: Weigh Al powder, Mg powder, and B powder in a molar ratio of 1:1:14, and weigh TiO2 nanoparticles. The amount added is 10% of the total mass of Al powder, Mg powder, and B powder. Al powder, Mg powder, and B powder were mixed and heated to 950℃ at a heating rate of 10℃ / min for 1 hour, followed by heating to 1200℃ at a heating rate of 5℃ / min for 4 hours to obtain AlMgB14 ceramic powder. 14 Ceramic powder, TiO2 nanoparticles, and anhydrous ethanol were placed in a planetary ball mill at a ball-to-particle ratio of 10:1 and milled at 300 rpm for 4 hours to obtain a uniformly mixed powder. After vacuum drying, the powder was sintered at 1000℃ and 40 MPa for 2 hours to obtain the nanophase. The amount of anhydrous ethanol added was AlMgB. 14 0.4 times the total mass of ceramic powder and TiO2 nanoparticles; (3) Mixing: Weigh out the toughening phase 15%, nano phase 10%, and aluminum alloy powder 75% by weight percentage; mix the toughening phase, nano phase, and aluminum alloy powder evenly, add them to a ball mill and ball mill to obtain mixture A; weigh out the nano phase 5% and aluminum alloy powder 95% by weight percentage; mix the nano phase and aluminum alloy powder evenly, add them to a ball mill and ball mill to obtain mixture B; the ball-to-material ratio is 8:1, the rotation speed is 180 rpm, and the ball milling time is 3 hours. (4) Cold pressing: The mixed powder is loaded into the mold using an interlayer laying method, and the following steps are followed: a. A 0.5 mm thick layer of pure aluminum alloy powder is laid on the bottom of the mold; b. Lay a 0.3mm thick layer of mixed material A (fiber orientation parallel to the X-axis); c. Lay a 0.1 mm thick layer of mixed material B; d. Lay a 0.3 mm thick layer of mixed material A (fiber orientation parallel to the Y-axis); e. Lay a 0.1 mm thick layer of mixed material B; f. Repeat step be until the mold is full; g. A 0.5 mm thick aluminum alloy powder layer is laid on the top layer; The blank is pressed by holding the pressure at 600 MPa for 20 minutes.

[0021] (5) Vacuum hot pressing sintering: The billet is placed in a high temperature resistance furnace and heated to 575°C at a heating rate of 15°C / min. It is then held at 45MPa for 130min to obtain the alloy precursor. (6) T6 heat treatment: after solution treatment at 515℃ for 2 hours, water quenching and aging at 190℃ for 8 hours, high toughness aluminum alloy material is obtained.

[0022] Example 2: A high-toughness aluminum alloy material, the preparation method of the material is as follows: (1) Preparation of toughening phase: 17 μm silicon carbide fibers were ultrasonically cleaned and dried with acetone, annealed at 900 °C for 35 min in an Ar atmosphere, and then placed in a chemical vapor deposition reactor and evacuated to 10 °C. -3 Pa, introduce Ar protective gas (200 sccm), heat to 1000℃ at a rate of 10℃ / min, and reduce the silicon carbide fiber surface for 10 min by introducing H2 (200 sccm); chemically deposit TiB2-HfC gradient transition layer on the silicon carbide fiber surface in three stages. First stage of deposition: Temperature 1050℃, pressure 1.0 kPa, time 30 min; Gas composition: TiCl4 (20 sccm carried by Ar carrier gas), 5% B2H6 / H2 mixture (10 sccm), H2 (300 sccm, reducing agent), Ar (170 sccm, dilution gas); Second stage of deposition: Temperature 1010℃, pressure 1.2 kPa, time 40 min The gas composition for the first 20 minutes was: TiCl4 (10 sccm), 5% B2H6 / H2 mixture (5 sccm), H2 (300 sccm, reducing agent), CH4 (15 sccm, carbon source), HfCl4 (10 sccm, evaporator temperature 80℃), and Ar (170 sccm, dilution gas). The gas composition for the last 20 minutes was HfCl4 (flow rate 20 sccm, evaporator temperature 80℃), CH4 (30 sccm, carbon source), and H2 (300 sccm, reducing agent). Third stage of deposition: Temperature 1150℃, pressure 1.5 kPa, time 30 min; The gas composition at this stage is: HfCl4 (15 sccm, evaporator temperature 80℃), CH4 (gas flow rate 30 sccm, carbon source), H2 (300 sccm, reducing agent), and Ar (155 sccm, dilution gas). After deposition, the flow of TiCl4 and B2H6 / H2 mixed gas was stopped, and the reactor temperature was cooled to 200℃ at a rate of 5℃ / min under the protective atmosphere of H2 (100 sccm) and Ar (200 sccm). (2) Preparation of nanophase: Weigh Al powder, Mg powder, and B powder in a molar ratio of 1:1:14.3, and weigh TiO2 nanoparticles with a particle size of 50 nm. The amount of TiO2 added is 12% of the total mass of Al powder, Mg powder, and B powder. Al powder, Mg powder, and B powder were mixed and heated to 950℃ at a heating rate of 10℃ / min for 1 hour, followed by heating to 1200℃ at a heating rate of 5℃ / min for 4 hours to obtain AlMgB14 ceramic powder. 14 Ceramic powder, TiO2 nanoparticles, and anhydrous ethanol were placed in a planetary ball mill at a ball-to-particle ratio of 10:1 and milled at 300 rpm for 4 hours to obtain a uniformly mixed powder. After vacuum drying, the powder was sintered at 950℃ and 35 MPa for 1.5 hours to obtain the nanophase. The amount of anhydrous ethanol added was AlMgB. 14 The total mass of ceramic powder and TiO2 nanoparticles is 0.45 times.

[0023] (3) Mixing: Weigh out the toughening phase 17%, nano phase 11%, and aluminum alloy powder 72% by weight percentage; mix the toughening phase, nano phase, and aluminum alloy powder evenly, add them to a ball mill and ball mill to obtain mixture A; weigh out the nano phase 7% and aluminum alloy powder 93% by weight percentage; mix the nano phase and aluminum alloy powder evenly, add them to a ball mill and ball mill to obtain mixture B; the ball-to-material ratio is 9:1, the rotation speed is 170 rpm, and the ball milling time is 2.5 h; (4) Cold pressing: The mixed powder is loaded into the mold using an interlayer laying method, and the following steps are followed: a. A 0.5 mm thick layer of pure aluminum alloy powder is laid on the bottom of the mold; b. Lay a 0.3mm thick layer of mixed material A (fiber orientation parallel to the X-axis); c. Lay a 0.1 mm thick layer of mixed material B; d. Lay a 0.3 mm thick layer of mixed material A (fiber orientation parallel to the Y-axis); e. Lay a 0.1 mm thick layer of mixed material B; f. Repeat step be until the mold is full; g. A 0.5 mm thick aluminum alloy powder layer is laid on the top layer; The blank was pressed by holding the pressure at 600 MPa for 17 minutes. (5) Vacuum hot pressing sintering: The billet is placed in a high temperature resistance furnace and heated to 560°C at a heating rate of 15°C / min. It is then held at 45MPa for 125min to obtain the alloy precursor. (6) T6 heat treatment: after solution treatment at 515℃ for 2 hours, water quenching and aging at 190℃ for 8 hours, high toughness aluminum alloy material is obtained.

[0024] Example 3: A high-toughness aluminum alloy material, the preparation method of the material is as follows: (1) Preparation of toughening phase: 18 μm silicon carbide fibers were ultrasonically cleaned and dried with acetone, annealed at 900 °C for 30 min in an Ar atmosphere, and then placed in a chemical vapor deposition reactor and evacuated to 10 °C. -3 Pa, introduce Ar protective gas (200 sccm), heat to 1000℃ at a rate of 10℃ / min, and reduce the silicon carbide fiber surface for 10 min by introducing H2 (200 sccm); chemically deposit TiB2-HfC gradient transition layer on the silicon carbide fiber surface in three stages. First stage of deposition: Temperature 1050℃, pressure 1.0 kPa, time 30 min; Gas composition: TiCl4 (20 sccm carried by Ar carrier gas), 5% B2H6 / H2 mixture (10 sccm), H2 (300 sccm, reducing agent), Ar (170 sccm, dilution gas); Second stage of deposition: Temperature 1010℃, pressure 1.2 kPa, time 40 min The gas composition for the first 20 minutes was: TiCl4 (10 sccm), 5% B2H6 / H2 mixture (5 sccm), H2 (300 sccm, reducing agent), CH4 (15 sccm, carbon source), HfCl4 (10 sccm, evaporator temperature 80℃), and Ar (170 sccm, dilution gas). The gas composition for the last 20 minutes was HfCl4 (flow rate 20 sccm, evaporator temperature 80℃), CH4 (30 sccm, carbon source), and H2 (300 sccm, reducing agent). Third stage of deposition: Temperature 1150℃, pressure 1.5 kPa, time 30 min; The gas composition at this stage is: HfCl4 (15 sccm, evaporator temperature 80℃), CH4 (gas flow rate 30 sccm, carbon source), H2 (300 sccm, reducing agent), and Ar (155 sccm, dilution gas). After deposition, the flow of TiCl4 and B2H6 / H2 mixed gas was stopped, and the reactor temperature was cooled to 200℃ at a rate of 5℃ / min under the protective atmosphere of H2 (100 sccm) and Ar (200 sccm). (2) Preparation of nanophase: Weigh Al powder, Mg powder, and B powder in a molar ratio of 1:1:14.5, and weigh TiO2 nanoparticles with a particle size of 50 nm. The amount of TiO2 added is 15% of the total mass of Al powder, Mg powder, and B powder. Al powder, Mg powder, and B powder were mixed and heated to 950℃ at a heating rate of 10℃ / min for 1 hour, followed by heating to 1200℃ at a heating rate of 5℃ / min for 4 hours to obtain AlMgB14 ceramic powder. 14 Ceramic powder, TiO2 nanoparticles, and anhydrous ethanol were placed in a planetary ball mill at a ball-to-particle ratio of 10:1 and milled at 300 rpm for 4 hours to obtain a uniformly mixed powder. After vacuum drying, the powder was sintered at 900℃ and 30 MPa for 1 hour to obtain the nanophase. The amount of anhydrous ethanol added was AlMgB. 14 0.5 times the total mass of ceramic powder and TiO2 nanoparticles; (3) Mixing: Weigh out the toughening phase 20%, nano phase 12%, and aluminum alloy powder 68% by weight percentage; mix the toughening phase, nano phase, and AA2024 aluminum alloy powder evenly, add them to a ball mill and ball mill to obtain mixture A; weigh out the nano phase 10% and aluminum alloy powder 90% by weight percentage; mix the nano phase and aluminum alloy powder evenly, add them to a ball mill and ball mill to obtain mixture B; the ball-to-material ratio is 10:1, the rotation speed is 150 rpm, and the ball milling time is 2 hours; (4) Cold pressing: The mixed powder is loaded into the mold using an interlayer laying method, and the following steps are followed: a. A 0.5 mm thick layer of pure aluminum alloy powder is laid on the bottom of the mold; b. Lay a 0.3mm thick layer of mixed material A (fiber orientation parallel to the X-axis); c. Lay a 0.1 mm thick layer of mixed material B; d. Lay a 0.3 mm thick layer of mixed material A (fiber orientation parallel to the Y-axis); e. Lay a 0.1 mm thick layer of mixed material B; f. Repeat step be until the mold is full; g. A 0.5 mm thick aluminum alloy powder layer is laid on the top layer; The blank was pressed by holding the pressure at 600 MPa for 15 minutes. (5) Vacuum hot pressing sintering: The billet is placed in a high temperature resistance furnace and heated to 550°C at a heating rate of 15°C / min. It is then held at 45MPa for 120min to obtain the alloy precursor. (6) T6 heat treatment: after solution treatment at 515℃ for 2 hours, water quenching and aging at 190℃ for 8 hours, high toughness aluminum alloy material is obtained.

[0025] Comparative Example 1: The difference between the preparation method of the high-toughness aluminum alloy material in Comparative Example 1 and Example 2 is that the silicon carbide fiber is not modified; specifically, step (1) is not included; step (3) is modified as follows: weigh 17% silicon carbide fiber, 11% nano phase, and 70% aluminum alloy powder by weight percentage; mix the silicon carbide fiber, nano phase, and aluminum alloy powder, add them to a ball mill for ball milling, and obtain mixture A; weigh 7% nano phase and 93% aluminum alloy powder by weight percentage; mix the nano phase and aluminum alloy powder, add them to a ball mill for ball milling, and obtain mixture B; the ball-to-material ratio is 9:1, the rotation speed is 170 rpm, and the ball milling time is 2.5 h.

[0026] Comparative Example 2: The difference between the preparation method of the high-toughness aluminum alloy material in Comparative Example 2 and Example 2 is that it does not contain the nano phase, specifically step (2) is not included, and step (3) is modified as follows: Mixing: Weigh 17% toughening phase and 93% aluminum alloy powder by weight percentage; mix the toughening phase and aluminum alloy powder evenly and add them to a ball mill for ball milling to obtain mixture A; Weigh 100% aluminum alloy powder by weight percentage and add it to a ball mill for ball milling to obtain mixture B; The ball-to-material ratio is 9:1, the rotation speed is 170 rpm, and the ball milling time is 2.5 h.

[0027] Comparative Example 3: The difference between the preparation method of the high-toughness aluminum alloy material in Comparative Example 3 and Example 2 lies in the different interlayer layup method. Specifically, step (4) is modified to: cold pressing: the mixed powder is loaded into the mold using the interlayer layup method and laid up according to the following steps: a. A 0.5 mm thick layer of pure aluminum alloy powder is laid on the bottom of the mold; b. Lay a 0.3mm thick layer of mixed material A; c. Lay a 0.1 mm thick layer of mixed material B; d. Lay a 0.3 mm thick layer of mixed material A; e. Lay a 0.1 mm thick layer of mixed material B; f. Repeat step be until the mold is full; g. A 0.5 mm thick aluminum alloy powder layer is laid on the top layer; The blank was pressed by holding the pressure at 600 MPa for 17 minutes.

[0028] Test example: Mechanical property testing methods: Tensile strength and elongation were tested to evaluate the mechanical properties of the prepared high-toughness aluminum alloy material. The specific testing methods are as follows: Mechanical property testing was conducted according to GB / T 228.1-2021. The sample length was 140 mm, the width was 18 mm, the gauge length was 50 mm, the thickness was 3 mm, and the tensile speed was 3 mm / min. Tensile strength, yield strength, and elongation were tested. Five samples were tested in each group, and the average value was recorded. The results are shown in Table 1: A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-2 in Table 1 reveals that the high-toughness aluminum alloy material prepared by this invention has good tensile strength and elongation.

[0029] The mechanical properties of Examples 1-3 are superior to those of the comparative examples, indicating that AlMgB 14 - The toughening mechanism of TiO2 nanocomposite ceramic phases exhibits multi-level response characteristics: ball milling process in AlMgB 14 In-situ embedded TiO2 nanoislands at grain boundaries form semi-coherent interfaces, becoming energy traps for dislocation motion; AlMgB2 exhibits high hardness under load. 14 The skeleton forces the crack to bypass, while the local shear strain field induced by TiO2 particles activates aluminum lattice distortion, causing the crack tip to continuously consume kinetic energy.

[0030] The interlayered structure constructs a three-dimensional toughened skeleton, with orthogonally arranged silicon carbide fiber layers forming a spatial defense network: the crack is first forced to turn and propagate along the X-axis fiber, and when it penetrates the B layer of the mixture, the nanophase triggers micro-region plastic deformation to form the first energy dissipation barrier; when the crack continues to invade the vertical Y-axis fiber layer, the crack path is again forcibly deflected by 90°; this periodically occurring orthogonal turning structure causes the crack kinetic energy to decay, and the nanophase composite matrix in the B layer of the mixture plays a key pivotal role—both buffering the stress interference of adjacent fiber layers and delaying interface debonding through nanoparticle bridging; while the surface pure aluminum layer contains residual energy through large-scale plastic deformation in the final fracture stage.

[0031] The synergistic effect of the three components forms a full-scale protection system: the gradient layer resolves the stress concentration at the interface and inhibits crack initiation from the source; the nanophase lays up a microscopic barrier network in the matrix to dissipate the kinetic energy of crack propagation; the orthogonal lay-up transforms the linearly propagating crack into a tortuous energy-dissipating path; and the surface pure aluminum finally completes the energy dissipation closed loop, which enables the material to maintain structural integrity under extreme conditions such as ultra-low temperature impact and high cycle fatigue.

[0032] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No markings in the claims should be construed as limiting the scope of the claims.

Claims

1. A method for preparing a high-toughness aluminum alloy material, comprising the following steps: (1) Preparation of toughening phase: The toughening phase is obtained by forming a TiB2-HfC gradient transition layer on the surface of silicon carbide fiber in three stages; (2) Preparation of nanophase: Al powder, Mg powder and B powder were mixed and heat-treated to obtain AlMgB 14 Ceramic powder; AlMgB 14 The nanophase was obtained by ball milling a mixture of ceramic powder and TiO2 nanoparticles. (3) Mixing: The toughening phase, nano phase and aluminum alloy powder are mixed and ball-milled to obtain mixture A; the nano phase and aluminum alloy powder are mixed to obtain mixture B; (4) Cold pressing: The mixture and aluminum alloy powder are loaded into the mold by interlayer laying method and pressed into a blank; (5) Vacuum hot pressing sintering: The billet is placed in a high temperature resistance furnace, heated to 550-575℃, and held at 45MPa for 120-130min to obtain the alloy precursor; (6) T6 heat treatment: after solution treatment at 515℃ for 2 hours, water quenching and aging at 190℃ for 8 hours, high toughness aluminum alloy material is obtained.

2. The method for preparing high-toughness aluminum alloy material according to claim 1, characterized in that, The preparation method of the toughening phase in step (1) is as follows: after annealing silicon carbide fibers in an Ar atmosphere at 900°C for 30-40 min, the fibers are placed in a chemical vapor deposition reactor and evacuated to 10°C. -3 Pa, Ar gas is introduced for protection, the temperature is raised to 1000℃, and H2 is introduced for 10 min to reduce the surface of silicon carbide fiber; TiB2-HfC gradient transition layer is formed by chemical deposition on the surface of silicon carbide fiber in three stages. First stage of deposition: Temperature 1050℃, pressure 1.0 kPa, time 30 min; gas Composition: TiCl4, 5% B2H6 / H2 mixture, H2 gas, Ar gas; Second stage of deposition: Temperature 1010℃, pressure 1.2 kPa, time 40 min The gas composition for the first 20 minutes was: TiCl4, 5% B2H6 / H2 mixture, H2, CH4, HfCl4, and Ar; The gas composition for the last 20 minutes was HfCl4, CH4, and H2; Third stage of deposition: Temperature 1150℃, pressure 1.5 kPa, time 30 min; The gas composition at this stage is: HfCl4, CH4, H2, and Ar.

3. The method for preparing high-toughness aluminum alloy material according to claim 1, characterized in that, The preparation method of the nanophase in step (2) is as follows: Al powder, Mg powder and B powder are mixed, heated to 950℃ and heat-treated for 1 hour, then heated to 1200℃ and heat-treated for 4 hours to obtain AlMgB. 14 ceramic powder, AlMgB 14 Ceramic powder, TiO2 nanoparticles, and anhydrous ethanol were added to a planetary ball mill at a ball-to-particle ratio of 10:

1. The mixture was ball-milled at 300 rpm for 4 hours and then sintered at 900-1000℃ and 30-40 MPa for 1-2 hours to obtain a nanophase.

4. The method for preparing the high-toughness aluminum alloy material according to claim 3, characterized in that, In step (2), the molar ratio of the alloy powder (Al, Mg, B) is 1:1:(14-14.5); the amount of TiO2 added is 10%-15% of the total mass of Al, Mg, and B powders; and the amount of anhydrous ethanol added is AlMgB. 14 The total mass of ceramic powder and TiO2 nanoparticles is 0.4-0.5 times.

5. The method for preparing high-toughness aluminum alloy material according to claim 1, characterized in that, The preparation method of the mixture A in step (3) is as follows: weigh out the toughening phase 15%-20%, the nano phase 10%-12%, and the aluminum alloy powder 68%-75% by weight percentage; mix the toughening phase, the nano phase, and the aluminum alloy powder evenly, add them to a ball mill and ball mill to obtain the mixture A.

6. The method for preparing high-toughness aluminum alloy material according to claim 1, characterized in that, The preparation method of the mixture B in step (3) is as follows: weigh 5%-10% of nano phase and 90%-95% of aluminum alloy powder by weight percentage; mix the nano phase and aluminum alloy powder evenly, add them to a ball mill for ball milling, and obtain mixture B.

7. The method for preparing the high-toughness aluminum alloy material according to any one of claims 5 or 6, characterized in that, The ball milling conditions are as follows: ball-to-material ratio of (8-10):1, rotation speed of 150-180 rpm, and ball milling time of 2-3 hours.

8. The method for preparing high-toughness aluminum alloy material according to claim 1, characterized in that, The preparation method of the green body in step (4) is as follows: the mixed powder is loaded into the mold by interlayer placement, and the powder is laid out according to the following steps: a. A 0.5 mm thick layer of pure aluminum alloy powder is laid on the bottom of the mold; b. Lay a 0.3mm thick layer of mixed material A (fiber orientation parallel to the X-axis); c. Lay a 0.1 mm thick layer of mixed material B; d. Lay a 0.3 mm thick layer of mixed material A (fiber orientation parallel to the Y-axis); e. Lay a 0.1 mm thick layer of mixed material B; f. Repeat step be until the mold is full; g. A 0.5 mm thick aluminum alloy powder layer is laid on the top layer; Press the blank by holding the pressure at 600 MPa for 15-20 minutes.

9. The method for preparing high-toughness aluminum alloy material according to claim 1, characterized in that, The silicon carbide fiber mentioned in step (1) is a 15-18 μm fiber.

10. A high-toughness aluminum alloy material prepared by the method according to claim 1.

Images