Micro-nano reinforced high-iron-content 6-series aluminum alloy and preparation method thereof

Abstract

This invention proposes a micro-nano reinforced high-iron-content 6-series aluminum alloy and its preparation method, belonging to the field of aluminum alloy technology. A second mixed particle is prepared by rotary coating a mixture of aluminum-magnesium-silicon alloy strips with a homogeneous mixture of nanoparticles and aluminum-magnesium-silicon alloy powder, forming a mixed particle wire. Recycled aluminum is formulated into a 6-series aluminum-magnesium-silicon alloy and melted in a fuel gas atmosphere. The molten aluminum is then poured into a heat-insulated flow bath, where nitrogen is blown in to purify the flow. Subsequently, the mixed particle wire is added along with the molten aluminum, casting it into a semi-continuous casting ingot. After homogenization, the ingot is extruded. Following T6 heat treatment, a micro-nano reinforced high-iron-content 6-series aluminum alloy is obtained. This invention improves the strength of recyclable 6-series aluminum alloys, offers a simple and efficient preparation method, a short manufacturing cycle, durability, and a smooth, crack-free module surface, making it of significant importance.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy technology, specifically to a micro-nano reinforced 6-series aluminum alloy with high iron content and its preparation method. Background Technology

[0002] 6-series aluminum alloys possess advantages such as good mechanical properties, excellent weldability, superior formability, and fine machining capabilities. Furthermore, they exhibit low density and corrosion resistance, making them widely used in lightweight profiles for new energy vehicles, where high performance requirements and large demand are present. With the continuous increase in aluminum consumption, the amount of scrap aluminum generated is also increasing. However, due to the difficulty in effectively removing Fe during recycling, high-Fe content 6-series aluminum alloys not only induce harmful precipitates that degrade performance but are also difficult to remove effectively during recycling, limiting their use and recycling. It is worth noting that 6-series aluminum alloys have poor high-temperature performance, and high alloy content makes formability extremely difficult, which will also negatively impact the processing and application of aluminum alloy profiles. Therefore, to address the current industrial demand for high-performance aluminum alloys and solve the challenges of forming high-Fe content aluminum alloys, developing a high-performance, recyclable 6-series aluminum alloy is of great significance. Summary of the Invention

[0003] The purpose of this invention is to propose a micro-nano reinforced 6-series aluminum alloy with high iron content and its preparation method. By using micro-nano particles, the strength of recyclable 6-series aluminum alloy is improved. The preparation method is simple and efficient, with a short manufacturing cycle, and is durable. The module surface is smooth and crack-free. This invention is of great significance for improving the quality and performance level of domestic recyclable 6-series aluminum alloy and reducing production costs.

[0004] The technical solution of this invention is implemented as follows:

[0005] This invention provides a method for preparing micro / nano-reinforced high-iron-content 6-series aluminum alloys, comprising the following steps:

[0006] Step 1: The Ti-Zr-Al alloy wire is fed into an electro-explosion reaction device. After the Ti-Zr-Al alloy wire is electro-exploded and atomized, it reacts with nitrogen to form micro-nano titanium nitride, zirconium nitride and aluminum nitride particles, resulting in a mixture of three micro-nano ceramic particles. This process prepares the first mixed nanoparticle containing micro-nano titanium nitride, zirconium nitride and aluminum nitride particles.

[0007] Step 2: Rotate and coat the first mixed nanoparticles and the second mixed particles, which are uniformly mixed with aluminum-magnesium-silicon alloy powder, with an aluminum-magnesium-silicon alloy strip to prepare a mixed particle wire.

[0008] Step 3: The recycled aluminum is formulated into a six-series aluminum-magnesium-silicon alloy, which is then melted into molten aluminum in a gas atmosphere. After the molten aluminum is produced, it enters a heat-insulating flow tank. Nitrogen gas is blown into the flow tank for purification. Then, along with the molten aluminum, the mixed granular wire is added. Subsequently, online mechanical stirring and ultrasonic treatment are added to the flow tank to cast it into a semi-continuous casting ingot. Ultrasonic treatment is applied to the top of the semi-continuous casting ingot until the casting of the semi-continuous casting ingot is completed.

[0009] Step 4: After homogenization treatment, the ingot is extruded and formed; after T6 heat treatment, a micro-nano reinforced aluminum alloy with high iron content is obtained.

[0010] As a further improvement of the present invention, in step one, the preparation of the first mixed nanoparticles includes the following steps:

[0011] Step 1: The Ti-Zr-Al alloy wire is fed into the electro-explosion reaction device. After the titanium alloy is electro-exploded and atomized, it reacts with nitrogen to form micro-nano titanium nitride, zirconium nitride and aluminum nitride particles, resulting in a mixed particle of the three ceramics, which is the first mixed particle; high voltage and high frequency voltage 500-2200V, current 30-45A;

[0012] Step 2: In the mixed powder, the mass fraction of micro-nano titanium nitride, zirconium nitride and aluminum nitride particles is 1.5%-15%, and the remainder is aluminum-magnesium-silicon alloy powder, which is the second mixed particle.

[0013] Step 3: Refining aluminum alloy with nitrogen blowing; ultrasonic treatment frequency of 20,000 Hz, casting 20 tons of semi-continuous casting ingots at one time;

[0014] Step 4: Extrusion temperature 450-540℃, extrusion rate 0.15-3.2m / min; Heat treatment process: solution treatment at 525-548℃ for 8-15h, followed by water quenching and immediate artificial aging treatment at 150-190℃ for 5-20h.

[0015] As a further improvement of the present invention, the composition of the aluminum-magnesium-silicon alloy powder is: Fe: 0.8-1.6 wt.%, Mn: 0.8-1.6 wt.%, Mg: 0.5-1.5 wt.%, Si: 0.8-1.9 wt.%, Zn: 0.15-0.45 wt.%, Cu: 0.0-0.36 wt.%, Cr: 0.10-0.20 wt.%, Mo: 0.10-0.20 wt.%, Zr: 0.12-0.25 wt.%, Al: balance; the composition of the aluminum-magnesium-silicon alloy strip is: Fe: 0.8-1.6 wt.%, Mn: 0.8-1.6 wt. The composition of the Ti-Zr-Al alloy wire is as follows: Ti: 0.55-0.80, Zr: 0.15-0.45, Al: 0.0-0.36 wt.%, Mg: 0.5-1.5 wt.%, Si: 0.8-1.9 wt.%, Zn: 0.15-0.45 wt.%, Cu: 0.0-0.36 wt.%, Cr: 0.10-0.20 wt.%, Mo: 0.10-0.20 wt.%, Zr: 0.12-0.25 wt.%, Al: balance; the purity of the nitrogen gas is 99.9-99.999 vol.%, and the composition of the wire is as follows: Ti: 0.55-0.80, Zr: 0.15-0.45, Al: 0.05-0.10; diameter 2.5-3.5 mm.

[0016] As a further improvement of the present invention, in step two, the rotation speed of the mixer is set to 50-100 r / min, and the mixing time is set to 20-30 h.

[0017] As a further improvement of the present invention, in step two, nitrogen gas is introduced into the vacuum reaction chamber to control the gas pressure in the vacuum reaction chamber at 0.05MPa-0.25MPa.

[0018] As a further improvement of the present invention, in step three, the temperature of the resistance furnace is set to 1123K, and Mn element is added after the temperature of the aluminum alloy melt reaches 1073K.

[0019] As a further improvement of the present invention, in step three, the amount of mixed particle wire added is controlled so that the total mass of micro-nano titanium nitride, aluminum nitride and vanadium nitride particles accounts for 0.015-0.3 wt.% of the mass of aluminum liquid, and the mixed particle wire is preheated to 500°C before being added.

[0020] As a further improvement of the present invention, in step four, the aluminum ingot is heated to 450-540°C and extruded at a rate of 0.15-3.2 m / min.

[0021] As a further improvement of the present invention, in step four, the heat treatment process is as follows: solution treatment at 525-548℃ for 8-15 hours, followed by water quenching and then artificial aging treatment at 150-190℃ for 5-20 hours.

[0022] This invention further protects a micro-nano reinforced high-iron-content 6-series aluminum alloy prepared by the above-described preparation method.

[0023] The present invention has the following beneficial effects:

[0024] This invention improves the strength of recyclable 6-series aluminum alloys by using micro-nano particles. The preparation method is simple and efficient, with a short manufacturing cycle, and the alloys are durable. The module surface is smooth and crack-free. It solves the adverse effects of iron-rich phases to a certain extent and facilitates the extrusion molding of high-alloy 6-series aluminum alloys, resulting in better room temperature and high temperature performance. This invention is of great significance for improving the quality and performance of domestic recyclable 6-series aluminum alloys and reducing production costs. Attached image description:

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a microstructure diagram of the extruded EBSD of Embodiment 1 of the present invention.

[0027] Figure 2 This is a diagram showing the room temperature tensile properties of Example 1 of the present invention.

[0028] Figure 3 This is a diagram showing the high-temperature tensile properties of Example 1 of the present invention.

[0029] Figure 4 This is a microstructure diagram of the compressed EBSD in Embodiment 2 of the present invention.

[0030] Figure 5 This is a diagram showing the room temperature tensile properties of Example 2 of the present invention.

[0031] Figure 6 This is a high-temperature tensile property diagram of Example 2 of the present invention.

[0032] Figure 7 This is a microstructure diagram of the compressed EBSD in Example 3 of the present invention.

[0033] Figure 8 This is a diagram showing the room temperature tensile properties of Example 3 of the present invention.

[0034] Figure 9 This is a high-temperature tensile property diagram of Example 3 of the present invention.

[0035] Figure 10This is a microstructure diagram of the compressed EBSD of Comparative Example 1 of the present invention.

[0036] Figure 11 This is a diagram showing the room temperature tensile properties of Comparative Example 1 of the present invention.

[0037] Figure 12 This is a diagram showing the high-temperature tensile properties of Comparative Example 1 of the present invention. Detailed Implementation

[0038] 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.

[0039] The composition of aluminum-magnesium-silicon alloy powder is as follows: Fe: 0.8-1.6 wt.%, Mn: 0.8-1.6 wt.%, Mg: 0.5-1.5 wt.%, Si: 0.8-1.9 wt.%, Zn: 0.15-0.45 wt.%, Cu: 0.0-0.36 wt.%, Cr: 0.10-0.20 wt.%, Mo: 0.10-0.20 wt.%, Zr: 0.12-0.25 wt.%, Al: balance.

[0040] The composition of the aluminum-magnesium-silicon alloy strip is as follows: Fe: 0.8-1.6 wt.%, Mn: 0.8-1.6 wt.%, Mg: 0.5-1.5 wt.%, Si: 0.8-1.9 wt.%, Zn: 0.15-0.45 wt.%, Cu: 0.0-0.36 wt.%, Cr: 0.10-0.20 wt.%, Mo: 0.10-0.20 wt.%, Zr: 0.12-0.25 wt.%, Al: balance.

[0041] The composition of Ti-Zr-Al alloy wire is: Ti: 0.55-0.80, Zr: 0.15-0.45, Al: 0.05-0.10; diameter 2.5-3.5 mm.

[0042] Preparation Example 1: Preparation of the First Hybrid Nanoparticle

[0043] Includes the following steps:

[0044] Step 1: The Ti-Zr-Al alloy wire is fed into the electro-explosion reaction device. After the titanium alloy is electro-exploded and atomized, it reacts with nitrogen to form micro-nano titanium nitride, zirconium nitride and aluminum nitride particles, resulting in a mixed particle of the three ceramics, which is the first mixed particle; high voltage and high frequency: 1200V, current 37A.

[0045] Step 2: In the mixed powder, the mass fraction of micro-nano titanium nitride, zirconium nitride and aluminum nitride particles is 10%, and the remainder is aluminum-magnesium-silicon alloy powder, which is the second mixed particle.

[0046] Step 3: Refining aluminum alloy with nitrogen blowing; ultrasonic treatment frequency of 20,000 Hz, casting 20 tons of semi-continuous casting ingots at one time;

[0047] Step 4: Extrusion temperature 490℃, extrusion rate 2.2m / min; Heat treatment process: solution treatment at 538℃ for 12h, followed by water quenching and immediate artificial aging treatment at 170℃ for 10h.

[0048] Example 1

[0049] This embodiment provides a method for preparing micro / nano-reinforced high-iron-content 6-series aluminum alloys, comprising the following steps:

[0050] (1) Nitrogen gas was introduced into the vacuum reaction chamber to control the gas pressure in the vacuum reaction chamber at 0.05 MPa. The first mixed nanoparticles prepared in Example 1 were prepared by rotating and coating with aluminum-magnesium-silicon alloy strips, and the second mixed particles were mixed evenly with aluminum-magnesium-silicon alloy powder. The speed of the mixer was set to 50 r / min and the mixing time was set to 20 h to prepare mixed particle wire.

[0051] (2) Prepare a six-series aluminum-magnesium-silicon alloy from recycled aluminum (Fe: 1.20wt.%, Mn: 0.75wt.%, Mg: 1.0wt.%, Si: 1.2wt.%, Zn: 0.20wt.%, Cu: 0.30wt.%, Cr: 0.10wt.%, Zr: 0.12wt.%, Al: balance), turn on the resistance furnace to melt the alloy into aluminum liquid, and after the aluminum liquid is discharged, it enters the heat preservation flow tank, and nitrogen is blown into the flow tank for purification;

[0052] (3) Subsequently, along with the aluminum liquid, the mixed particle wire is added, and then online mechanical stirring and ultrasonication are added in the flow channel to cast a semi-continuous casting ingot. Ultrasonication is added to the top of the semi-continuous casting rod until the casting of the semi-continuous casting rod is completed. Mn element is added after the temperature of the aluminum alloy melt reaches 1073K.

[0053] (4) After homogenization treatment, the ingot is extruded and formed; after T6 heat treatment, a six-series aluminum alloy with micro-nano strengthening and high iron content is obtained. The aluminum ingot is heated to 450℃ and extruded and formed at an extrusion rate of 0.15m / min and an extrusion wall thickness of 1.5mm. The heat treatment process is as follows: solution treatment at 525℃ for 8 hours, water quenching, and then artificial aging treatment at 150℃ for 5 hours.

[0054] The final composition of the high-speed rail VI series aluminum alloy is as follows: Fe: 1.2 wt.%, Mn: 1.3 wt.%, Mg: 1.0 wt.%, Si: 1.2 wt.%, Zn: 0.20 wt.%, Cu: 0.30 wt.%, Cr: 0.10 wt.%, Zr: 0.12 wt.%, Al: balance.

[0055] The temperature of the electric furnace is 1123K.

[0056] The nitrogen gas has a purity of 99.9-99.999 vol.%.

[0057] The addition of the Mn element requires wrapping pure Mn powder in aluminum foil and pressing it into a block. The three types of micro / nano particle wires need to be preheated to 723K before addition.

[0058] The particle content is 0.30 wt.%.

[0059] The homogenization process was performed at 560℃ for 12 hours.

[0060] Compared to the alloy in Comparative Example 1, the micro / nano high-iron content hexagonal aluminum alloy obtained through the examples exhibits a more uniform extrusion deformation structure, which facilitates anisotropy elimination. Its yield strength, ultimate tensile strength, and elongation at break are 428.1 MPa, 451.6 MPa, and 15.3%, respectively. Compared to the industrially produced low-iron hexagonal alloy in Comparative Example 1, the micro / nano high-iron content hexagonal aluminum alloy maintains its original high plasticity while significantly improving its strength, specifically, the yield strength and ultimate tensile strength increase by 50.4% and 46%, respectively. Under 573 K conditions, compared to the industrially produced low-iron content hexagonal alloy in Comparative Example 1, the yield strength, ultimate tensile strength, and elongation at break are increased by 29.8%, 21.0%, and 5.3%, respectively, reaching 126.8 MPa, 132.3 MPa, and 29.9%.

[0061] Example 2

[0062] This embodiment provides a method for preparing micro / nano-reinforced high-iron-content 6-series aluminum alloys, comprising the following steps:

[0063] (1) Nitrogen gas was introduced into the vacuum reaction chamber to control the gas pressure in the vacuum reaction chamber at 0.25 MPa. The first mixed nanoparticles prepared in Example 1 were prepared by rotating and coating with aluminum-magnesium-silicon alloy strips, and the second mixed particles were mixed evenly with aluminum-magnesium-silicon alloy powder. The speed of the mixer was set to 100 r / min and the mixing time was set to 30 h to prepare mixed particle wire.

[0064] (2) Prepare a six-series aluminum-magnesium-silicon alloy from recycled aluminum (Fe: 1.30wt.%, Mn: 0.8wt.%, Mg: 1.0wt.%, Si: 1.2wt.%, Zn: 0.35wt.%, Cu: 0.30wt.%, Cr: 0.10wt.%, Zr: 0.12wt.%, Al: balance), turn on the resistance furnace to melt the alloy into aluminum liquid, and after the aluminum liquid is discharged, it enters the heat preservation flow tank, and nitrogen is blown into the flow tank for purification.

[0065] (3) Subsequently, along with the aluminum liquid, the mixed particle wire is added, and then online mechanical stirring and ultrasonication are added in the flow channel to cast a semi-continuous casting ingot. Ultrasonication is added to the top of the semi-continuous casting rod until the casting of the semi-continuous casting rod is completed. Mn element is added after the temperature of the aluminum alloy melt reaches 1073K.

[0066] (4) After homogenization treatment, the ingot is extruded and formed; after T6 heat treatment, a six-series aluminum alloy with micro-nano strengthening and high iron content is obtained. The aluminum ingot is heated to 540℃ and extruded and formed at an extrusion rate of 3.2m / min and an extrusion wall thickness of 2.5mm. The heat treatment process is as follows: solution treatment at 548℃ for 15h, water quenching, and then artificial aging treatment at 190℃ for 20h.

[0067] The final composition of the high-speed rail VI series aluminum alloy is as follows: Fe: 1.3 wt.%, Mn: 1.35 wt.%, Mg: 1.0 wt.%, Si: 1.2 wt.%, Zn: 0.35 wt.%, Cu: 0.30 wt.%, Cr: 0.10 wt.%, Zr: 0.12 wt.%, Al: balance.

[0068] The temperature of the electric furnace is 1123K.

[0069] The nitrogen gas has a purity of 99.9-99.999 vol.%.

[0070] The process of adding nitrogen gas for in-flow purification in the flow channel and performing the process at 1100K for 30 minutes was described.

[0071] The particle content is 0.15 wt.%.

[0072] The homogenization process was performed at 560℃ for 12 hours.

[0073] The micro / nano high-iron-content hexagonal aluminum alloy obtained in this example exhibits a more uniform and finer extruded microstructure compared to the alloy in Comparative Example 1, while also exhibiting a weakened texture. At room temperature, the yield strength, ultimate tensile strength, and elongation at break are 396.3 MPa, 429.1 MPa, and 18.1%, respectively. Compared to the industrially produced low-iron-content hexagonal alloy in Comparative Example 1, the micro / nano high-iron-content hexagonal aluminum alloy shows a 13.8% increase in plasticity, while simultaneously increasing the yield strength by 39.3% and the ultimate tensile strength by 38.8%. At 573 K, the yield strength, ultimate tensile strength, and elongation at break are 116.7 MPa, 119.3 MPa, and 30.8%, respectively. Compared to the industrially produced low-iron-content hexagonal alloy in Comparative Example 1, the yield strength, ultimate tensile strength, and elongation at break are increased by 19.4%, 9.1%, and 8.5%, respectively.

[0074] Example 3

[0075] This embodiment provides a method for preparing micro / nano-reinforced high-iron-content 6-series aluminum alloys, comprising the following steps:

[0076] (1) Nitrogen gas was introduced into the vacuum reaction chamber to control the gas pressure in the vacuum reaction chamber at 0.15 MPa. The first mixed nanoparticles prepared in Example 1 were prepared by rotating and coating with aluminum-magnesium-silicon alloy strips, and the second mixed particles were mixed evenly with aluminum-magnesium-silicon alloy powder. The speed of the mixer was set to 70 r / min and the mixing time was set to 25 h to prepare mixed particle wire.

[0077] (2) Prepare a six-series aluminum-magnesium-silicon alloy from recycled aluminum (Fe: 1.50wt.%, Mn: 0.8wt.%, Mg: 1.0wt.%, Si: 1.2wt.%, Zn: 0.35wt.%, Cu: 0.30wt.%, Cr: 0.10wt.%, Zr: 0.12wt.%, Al: balance), turn on the resistance furnace to melt the alloy into aluminum liquid, and after the aluminum liquid is discharged, it enters the heat preservation flow tank, and nitrogen is blown into the flow tank for purification.

[0078] (3) Subsequently, along with the aluminum liquid, the mixed particle wire is added, and then online mechanical stirring and ultrasonication are added in the flow channel to cast a semi-continuous casting ingot. Ultrasonication is added to the top of the semi-continuous casting rod until the casting of the semi-continuous casting rod is completed. Mn element is added after the temperature of the aluminum alloy melt reaches 1073K.

[0079] (4) After homogenization treatment, the ingot is extruded and formed; after T6 heat treatment, a six-series aluminum alloy with micro-nano strengthening and high iron content is obtained. The aluminum ingot is heated to 480℃ and extruded and formed at an extrusion rate of 2.2m / min and an extrusion wall thickness of 3.5mm. The heat treatment process is as follows: solution treatment at 538℃ for 10h, water quenching, and then artificial aging treatment at 170℃ for 10h.

[0080] The final composition of the high-speed rail VI series aluminum alloy is as follows: Fe: 1.5 wt.%, Mn: 1.5 wt.%, Mg: 1.0 wt.%, Si: 1.2 wt.%, Zn: 0.35 wt.%, Cu: 0.30 wt.%, Cr: 0.10 wt.%, Zr: 0.12 wt.%, Al: balance.

[0081] The temperature of the electric furnace is 1123K.

[0082] The nitrogen gas has a purity of 99.9-99.999 vol.%.

[0083] The nitrogen-blowing purification process in the flow channel was carried out at 1123K for 35 minutes.

[0084] The particle content is 0.10 wt.%.

[0085] The homogenization process was performed at 560℃ for 12 hours.

[0086] Compared to the alloy in Comparative Example 1, the microstructure of the extruded sheet of the high-iron-content six-series aluminum alloy obtained through this example is significantly refined. The yield strength, ultimate tensile strength, and elongation at break under room temperature conditions reach 367.2 MPa, 400.8 MPa, and 19.2%, respectively, representing increases of 29.1%, 29.6%, and 20.7%. The strength-ductility product also increases from 4524 MPa·% to 7050 MPa·%, an increase of 55.8%. Under 573 K conditions, the yield strength, ultimate tensile strength, and elongation at break of the high-iron-content six-series aluminum alloy are 108.2 MPa, 113.5 MPa, and 32.1%, respectively, with yield strength and ultimate tensile strength increasing by 10.7% and 3.8%, respectively, and ductility increasing by 13.0%.

[0087] Comparative Example 1

[0088] This comparative example is a low-iron-content six-series aluminum alloy without added nanoparticles, as detailed below:

[0089] (1) Commercial 6061 aluminum rods (Fe: 0.2wt.%, Mn: 0.8wt.%, Mg: 1.0wt.%, Si: 1.2wt.%, Zn: 0.35wt.%, Cu: 0.30wt.%, Al: balance) are placed in an electric resistance furnace to melt the alloy into aluminum liquid. After the aluminum liquid is discharged, it enters a heat-insulating flow tank. Nitrogen gas is blown into the flow tank for purification.

[0090] (2) Add 0.8 wt.% of the total mass of the melt to the melt and stir continuously. Cast the melt after the temperature reaches 1023 K.

[0091] (3) After homogenization treatment, the ingot is extruded and formed; after T6 heat treatment, a micro-nano reinforced high iron content six-series aluminum alloy is obtained. The aluminum ingot is heated to 450℃ and extruded and formed at an extrusion rate of 0.15m / min. The extruded wall thickness is 2.5mm. The heat treatment process is as follows: solution treatment at 525℃ for 8h, water quenching, and then artificial aging treatment at 150℃ for 5h immediately.

[0092] The temperature of the electric furnace is 1123K.

[0093] The nitrogen gas has a purity of 99.9-99.999 vol.%.

[0094] The process of adding nitrogen gas for in-flow purification in the flow channel and performing the purification at 1123K for 30 minutes was described.

[0095] The homogenization process was performed at 560℃ for 12 hours.

[0096] The industrial low-iron-content VI-series aluminum alloy obtained through this step differs from that in Examples 1-3 in that it does not contain the first mixed nanoparticles prepared in Preparation Example 1 and has a very low content of the harmful element Fe. The alloy of Comparative Example 1 exhibits a yield strength, ultimate tensile strength, and elongation at break of 284.5 MPa, 309.2 MPa, and 15.9%, respectively, at room temperature. At a high temperature of 573 K, the yield strength, ultimate tensile strength, and elongation at break are 97.7 MPa, 109.3 MPa, and 28.4%, respectively.

[0097] The performance of the micro-nano reinforced high iron content six-series aluminum alloys prepared in Examples 1-3 and Comparative Example 1 of this invention was tested, and the results are shown in Table 1.

[0098] Table 1

[0099]

[0100]

[0101] As shown in the table above, the high-iron-content hexa-series aluminum alloys reinforced with micro-nano particles obtained in Examples 1-3 of this invention, using micro-nano titanium nitride, zirconium nitride, and aluminum nitride particles prepared by an electro-explosion reaction device, are easily dispersed in the melt and maintain good interfacial bonding. Simultaneously, when mixed with hexa-series aluminum powder and added to the molten aluminum in wire form, this contributes to the uniform distribution of micro-nano particles in the melt. During high-temperature extrusion, the addition of micro-nano particles, acting as hard points for high-temperature thermal stability, effectively pins dislocation movement and hinders grain boundary movement during hot deformation, accelerating dynamic recrystallization and dynamic recovery, ultimately resulting in finer recrystallized grains. The presence of these particles significantly improves the segregation phenomenon caused by alloying elements, especially the morphology of the iron-rich phase under high Fe content. This weakens the adverse effects of Fe, resulting in stronger room-temperature strength and plasticity. Furthermore, the finer, more dispersed high-temperature precipitates introduced by the particles greatly improve the mechanical properties under high-temperature conditions.

[0102] The micro-nano reinforced high-iron-content hexagonal aluminum alloy provided by this invention effectively solves the problem of insufficient performance of high-iron-content recycled aluminum, and contributes to the further development of high-performance recyclable hexagonal aluminum alloys.

[0103] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a micro-nano reinforced high-iron-content 6-series aluminum alloy, characterized in that, Includes the following steps: Step 1: The Ti-Zr-Al alloy wire is fed into an electro-explosion reaction device. After electro-explosion atomization, the Ti-Zr-Al alloy wire reacts with nitrogen gas to form micro-nano titanium nitride, zirconium nitride, and aluminum nitride particles, resulting in a mixture of three micro-nano ceramic particles. This process prepares the first mixed nanoparticles containing micro-nano titanium nitride, zirconium nitride, and aluminum nitride particles. The composition of the Ti-Zr-Al alloy wire is: Ti: 0.55-0.80, Zr: 0.15-0.45, Al: 0.05-0.

10. Step 2: Rotate and coat the first mixed nanoparticles and the second mixed particles, which are uniformly mixed with aluminum-magnesium-silicon alloy powder, with an aluminum-magnesium-silicon alloy strip to prepare a mixed particle wire. Step 3: The recycled aluminum is formulated into a six-series aluminum-magnesium-silicon alloy and smelted into molten aluminum in a fuel gas atmosphere. After the molten aluminum is discharged, it enters a heat-insulating flow tank. Nitrogen gas is blown into the flow tank for purification. Subsequently, mixed granular wire is added along with the molten aluminum. Online mechanical stirring and ultrasonication are then applied in the flow tank to cast a semi-continuous casting ingot. Ultrasonication is continued at the top of the semi-continuous casting ingot until casting is complete. The amount of mixed granular wire added is controlled so that the total mass of micro / nano titanium nitride, aluminum nitride, and vanadium nitride particles accounts for 0.015-0.3 wt.% of the molten aluminum. Step 4: After homogenization treatment, the ingot is extruded and formed; after T6 heat treatment, a micro-nano reinforced aluminum alloy with high iron content is obtained.

2. The production method according to claim 1, characterized by, In step one, the preparation of the first mixed nanoparticles includes the following steps: Step 1: The Ti-Zr-Al alloy wire is fed into the electro-explosion reaction device. After the titanium alloy is electro-exploded and atomized, it reacts with nitrogen to form micro-nano titanium nitride, zirconium nitride and aluminum nitride particles, resulting in a mixed particle of the three ceramics, which is the first mixed nanoparticle; high voltage and high frequency: 500-2200V, current 30-45A. Step 2: In the first mixed nanoparticles, the mass fraction of micro-nano titanium nitride, zirconium nitride and aluminum nitride particles is 1.5%-15%, and the remainder is aluminum-magnesium-silicon alloy powder, which is the second mixed particle. Step 3: Refining aluminum alloy with nitrogen blowing; ultrasonic treatment frequency of 20,000 Hz, casting 20 tons of semi-continuous casting ingots at one time; Step 4: Extrusion temperature 450-540℃, extrusion rate 0.15-3.2m / min; Heat treatment process: solution treatment at 525-548℃ for 8-15h, followed by water quenching and immediate artificial aging treatment at 150-190℃ for 5-20h.

3. The method of claim 2, wherein, The composition of the aluminum-magnesium-silicon alloy powder is: Fe: 0.8-1.6 wt.%, Mn: 0.8-1.6 wt.%, Mg: 0.5-1.5 wt.%, Si: 0.8-1.9 wt.%, Zn: 0.15-0.45 wt.%, Cu: 0.0-0.36 wt.%, Cr: 0.10-0.20 wt.%, Mo: 0.10-0.20 wt.%, Zr: 0.12-0.25 wt.%, Al: balance; the composition of the aluminum-magnesium-silicon alloy strip is: Fe: 0.8-1.6 wt.%, Mn: 0.8-1.6 wt.%, Mg: 0.5-1.5 wt.%, Si: 0.8-1.9 wt.%, Zn: 0.15-0.45 wt.%, Cu: 0.0-0.36 wt.%. wt.%, Cr: 0.10-0.20wt.%, Mo: 0.10-0.20wt.%, Zr: 0.12-0.25wt.%, Al: balance, the nitrogen purity is 99.9-99.999 vol.%, the Ti-Zr-Al alloy wire composition is: Ti: 0.55-0.80, Zr: 0.15-0.45, Al: 0.05-0.10; diameter 2.5-3.5 mm.

4. The preparation method according to claim 3, characterized in that, In step two, the speed of the mixer is set to 50-100 r / min, and the mixing time is set to 20-30 h.

5. The preparation method according to claim 4, characterized in that, In step two, nitrogen gas is introduced into the vacuum reaction chamber to control the gas pressure inside the vacuum reaction chamber at 0.05 MPa-0.25 MPa.

6. The preparation method according to claim 5, characterized in that, In step three, the temperature of the resistance furnace is set to 1123K, and Mn is added after the temperature of the aluminum alloy melt reaches 1073K.

7. The production method according to claim 6, wherein In step three, the mixed granular wire must be preheated to 500°C before being added.

8. The production method according to claim 7, characterized by, In step four, the aluminum ingot is heated to 450-540℃ and extruded at a rate of 0.15-3.2 m / min.

9. The preparation method according to claim 8, characterized in that, In step four, the heat treatment process is as follows: solution treatment at 525-548℃ for 8-15 hours, followed by water quenching and then artificial aging treatment at 150-190℃ for 5-20 hours.

10. A micro-nano reinforced high-iron-content 6-series aluminum alloy prepared by the preparation method according to any one of claims 1-9.

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