Aluminum alloy material and preparation method and application thereof

Abstract

The invention discloses an aluminum alloy material and a preparation method and application thereof, and relates to the technical field of alloy materials. The aluminum alloy material disclosed by the invention comprises the following components: 0.60 to 0.85 percent of Si, 0 to 0.10 percent of Fe, 0.50 to 1.2 percent of Cu, 0.15 to 0.25 percent of Mn, 0.75 to 0.90 percent of Mg, 0.05 to 0.10 percent of Cr, 0.05 to 0.10 percent of La, 0.05 to 0.10 percent of Zr, 0.003 to 0.02 percent of Ti, 0 to 0.02 percent of Zn, less than or equal to 0.1 percent of other inevitable impurities, and the balance of Al. Under the condition that the extrusion property of the aluminum alloy material is guaranteed, the mechanical properties including the tensile strength, the yield strength and the percentage elongation after fracture are improved, and the problem of material lines after extrusion is solved.

Description

Technical Field

[0001] This invention relates to the field of alloy materials technology, and in particular to an aluminum alloy material, its preparation method, and its application. Background Technology

[0002] Al-Mg-Si-Cu aluminum alloys have been widely used in the 3C industry due to their advantages such as beautiful appearance after anodizing, excellent mechanical properties, good corrosion resistance, and ease of processing.

[0003] With the increasing popularity of foldable phones, higher strength requirements have been placed on aluminum alloy materials in end products. Against this backdrop, many manufacturers have begun to use 7xxx series aluminum alloys (high-strength aluminum alloys with zinc as the main alloying element, and also containing magnesium, copper, and other elements) for the manufacture of mobile phone components. However, 7xxx series aluminum alloys have significant drawbacks: poor corrosion resistance, stringent processing requirements, and unsatisfactory anodizing results. While 6xxx series aluminum alloys (heat-treatable aluminum alloys with magnesium and silicon as the main alloying elements) are more suitable for the needs of the 3C industry in terms of anodizing performance and processing adaptability, their extruded profiles generally suffer from low mechanical properties (tensile strength ≤400MPa) due to limitations in current production technology.

[0004] In addition, aluminum alloy materials used in the 3C field often exhibit surface defects such as grain lines, spots, and discoloration after anodizing. Grain lines, in particular, are difficult to avoid due to the influence of metal flow characteristics during extrusion processing. Summary of the Invention

[0005] The present invention aims to at least solve one of the aforementioned technical problems existing in the prior art. Therefore, one objective of the present invention is to provide an aluminum alloy material that, through designing the alloy composition, improves mechanical properties and mitigates the problem of material texture after extrusion while ensuring the extrudability of the aluminum alloy material.

[0006] The second objective of this invention is to provide a method for preparing aluminum alloy materials.

[0007] The third objective of this invention is to provide an extruded profile.

[0008] The fourth objective of this invention is to provide a method for preparing extruded profiles.

[0009] The fifth objective of this invention is to provide an application of aluminum alloy materials or extruded profiles.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A first aspect of the present invention provides an aluminum alloy material, wherein the aluminum alloy material comprises the following components by weight percentage: Si: 0.60~0.85%, Fe: 0~0.10%, Cu: 0.50~1.2%, Mn: 0.15~0.25%, Mg: 0.75~0.90%, Cr: 0.05~0.10%, La: 0.05~0.10%, Zr: 0.05~0.10%, Ti: 0.003~0.02%, Zn: 0~0.02%, other unavoidable impurities ≤0.1%, balance Al.

[0011] In the aluminum alloy material of the present invention, when both Si and Mg elements are present, age-strengthening phases such as Mg2Si are formed. As the content of Si and Mg increases, the tensile strength of the resulting aluminum alloy material also increases. However, the increase of Mg and Si content will increase the extrusion difficulty and solid solution difficulty, resulting in a reduction in the anode effect of the extruded profile of the aluminum alloy material.

[0012] Cu can improve the dispersion of precipitated phases in aluminum alloys, forming the AlMgSi(Cu) phase together with Mg and Si. It also plays a role in solid solution strengthening. However, excessive Cu will increase the high-temperature flow resistance of aluminum alloys, reduce extrusion performance, increase the difficulty of extrusion production, and is not conducive to reducing production costs.

[0013] Mn, Cr, and Zr are trace alloying elements in the aluminum alloy material of this invention, playing a role in dispersion strengthening and controlling grain structure while inhibiting grain growth. During homogenization, Mn forms dispersed MnAl phases of varying sizes. These dispersed phases effectively prevent grain nucleation and growth during hot working or heat treatment, promote fibrous structure formation, or block recrystallized grain growth, thereby improving the strength of the aluminum alloy material. Mn also facilitates the transformation of acicular β (AlFeSi) phase into spherical α (AlFeMnSi) phase, improving extrusion performance. However, when the Mn content increases to a certain level, coarse MnAl compound particles are easily generated, increasing extrusion difficulty and quenching sensitivity. Cr has a similar effect to Mn, effectively inhibiting grain growth. However, Mn has low solid solubility in aluminum, easily causing segregation during casting. To better inhibit recrystallization, a certain amount of Cr is added, but excessive addition is not advisable, as excessive dispersed phases increase the rheological stress of the material, significantly increasing the extrusion difficulty. The addition of Zr can better serve as a nucleation site for the precipitation of Mn and Cr elements, refine Mn and Cr compounds, and at the same time, Al3Zr particles can also play a role in inhibiting recrystallization, thus better controlling the grain size.

[0014] The presence of Fe is detrimental to the mechanical properties of aluminum alloys and increases their recrystallization temperature, hindering the formation of recrystallized structures during hot working. When Fe and Si coexist, they form AlFeSi(Mn) phases, existing as eutectic compounds. The presence of Fe phases in insoluble or sparingly soluble aluminum matrices easily leads to the formation of micropores on the anodized surface, reducing its gloss and the anodizing effect. Therefore, this invention requires controlling the Fe content.

[0015] In the casting stage, La can effectively refine the grains of the cast rod, improve the strength and toughness of materials resistant to hot cracking, and enhance the machinability of aluminum alloys, making them less prone to cracking during large deformation extrusion. The formed Al-La compounds can also serve as nucleation sites for Mg2Si precipitation strengthening phases, further improving the strength of aluminum alloys. However, excessive La can agglomerate with Ti, producing large compound particles that affect the anodizing effect of aluminum alloys; therefore, its addition amount needs to be strictly controlled.

[0016] In some embodiments, the mass ratio of Mg to Si in the aluminum alloy material satisfies Mg / Si = 0.95~1.35. It should be understood that Mg / Si is the mass ratio of Mg:Si, i.e., Mg / Si = 0.95~1.35 means Mg:Si = (0.95~1.35):1. Wherein, Mg / Si can be 0.95, 0.97, 0.98, 0.99, 1.0, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, or 1.35, or any other value within the above range. Preferably, the mass ratio of Mg to Si satisfies Mg / Si = 1.0~1.2; more preferably 1.0~1.1; and even more preferably 1.0~1.06.

[0017] By further optimizing the Mg / Si ratio, the strength of aluminum alloy materials can be improved, and the extrusion difficulty can be controlled. In particular, when the Mg / Si ratio is controlled at 1.0~1.2, the improvement effect of this ratio on strength and extrusion difficulty can be maximized.

[0018] In some embodiments, the mass percentage of Si in the aluminum alloy material can be 0.60%, 0.61%, 0.62%, 0.63%, 0.65%, 0.68%, 0.70%, 0.72%, 0.73%, 0.75%, 0.76%, 0.77%, 0.78%, 0.80%, 0.82%, 0.83%, 0.84%, or 0.85%, or any other value within the range of 0.60% to 0.85%. Preferably, the mass percentage of Si is 0.7% to 0.85%; more preferably, it is 0.8% to 0.85%.

[0019] In some embodiments, the mass percentage of Fe in the aluminum alloy material can be 0%, 0.05%, 0.06%, 0.065%, 0.07%, 0.075%, 0.08%, 0.083%, 0.085%, 0.09%, or 0.1%, or any other value within the range of 0 to 0.1% or any other range composed of any two points, such as 0.05 to 0.1%, 0.06 to 0.1%, 0.07 to 0.1%, or 0.08 to 0.1%. Theoretically, the lower the Fe content, the more beneficial it is for improving the anodizing effect and mechanical properties of the aluminum alloy material. However, this invention controls it to below 0.1%, and in conjunction with the design of other components, it can also enable the aluminum alloy material to have excellent mechanical properties and extrudability, resulting in extruded profiles with good mechanical properties and anodizing effect.

[0020] In some embodiments, the mass percentage of Cu in the aluminum alloy material can be 0.50%, 0.52%, 0.54%, 0.55%, 0.56%, 0.60%, 0.62%, 0.65%, 0.68%, 0.70%, 0.72%, 0.73%, 0.75%, 0.78%, 0.80%, 0.83%, 0.85%, 0.88%, 0.90%, 0.92%, 0.95%, 0.98%, 1.0%, 1.05%, 1.08%, 1.1%, 1.13%, 1.15%, 1.16%, 1.17%, 1.18%, or 1.2%, or any other value within the range of 0.50% to 1.2%. Preferably, the mass percentage of Cu is 0.7% to 1.2%; more preferably, 1.9% to 1.2%; and even more preferably, 1.0% to 1.2%.

[0021] In some embodiments, the mass percentage of Mn in the aluminum alloy material can be 0.15%, 0.16%, 0.17%, 0.18%, 0.2%, 0.22%, 0.23%, 0.24%, or 0.25%, or any other value within the range of 0.15% to 0.25%. Preferably, the mass percentage of Mn is 0.2% to 0.25%; more preferably, it is 0.22% to 0.25%.

[0022] In some embodiments, the mass percentage of Mg in the aluminum alloy material can be 0.75%, 0.76%, 0.78%, 0.80%, 0.82%, 0.83%, 0.85%, 0.86%, 0.88%, 0.89%, or 0.90%, or any other value within the range of 0.75% to 0.90%. Preferably, the mass percentage of Mg is 0.80% to 0.90%; more preferably, it is 0.85% to 0.90%; and even more preferably, it is 0.86% to 0.90%.

[0023] In some embodiments, the mass percentage of Cr in the aluminum alloy material can be 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, or 0.10%, or any other value within the range of 0.05% to 0.10%. Preferably, the mass percentage of Cr is 0.06% to 0.10%; more preferably, it is 0.06% to 0.09%; and even more preferably, it is 0.06% to 0.08%.

[0024] In some embodiments, the mass percentage of La in the aluminum alloy material can be 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, or 0.10%, or any other value within the range of 0.05% to 0.10%. Preferably, the mass percentage of La is 0.06% to 0.10%; more preferably, it is 0.06% to 0.08%; and even more preferably, it is 0.06% to 0.07%.

[0025] In some embodiments, the mass percentage of Zr in the aluminum alloy material can be 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, or 0.10%, or any other value within the range of 0.05% to 0.10%. Preferably, the mass percentage of Zr is 0.06% to 0.10%; more preferably, 0.06% to 0.09%; more preferably, 0.06% to 0.08%; and even more preferably, 0.06% to 0.07%.

[0026] In some embodiments, the mass percentage of Ti in the aluminum alloy material can be 0.003%, 0.004%, 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, 0.01%, 0.012%, 0.013%, 0.015%, 0.018%, or 0.02%, or any other value within the range of 0.003% to 0.02%. Preferably, the mass percentage of Ti is 0.005% to 0.015%; more preferably, it is 0.007% to 0.015%; and even more preferably, it is 0.01% to 0.015%.

[0027] In some embodiments, the mass percentage of Zn in the aluminum alloy material can be 0, 0.001%, 0.005%, 0.01%, 0.015%, or 0.02%, or any other value within the range of 0 to 0.02%. Specifically, the mass percentage of Zn in the aluminum alloy material is 0%.

[0028] A second aspect of the present invention provides a method for preparing the aluminum alloy material described in the first aspect of the present invention, comprising the following steps: The aluminum alloy material is obtained by mixing and melting various raw materials containing aluminum alloy components, followed by refining, casting, and homogenization.

[0029] In some embodiments, the mixed melting includes the following steps: heating and melting aluminum ingots to obtain aluminum melt I; adding aluminum-zirconium master alloy to aluminum melt I, and then adding magnesium ingots, aluminum-silicon master alloy, aluminum-manganese master alloy, aluminum-chromium master alloy and aluminum-copper master alloy after melting to obtain aluminum melt II.

[0030] In some embodiments, the refining temperature is 700-800°C. Preferably, the refining temperature is 720-780°C; more preferably, it is 730-750°C.

[0031] In some embodiments, the refining time is 30-60 minutes. Preferably, the refining time is 30-50 minutes; more preferably, it is 35-45 minutes.

[0032] In some embodiments, argon gas is introduced during the refining process for stirring, venting, and slag removal. Preferably, the pressure of the argon gas is 0.05~0.1MPa; the flow rate of the argon gas is 5~15L / min, more preferably 8~12L / min.

[0033] In some embodiments, the refining process further includes a settling, hydrogen removal, and purification step. The settling time is 20-50 minutes; preferably 20-40 minutes. The hydrogen content after hydrogen removal is 0.1-0.14 mL / 100gAl. The purification is carried out through a filtration system.

[0034] In some embodiments, the casting is a semi-continuous water-cooled casting method.

[0035] In some embodiments, the casting temperature is 700~800°C. Preferably, the casting temperature is 700~750°C; more preferably, it is 710~730°C.

[0036] In some embodiments, a Ti-containing material, such as aluminum-titanium-boron alloy wire, is added during the casting process.

[0037] In some embodiments, the homogenization process includes a two-stage homogenization process, wherein: First stage: Temperature 400~500℃, heat preservation time 3~7h; Second stage: Temperature 520~620℃, heat preservation time 6~15h.

[0038] Specifically, in the homogenization process, the temperature of the first stage can be 400℃, 420℃, 430℃, 450℃, 460℃, 480℃, 500℃, or any other value within the above temperature range. Preferably, the temperature of the first stage is 420~480℃; more preferably, 430~470℃; and even more preferably, 440~460℃. Preferably, the heat preservation time of the first stage is 4~6 hours.

[0039] Specifically, in the homogenization process, the temperature of the second stage can be 520℃, 550℃, 555℃, 560℃, 565℃, 570℃, 575℃, 580℃, 600℃, or 620℃, or any other value within the above temperature range. Preferably, the temperature of the second stage is 550~580℃; more preferably, 555~575℃; and even more preferably, 560~570℃. Preferably, the heat preservation time of the second stage is 8~12 hours.

[0040] In some embodiments, the homogenization process includes a cooling step; the cooling is achieved using water mist cooling.

[0041] A third aspect of the present invention provides an extruded profile, wherein the raw materials for preparing the extruded profile include the aluminum alloy material described in the first aspect of the present invention.

[0042] A fourth aspect of the present invention provides a method for preparing the extruded profile described in the third aspect of the present invention, comprising the following steps: The aluminum alloy material is heated and then subjected to extrusion, quenching, stretching, and aging to obtain the extruded profile.

[0043] In some embodiments, the aluminum alloy material is heated to 540~560°C, that is, the temperature of the aluminum alloy material itself is controlled at 540~560°C before extrusion; more preferably, it is 555~560°C.

[0044] In some embodiments, the extrusion ratio is 15-30; more preferably 20-30; and even more preferably 22-25.

[0045] In some embodiments, the extrusion speed is 1~5 mm / s; more preferably 1~2 mm / s.

[0046] In some embodiments, the quenching cooling rate is ≥50°C / s. Specifically, the cooling rate is achieved by immersing the extruded product in water at 10~50°C for 5 seconds. For example, the water temperature can be 10°C, 20°C, 30°C, 40°C, 50°C, or other ranges composed of point values, such as 20~30°C.

[0047] In some embodiments, the stretching amount is 0.5-3%; more preferably 0.5-2%; and even more preferably 1-2%. Stretching achieves material straightening while removing residual stress.

[0048] In some embodiments, the aging temperature is 160~200℃; more preferably 170~190℃. The aging time is 5~15h; more preferably 8~12h.

[0049] In some embodiments, the mold used in the extrusion process includes a mold body; a forming channel is provided in the mold body; the forming channel includes, in sequence along the material conveying direction, a feed hole, a guide hole, a deformation channel, a sizing belt and a discharge hole; wherein, the deformation channel includes at least one blocking part, the blocking part being able to prevent the projection of the feed hole and the guide hole along the material conveying direction from passing through the deformation channel.

[0050] This invention utilizes a special mold design to alter the deformation during the extrusion process, combined with the composition design of the aluminum alloy material, to achieve the effects of fine grains and high strength in the extruded material. Specifically, the extrusion mold of this invention is divided into three parts. The first part is the guide section (including the feed hole and guide hole), whose main function is to guide the material into the mold and control the amount of material entering to control the material size and pre-deformation. The second part is the high-deformation zone (i.e., the deformation channel), which, through a special channel design, increases the degree of material deformation, thereby allowing the material to recrystallize. Under the control of the material composition, the recrystallized size is small and uniform, while the design details of the deformation zone must be controlled to prevent the degree of deformation from being too high, which would make extrusion difficult. The third part is the sizing section (sizing zone), which functions similarly to the working zone of a conventional extrusion mold, ensuring that the dimensions of the extruded product meet the usage requirements.

[0051] In other embodiments, the blocking part is an upwardly convex structure; the guide hole is smaller than the feed hole; the highest point of the blocking part is higher than the upper edge of the inlet of the guide hole; or the highest point of the blocking part is level with the upper edge of the inlet of the guide hole.

[0052] In other embodiments, the deformable channel includes an upwardly protruding curved channel, the lower part of which forms the blocking portion. Specifically, the curved channel has an inverted V-shaped structure, and the included angle α between the two sides of the blocking portion is 90° to 120°.

[0053] In other embodiments, the material conveying direction is set from front to back, and the height of the sizing belt is less than the height of the discharge hole, so as to form a stepped empty blade position at the junction of the sizing belt and the discharge hole, with the upper part of the empty blade position located behind the lower part of the empty blade position.

[0054] In other embodiments, the upper length of the sizing belt is E, and the lower length of the sizing belt is F, where E = F ± ΔL, and ΔL is a set error range. Specifically, E = 3mm~10mm, F = 3mm~10mm, and ΔL = 0.5mm.

[0055] In other embodiments, the sizing belt maintains a consistent length in all directions or is within a set error range.

[0056] In other embodiments, the discharge port has a flared structure along the material conveying direction.

[0057] In other embodiments, the depth of the feed hole is 10mm to 20mm.

[0058] The fifth aspect of the present invention provides an application of the aluminum alloy material described in the first aspect of the present invention or the extruded profile described in the third aspect of the present invention in the preparation of 3C products.

[0059] Compared with the prior art, the beneficial effects of the present invention are: 1) This invention provides an aluminum alloy material that, through special composition design, improves mechanical properties, including tensile strength, yield strength, and elongation after fracture, while ensuring the extrudability of the aluminum alloy material, and improves the problem of material texture after extrusion. The profile obtained after extrusion of this aluminum alloy material has a tensile strength ≥410MPa, a yield strength ≥400MPa, and an elongation after fracture ≥10% in the T6 state.

[0060] 2) The extruded profile of the present invention uses the aluminum alloy material of the present invention as raw material. It has excellent mechanical properties, high tensile strength, high yield strength and good elongation after fracture. At the same time, the anodizing effect is significantly improved, overcoming the surface defects such as material texture, spots and discoloration that often occur after anodizing of aluminum alloy materials used in the traditional 3C field. In particular, it has a significant improvement on material texture and is suitable for the preparation of 3C products. Attached Figure Description

[0061] Figure 1 This is a schematic diagram of the structure of the extrusion die for high-strength materials according to an embodiment of the present invention; Figure 2 This is a front view of the extrusion die for high-strength materials according to an embodiment of the present invention; Figure 3 for Figure 2 Schematic diagram of the cross-sectional structure of AA; Figure 4 for Figure 3 A magnified view of part B in the diagram.

[0062] right Figures 1-4The numbering of the attached figures is explained as follows: The mold body 100, feed hole 101, guide hole 102, deformation channel 103, sizing band 104, discharge hole 105, blocking part 110, upper part of empty tool position 106a, and lower part of empty tool position 106b. Detailed Implementation

[0063] The present invention will be further described in detail below through specific embodiments. Unless otherwise specified, the raw materials, reagents, or apparatus used in the embodiments and comparative examples are all available from conventional commercial sources or can be obtained by existing technical methods. Unless otherwise specified, the test or experimental methods are conventional methods in the art.

[0064] The raw materials used in the following embodiments and comparative examples of the present invention are described below: Aluminum ingots: Al 99.7 grade aluminum ingots are used, with Al content of 99.70% or higher, Fe content of less than 0.06%, and Zn content of less than 0.02%, conforming to standard GB / T 1196-2023.

[0065] Magnesium ingots: Magnesium ingots of grade Mg99.90 are used, with a Mg mass percentage of over 99.9%, conforming to standard GB / T 3499-2023.

[0066] Alloy additives: Aluminum silicon, aluminum manganese, aluminum chromium, and aluminum zirconium are made from AlSi. 12 AlMn 10 AlCr 10 The AlZr5 master alloy conforms to the GB / T 27677-2017 standard; the aluminum and copper alloys are made of AlCu. 40 The intermediate alloy conforms to the YS / T282-2000 standard.

[0067] Grain refiner: Aluminum-titanium-boron alloy wire, conforming to YS / T 447.1-2023 Alloy wire for grain refinement of aluminum and aluminum alloys, Part 1.

[0068] Refining agent: PROMAG RI granular refining agent is used, conforming to standard YS / T491-2020.

[0069] The mold structure used in the following embodiments of the present invention is as follows: Figures 1-4 As shown, the mold includes a mold body 100, and a forming channel is provided inside the mold body 100. The forming channel includes, in sequence along the material conveying direction, a feed hole 101, a guide hole 102, a deformation channel 103, a sizing belt 104, and a discharge hole 105. The depth C of the feed hole is 10mm~20mm, which can be adjusted according to the material feeding situation.

[0070] The deformation channel 103 includes an upwardly protruding curved channel, and a blocking part 110 is formed at the lower part of the curved channel. The curved channel has an inverted V-shaped structure. The flow distance of the material at the lower part of the deformation channel 103 is less than that of the material at the upper part of the deformation channel 103, so that the lower material enters the sizing belt 104 before the upper material. The included angle α on both sides of the blocking part 110 is 90°~120°, for example, it can be 120° in the embodiment of the present invention.

[0071] The blocking part 110 can prevent the projection of the guide hole 102 along the material conveying direction from passing through the deformation channel 103, so that the material will not pass directly through the deformation channel 103. All materials must be squeezed and deformed by the deformation channel 103 before they can pass through. The highest point of the blocking part 110 is higher than the upper edge of the inlet of the guide hole 102, or the highest point of the blocking part 110 is level with the upper edge of the inlet of the guide hole 102. That is, the height difference between the highest point of the blocking part 110 and the upper edge of the inlet of the guide hole 102 is B, B≥0mm. Thus, the blocking part 110 can completely prevent the material from passing directly from front to back through the deformation channel 103, ensuring the amount of material deformation.

[0072] The sizing belt 104 maintains a consistent length in all directions or falls within a set error range. This means the inner wall extension length of the sizing belt 104 remains consistent at all positions or falls within a set error range, ensuring that the material passes through the sizing belt 104 at equal intervals. The set error range can be set according to the characteristics of the material; for example, in this embodiment, it is set to ±0.5 mm. The upper length of the sizing belt is E, and the lower length is F, where E = F ± ΔL, and ΔL is the set error range. Specifically, E = 3 mm to 10 mm, F = 3 mm to 10 mm, and ΔL = 0.5 mm. This error range can be adjusted based on the material discharge during extrusion to ensure smooth material extrusion.

[0073] The material conveying direction is set from front to back, and the height of the sizing belt 104 is less than the height of the discharge hole 105, so that a stepped empty blade position is formed at the junction of the sizing belt 104 and the discharge hole 105. The empty blade position refers to the recessed structure (stepped structure) behind the mold working belt (sizing belt 104) to reduce friction and optimize the smoothness of material discharge. Setting the discharge hole 105 as a flared structure can further reduce friction and reduce the resistance of material forming output. The upper part 106a of the empty blade position is located behind the lower part 106b of the empty blade position. After the material is output to the sizing belt 104 through the deformation channel 103, it first enters the discharge hole 105 from the lower part 106b of the empty blade position, and then enters the discharge hole 105 from the upper part 106a of the empty blade position to improve the uniformity of material extrusion at the sizing belt 104.

[0074] The following detailed description is provided in conjunction with specific embodiments and comparative examples.

[0075] Example 1 An aluminum alloy material, the composition of which is shown in Table 1, is prepared by the following steps: S1. Prepare the raw materials according to the formula ratio in Table 1, and put the aluminum ingots into the smelting furnace (regenerative energy-saving furnace). The temperature inside the furnace is controlled at 750~780℃ so that the aluminum ingots are completely melted into aluminum melt I. S2. Add AlZr5 master alloy to the aluminum melt I obtained in step S1. After it has fully melted, add magnesium ingot and other master alloys (AlSi). 12 AlMn 10 AlCr 10 AlCu 40 The mixture is stirred and melted to perform preliminary alloying, resulting in aluminum melt II. S3. Add a refining agent to the aluminum melt II obtained in step S2 at a dosage of 1 kg / ton of aluminum melt II. The refining temperature is 730~750℃ and the refining time is 40 min. During the refining process, the aluminum melt is subjected to chemical composition analysis. If the alloy composition is not within the range of the proportions in Table 1, the alloy composition is controlled within the range of the proportions in Table 1 by fine-tuning the composition. At the same time as refining, high-purity argon gas (purity ≥99.999%) is introduced into the aluminum melt through the permeable bricks at the bottom of the furnace for stirring and venting. Then, the slag is removed to obtain aluminum melt III. The argon gas pressure is controlled at 0.05~0.1 MPa and the flow rate is controlled at 10 L / min. S4. Perform alloy element analysis on the aluminum melt III obtained after refining in step S3. If the alloy composition is not within the range of proportions in Table 1, adjust the composition to control it within the range of proportions in Table 1. Then let the aluminum melt III stand for 30 minutes to obtain aluminum melt IV. S5. Use a degassing device to remove hydrogen, and control the hydrogen content of the aluminum melt IV obtained in step S4 to 0.12 mL / 100 g; S6. A two-stage filtration system is used for purification, namely, filtration using an 80-mesh foam ceramic filter plate and an RD tubular filter; S7. A semi-continuous water-cooled casting method is adopted, the casting temperature is controlled at 720℃, and aluminum alloy ingots are obtained by casting. During the casting process, a finer agent is added according to the proportion in Table 1. S8. Place the aluminum alloy ingot obtained in step S7 in a homogenization heat treatment furnace, heat it to 450°C for 5 hours within 3 hours, then heat it to 565°C for 10 hours to perform homogenization treatment, and then cool it rapidly with water mist to room temperature for 1 hour to obtain aluminum alloy material.

[0076] The aluminum alloy material obtained in this embodiment is prepared into an extruded profile, and the preparation method is as follows: 1) Cut the aluminum alloy material (aluminum rod) obtained in this embodiment into 500mm lengths and heat it in a slow-speed aluminum rod heating furnace. The temperature of Zone 1 (inlet preheating zone) is 500℃, the temperature of Zone 2 (intermediate heat preservation zone) is 565℃, and the temperature of Zone 3 (outlet zone) is 555℃. Heat for 2 hours (from inlet to outlet). 2) The heated aluminum alloy material from step 1) is loaded into an extrusion press for extrusion. The extrusion die uses the improved deformation die of this invention (e.g., Figures 1-4 As shown), the temperature of the aluminum alloy material before entering the extruder ingot cylinder is 555~560℃. During extrusion, the extrusion ratio (i.e., the extrusion coefficient, the ratio of the cross-sectional area of ​​the extrusion cylinder cavity to the total cross-sectional area of ​​the extruded product) is set to 24, the extrusion speed (main cylinder forward speed) is 1.5mm / s, and the extrusion outlet temperature is 558~568℃. 3) After the alloy product comes out of the extrusion die, it enters a water bath at 25°C within 5 seconds to achieve a cooling rate of more than 50°C / s, thus enabling the alloy product to be quenched online. 4) Use a stretching machine to stretch the alloy product, controlling the stretching amount to 1.0%; 5) Hold at 180℃ for 10 hours and then perform artificial aging to obtain the extruded profile.

[0077] Examples 2-4 An aluminum alloy material, the composition ratio of which is shown in Table 1, is prepared using the same method as in Example 1.

[0078] Extruded profiles were prepared using the aluminum alloy materials of Examples 2-4, and the preparation method was the same as that of Example 1.

[0079] Comparative Examples 1-3 An aluminum alloy material, the composition ratio of which is shown in Table 1, is prepared using the same method as in Example 1.

[0080] Extruded profiles were prepared using aluminum alloy materials from Comparative Examples 1 to 3, and the preparation method was the same as in Example 1.

[0081] Comparative Example 4 An aluminum alloy material, the composition ratio of which is shown in Table 1, is prepared in a way that differs from that of Example 1 in that the special mold designed in this invention is not used in the extrusion process, but a conventional aluminum alloy profile mold is used; the rest is the same as in Example 1.

[0082] Extruded profiles were prepared using aluminum alloy material from Comparative Example 4, and the preparation method was the same as in Example 1.

[0083] Comparative Examples 5-6 An aluminum alloy material, the composition ratio of which is shown in Table 1, is prepared using the same method as in Example 1.

[0084] Extruded profiles were prepared using aluminum alloy materials from Comparative Examples 5 and 6, respectively, using the same preparation method as in Example 1.

[0085] Comparative Example 7 An aluminum alloy material, the composition ratio of which is shown in Table 1, is prepared in a way that differs from that of Example 1 in that: the homogenization heat treatment does not employ a two-stage homogenization heat treatment, but directly heats to 565℃ and holds for 10 hours; the rest is the same as in Example 1.

[0086] Extruded profiles were prepared using aluminum alloy material from Comparative Example 7, and the preparation method was the same as in Example 1.

[0087] Comparative Example 8 An aluminum alloy material, the composition ratio of which is shown in Table 1, is prepared using the same method as in Example 1.

[0088] Extruded profiles were prepared using aluminum alloy material of Comparative Example 8. The preparation method differed from that of Example 1 in that: in step 2), the temperature of the aluminum alloy material before entering the extruder ingot cylinder was 540~550℃, and the heating temperature in step 1) was adjusted according to this temperature; the rest was the same as in Example 1.

[0089] Comparative Examples 9-12 An aluminum alloy material, the composition ratio of which is shown in Table 1, is prepared using the same method as in Example 1.

[0090] Extruded profiles were prepared using aluminum alloy materials from Comparative Examples 9 to 12, and the preparation method was the same as in Example 1.

[0091] Table 1. Composition ratio of aluminum alloy materials in the examples and comparative examples (by mass percentage)

[0092] Table 1 shows that the total amount of other unavoidable impurities in aluminum alloy materials is ≤0.1%.

[0093] Result detection The extruded profiles obtained in the above embodiments and comparative examples were tested.

[0094] The extruded profile is a sheet material with a diameter of 88*9mm. During the extrusion process, the edge cracking is observed with the naked eye.

[0095] Mechanical properties (including tensile strength, yield strength and elongation after fracture) test standard: GB / T 228.1-2021 Metallic materials, tensile testing - Part 1: Test method at room temperature.

[0096] After sampling the extruded profile products, the width and thickness directions are machined by CNC (computer numerical control) to 3mm and 0.5mm respectively, followed by mechanical mirror polishing, and then degreasing sulfuric acid anodizing. The appearance effect is observed by the naked eye, and the thickness of the anodized film is 10μm.

[0097] The test results are shown in Table 2 below.

[0098] Table 2. Extrusion of Aluminum Alloy Materials and Test Results of Extruded Profiles

[0099] Based on the test results in Table 2, the performance analysis of the aluminum alloy materials and extruded profiles in the examples and comparative examples is as follows: In Comparative Examples 1 and 2, increasing the content of trace elements Mn, Cr, and Zr and main alloying elements Si, Mg, and Cu in the aluminum alloy materials significantly increases the extrusion deformation resistance of the resulting aluminum alloy materials. However, the mold designed in this invention can increase the degree of deformation and greatly improve the extrusion rheological stress, causing the aluminum alloy materials of Comparative Examples 1 and 2 to be unable to be extruded due to excessive extrusion deformation resistance.

[0100] Comparative Example 3 reduced the content of the main alloying elements, which led to a decrease in the effect of second phase precipitation strengthening in aluminum alloy materials, resulting in a decrease in the mechanical properties of the extruded profiles and failure to meet the expected requirements.

[0101] Comparative Example 4 uses the same chemical composition as the aluminum alloy material in Example 2, but it is produced using a conventional extrusion die. The resulting extruded profile not only has low mechanical properties, but also has serious material texture defects after anodizing due to uneven deformation after processing.

[0102] Comparative Example 5 reduced trace elements such as Mn, Cr, and Zr to reduce extrusion deformation resistance. However, the reduction in element content led to a decrease in the number of high-temperature dispersed phases, which could not suppress abnormal grain growth to the greatest extent under extrusion deformation. This resulted in coarse-grained structure in the extruded profile, low mechanical properties, especially a significant decrease in elongation.

[0103] In Comparative Example 6, no rare earth element La was added. Due to the absence of the relevant effect of La, the high-temperature crack resistance of the material decreased under large deformation extrusion conditions, resulting in cracking of the extruded profile and failing to maximize the deformation effect of the extrusion die.

[0104] Comparative Example 7 uses the same aluminum alloy material chemical composition as Example 2, but omits the first-stage homogenization process (i.e., only one homogenization step is used). Due to the lack of the first-stage targeted precipitation treatment, the precipitated particles of the high-temperature dispersed phase are larger, which reduces the effect of controlling the grain size in the homogenization process. As a result, large-sized grains are generated after extrusion, and the mechanical properties of the extruded profile are reduced.

[0105] Comparative Example 8 uses the same aluminum alloy material chemical composition as in Example 3. The extrusion temperature was lowered during the extrusion stage, which helped improve extrusion efficiency and reduce the risk of cracking. However, due to the lower extrusion temperature, the aluminum alloy material could not be completely solution extruded, resulting in the precipitation of a large number of Mg2Si or AlMgSiCu particles. These particles not only failed to play a strengthening role but also reduced the mechanical properties of the extruded profile. Furthermore, they detached during the anodizing process of the product, generating a large number of micropores, which led to the "numbness" phenomenon in the anodizing effect of the extruded profile.

[0106] The aluminum alloy material in Comparative Example 9 was designed with a high La content to improve extrusion efficiency without cracking. However, the excessive La element resulted in an excessive number of AlLa compounds, which could not be completely dissolved during the extrusion process. As coarse compounds, they were arranged along the extrusion direction after extrusion, resulting in slight texture defects in the extruded profile after anodizing.

[0107] Comparative Examples 10 and 11 were designed with different Mg / Si ratios. Compared with Example 4, Comparative Example 10 had a lower Mg / Si ratio, resulting in a higher Si content. During extrusion quenching, Si agglomerated at grain boundaries, increasing quenching sensitivity, lower extrusion speed, and unsatisfactory quenching effect, leading to a decrease in the elongation of the extruded profile. Compared with Example 1, Comparative Example 11 had a higher Mg / Si ratio, resulting in insufficient Si content. This prevented the Mg2Si or AlMgSiCu phases from precipitating to their fullest extent and becoming finely dispersed. Even with a higher total Mg / Si content, the strengthening phase advantage could not be maximized, resulting in a lower yield strength of the extruded profile.

[0108] Comparative Example 12 adopted a high Mn composition design. Due to the increased Mn content, the extrusion difficulty of the aluminum alloy material was increased, which made it impossible to increase the extrusion speed. At the same time, Mn also increased the quenching sensitivity of the material. The combined effect of these two factors led to the premature precipitation of the strengthening phase during the extrusion process, which reduced the strengthening effect and resulted in lower mechanical properties of the extruded profile.

[0109] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. An aluminum alloy material, characterized in that, The aluminum alloy material comprises the following components by weight percentage: Si: 0.60~0.85%, Fe: 0~0.10%, Cu: 0.50~1.2%, Mn: 0.15~0.25%, Mg: 0.75~0.90%, Cr: 0.05~0.10%, La: 0.05~0.10%, Zr: 0.05~0.10%, Ti: 0.003~0.02%, Zn: 0~0.02%, other unavoidable impurities ≤0.1%, balance Al.

2. The aluminum alloy material according to claim 1, characterized in that, In the aluminum alloy material, the mass ratio of Mg to Si satisfies Mg / Si = 0.95~1.

35.

3. A method for preparing the aluminum alloy material according to claim 1 or 2, characterized in that, Includes the following steps: The aluminum alloy material is obtained by mixing and melting various raw materials containing aluminum alloy components, followed by refining, casting, and homogenization.

4. The preparation method according to claim 3, characterized in that, The refining temperature is 700~800℃; And / or, the refining time is 30-60 minutes.

5. The preparation method according to claim 3, characterized in that, The casting temperature is 700~800℃.

6. The preparation method according to claim 3, characterized in that, The homogenization process includes a two-stage homogenization process, wherein: First stage: Temperature 400~500℃, heat preservation time 3~7h; Second stage: Temperature 520~620℃, heat preservation time 6~15h.

7. An extruded profile, characterized in that, The raw materials for preparing the extruded profile include the aluminum alloy material as described in claim 1 or 2.

8. A method for preparing an extruded profile according to claim 7, characterized in that, Includes the following steps: The aluminum alloy material is heated and then subjected to extrusion, quenching, stretching, and aging to obtain the extruded profile.

9. The method for preparing extruded profiles according to claim 8, characterized in that, The mold used in the extrusion process includes a mold body; a forming channel is provided in the mold body; the forming channel includes, in sequence along the material conveying direction, a feed hole, a guide hole, a deformation channel, a sizing belt and a discharge hole; wherein, the deformation channel includes at least one blocking part, the blocking part can prevent the projection of the feed hole and the guide hole along the material conveying direction from passing through the deformation channel.

10. The application of the aluminum alloy material of claim 1 or 2 or the extruded profile of claim 7 in the manufacture of 3C products.

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