High-strength aluminum alloy building material for door and window curtain walls and preparation method of high-strength aluminum alloy building material

Abstract

The invention belongs to the technical field of aluminum alloy building profiles, and provides a high-strength aluminum alloy building material for door and window curtain walls and a preparation method of the high-strength aluminum alloy building material. The aluminum alloy bar is sequentially subjected to heating, extrusion, cooling and saw cutting, the aluminum alloy profile is prepared, the bar temperature of the heated aluminum alloy bar ranges from 450 DEG C to 510 DEG C, the extrusion speed ranges from 1 m / min to 10 m / min, the outlet temperature after extrusion is larger than or equal to 515 DEG C, and according to the cooling speed, the cooling time for cooling to 100 DEG C is smaller than or equal to 2 min; and the aluminum alloy section is subjected to aging treatment, the high-strength aluminum alloy building material is prepared, the aging treatment temperature ranges from 160 DEG C to 210 DEG C, and the heat preservation time of aging treatment ranges from 2 h to 12 h. According to the preparation method of the high-strength aluminum alloy building material for the door and window curtain wall, process parameters are optimized, the coupling property of a process chain is enhanced, the prepared aluminum alloy building material can have the high strength performance, and the percentage elongation after fracture reaches 10% or above.

Description

Technical Field

[0001] The present application relates to the technical field of aluminum alloy building profiles, and in particular to a high-strength aluminum alloy building material for doors, windows, and curtain walls and a preparation method thereof. Background Art

[0002] Aluminum alloy architectural profiles are materials with specific cross-sectional shapes and dimensions, manufactured through processes such as extrusion, cutting, and drilling. They are primarily used in building structures such as doors, windows, curtain walls, and roofs. Currently, the aluminum alloy architectural profiles widely used in industry are generally produced using 6063, an aluminum-magnesium-silicon alloy belonging to the 6-series aluminum alloy. Its specific composition includes aluminum (Al), magnesium (Mg), and silicon (Si), with the magnesium content ranging from 0.45% to 0.9% and the silicon content from 0.2% to 0.6%. Furthermore, 6063-T5 refers to profiles that are formed at high temperature, then naturally cooled, and then artificially aged (at 170°C to 180°C for 6-8 hours) to uniformly precipitate the Mg2Si phase. This results in 6063-T5's performance characteristics, including a tensile strength of 160 MPa or higher, a yield strength of >110 MPa, and an elongation of 8% or higher.

[0003] Prior art, such as patent publication number CN107686915A, discloses a 6063 aluminum profile composed of the following alloy components by weight: Si 0.42-0.45%, Mg 0.58-0.62%, Fe ≤ 0.15%, Cu ≤ 0.1%, Cr 0.04-0.05%, Nb ≤ 0.05%, YAG:Ce phosphor ≤ 0.005%, La ≤ 0.05%, with the balance being Al. This optimized composition enhances the alloy's rheological properties, reduces extrusion pressure, increases extrusion speed, and improves machinability. Furthermore, a specific process design results in a more uniform material structure and significantly enhances plastic extrusion performance, resulting in the 6063 aluminum profile possessing superior overall mechanical properties, including a tensile strength of ≥ 200 MPa and an elongation of ≥ 12%. While this aluminum profile exhibits a sufficiently high elongation, its strength is low, failing to meet the demand for high-strength building materials in specialized applications.

[0004] In order to meet the high-strength requirements of modern industry, especially in areas prone to strong winds and typhoons, or in large-section application scenarios, high-strength aluminum alloy building profiles have gradually become mainstream. Building materials produced using aluminum alloy materials such as 6005 (6005 belongs to the Al-Mg series rust-proof aluminum alloy and is a representative of medium-strength aluminum alloys. The main alloying elements include magnesium, silicon and iron, etc.) and 6061 (6061 belongs to the Al-Mg-Si series heat-treated strengthened alloy. The core components are magnesium (Mg 0.8%~1.2%) and silicon (Si 0.4%~0.8%), forming a strengthening phase Mg2Si, and also contain a small amount of copper (Cu 0.15%~0.4%). The mechanical properties such as tensile strength and yield strength of the building materials have been greatly improved. For example, 6005-T5, tensile strength ≥ 270MPa, yield strength > 250MPa, elongation at break ≥ 6%; 6061-T6, tensile strength ≥ 265MPa, yield strength > 245MPa, elongation at break ≥ 8%.

[0005] However, if the above-mentioned aluminum alloy material is used to produce strip-through thermal insulation building profiles (strip-through thermal insulation aluminum profiles are composite structural materials formed by connecting aluminum profiles with nylon insulation strips, and the thermal insulation bridge is constructed by mechanical strip-through and roller forming processes), due to process requirements, the profiles need to be toothed, rolled, pressed, and other operations to make the aluminum profiles and the insulation strips compositely connected to form a structural unit that blocks heat conduction. However, during the pressing process of the above-mentioned aluminum alloy material, the aluminum alloy profiles will crack, resulting in waste products and a very low yield rate. The reason is that the building materials produced by the existing production process based on the above-mentioned aluminum alloy material, while maintaining a relatively high tensile strength and yield strength, it is difficult for the elongation after fracture to exceed 10%.

[0006] Therefore, it is necessary to develop an aluminum alloy building material that can simultaneously meet the requirements of high strength and high elongation. Summary of the Invention

[0007] In view of the deficiencies of the existing technology, the present invention provides a high-strength aluminum alloy building material for doors, windows and curtain walls and a preparation method thereof. By optimizing the process parameters, the prepared aluminum alloy building material can have high strength performance and an elongation after fracture of more than 10%.

[0008] To achieve the above object, the present invention adopts the following technical solutions:

[0009] A first aspect of the present invention provides a method for preparing a high-strength aluminum alloy building material for doors, windows, and curtain walls, comprising the following steps:

[0010] (1) preparing an aluminum alloy rod from an aluminum alloy raw material;

[0011] (2) heating, extruding, cooling, and sawing the aluminum alloy rod in sequence to produce an aluminum alloy profile, wherein the rod temperature of the aluminum alloy rod after heating is 450° C. to 510° C., the extrusion speed is 1 m / min to 10 m / min, the outlet temperature after extrusion is ≥ 515° C., and the cooling speed is such that the cooling time to 100° C. is ≤ 2 min;

[0012] (3) The aluminum alloy profile is subjected to aging treatment to obtain a high-strength aluminum alloy building material, wherein the aging treatment temperature is 160° C. to 210° C. and the aging treatment holding time is 2 h to 12 h.

[0013] Furthermore, in step (2), the extrusion speed is 2 m / min to 5 m / min.

[0014] Furthermore, the outlet temperature after extrusion in step (2) is 515°C to 530°C.

[0015] Furthermore, the cooling method in step (2) is selected from at least one of air cooling, mist cooling, and water cooling.

[0016] Furthermore, during the cooling process of step (2), the length of the cooling path is ≤10m.

[0017] Furthermore, the holding time of the aging treatment in step (3) is 8h to 10h.

[0018] Furthermore, the aluminum alloy raw material in step (1) is selected from 6061 aluminum alloy or 6005 aluminum alloy.

[0019] A second aspect of the present invention provides a high-strength aluminum alloy building material for doors, windows, and curtain walls, which is prepared according to the above-mentioned preparation method.

[0020] Furthermore, the high-strength aluminum alloy building material has an elongation after fracture of ≥10%, and at the same time, a tensile strength of ≥280 MPa and a yield strength of ≥250 MPa.

[0021] Furthermore, the high-strength aluminum alloy building material has an elongation after fracture of 10% to 14%, a tensile strength of 280 MPa to 320 MPa, and a yield strength of 250 MPa to 280 MPa.

[0022] The beneficial technical effects of the present invention are:

[0023] Through a large number of experimental studies, the present invention creatively discovered that aluminum alloy building materials are very sensitive to the process during the preparation process, and the product performance is closely related to the process parameters. If one parameter does not meet the requirements, the final product will find it difficult to meet the performance requirements. The present invention optimizes and fine-tunes multiple process parameters in the preparation method of high-strength aluminum alloy building materials for doors, windows and curtain walls, strengthens the coupling of the process chain, and ensures that the final product meets the mechanical performance requirements of high strength and high elongation. Dynamic parameter control and collaborative optimization are performed on the rod temperature, extrusion speed, outlet temperature after extrusion, cooling speed, aging treatment temperature and holding time of the aluminum alloy rod after heating in the processing of building materials made of 6061 aluminum alloy or 6005 aluminum alloy as raw materials. By optimizing the rod temperature and extrusion speed of the aluminum alloy rod after heating, the solubility of alloy elements and deformation uniformity in the building materials are optimized; by optimizing the outlet temperature and cooling speed after extrusion, the nucleation of the precipitate phase is affected; by optimizing the aging treatment parameters, the growth and distribution of the precipitate phase are optimized, thereby simultaneously improving the tensile strength, yield strength and elongation after fracture of the prepared aluminum alloy building materials.

[0024] The aluminum alloy building materials of the present invention can ensure that no cracks occur during the pressing process when used to produce strip-type thermal insulation building profiles, and meet the high strength and durability requirements of aluminum alloy building materials for doors, windows and curtain walls in special scenarios such as typhoons and large sections in special areas.

[0025] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. DETAILED DESCRIPTION

[0026] Unless otherwise defined, all technical and / or scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the invention pertains. It should be understood that certain features of the present invention (described in the context of separate embodiments for clarity) may also be provided in combination in a single embodiment. On the contrary, a plurality of features of the present invention (described in the context of a single embodiment for brevity) may also be provided separately or in any suitable combination or in any other described embodiment of the present invention when appropriate. Certain features described in the context of various embodiments will not be considered as essential features of those embodiments unless the embodiment is inoperable without those elements. The present invention will be further described below by specific examples, but it should be noted that the specific process conditions and results described in the embodiments of the present invention are only used to illustrate the present invention and cannot limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and substance of the present invention should be included within the scope of protection of the present invention.

[0027] First of all, it should be noted that the raw materials used in the examples and comparative examples of the present application are all commercially available.

[0028] In areas prone to strong winds and typhoons, or in large-section applications, aluminum alloy building profiles are required to have high tensile strength and yield strength. However, when existing high-strength aluminum alloy building profiles are used to produce through-strip insulation building profiles, the profiles need to be toothed, rolled, and pressed together to compositely connect the aluminum profiles with the insulation strips to form a structural unit that blocks heat conduction. However, during the pressing process, the high-strength aluminum alloy profiles will crack, resulting in waste. The main reason is that the building materials produced by the existing production process based on high-strength aluminum alloy profiles, while maintaining high tensile strength and yield strength, have a low elongation after fracture exceeding 10%. The elongation after fracture directly reflects the plastic deformation ability or ductility of the material. Aluminum alloys with high elongation after fracture can withstand a large amount of plastic deformation before breaking and have good ductility. When subjected to external forces (such as impact, bending, and stretching), they will first undergo significant shape changes (plastic deformation), absorb a large amount of energy, and finally slowly undergo ductile fracture.

[0029] In view of the above problems, the present invention provides a method for preparing a high-strength aluminum alloy building material for doors, windows and curtain walls, comprising the following steps:

[0030] (1) preparing an aluminum alloy rod from an aluminum alloy raw material;

[0031] (2) heating, extruding, cooling, and sawing the aluminum alloy rod in sequence to produce an aluminum alloy profile, wherein the rod temperature of the aluminum alloy rod after heating is 450° C. to 510° C., the extrusion speed is 1 m / min to 10 m / min, the outlet temperature after extrusion is ≥ 515° C., and the cooling speed is such that the cooling time to 100° C. is ≤ 2 min;

[0032] (3) The aluminum alloy profile is subjected to aging treatment to obtain a high-strength aluminum alloy building material, wherein the aging treatment temperature is 160° C. to 210° C. and the aging treatment holding time is 2 h to 12 h.

[0033] In one embodiment of the present application, the aluminum alloy raw material in step (1) is selected from 6061 aluminum alloy or 6005 aluminum alloy, wherein:

[0034] The mass percentages of the elements in the 6005 aluminum alloy are: Si 0.6% to 0.9%, Fe ≤ 0.35%, Cu ≤ 0.1%, Mn ≤ 0.1%, Mg 0.4% to 0.6%, Cr ≤ 0.1%, Zn ≤ 0.1%, Ti ≤ 0.1%, other individual impurities ≤ 0.05%, unavoidable impurities ≤ 0.15% in total, and the balance is Al;

[0035] The mass percentages of the elements in the 6061 aluminum alloy are: Si 0.4%-0.8%, Fe≤0.7%, Cu0.15%-0.40%, Mn≤0.15%, Mg 0.8%-1.2%, Cr 0.04%-0.35%, Zn≤0.25%, Ti≤0.15%, other individual impurities≤0.05%, unavoidable impurities total 0.15%, and the balance is Al;

[0036] In one embodiment of the present application, in step (1), the aluminum alloy raw material is melted, refined, and cast to obtain an aluminum alloy rod, wherein the melting, refining, and casting use existing processes (using existing dedicated equipment such as a resistance furnace, etc., which will not be repeated here), for example:

[0037] When the aluminum alloy raw material is 6005 aluminum alloy, the melting temperature is 720℃~760℃, the refining temperature is 715℃~735℃, and the casting temperature is 680℃~720℃;

[0038] When the aluminum alloy raw material is 6061 aluminum alloy, the melting temperature is 730℃~750℃, the refining temperature is 735℃~745℃, and the casting temperature is 720℃~740℃;

[0039] In one embodiment of the present application, the aluminum alloy rod is heated in step (2), and the rod temperature of the aluminum alloy rod after heating is 450℃~510℃, for example, it can be 450℃, 460℃, 470℃, 480℃, 490℃, 500℃ and 510℃, but it is not limited to the listed values. Other values ​​not listed within the above numerical range are also applicable. Since the rod temperature of the aluminum alloy rod after heating directly affects the fluidity of the alloy melt, if the temperature is insufficient, it will lead to increased deformation resistance during the subsequent extrusion process, and it is easy to produce defects such as surface cracks; and controlling the rod temperature of the aluminum alloy rod after heating can ensure that the alloy elements are fully dissolved and form a uniform supersaturated solid solution; for example, if the rod temperature of the 6061 aluminum alloy rod after heating is insufficient, it is difficult to dissolve the Mn element, which will affect its performance such as yield strength after extrusion. Therefore, the present application optimizes the rod temperature parameters of the aluminum alloy rod after heating.

[0040] In one embodiment of the present application, the extrusion speed of the aluminum alloy rod is controlled in step (2), and the extrusion speed is 1m / min to 10m / min, for example, 1m / min, 2m / min, 3m / min, 4m / min, 5m / min, 6m / min, 7m / min, 8m / min, 9m / min and 10m / min, but is not limited to the values ​​listed, and other values ​​not listed within the above numerical range are also applicable. The extrusion speed of the aluminum alloy rod is related to its deformation rate. When the extrusion speed is insufficient, the alloy grain refinement effect is poor, and the tensile strength decreases after cooling. Excessive extrusion speed will cause deformation heat accumulation, affecting the subsequent cooling effect. Therefore, the present application optimizes the extrusion speed parameters.

[0041] In one embodiment of the present application, in step (2), the outlet temperature of the long strip aluminum alloy profile formed after the aluminum alloy rod is extruded is controlled. The outlet temperature after extrusion is ≥515°C and can reach a maximum of 530°C. For example, it can be 515°C, 520°C, 525°C and 530°C, but is not limited to the listed values. Other values ​​not listed within the above numerical range are also applicable. The outlet temperature of the aluminum alloy rod after extrusion determines the starting point of quenching cooling. If the temperature is too high and the cooling rate is insufficient, the supersaturated solid solution will decompose and a coarse Mg2Si phase will precipitate, affecting the improvement of the elongation after fracture. Therefore, the present application optimizes the outlet temperature parameter after extrusion.

[0042] In one embodiment of the present application, the cooling method in step (2) is selected from at least one of air cooling, mist cooling, and water cooling, wherein water cooling includes large water cooling and water cooling, wherein,

[0043] Air cooling is natural cooling or forced cooling. The heat is removed by air convection. The cooling rate is controlled to avoid deformation or cracking of the aluminum alloy. The air cooling rate is 0.5℃ / s to 4℃ / s. It is suitable for thin-walled 6061, 6005 aluminum alloy and other profiles.

[0044] Mist cooling is a mixed cooling method of air and mist. It balances the cooling speed and deformation control by mixing atomized water droplets with air. The cooling rate is 5℃ / s to 15℃ / s. It is suitable for profiles with thin wall thickness such as 6061 and 6005 aluminum alloys.

[0045] Water cooling is spray or soak cooling, which uses high-speed water flow to quickly cool down and improve material strength. The cooling rate is 20℃ / s to 50℃ / s, which is suitable for thick-walled 6061 aluminum alloy, 6005 aluminum alloy and other profiles.

[0046] Large water cooling is a strong water flow impact cooling, which achieves rapid cooling through high-pressure water flow impact, breaking through the critical cooling speed of the material, with a cooling rate of >100℃ / s, which is suitable for rapid quenching of special cross-sections such as large thick-walled pipes;

[0047] Through-water cooling is a continuous water flow cooling method that achieves uniform and rapid cooling through dynamic water contact, reducing thermal stress. The cooling rate is 30°C / s to 80°C / s and is suitable for large aluminum alloys or special profiles such as 6061-T6. This application selects the appropriate cooling method based on the different aluminum alloy raw materials. It can be a single cooling method or a combination of cooling methods, such as air cooling followed by water cooling for 6061 aluminum alloy.

[0048] In one embodiment of the present application, during the cooling process of step (2), the length of the cooling path of the extruded long strip aluminum alloy profile is ≤10m. The cooling path length is within 10m, and in the critical temperature range where the extrusion temperature drops to about 200°C or below, short-distance rapid cooling is achieved, which is beneficial to grain refinement and prevents the formation of coarse precipitated phases. An excessively long cooling path will aggravate the head-to-tail temperature difference and the cross-sectional temperature difference, resulting in stress differences, uneven performance, and deformation distortion. The core purpose of the present application for a cooling length of ≤10m is to achieve high-quality production of aluminum alloy profiles through thermal stress control, phase transformation uniformity assurance, and production line efficiency optimization. Among them, the cooling length for 6061 aluminum alloy rods can be 8m to 10m, and the cooling length for 6005 aluminum alloy rods can be 7m to 9m.

[0049] In one embodiment of the present application, the cooling rate in step (2) is a cooling time of ≤2 min to 100° C., for example, it can be 110 s, 100 s, 90 s, 80 s, 70 s and 60 s, but is not limited to the listed values. Other values ​​not listed within the above numerical range are also applicable. The purpose of this cooling rate is to suppress the precipitation of the second phase (the second phase specifically refers to a strengthening phase (such as Mg2Si) or an impurity phase (Al-Fe-Si phase) formed by solute atoms (such as Mg, Si, Cu, Zn, etc.) or compounds in addition to the matrix phase (α-Al solid solution)) by rapid cooling, retain the supersaturated solid solution, and create the best conditions for subsequent aging strengthening.

[0050] In one embodiment of the present application, the sawing in step (2) is performed mechanically by using special equipment such as a circular saw or a band saw, and the sawing method adopts the existing technology, which will not be described in detail here.

[0051] In one embodiment of the present application, the temperature of the aging treatment in step (3) is 160°C to 210°C, for example, it can be 160°C, 170°C, 180°C, 190°C, 200°C and 210°C, but it is not limited to the listed values. Other values ​​not listed within the above numerical range are also applicable. The accuracy of the temperature control of the aging treatment directly affects the microstructure and properties of the material. The present application achieves the following purposes by controlling the temperature of the aging treatment: 1) Avoid over-aging and under-aging: Over-aging refers to excessively high temperatures, such as exceeding the solubility curve temperature of the alloy, which will cause the precipitate phase to coarsen, such as the Mg2Si phase size > 100nm, the dislocation cutting becomes a bypass mechanism, and the strength decreases; under-aging refers to excessively low temperatures, such as below the precipitation phase nucleation temperature, solute atoms are not fully diffused, the precipitate phase is small and unevenly distributed, and effective strengthening cannot be formed. 2) Inhibit the formation of non-equilibrium phases: High temperatures, such as exceeding 250°C, may induce the precipitation of brittle phases such as Al-Fe-Si, destroying the continuity of grain boundaries. 3) Matching alloy composition characteristics: The aging responses of different alloys vary significantly. For example, the aging temperature of 6005 aluminum alloy rods is 170℃~190℃, and the aging temperature of 6061 aluminum alloy rods is 190℃~210℃.

[0052] In one embodiment of the present application, the holding time of the aging treatment in step (3) is 2h to 12h, for example, it can be 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h and 12h, but is not limited to the listed values, and other values ​​not listed within the above numerical range are also applicable. The purpose of accurately controlling the holding time in the aging treatment of the present application is to optimize the performance of the building material by regulating the nucleation, growth and coarsening process of the precipitate phase. For example, if the 6061 type aluminum alloy rod is not kept warm enough, the precipitate phase is not fully formed, affecting its yield strength; if the 6005 type aluminum alloy rod is kept warm for too long, the precipitate phase coarsens and melts, affecting its tensile strength and yield strength.

[0053] The present invention also provides a high-strength aluminum alloy building material for doors, windows, and curtain walls, produced according to the above-described preparation method. The high-strength aluminum alloy building material has an elongation of 10% or greater, a tensile strength of 280 MPa or greater, and a yield strength of 250 MPa or greater. Furthermore, the high-strength aluminum alloy building material has an elongation of 10% to 14%, a tensile strength of 280 MPa to 320 MPa, and a yield strength of 250 MPa to 280 MPa.

[0054] The present invention ensures that the final product meets the mechanical property requirements of high strength and high elongation through the optimization and adjustment of the above-mentioned multiple process parameters. Dynamic parameter control and collaborative optimization are performed on the rod temperature, extrusion speed, outlet temperature after extrusion, cooling rate, aging treatment temperature and holding time of the aluminum alloy rod after heating in the building material processing process using 6061 aluminum alloy or 6005 aluminum alloy as raw materials, so that the prepared aluminum alloy building materials can improve the elongation while meeting the high strength performance. When the aluminum alloy building materials of the present invention are used to produce strip-type thermal insulation building profiles, it can ensure that no cracks occur in the pressing process, and meet the high strength and durability requirements of aluminum alloy building materials for doors, windows and curtain walls in special scenarios such as typhoons in special areas and large cross-sections.

[0055] The present invention is described in detail below by way of specific examples. It should also be understood that the following examples are only used to specifically illustrate the present invention and are not to be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention all fall within the scope of protection of the present invention. The specific process parameters and the like in the following examples are only examples within a suitable range, and those skilled in the art can make selections within a suitable range through the description herein, and are not to be limited to the specific numerical values ​​exemplified below.

[0056] Example 1

[0057] (1) melting, refining, and casting a 6005 aluminum alloy to prepare a 6005 aluminum alloy rod, wherein the mass percentages of the elements in the 6005 aluminum alloy are as follows: Si 0.67%, Fe 0.1%, Cu 0.1%, Mn 0.1%, Mg 0.60%, Cr 0.08%, Zn 0.1%, Ti 0.1%, unavoidable impurities totaling 0.15%, and the balance being Al;

[0058] When the aluminum alloy raw material is 6005 aluminum alloy, the melting temperature is 760℃, the refining temperature is 735℃, and the casting temperature is 720℃.

[0059] (2) The 6005 aluminum alloy rod is heated, extruded, cooled and sawed in sequence to produce a 6005 aluminum alloy profile, wherein the rod temperature of the aluminum alloy rod after heating is 480°C, the extrusion speed is 2m / min, the outlet temperature after extrusion is 515°C, the cooling speed is 2min to 100°C, and the cooling method is water cooling.

[0060] (3) The 6005 aluminum alloy profile is subjected to aging treatment to produce high-strength aluminum alloy building materials, wherein the aging treatment temperature is 190°C and the aging treatment holding time is 8 hours.

[0061] Example 2

[0062] (1) melting, refining, and casting a 6061 aluminum alloy to prepare a 6061 aluminum alloy rod, wherein the mass percentages of the elements in the 6061 aluminum alloy are as follows: Si 0.54%, Fe 0.18%, Cu 0.19%, Mn 0.13%, Mg 0.89%, Cr 0.17%, Zn 0.07%, Ti 0.03%, unavoidable impurities totaling 0.15%, and the balance being Al;

[0063] When the aluminum alloy raw material is 6061 aluminum alloy, the melting temperature is 750°C, the refining temperature is 745°C, and the casting temperature is 740°C.

[0064] (2) heating, extruding, cooling, and sawing a 6061 aluminum alloy rod in sequence to obtain a 6061 aluminum alloy profile, wherein the rod temperature of the aluminum alloy rod after heating is 490°C, the extrusion speed is 4 m / min, the outlet temperature after extrusion is 520°C, the cooling speed is 2 min to 100°C, and the cooling method is mist cooling;

[0065] (3) The 6061 aluminum alloy profile is subjected to aging treatment to produce high-strength aluminum alloy building materials, wherein the aging treatment temperature is 190°C and the aging treatment holding time is 12 hours.

[0066] Example 3

[0067] The difference between this embodiment and embodiment 1 is that: (2) the 6005 type aluminum alloy rod is heated, extruded, cooled and sawed in sequence to obtain the 6005 type aluminum alloy profile, wherein the rod temperature of the aluminum alloy rod after heating is 500°C, the extrusion speed is 2m / min, the outlet temperature after extrusion is 515°C, the cooling speed is 2min, and the cooling time to 100°C is 2min, and the cooling method is water cooling.

[0068] Example 4

[0069] The difference between this embodiment and embodiment 1 is that:

[0070] (2) The 6005 aluminum alloy rod is heated, extruded, cooled and sawed in sequence to produce a 6005 aluminum alloy profile, wherein the rod temperature of the aluminum alloy rod after heating is 480°C, the extrusion speed is 5m / min, the outlet temperature after extrusion is 525°C, the cooling speed is 2min to 100°C, and the cooling method is water cooling.

[0071] Example 5

[0072] The difference between this embodiment and embodiment 1 is that:

[0073] (2) The 6005 aluminum alloy rod is heated, extruded, cooled and sawed in sequence to produce a 6005 aluminum alloy profile, wherein the rod temperature of the aluminum alloy rod after heating is 480°C, the extrusion speed is 2m / min, the outlet temperature after extrusion is 515°C, the cooling speed is 100°C, the cooling time is 100s, and the cooling method is water cooling.

[0074] Example 6

[0075] The difference between this embodiment and embodiment 1 is that:

[0076] (3) The 6005 aluminum alloy profile is subjected to aging treatment to produce high-strength aluminum alloy building materials, wherein the aging treatment temperature is 170°C and the aging treatment holding time is 12 hours.

[0077] Example 7

[0078] The difference between this embodiment and embodiment 2 is that:

[0079] (2) The 6061 aluminum alloy rod is heated, extruded, cooled and sawed in sequence to produce a 6061 aluminum alloy profile, wherein the rod temperature of the aluminum alloy rod after heating is 510°C, the extrusion speed is 4 m / min, the outlet temperature after extrusion is 520°C, the cooling speed is 2 min to 100°C, and the cooling method is mist cooling.

[0080] Example 8

[0081] The difference between this embodiment and embodiment 2 is that:

[0082] (2) The 6061 aluminum alloy rod is heated, extruded, cooled and sawed in sequence to produce a 6061 aluminum alloy profile, wherein the rod temperature of the aluminum alloy rod after heating is 490°C, the extrusion speed is 7 m / min, the outlet temperature after extrusion is 530°C, the cooling speed is 2 min to 100°C, and the cooling method is mist cooling.

[0083] Example 9

[0084] The difference between this embodiment and embodiment 2 is that:

[0085] (2) The 6061 aluminum alloy rod is heated, extruded, cooled and sawed in sequence to produce a 6061 aluminum alloy profile, wherein the rod temperature of the aluminum alloy rod after heating is 490°C, the extrusion speed is 4m / min, the outlet temperature after extrusion is 520°C, the cooling speed is 90s to 100°C, and the cooling method is mist cooling.

[0086] Example 10

[0087] The difference between this embodiment and embodiment 2 is that:

[0088] (3) The 6061 aluminum alloy profile is subjected to aging treatment to produce high-strength aluminum alloy building materials, wherein the aging treatment temperature is 210°C and the aging treatment holding time is 8 hours.

[0089] Comparative Example 1

[0090] The difference between this comparative example and Example 1 is:

[0091] (2) The 6005 aluminum alloy rod is heated, extruded, cooled and sawed in sequence to produce a 6005 aluminum alloy profile, wherein the rod temperature of the aluminum alloy rod after heating is 520°C, the extrusion speed is 2m / min, the outlet temperature after extrusion is 530°C, the cooling speed is 2min to 100°C, and the cooling method is water cooling.

[0092] Comparative Example 2

[0093] The difference between this comparative example and Example 1 is:

[0094] (2) The 6005 aluminum alloy rod is heated, extruded, cooled and sawed in sequence to produce a 6005 aluminum alloy profile, wherein the rod temperature of the aluminum alloy rod after heating is 480°C, the extrusion speed is 2m / min, the outlet temperature after extrusion is 515°C, the cooling speed is 3min to 100°C, and the cooling method is water cooling.

[0095] Comparative Example 3

[0096] The difference between this comparative example and Example 1 is:

[0097] (2) The 6005 aluminum alloy rod is heated, extruded, cooled and sawed in sequence to produce a 6005 aluminum alloy profile, wherein the rod temperature of the aluminum alloy rod after heating is 480°C, the extrusion speed is 2m / min, the outlet temperature after extrusion is 505°C, the cooling speed is to cool to 100°C for 2min, and the cooling method is water cooling.

[0098] Comparative Example 4

[0099] The difference between this comparative example and Example 1 is:

[0100] (3) The 6005 aluminum alloy profile is subjected to aging treatment to produce high-strength aluminum alloy building materials, wherein the aging treatment temperature is 150°C and the aging treatment holding time is 12 hours.

[0101] Comparative Example 5

[0102] The difference between this comparative example and Example 2 is:

[0103] (2) The 6061 aluminum alloy rod is heated, extruded, cooled and sawed in sequence to produce a 6061 aluminum alloy profile, wherein the rod temperature of the aluminum alloy rod after heating is 440°C, the extrusion speed is 4 m / min, the outlet temperature after extrusion is 515°C, the cooling speed is 2 min to 100°C, and the cooling method is mist cooling.

[0104] Comparative Example 6

[0105] The difference between this comparative example and Example 2 is:

[0106] (2) The 6061 aluminum alloy rod is heated, extruded, cooled and sawed in sequence to produce a 6061 aluminum alloy profile, wherein the rod temperature of the aluminum alloy rod after heating is 490°C, the extrusion speed is 10m / min, the outlet temperature after extrusion is 540°C, the cooling speed is 2min to 100°C, and the cooling method is mist cooling.

[0107] Comparative Example 7

[0108] The difference between this comparative example and Example 2 is:

[0109] (2) The 6061 aluminum alloy rod is heated, extruded, cooled and sawed in sequence to produce a 6061 aluminum alloy profile, wherein the rod temperature of the aluminum alloy rod after heating is 500°C, the extrusion speed is 4 m / min, the outlet temperature after extrusion is 550°C, the cooling speed is 2 min to 100°C, and the cooling method is mist cooling.

[0110] Comparative Example 8

[0111] The difference between this comparative example and Example 2 is:

[0112] (3) The 6061 aluminum alloy profile is subjected to aging treatment to produce high-strength aluminum alloy building materials, wherein the aging treatment temperature is 220°C and the aging treatment holding time is 8 hours.

[0113] Performance testing

[0114] Tensile strength: According to GB / T 228.1-2021 standard, the tensile strength of the aluminum alloy building materials of each embodiment and each comparative example was tested using a universal testing machine. The test results are shown in Table 1.

[0115] Yield strength: According to GB / T 228.1-2021 standard, the yield strength of the aluminum alloy building materials of each embodiment and each comparative example was tested using a unified yield strength test method. The test results are shown in Table 1.

[0116] Elongation after fracture: According to the elongation calculation method and allowable error specified in GB / T 228.1-2021, the elongation after fracture of the aluminum alloy building materials of each embodiment and each comparative example was tested. The test results are shown in Table 1.

[0117] The experimental data and analysis are as follows:

[0118] Table 1 Properties of aluminum alloy building materials in various embodiments and comparative examples

[0119]

[0120]

[0121] As can be seen from Table 1, the embodiments of the present application perform dynamic parameter control and collaborative optimization for the rod temperature, extrusion speed, outlet temperature after extrusion, cooling rate, aging treatment temperature and holding time of the heated aluminum alloy rod in the processing process of building materials using 6061 aluminum alloy and 6005 aluminum alloy as raw materials. The solubility of alloy elements and deformation uniformity in the building materials are optimized by optimizing the rod temperature and extrusion speed of the heated aluminum alloy rod; the nucleation of the precipitate phase is affected by optimizing the outlet temperature and cooling rate after extrusion; the growth and distribution of the precipitate phase are optimized by optimizing the aging treatment parameters, thereby simultaneously improving the tensile strength, yield strength and elongation of the prepared aluminum alloy building materials, which can solve the problem that the elongation of high-strength aluminum alloy building materials is difficult to reach more than 10%.

[0122] During the preparation of the 6005 aluminum alloy building materials in Comparative Examples 1 to 4, the rod temperature, extrusion speed, outlet temperature after extrusion, and aging treatment control parameters after heating the aluminum alloy rod were outside the specified ranges of this application, resulting in uneven precipitation. Insufficient cooling led to decomposition of the supersaturated solid solution and precipitation of coarse Mg2Si phases, resulting in decreased tensile strength, yield strength, and elongation of the 6005 aluminum alloy building materials compared to Example 1. Although the elongation of Comparative Example 1 reached over 10%, its tensile strength and yield strength were significantly lower than those of Example 1.

[0123] During the preparation of 6061 aluminum alloy building materials in Comparative Examples 5 to 8, the rod temperature, extrusion speed, outlet temperature after extrusion, and aging treatment control parameters of the heated aluminum alloy rod are not within the specified range of this application, affecting the improvement of properties such as elongation after fracture.

[0124] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A method for preparing high-strength aluminum alloy building materials for doors, windows and curtain walls, characterized in that: The following steps are involved: (1) preparing an aluminum alloy rod from an aluminum alloy raw material; (2) heating, extruding, cooling, and sawing the aluminum alloy rod in sequence to produce an aluminum alloy profile, wherein the rod temperature of the aluminum alloy rod after heating is 450° C. to 510° C., the extrusion speed is 1 m / min to 10 m / min, the outlet temperature after extrusion is ≥515° C., and the cooling speed is such that the cooling time to 100° C. is ≤2 min; (3) subjecting the aluminum alloy profile to aging treatment to obtain the high-strength aluminum alloy building material, wherein the aging treatment temperature is 160° C. to 210° C., and the aging treatment holding time is 2 h to 12 h.

2. The preparation method according to claim 1, characterized in that The extrusion speed in step (2) is 2 m / min to 5 m / min.

3. The preparation method according to claim 1, characterized in that The outlet temperature after extrusion in step (2) is 515°C to 530°C.

4. The preparation method according to claim 1, characterized in that The cooling method in step (2) is selected from at least one of air cooling, mist cooling, and water cooling.

5. The preparation method according to claim 1, characterized in that During the cooling process of step (2), the length of the cooling path is ≤10m.

6. The preparation method according to claim 1, characterized in that The holding time of the aging treatment in step (3) is 8h to 10h.

7. The preparation method according to any one of claims 1 to 6, characterized in that The aluminum alloy raw material in step (1) is selected from 6061 aluminum alloy or 6005 aluminum alloy.

8. A high-strength aluminum alloy building material for doors, windows and curtain walls, characterized in that: The high-strength aluminum alloy building material is prepared according to the preparation method according to any one of claims 1 to 7.

9. The high-strength aluminum alloy building material according to claim 8, characterized in that: The high-strength aluminum alloy building material has an elongation after fracture of ≥10%, a tensile strength of ≥280 MPa, and a yield strength of ≥250 MPa.

10. The high-strength aluminum alloy building material according to claim 9, characterized in that: The high-strength aluminum alloy building material has an elongation after fracture of 10% to 14%, a tensile strength of 280 MPa to 320 MPa, and a yield strength of 250 MPa to 280 MPa.

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