6061 aluminum alloy processing technology

Abstract

The invention discloses a 6061 aluminum alloy processing technology, which comprises the following steps: smelting, refining, stirring, degassing, slagging off and standing raw materials to obtain molten aluminum, draining, filtering and cooling the molten aluminum to obtain a cast rod, sawing the head and the tail of the aluminum rod, homogenizing to obtain a homogenized aluminum rod, heating the homogenized aluminum rod by a rod furnace, and extruding and molding by an extruder, thereby obtaining the 6061 aluminum alloy. Wherein the heating temperature of the round cast ingot is 505-525 DEG C, the temperature of a mold is 460-500 DEG C, the temperature of an extrusion container is 410-430 DEG C, the speed of an extrusion rod is 1.61-2.27 mm / s, the time of heating the round cast ingot from a rod furnace to extrusion rod feeding production is controlled within 1 minute, then air cooling and straightening by a straightening machine are carried out, the stretching rate in the straightening process is 0.3-0.8%, head and tail waste materials of a straightened profile are removed, and saw cutting is carried out. And finally, the aluminum profile with the fixed length is subjected to aging treatment by keeping the temperature of 180 DEG C for 9 hours. The 6061 aluminum alloy provided by the invention has the advantages of high mechanical strength, good surface quality and high ductility, meets higher requirements of customers, and realizes large-batch and high-quality production of 6061 aluminum alloy materials.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum alloy processing, in particular to a 6061 aluminum alloy processing technology. Background Art

[0002] 6061 is a heat-treatable alloy with excellent processing performance, excellent welding characteristics and electroplating properties, good corrosion resistance, high toughness and no deformation after processing, dense material without defects and easy polishing, easy color film, excellent oxidation effect and other excellent characteristics. It is widely used in various vehicles. However, with the popularization and promotion of new energy vehicles, customers have put forward higher new demands for aluminum alloys, namely, tensile strength ≥280Mpa, yield strength ≥240Mpa, elongation after fracture ≥10%, hardness ≥104HV. The original 6061 aluminum alloy extrusion process not only has low production efficiency and high production cost, but also produces poor surface quality of aluminum alloy, low mechanical strength, low elongation, and the mechanical properties of the product cannot meet the new requirements of safety and lightweight materials for new energy vehicles. It is urgent to meet higher demands by optimizing the production process. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a 6061 aluminum alloy processing technology that can improve mechanical strength, surface quality and elongation.

[0004] The purpose of the present invention is achieved through the following technical solutions: A 6061 aluminum alloy processing technology comprises the following steps:

[0005] S1. Melting, weighing raw materials as needed and adding them into the melting furnace for melting, and then refining, stirring, degassing, slagging, and standing to obtain aluminum liquid;

[0006] S2. Casting, draining the refined aluminum liquid, filtering it, and cooling it in a casting well to obtain a cast rod;

[0007] S3. Homogenization, the cast aluminum rod is cut into ends and then homogenized to obtain a homogeneous aluminum rod;

[0008] S4. Extrusion, the homogeneous aluminum rod is heated in a rod furnace and then extruded through an extruder, wherein the round ingot heating temperature is 505-525°C, the mold temperature is 460-500°C, the extrusion barrel temperature is 410-430°C, the extrusion rod speed is 1.61-2.27mm / s, and the time from the heating round ingot from the rod furnace to the extrusion of the rod production is controlled within 1 minute;

[0009] S5. Quenching, the extruded profile is rapidly cooled by air cooling to change the structure and properties of the metal;

[0010] S6. Straightening: the extruded profile is straightened and stress released by a straightening machine, and the elongation rate of the straightening process is 0.3-0.8%;

[0011] S7. Sawing: remove the head and tail waste of the straightened profile and saw it into the required length;

[0012] S8. Aging treatment: subject the aluminum profile of fixed length to a heat preservation treatment at 180°C for 9 hours.

[0013] Preferably, the aluminum alloy ingot composition includes 0.48-0.52% silicon, 0.15-0.20% copper, 0.85-0.90% magnesium, 0-0.02% zinc, 0-0.02% manganese, 0-0.05% titanium, 0.040-0.045% chromium, 0-0.15% iron, other single impurities ≤ 0.05, total impurities ≤ 0.15, and the balance is aluminum.

[0014] Preferably, the aluminum alloy ingot composition includes 0.50% silicon, 0.175% copper, 0.875% magnesium, 0.005% zinc, 0.005% manganese, 0.025% titanium, 0.042% chromium, 0.06% iron, other single impurities ≤ 0.05, total impurities ≤ 0.15, and the balance is aluminum.

[0015] Preferably, in the homogenization treatment of step S3, the aluminum rod is first kept at 580°C for 2 hours and then kept at 565°C for 6 hours.

[0016] Preferably, in the extrusion process of step S4, the round ingot heating temperature is 510-520°C, the mold temperature is 480-490°C, and the extrusion barrel temperature is 420°C.

[0017] Preferably, in step S6, the stretching rate during the straightening process is 0.4-0.7%.

[0018] Preferably, in step S8, the aluminum profile of fixed length is subjected to a heat preservation treatment at 190° C. for 7 hours.

[0019] The present invention has the following advantages:

[0020] 1. The present invention provides a 6061 aluminum alloy processing technology, which improves the mechanical strength, surface quality and elongation of 6061 aluminum profiles through multiple steps such as smelting, casting, homogenization, extrusion, quenching, straightening, sawing, aging treatment, etc., solves the problem that aluminum profiles produced by existing extrusion processes cannot meet the lightweight and safety requirements of new energy vehicles, meets higher requirements of customers, and realizes large-scale and high-quality production of 6061 aluminum alloy materials.

[0021] 2. By adjusting the lower limit of alloy elements within the range, the fluidity of the material during the forming process can be effectively improved;

[0022] 3. Through the adjustment of the homogenization process, the grains are refined, the homogenization effect is better, the stress of the aluminum rod is effectively released, and the difficulty of extrusion is reduced;

[0023] 4. By controlling the ingot temperature, mold temperature, and extrusion barrel temperature, the product quality risk caused by excessively high temperature and the risk of being unable to press and difficult to form caused by too low temperature can be reduced;

[0024] 5. By controlling the preparation time of the ingot, the exposure time of the round ingot to the air before loading the machine can be reduced to avoid the risk of extrusion failure caused by excessive temperature drop;

[0025] 6. By controlling the quenching process and using air cooling for quenching, the risk of deformation caused by uneven cooling during the extrusion process of the extruded profile can be reduced;

[0026] 7. By controlling the extrusion speed, the risk of surface particles and dragging caused by excessive extrusion heat due to excessive friction between the molten aluminum and the mold and extrusion barrel can be reduced;

[0027] 8. Reduce the risk of deformation caused by uneven stress release of profiles through elongation control and operation requirements;

[0028] 9. Through aging control and operation requirements, the Mg2Si strengthening phase is fully precipitated to ensure mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a crystal image of an aluminum rod according to Example 3 of the present invention;

[0030] Figure 2 is a crystal image of the aluminum rod of Comparative Example 5 of the present invention;

[0031] Figure 3 It is a crystal image of the aluminum rod of Comparative Example 6 of the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Example 1, a 6061 aluminum alloy processing technology, processing according to the following steps:

[0035] S1. Melting, weighing raw materials as needed and adding them into the smelting furnace for melting, and then standing and refining, stirring, degassing, slagging, and standing to obtain aluminum liquid;

[0036] S2. Casting, draining the refined aluminum liquid, filtering it, and cooling it in a casting well to obtain a cast rod;

[0037] S3. Homogenization, the cast aluminum rod is cut into ends and then homogenized to obtain a homogeneous aluminum rod;

[0038] S4. Extrusion, the homogeneous aluminum rod is heated in a rod furnace and then extruded through an extruder, wherein the round ingot heating temperature is 505-525°C, the mold temperature is 460-500°C, the extrusion barrel temperature is 410-430°C, the extrusion rod speed is 1.61-2.27mm / s, and the time from the heating round ingot from the rod furnace to the extrusion of the rod production is controlled within 1 minute;

[0039] S5. Quenching, the extruded profile is rapidly cooled by air cooling to change the structure and properties of the metal;

[0040] S6. Straightening: the extruded profile is straightened and stress released by a straightening machine, and the elongation rate of the straightening process is 0.3-0.8%;

[0041] S7. Sawing: remove the head and tail waste of the straightened profile and saw it into the required length;

[0042] S8. Aging treatment: the fixed-length aluminum profile is kept at 180 degrees for 9 hours.

[0043] Comparative Examples 1 and 2 were conducted on the basis of Example 1. The difference between Comparative Examples 1 and 2 and Example 1 is that only the heating temperature of the aluminum rod is changed, and other processes remain unchanged. The test results are shown in the following table.

[0044]

[0045] From the comparison results, it can be seen that when the heating temperature of the extruder is 508-523℃, the surface extrusion lines are shallow, there are no obvious particle points, the surface roughness is low, the main cylinder pressure is small, the discharge is smooth, and the comprehensive performance is the best.

[0046] On the basis of Example 1, only the straightening rate was adjusted to carry out Example 2, Comparative Example 3 and Comparative Example 4. The measurement results are shown in the following table.

[0047]

[0048] It can be seen from the results in the above table that when the straightening rate is 0.4-0.7%, the aluminum alloy profile not only meets the straightness requirements, but also has a qualified surface effect and the best comprehensive performance.

[0049] On the basis of Example 2, only the homogenization process was changed to carry out the experiments of Example 3, Comparative Example 5 and Comparative Example 6, and the measurement results are shown in the following table.

[0050]

[0051] Depend on Figure 1 , Figure 2 , Figure 3 The results show that when the homogenization process is 580℃ for 2 hours and 565℃ for 6 hours, the hardness of the aluminum rod is relatively low, the iron phase and titanium particles are relatively dispersed, the grain size is small, and the homogenization effect is the best. When the homogenization process is 560 degrees for 9 hours, the hardness of the aluminum rod is higher, the iron phase and titanium particles are more seriously aggregated, the grain size is larger, and the homogenization effect is poor. When it is not homogenized, the hardness of the aluminum rod is higher, the iron phase and titanium particles are seriously aggregated, the grain size is large, and the quality is the worst.

[0052] On the basis of Example 3, only the aging treatment steps were changed to carry out the experiments of Example 4, Comparative Example 7, Comparative Example 8 and Comparative Example 9, and the measurement results are shown in the following table.

[0053]

[0054] From the measurement results of Example 4, Comparative Example 7, Comparative Example 8 and Comparative Example 9, it can be seen that the yield strength, tensile strength and elongation of Example 4 meet the requirements of national standards, and meet the customer's requirements of tensile strength ≥280Mpa, yield strength ≥240Mpa, elongation after fracture ≥10%, hardness ≥104HV, and greatly improve the mechanical properties; although the mechanical properties of Comparative Example 7 meet the national standards, they do not meet customer needs; the mechanical properties of Comparative Examples 8 and 9 do not meet the national standards.

[0055] All aluminum profiles of Examples 1-4 were tested for their components, wherein the component ratios were 0.48-0.52% silicon, 0.15-0.20% copper, 0.85-0.90% magnesium, 0-0.02% zinc, 0-0.02% manganese, 0-0.05% titanium, 0.040-0.045% chromium, 0-0.15% iron, other single impurities ≤0.05, total impurities ≤0.15, and the balance was aluminum; wherein the aluminum profile obtained in Example 4 had the best performance, and its components included 0.50% silicon, 0.175% copper, 0.875% magnesium, 0.005% zinc, 0.005% manganese, 0.025% titanium, 0.042% chromium, 0.06% iron, other single impurities ≤0.05, total impurities ≤0.15, and the balance was aluminum.

[0056] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A 6061 aluminum alloy processing technology, characterized in that: The following steps are included: S1. Melting, weighing raw materials as needed and adding them into the melting furnace for melting, and then refining, stirring, degassing, slagging, and standing to obtain aluminum liquid; S2. Casting, draining the refined aluminum liquid, filtering it, and cooling it in a casting well to obtain a cast rod; S3. Homogenization, the cast aluminum rod is cut into ends and then homogenized to obtain a homogeneous aluminum rod; S4. Extrusion, the homogeneous aluminum rod is heated in a rod furnace and then extruded through an extruder, wherein the round ingot heating temperature is 505-525°C, the mold temperature is 460-500°C, the extrusion barrel temperature is 410-430°C, the extrusion rod speed is 1.61-2.27mm / s, and the time from the heating round ingot from the rod furnace to the extrusion of the rod production is controlled within 1 minute; S5. Quenching, the extruded profile is rapidly cooled by air cooling to change the structure and properties of the metal; S6. Straightening: the extruded profile is straightened and stress released by a straightening machine, and the elongation rate of the straightening process is 0.3-0.8%; S7. Sawing: remove the head and tail waste of the straightened profile and saw it into the required length; S8. Aging treatment: subject the aluminum profile of fixed length to a heat preservation treatment at 180°C for 9 hours.

2. A 6061 aluminum alloy processing technology according to claim 1, characterized in that: The aluminum alloy ingot composition includes 0.48-0.52% silicon, 0.15-0.20% copper, 0.85-0.90% magnesium, 0-0.02% zinc, 0-0.02% manganese, 0-0.05% titanium, 0.040-0.045% chromium, 0-0.15% iron, other single impurities ≤ 0.05, total impurities ≤ 0.15, and the balance is aluminum.

3. A 6061 aluminum alloy processing technology according to claim 2, characterized in that: The aluminum alloy ingot composition includes 0.50% silicon, 0.175% copper, 0.875% magnesium, 0.005% zinc, 0.005% manganese, 0.025% titanium, 0.042% chromium, 0.06% iron, other single impurities ≤ 0.05, total impurities ≤ 0.15, and the balance is aluminum.

4. A 6061 aluminum alloy processing technology according to claim 1, characterized in that: In the homogenization treatment of step S3, the aluminum rod is first kept at 580°C for 2 hours and then kept at 565°C for 6 hours.

5. A 6061 aluminum alloy processing technology according to claim 1, characterized in that: In the extrusion process of step S4, the round ingot heating temperature is 510-520°C, the mold temperature is 480-490°C, and the extrusion barrel temperature is 420°C.

6. A 6061 aluminum alloy processing technology according to claim 1, characterized in that: In step S6, the stretching rate during the straightening process is 0.4-0.7%.

7. A 6061 aluminum alloy processing technology according to claim 1, characterized in that: In step S8, the aluminum profile of fixed length is subjected to a heat preservation treatment at 190° C. for 7 hours.

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