Preparation method of aluminum alloy rod for extrusion
By controlling the concentration of various elements in the aluminum liquid and synergistic refining, temperature control, and degassing, the problems of impurities introduction and uneven microstructure in the preparation of traditional aluminum alloy rods are solved, and the preparation of aluminum alloy rods with high mechanical properties and stability is achieved.
Patent Information
- Application Number
- CN202411923346.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-25
- Publication Date
- 2025-03-25
AI Technical Summary
In the traditional aluminum alloy rod preparation method, impurities are easily introduced in the smelting and casting process, which affects the purity and performance of the aluminum alloy rod. The microstructure of the material is not uniform enough during the extrusion process, resulting in unstable performance.
By controlling the final concentration of each metal element in the aluminum liquid, and performing coordinated refining, temperature control, degassing, casting and other steps to reduce pore defects and annealing after forming the rod, improving the mechanical properties of the aluminum alloy rod.
It effectively reduces pore defects, improves the density of the material, enhances the strength and hardness of the aluminum alloy rod, and improves its mechanical properties and stability.
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of aluminum alloy rods and relates to a method for preparing an aluminum alloy rod for extrusion. Background Art
[0002] Aluminum alloy rod is a synthetic material with aluminum as the matrix and other metal elements added. It usually exists in the shape of a cylinder or other cross-sections. Extruded aluminum alloy rod is an aluminum alloy material produced by extrusion process. It is widely used in the fields of construction, transportation, electronic appliances, etc. The traditional aluminum alloy rod preparation method includes smelting, casting, homogenization treatment, extrusion molding and other steps. There are still limitations in actual operation. For example, impurities are easily introduced during smelting and casting, affecting the purity and performance of the aluminum alloy rod; or the microstructure of the material may not be uniform during the extrusion process, resulting in unstable performance, etc. These problems need to be further solved. Summary of the invention
[0003] The object of the present invention is to provide a method for preparing an aluminum alloy rod for extrusion. The present invention reduces pore defects and improves the mechanical properties of the aluminum alloy rod by controlling the final concentration of each metal element in the aluminum liquid and coordinating various steps such as refining, temperature control, degassing, and casting.
[0004] The purpose of the present invention can be achieved through the following technical solutions:
[0005] A method for preparing an aluminum alloy rod for extrusion, the method comprising the following steps:
[0006] (1) After melting the aluminum ingot, keep the temperature unchanged, add silicon-containing raw materials, iron-containing raw materials, copper-containing raw materials, manganese-containing raw materials, zinc-containing raw materials, titanium-containing raw materials, scandium-containing raw materials, lanthanum-containing raw materials and cerium-containing raw materials, stir, alloy, and obtain aluminum liquid;
[0007] (2) blowing 0.1-0.2wt% of a refining agent into the aluminum liquid, controlling the temperature, stirring and standing once, blowing 0.05-0.15wt% of a refining agent into the aluminum liquid again, stirring and standing for the second time, then skimming, degassing, filtering, and obtaining a melt;
[0008] (3) The melt is cast, extruded, rolled, cooled with cold water to form a rod, and then annealed to obtain an aluminum alloy rod for extrusion.
[0009] Furthermore, the mass fraction of the aluminum ingot in step (1) is 99.8wt%; the final concentration of each alloy element in the aluminum liquid is: 0.041-0.043wt% silicon, 0.116-0.118wt% iron, 0.05-0.10wt% copper, 0.2-0.3wt% manganese, 0.1-0.3wt% zinc, 0.04-0.1wt% titanium, 0.02-0.025wt% scandium, 0.016-0.018wt% lanthanum, 0.016-0.018wt% cerium, 0.001-0.01wt% other impurities and the remainder aluminum.
[0010] Furthermore, in step (1), the melting temperature is 730-740°C; the stirring speed and time are 60-80 rpm and 5-15 min, respectively; and the alloying temperature and time are 742-748°C and 15-25 min, respectively.
[0011] Furthermore, the temperature of the temperature control in step (2) is 745-755°C; the parameters of the first stirring and standing are: the stirring speed and time are 40-60rmp and 2-8min respectively, and the standing time is 5-15min; the second stirring and standing refers to stirring 3 times, each stirring time is 1-3min, and the interval between each two stirrings is 5min, and standing for 10-20min after the last stirring.
[0012] Furthermore, the degassing in step (2) refers to three cycles of degassing using argon, during which the argon flow rate is 0.3-0.7L / min, the time for blowing argon in the first cycle is 4-6min, and the time for blowing argon in subsequent cycles is shortened to 2.5-3.5min, and after each cycle, the pressure in the furnace is reduced by 0.1bar.
[0013] Furthermore, the filtration in step (2) is performed three times using a 40-60 mesh ceramic filter plate.
[0014] Furthermore, the casting in step (3) refers to preheating the casting mold to 200-300°C, pouring the melt into it, controlling the casting speed to 390-410rmp and the casting current to 550-620A for casting, and cooling to room temperature after the casting is completed.
[0015] Furthermore, the extrusion in step (3) refers to heating the cast product to 450-470° C. and then extruding it at an extrusion ratio of 10-30:1.
[0016] Furthermore, the rolling in step (3) refers to controlling the rolling speed to 2-3 m / min, first performing initial rolling and then performing finish rolling, the initial rolling is 6-12 passes of rolling at room temperature, each time the reduction is controlled at 10-15%, and the finish rolling is further rolling to a final thickness of 7-9 mm, each time the reduction is controlled at 5-9%.
[0017] Furthermore, the annealing treatment in step (3) is to place the rod in an annealing furnace and heat it to 415-425° C. and keep it warm for 8-12 hours.
[0018] Beneficial effects of the present invention:
[0019] (1) The present invention controls the concentration of each element in the aluminum liquid to promote the uniform distribution of each element and avoid element segregation. In the subsequent steps of using two refining agents, temperature control, degassing, casting, extrusion, rolling, etc., the porosity defects are synergistically reduced and the density of the material is improved. After the rod is formed, annealing treatment is performed to further improve the strength and hardness of the aluminum alloy rod.
[0020] (2) The present invention uses scandium-containing raw materials, lanthanum-containing raw materials and cerium-containing raw materials to introduce scandium, lanthanum and cerium elements, which can synergistically refine the grain structure, improve the strength and toughness of the aluminum alloy rod, and reduce the tendency of thermal cracking during the casting process. Scandium forms a stable Al3Sc phase with aluminum, which effectively hinders dislocation movement, significantly improves the yield strength and creep resistance of the aluminum alloy rod, and at the same time increases the recrystallization temperature and improves thermal stability. The synergistic use of the three can effectively improve the mechanical properties of the aluminum alloy rod and increase the stability and service life of the aluminum alloy rod. DETAILED DESCRIPTION
[0021] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in combination with the embodiments.
[0022] Example 1
[0023] A method for preparing an aluminum alloy rod for extrusion, the preparation method of this embodiment comprises the following steps:
[0024] (1) After melting the aluminum ingot, keep the temperature unchanged, add silicon-containing raw materials, iron-containing raw materials, copper-containing raw materials, manganese-containing raw materials, zinc-containing raw materials, titanium-containing raw materials, scandium-containing raw materials, lanthanum-containing raw materials and cerium-containing raw materials, stir, alloy, and obtain aluminum liquid;
[0025] (2) blowing 0.1 wt% of hexachloroethane, a refining agent, into the aluminum liquid, controlling the temperature, stirring and letting it stand, blowing 0.05 wt% of hexachloroethane into the aluminum liquid again, stirring and letting it stand for the second time, then skimming, degassing, filtering and obtaining a melt;
[0026] (3) The melt is cast, extruded, rolled, cooled with cold water to form a rod, and then annealed to obtain an aluminum alloy rod for extrusion.
[0027] The mass fraction of the aluminum ingot in step (1) of this embodiment is 99.8wt%; the final concentration of each alloy element in the aluminum liquid is: 0.041wt% silicon, 0.116wt% iron, 0.05wt% copper, 0.2wt% manganese, 0.1wt% zinc, 0.04wt% titanium, 0.02wt% scandium, 0.016wt% lanthanum, 0.016wt% cerium, 0.001wt% other impurities and the remainder aluminum.
[0028] In step (1) of this embodiment, the melting temperature is 730° C.; the stirring speed and time are 60 rpm and 5 min, respectively; and the alloying temperature and time are 742° C. and 15 min, respectively.
[0029] The temperature of the temperature control in step (2) of this embodiment is 745°C; the parameters of the first stirring and standing are: the stirring speed and time are 40 rpm and 2 min respectively, and the standing time is 5 min; the second stirring and standing means stirring 3 times, each stirring time is 1 min, and the interval between each two stirrings is 5 min, and standing for 10 min after the last stirring.
[0030] The degassing in step (2) of this embodiment refers to three cycles of degassing using argon, during which the flow rate of argon is 0.3L / min, the time for blowing argon in the first cycle is 4min, and the time for blowing argon in the subsequent cycles is shortened to 2.5min, and after each cycle, the pressure in the furnace is reduced by 0.1bar.
[0031] The filtration in step (2) of this embodiment is performed by filtering three times using a 40-mesh ceramic filter plate.
[0032] The casting in step (3) of this embodiment refers to preheating the casting mold to 200° C., pouring the melt into the mold, controlling the casting speed to 390 rpm and the casting current to 550 A for casting, and cooling to room temperature after the casting is completed.
[0033] The extrusion in step (3) of this embodiment refers to heating the cast product to 450° C. and then extruding it at an extrusion ratio of 10:1.
[0034] The rolling in step (3) of this embodiment refers to controlling the rolling speed to 2m / min, first performing initial rolling and then performing finish rolling. The initial rolling is performed 6 times at room temperature, and the reduction amount each time is controlled to 10%. The finish rolling is further rolled to a final thickness of 7mm, and the reduction amount each time is controlled to 5%.
[0035] The annealing treatment in step (3) of this embodiment is to place the rod in an annealing furnace, heat it to 415° C., and keep it warm for 8 hours.
[0036] Example 2
[0037] A method for preparing an aluminum alloy rod for extrusion, the preparation method of this embodiment comprises the following steps:
[0038] (1) After melting the aluminum ingot, keep the temperature unchanged, add silicon-containing raw materials, iron-containing raw materials, copper-containing raw materials, manganese-containing raw materials, zinc-containing raw materials, titanium-containing raw materials, scandium-containing raw materials, lanthanum-containing raw materials and cerium-containing raw materials, stir, alloy, and obtain aluminum liquid;
[0039] (2) blowing 0.2 wt% of hexachloroethane, a refining agent, into the aluminum liquid, controlling the temperature, stirring and letting it stand once, blowing 0.15 wt% of hexachloroethane into the aluminum liquid again, stirring and letting it stand for the second time, then skimming, degassing, filtering and obtaining a melt;
[0040] (3) The melt is cast, extruded, rolled, cooled with cold water to form a rod, and then annealed to obtain an aluminum alloy rod for extrusion.
[0041] The mass fraction of the aluminum ingot in step (1) of this embodiment is 99.8wt%; the final concentration of each alloy element in the aluminum liquid is: 0.043wt% silicon, 0.118wt% iron, 0.10wt% copper, 0.3wt% manganese, 0.3wt% zinc, 0.1wt% titanium, 0.025wt% scandium, 0.018wt% lanthanum, 0.018wt% cerium, 0.01wt% other impurities and the remainder aluminum.
[0042] In step (1) of this embodiment, the melting temperature is 740° C.; the stirring speed and time are 80 rpm and 15 min, respectively; and the alloying temperature and time are 748° C. and 25 min, respectively.
[0043] The temperature of the temperature control in step (2) of this embodiment is 755°C; the parameters of the first stirring and standing are: the stirring speed and time are 60 rpm and 8 min respectively, and the standing time is 15 min; the second stirring and standing means stirring 3 times, each stirring time is 3 min, and the interval between each two stirrings is 5 min, and standing for 20 min after the last stirring.
[0044] The degassing in step (2) of this embodiment refers to three cycles of degassing using argon, during which the flow rate of argon is 0.7L / min, the time of blowing argon in the first cycle is 6min, and the time of blowing argon in the subsequent cycles is shortened to 3.5min, and after each cycle, the pressure in the furnace is reduced by 0.1bar.
[0045] The filtration in step (2) of this embodiment is performed by filtering three times using a 60-mesh ceramic filter plate.
[0046] The casting in step (3) of this embodiment refers to preheating the casting mold to 300° C., pouring the melt into the mold, controlling the casting speed to 410 rpm and the casting current to 620 A for casting, and cooling to room temperature after the casting is completed.
[0047] The extrusion in step (3) of this embodiment refers to heating the cast product to 470° C. and then extruding it at an extrusion ratio of 30:1.
[0048] The rolling in step (3) of this embodiment refers to controlling the rolling speed to 3m / min, first performing initial rolling and then performing finish rolling. The initial rolling is 12 passes of rolling at room temperature, and the reduction amount each time is controlled to 15%. The finish rolling is further rolling to a final thickness of 9mm, and the reduction amount each time is controlled to 9%.
[0049] The annealing treatment in step (3) of this embodiment is to place the rod in an annealing furnace, heat it to 425° C., and keep it warm for 12 hours.
[0050] Example 3
[0051] A method for preparing an aluminum alloy rod for extrusion, the preparation method of this embodiment comprises the following steps:
[0052] (1) After melting the aluminum ingot, keep the temperature unchanged, add silicon-containing raw materials, iron-containing raw materials, copper-containing raw materials, manganese-containing raw materials, zinc-containing raw materials, titanium-containing raw materials, scandium-containing raw materials, lanthanum-containing raw materials and cerium-containing raw materials, stir, alloy, and obtain aluminum liquid;
[0053] (2) blowing 0.15 wt% of hexachloroethane, a refining agent, into the aluminum liquid, controlling the temperature, stirring and standing once, blowing 0.1 wt% of hexachloroethane into the aluminum liquid again, stirring and standing for the second time, then skimming, degassing, filtering and obtaining a melt;
[0054] (3) The melt is cast, extruded, rolled, cooled with cold water to form a rod, and then annealed to obtain an aluminum alloy rod for extrusion.
[0055] The mass fraction of the aluminum ingot in step (1) of this embodiment is 99.8wt%; the final concentration of each alloy element in the aluminum liquid is: 0.042wt% silicon, 0.117wt% iron, 0.075wt% copper, 0.25wt% manganese, 0.2wt% zinc, 0.07wt% titanium, 0.023wt% scandium, 0.017wt% lanthanum, 0.017wt% cerium, 0.005wt% other impurities and the remainder aluminum.
[0056] In step (1) of this embodiment, the melting temperature is 735° C.; the stirring speed and time are 70 rpm and 10 min, respectively; and the alloying temperature and time are 745° C. and 20 min, respectively.
[0057] The temperature of the temperature control in step (2) of this embodiment is 750°C; the parameters of the first stirring and standing are: the stirring speed and time are 50 rpm and 5 min respectively, and the standing time is 10 min; the second stirring and standing means stirring 3 times, each stirring time is 2 min, and the interval between each two stirrings is 5 min, and standing for 15 min after the last stirring.
[0058] The degassing in step (2) of this embodiment refers to three cycles of degassing using argon, during which the flow rate of argon is 0.5L / min, the time of blowing argon in the first cycle is 5min, and the time of blowing argon in the subsequent cycles is shortened to 3min. After each cycle, the pressure in the furnace is reduced by 0.1bar.
[0059] The filtration in step (2) of this embodiment is performed by filtering three times using a 50-mesh ceramic filter plate.
[0060] The casting in step (3) of this embodiment refers to preheating the casting mold to 250° C., pouring the melt into the mold, controlling the casting speed to 400 rpm and the casting current to 585 A for casting, and cooling to room temperature after the casting is completed.
[0061] The extrusion in step (3) of this embodiment refers to heating the cast product to 460° C. and then extruding it at an extrusion ratio of 20:1.
[0062] The rolling in step (3) of this embodiment refers to controlling the rolling speed to 2.5m / min, first performing initial rolling and then performing finish rolling. The initial rolling is performed at room temperature for 9 passes, and the reduction amount each time is controlled to 12.5%. The finish rolling is further rolled to a final thickness of 8mm, and the reduction amount each time is controlled to 7%.
[0063] The annealing treatment in step (3) of this embodiment is to place the rod in an annealing furnace, heat it to 420° C., and keep it warm for 10 hours.
[0064] Comparative Example 1
[0065] On the basis of Example 3, keeping other conditions the same, the preparation method was changed to:
[0066] (1) After melting the aluminum ingot, keep the temperature unchanged, add silicon-containing raw materials, iron-containing raw materials, copper-containing raw materials, manganese-containing raw materials, zinc-containing raw materials, titanium-containing raw materials, scandium-containing raw materials, lanthanum-containing raw materials and cerium-containing raw materials, stir, alloy, and obtain aluminum liquid;
[0067] (2) blowing a refining agent, namely hexachloroethane, accounting for 0.15 wt% of the total mass of the aluminum liquid into the aluminum liquid, controlling the temperature, stirring once and standing, then skimming, degassing, and filtering to obtain a melt;
[0068] In step (2) of this comparative example, the stirring speed and time were 50 rpm and 5 min, respectively, and the standing time was 10 min;
[0069] (3) The melt is cast, extruded, rolled, cooled with cold water to form a rod, and then annealed to obtain an aluminum alloy rod for extrusion.
[0070] Comparative Example 2
[0071] On the basis of Example 3, keeping other conditions the same, the preparation method was changed to:
[0072] (1) After melting the aluminum ingot, keep the temperature unchanged, add silicon-containing raw materials, iron-containing raw materials, copper-containing raw materials, manganese-containing raw materials, zinc-containing raw materials, titanium-containing raw materials, scandium-containing raw materials, lanthanum-containing raw materials and cerium-containing raw materials, stir, alloy, and obtain aluminum liquid;
[0073] (2) blowing 0.25 wt% of hexachloroethane, a refining agent, into the aluminum liquid, controlling the temperature, stirring at 50 rpm for 5 min and letting it stand for 10 min, and then blowing 0.1 wt% of hexachloroethane into the aluminum liquid again, stirring at 50 rpm for 6 min and letting it stand for 15 min, then skimming, degassing, and filtering to obtain a melt;
[0074] (3) The melt is cast, extruded, rolled, cooled with cold water to form a rod, and then annealed to obtain an aluminum alloy rod for extrusion.
[0075] Comparative Example 3
[0076] On the basis of Example 3, keeping other conditions the same, the preparation method was changed to:
[0077] (1) After melting the aluminum ingot, keep the temperature unchanged, add silicon-containing raw materials, iron-containing raw materials, copper-containing raw materials, manganese-containing raw materials, zinc-containing raw materials, titanium-containing raw materials, scandium-containing raw materials, lanthanum-containing raw materials and cerium-containing raw materials, stir, alloy, and obtain aluminum liquid;
[0078] (2) blowing 0.15 wt% of hexachloroethane, a refining agent, into the aluminum liquid, controlling the temperature, stirring and standing once, blowing 0.1 wt% of hexachloroethane into the aluminum liquid again, stirring and standing for the second time, then skimming, degassing, filtering and obtaining a melt;
[0079] The degassing in step (2) of this comparative example is to control the flow rate of argon gas to 0.5L / min and blow it in for 11min;
[0080] (3) The melt is cast, extruded, rolled, cooled with cold water to form a rod, and then annealed to obtain an aluminum alloy rod for extrusion.
[0081] Comparative Example 4
[0082] On the basis of Example 3, keeping other conditions the same, the preparation method was changed to:
[0083] (1) After melting the aluminum ingot, keep the temperature unchanged, add silicon-containing raw materials, iron-containing raw materials, copper-containing raw materials, manganese-containing raw materials, zinc-containing raw materials, titanium-containing raw materials, scandium-containing raw materials, lanthanum-containing raw materials and cerium-containing raw materials, stir, alloy, and obtain aluminum liquid;
[0084] (2) blowing 0.15 wt% of hexachloroethane, a refining agent, into the aluminum liquid, controlling the temperature, stirring and standing once, blowing 0.1 wt% of hexachloroethane into the aluminum liquid again, stirring and standing for the second time, then skimming, degassing, filtering and obtaining a melt;
[0085] (3) The melt is cast, extruded, rolled, and cooled with cold water to obtain an aluminum alloy rod for extrusion.
[0086] Comparative Example 5
[0087] On the basis of Example 3, the scandium-containing raw material in step (1) was removed and replaced with an equal weight of lanthanum-containing raw material, and other conditions remained the same as in Example 3.
[0088] Comparative Example 6
[0089] On the basis of Example 3, the lanthanum-containing raw material in step (1) was removed and an equal weight of cerium-containing raw material was used, and other conditions remained the same as in Example 3.
[0090] Comparative Example 7
[0091] On the basis of Example 3, the cerium-containing raw material in step (1) was removed and replaced with an equal weight of scandium-containing raw material, and other conditions remained the same as in Example 3.
[0092] Comparative Example 8
[0093] On the basis of Example 3, the final concentration of the scandium element in the aluminum liquid in step (1) was changed to 0.015wt%, and the other conditions remained the same as in Example 3.
[0094] Comparative Example 9
[0095] On the basis of Example 3, keeping other conditions the same, the rolling conditions in step (3) are changed to: the rolling speed is controlled to 2.5 m / min, the reduction amount is controlled to 12.5% each time, and the rolling is stopped after the final thickness is 8 mm.
[0096] The aluminum alloy rods prepared in Examples 1-3 and Comparative Examples 1-9 were used as samples, the gauge length was controlled to be 50 mm, the tensile speed was 5 mm / min, and the tensile strength (MPa) and elongation at break (%) of the samples were tested according to GB / T 228-2002. The results are recorded in Table 1 below.
[0097] Table 1
[0098] Tensile strength(MPa) Elongation at break (%) Example 1 73 28 Example 2 72 29 Example 3 71 30 Comparative Example 1 62 20 Comparative Example 2 63 21 Comparative Example 3 65 23 Comparative Example 4 115 12 Comparative Example 5 67 26 Comparative Example 6 67 25 Comparative Example 7 68 25 Comparative Example 8 63 22 Comparative Example 9 72 21
[0099] As can be seen from Table 1, the aluminum alloy rods prepared in Examples 1-3 of the present invention have good tensile strength and elongation at break, meeting the needs of practical applications. Comparative Example 1 removes the secondary refining, which may result in more impurities, and the increase in impurities may lead to reduced plasticity. Comparative Example 2 removes the multiple and intermittent stirring treatments of the original secondary stirring and replaces it with continuous stirring. Compared with intermittent stirring, which allows bubbles to rise and escape, continuous stirring may lead to an increase in bubbles and inclusions. Comparative Example 3 changes the original cyclic degassing to one-time degassing, which may lead to insufficient degassing, thus affecting the tensile strength and elongation at break. Comparative Example 4 removes the annealing treatment. The aluminum alloy rod will be subjected to stress during the processing, resulting in changes in the grain size, thereby increasing the tensile strength of the material, but the elongation at break is not as good as the original one. The rate is reduced; Comparative Examples 5-7 replace any component of the scandium-containing raw material, the lanthanum-containing raw material and the cerium-containing raw material. The absence of the lanthanum-containing raw material and the cerium-containing raw material may lead to a reduction in the refinement effect of the grain structure, and the scandium-containing raw material may indeed lead to a reduction in the strengthening effect of the aluminum alloy rod, thereby affecting the tensile strength and elongation at break; Comparative Example 8 reduces the scandium content, which may lead to a decrease in the degree of grain refinement and a reduction in the Al3Sc precipitation phase, resulting in a significant decrease in strength, thereby affecting the tensile strength and elongation at break; Comparative Example 9 changes the rolling conditions, which may lead to work hardening and reduced plasticity, so the tensile strength and elongation at break are affected.
[0100] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any indirect modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.
Claims
1. A method for preparing an aluminum alloy rod for extrusion, characterized in that: The preparation method comprises the following steps: (1) After melting the aluminum ingot, keep the temperature unchanged, add silicon-containing raw materials, iron-containing raw materials, copper-containing raw materials, manganese-containing raw materials, zinc-containing raw materials, titanium-containing raw materials, scandium-containing raw materials, lanthanum-containing raw materials and cerium-containing raw materials, stir, alloy, and obtain aluminum liquid; (2) blowing 0.1-0.2wt% of a refining agent into the aluminum liquid, controlling the temperature, stirring and standing once, blowing 0.05-0.15wt% of a refining agent into the aluminum liquid again, stirring and standing for the second time, then skimming, degassing, filtering, and obtaining a melt; (3) The melt is cast, extruded, rolled, cooled with cold water to form a rod, and then annealed to obtain an aluminum alloy rod for extrusion.
2. The method for preparing an aluminum alloy rod for extrusion according to claim 1, characterized in that: The mass fraction of the aluminum ingot in step (1) is 99.8wt%; the final concentration of each alloy element in the aluminum liquid is: 0.041-0.043wt% silicon, 0.116-0.118wt% iron, 0.05-0.10wt% copper, 0.2-0.3wt% manganese, 0.1-0.3wt% zinc, 0.04-0.1wt% titanium, 0.02-0.025wt% scandium, 0.016-0.018wt% lanthanum, 0.016-0.018wt% cerium, 0.001-0.01wt% other impurities and the remainder aluminum.
3. The method for preparing an aluminum alloy rod for extrusion according to claim 1, characterized in that: The melting temperature of step (1) is 730-740°C; the stirring speed and time are 60-80rmp and 5-15min respectively; the alloying temperature and time are 742-748°C and 15-25min respectively.
4. The method for preparing an aluminum alloy rod for extrusion according to claim 1, characterized in that: The temperature of the temperature control in step (2) is 745-755°C; the parameters of the first stirring and standing are: the stirring speed and time are 40-60rmp and 2-8min respectively, and the standing time is 5-15min; the second stirring and standing refers to stirring 3 times, each stirring time is 1-3min, and the interval between each two stirrings is 5min, and standing for 10-20min after the last stirring.
5. The method for preparing an aluminum alloy rod for extrusion according to claim 1, characterized in that: The degassing in step (2) refers to three cycles of degassing using argon, during which the argon flow rate is 0.3-0.7L / min, the time for blowing argon in the first cycle is 4-6min, and the time for blowing argon in subsequent cycles is shortened to 2.5-3.5min, and after each cycle, the pressure in the furnace is reduced by 0.1bar.
6. The method for preparing an aluminum alloy rod for extrusion according to claim 1, characterized in that: The filtration in step (2) is performed by filtering three times using a 40-60 mesh ceramic filter plate.
7. The method for preparing an aluminum alloy rod for extrusion according to claim 1, characterized in that: The casting in step (3) refers to preheating the casting mold to 200-300°C, pouring the melt into it, controlling the casting speed to 390-410rmp and the casting current to 550-620A for casting, and cooling to room temperature after the casting is completed.
8. The method for preparing an aluminum alloy rod for extrusion according to claim 1, characterized in that: The extrusion in step (3) refers to heating the cast product to 450-470° C. and then extruding it at an extrusion ratio of 10-30:
1.
9. The method for preparing an aluminum alloy rod for extrusion according to claim 1, characterized in that: The rolling in step (3) refers to controlling the rolling speed to 2-3 m / min, first performing initial rolling and then performing finish rolling, the initial rolling is 6-12 passes of rolling at room temperature, each time the reduction is controlled at 10-15%, and the finish rolling is further rolling to a final thickness of 7-9 mm, each time the reduction is controlled at 5-9%.
10. The method for preparing an aluminum alloy rod for extrusion according to claim 1, characterized in that: The annealing treatment in step (3) is to place the rod in an annealing furnace and heat it to 415-425° C. and keep it warm for 8-12 hours.