An aluminum profile for a rail transit current collector and a preparation method thereof

Abstract

The present invention discloses an aluminum profile for a rail transit current collector and a production method thereof. The aluminum profile is composed of the following components by mass percentage: Si 0.38 - 0.42%, Mg 0.49 - 0.53%, Cu 0.02 - 0.05%, Mn 0.02 - 0.5%, Ti 0.01 - 0.015%, B 0.002 - 0.003%, Fe 0.1 - 0.15%, and the balance is Al and inevitable impurity elements, with a single impurity ≤ 0.05% and the total impurity content ≤ 0.15%. The tensile strength of the aluminum profile ≥ 250 MPa, the yield strength ≥ 210 MPa, the elongation after fracture ≥ 12%, and the resistivity at 20°C ≤ 0.03 Ω·mm 2 ·m ‑1 , and the conductivity ≥ 57.5% IACS. Compared with the traditional aluminum profile for a rail transit current collector, the strength of the aluminum profile of the present invention is increased by 10%, and the conductivity is increased by more than 1% IACS. The aluminum profile has the advantages of high strength, high conductivity, and uniform and stable tissue performance, meeting the requirements of the high-speed development of urban rail transit such as light rail, subway, and maglev trains.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum alloys, and particularly to an aluminum profile for a conductive busbar in rail transit and a preparation method thereof. Background Art

[0002] Aluminum profiles have the advantages of low density, high specific strength, corrosion resistance, good electrical conductivity, easy processing and forming, recyclability, etc., and are widely used in conductive busbars for urban rail transit such as light rails, subways, and maglev trains. The aluminum profile for a conductive busbar, commonly known as a conductive rail, is an important component in the power supply network system of urban rail transit. It not only has the function of clamping and fixing the contact wire but also has the function of carrying and transporting electric current. With the rapid development of rail transit in China, the comprehensive performance requirements for aluminum profiles for conductive busbars are getting higher and higher. On the one hand, it is required that the aluminum profile has a higher conductivity to improve the power transmission efficiency and reduce power consumption. On the other hand, it is required that the aluminum profile has a higher strength to improve the stability, safety, and service life of urban rail transit operation.

[0003] The patent application with publication number CN110983124A discloses a 6-series aluminum alloy with high conductivity and its production process. The composition of the aluminum alloy is: Si 0.55%-0.60%, Fe 0.10%-0.15%, Cu 0.05%-0.08%, Mn 0.01%-0.02%, Mg 0.60%-0.65%, Cr 0.01%-0.02%, Ti≤0.01%, Zn 0.05%-0.08%, V≤0.01%, Gd 0.15%-0.18%, B 0.015%-0.02%, single impurity≤0.03%, total impurities≤0.10%, and the balance is Al. The tensile strength of the aluminum alloy reaches 250 MPa, the yield strength reaches 210 MPa, the elongation after fracture reaches 16.7%, the electrical conductivity is 32.52 MS / m, and the hardness HB is 65.

[0004] The patent application with publication number CN109207817A discloses a preparation process for an aluminum alloy with high conductivity and high strength and the aluminum alloy. The preparation process includes melting pure aluminum, adding silicon, magnesium, iron, copper, manganese, and zinc. The components are: silicon 0.15-0.3%, iron≤0.2%, copper≤0.1%, manganese 0.04-0.06%, magnesium 0.3-0.5%, zinc 0.08-0.12%, and the balance is aluminum, extrusion molding, and aging. The electrical conductivity of the aluminum alloy is 34.2 Ms / m, and the tensile strength is 176 MPa. Although the electrical conductivity of this aluminum alloy is relatively high, its strength is still low.

[0005] The patent application with the publication number CN111961890A discloses a production process method for profiles used in high-conductivity and high-strength aluminum alloy electrical equipment. By controlling the melting, refining, casting, homogenization, extrusion, and aging processes of the aluminum alloy, the tensile strength of the aluminum profile is ≥350 Mpa, the yield strength is ≥320 Mpa, and the conductivity is ≥46% IACS. Although the strength of this aluminum profile is relatively high, its conductivity is still low.

[0006] From the perspective of production practice and the retrieval results of literature, there is a contradictory problem of mutual restriction and a trade-off between the strength and conductivity of aluminum profiles, making it difficult to balance the improvement of the strength and conductivity of aluminum profiles, and the existing aluminum profiles can no longer meet the requirements of the high-speed development of urban rail transit. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a preparation method for aluminum profiles of rail transit conductive busbars, which can produce aluminum profiles with high strength and high conductivity.

[0008] Another technical problem to be solved by the present invention is to provide an aluminum profile for rail transit conductive busbars.

[0009] To solve the above technical problems, the present invention provides an aluminum profile for rail transit conductive busbars, which is composed of the following components by mass percentage: Si 0.38 - 0.42%, Mg 0.49 - 0.53%, Cu 0.02 - 0.05%, Mn 0.02 - 0.05%, Ti 0.01 - 0.015%, B 0.002 - 0.003%, Fe 0.1 - 0.15%, and the balance is Al and inevitable impurity elements, with a single impurity ≤0.05% and the total impurity ≤0.15%.

[0010] Correspondingly, the present invention also discloses a production method for the above-mentioned aluminum profile of rail transit conductive busbars, which is characterized by successively including the following steps:

[0011] (1) According to the component composition and mass percentage of the aluminum profile, select aluminum ingots, magnesium ingots, aluminum-silicon alloy, aluminum-copper alloy, aluminum-manganese alloy, aluminum-iron alloy, and aluminum-titanium-boron alloy rods as raw materials for batching;

[0012] (2) Add the aluminum ingots, magnesium ingots, aluminum-silicon alloy, aluminum-copper alloy, aluminum-manganese alloy, and aluminum-iron alloy to a melting furnace and heat them to melt into an aluminum alloy liquid at 740 - 760 °C;

[0013] (3) Use argon gas and a refining agent to spray and refine the aluminum alloy liquid in the furnace for slag removal treatment, and then skim off the floating slag on the surface of the aluminum alloy liquid;

[0014] (4)A mixed gas composed of argon and chlorine is introduced into the molten aluminum alloy in the furnace through a porous plug installed at the bottom of the furnace for degassing treatment;

[0015] (5)The molten aluminum alloy is introduced into a launder, and then an aluminum-titanium-boron alloy rod accounting for 0.2 - 0.3% of the total weight of the raw materials is added for on-line grain refinement treatment;

[0016] (6)The molten aluminum alloy flows through a degassing box and a tubular filter box arranged on the launder in sequence for on-line degassing and filtering treatment;

[0017] (7)The molten aluminum alloy is semi-continuously cast into an aluminum alloy ingot at a temperature of 680 - 720 °C, a casting speed of 100 - 200 mm / min, and a cooling water temperature of 20 - 40 °C;

[0018] (8)The aluminum alloy ingot is heated at 565 - 575 °C for 5 - 6 hours for homogenization treatment, and then spray-cooled to room temperature;

[0019] (9)The aluminum alloy ingot is heated to 480 - 500 °C and then extruded into aluminum profiles;

[0020] (10)The aluminum profiles are heated at 180 - 190 °C for 4 - 5 hours for aging treatment to obtain the finished aluminum profiles for rail transit current collectors.

[0021] As an improvement of the above technical solution, in step (1), the aluminum content of the aluminum ingot ≥ 99.7 wt%, the magnesium content of the magnesium ingot ≥ 99.8 wt%, the silicon content of the aluminum-silicon alloy is 25 wt%, the copper content of the aluminum-copper alloy is 20 wt%, the manganese content of the aluminum-manganese alloy is 10 wt%, the iron content of the aluminum-iron alloy is 15 wt%, the titanium content of the aluminum-titanium-boron alloy rod is 5 wt%, the boron content is 1 wt%, and the balance is aluminum.

[0022] As an improvement of the above technical solution, in step (3), the purity of the argon ≥ 99.99%, the pressure of the argon is 0.3 - 0.5 MPa, the dosage of the refining agent is 0.1 - 0.2% of the weight of the molten aluminum alloy, and the blowing refining time is 15 - 25 minutes.

[0023] As an improvement of the above technical solution, the refining agent in step (3) is composed of the following components by mass percentage: ZnCl2 40 - 50%, K2CO3 20 - 30%, NaNO3 5 - 10%, KF 8 - 13%, K2SO4 5 - 8%, Li2SO4 3 - 5%.

[0024] As an improvement of the above technical solution, the production method of the refining agent in step (3) successively includes the following steps:

[0025] (i) Select ZnCl2, K2CO3, NaNO3, KF, K2SO4, Li2SO4 with a purity ≥ 99.8% as raw materials for batching;

[0026] (ii) Under the protection of argon with a purity ≥ 99.99%, heat the raw materials to melt at 1150 °C, and then cool and solidify the bulk refining agent;

[0027] (iii) Crush the bulk refining agent into powder with a particle size ≤ 2 mm to obtain the refining agent.

[0028] As an improvement of the above technical solution, in step (4), the purity of the argon ≥ 99.99%, the purity of the chlorine gas ≥ 99.9%, the volume percentage of chlorine gas in the mixed gas is 3 - 5%, the flow rate of the mixed gas is 0.3 - 0.6 m³ / min, and the degassing time is 10 - 20 minutes.

[0029] As an improvement of the above technical solution, in step (6), the rotation speed of the graphite rotor in the degassing box is 400 - 500 r / min, the gas flow rate on the graphite rotor is 2 - 3 m³ / h, the gas pressure is 0.4 - 0.6 MPa, the gas is a mixed gas composed of argon with a purity ≥ 99.99% and chlorine gas with a purity ≥ 99.9%, and the volume percentage of chlorine gas in the mixed gas is 5 - 10%.

[0030] As an improvement of the above technical solution, in step (9), the extrusion ratio of the extrusion is 10 - 30, the extrusion speed is 5 - 15 mm / s, and the heating temperature of the extrusion die is 420 - 460 °C.

[0031] As an improvement of the above technical solution, the tensile strength of the aluminum profile ≥ 250 MPa, the yield strength ≥ 210 MPa, the elongation after fracture ≥ 12%, and the resistivity at 20 °C ≤ 0.03 Ω·mm 2 ·m -1 , and the conductivity ≥ 57.5% IACS.

[0032] Implementing the present invention has the following beneficial effects:

[0033] By scientifically designing the composition of the aluminum profile and optimizing the production method of the aluminum profile, the present invention improves the cleanliness of the aluminum profile liquid, solves the contradictory problem of mutual restriction and trade - off between strength and conductivity, enables the strength and conductivity of the aluminum profile to be significantly improved simultaneously. The tensile strength of the aluminum profile ≥ 250 MPa, the yield strength ≥ 210 MPa, the elongation after fracture ≥ 12%, and the resistivity at 20 °C ≤ 0.03 Ω·mm 2 ·m -1 , and the conductivity ≥ 57.5% IACS. Brief Description of the Drawings

[0034] Figure 1 It is a flowchart of the preparation method of the aluminum profile for the rail transit conductive busbar in an embodiment of the present invention. Specific embodiments

[0035] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. It is hereby declared that the orientation terms such as up, down, left, right, front, back, inside and outside that appear or will appear in the text of the present invention are only based on the accompanying drawings of the present invention, and they do not specifically limit the present invention.

[0036] The first aspect of the present invention provides an aluminum profile for a rail transit conductive busbar. The characteristics are that the aluminum profile is composed of the following components by mass percentage: Si 0.38 - 0.42%, Mg 0.49 - 0.53%, Cu 0.02 - 0.05%, Mn 0.02 - 0.5%, Ti 0.01 - 0.015%, B 0.002 - 0.003%, Fe 0.1 - 0.15%, and the balance is Al and inevitable impurity elements, with a single impurity ≤ 0.05% and the total impurity content ≤ 0.15%.

[0037] Among them, Si and Mg are the main strengthening elements of the aluminum profile. In addition to the solid solution strengthening effect in the aluminum profile, Si and Mg can also significantly improve the strength of the aluminum profile by precipitating the Mg2Si strengthening phase during aging. If the contents of Si and Mg are too low, the strength of the aluminum profile will be too low. The higher the contents of Si and Mg, the higher the strength of the aluminum profile, but the conductivity will gradually decrease. Preferably, the content of Si is 0.38 - 0.42% and the content of Mg is 0.49 - 0.53%.

[0038] Cu has a strong strengthening effect in the aluminum profile. It can not only improve the strength of the aluminum profile through solid solution strengthening, but also enhance the strength of the aluminum profile by precipitating the CuAl2 phase during aging. The higher the Cu content, the higher the strength of the aluminum profile, but too high a Cu content will also reduce the conductivity of the aluminum profile. Preferably, the content of Cu is 0.02 - 0.05%.

[0039] In the aluminum profile, in addition to improving the strength, Mn can also increase the recrystallization temperature of the aluminum profile by inhibiting recrystallization, which is beneficial to increasing the extrusion temperature of the aluminum profile and improving the extrusion speed of the aluminum profile. The higher the Mn content, the higher the recrystallization temperature of the aluminum profile, but it will also reduce the conductivity of the aluminum profile. Preferably, the content of Mn is 0.02 - 0.05%.

[0040] Ti and B are added to the aluminum profile in the form of an aluminum-titanium-boron alloy rod. The main functions are to refine the grains of the aluminum alloy ingot, improve the uniformity of the tissue composition of the aluminum alloy ingot, and enhance the extrusion performance of the aluminum alloy ingot. If the content of Ti and B is too low, the grain refinement effect is not ideal. The higher the content of Ti and B, the finer the grains, but it will also increase the production cost. Preferably, the content of Ti is 0.01 - 0.015%, and the content of B is 0.002 - 0.003%.

[0041] In the aluminum profile, Fe can form intermetallic compounds such as FeAl3, Fe3SiAl 12 , Fe2SiAl9, etc. When these intermetallic compounds are dispersed in the aluminum profile, the strength of the aluminum profile can be improved through dispersion strengthening. However, if the Fe content is too high, it will also reduce the conductivity of the aluminum profile. Preferably, the content of Fe is 0.1 - 0.15%.

[0042] The second aspect of the present invention provides a production method of an aluminum profile for a rail transit conductive busbar, which is characterized by successively including the following steps:

[0043] (1) According to the component composition and mass percentage of the aluminum profile, select aluminum ingots, magnesium ingots, aluminum-silicon alloys, aluminum-copper alloys, aluminum-manganese alloys, aluminum-iron alloys, and aluminum-titanium-boron alloy rods as raw materials for batching;

[0044] (2) Add the aluminum ingots, magnesium ingots, aluminum-silicon alloys, aluminum-copper alloys, aluminum-manganese alloys, and aluminum-iron alloys to a melting furnace and heat them to melt into an aluminum alloy liquid at 740 - 760 °C;

[0045] (3) Use argon gas and a refining agent to blow and refine the aluminum alloy liquid in the furnace for slag removal treatment, and then skim off the floating slag on the surface of the aluminum alloy liquid;

[0046] (4) Pass a mixed gas composed of argon gas and chlorine gas into the aluminum alloy liquid in the furnace through a porous brick installed at the bottom of the furnace for degassing treatment;

[0047] (5) Introduce the aluminum alloy liquid into a launder, and then add an aluminum-titanium-boron alloy rod accounting for 0.2 - 0.3% of the total weight of the raw materials for on-line grain refinement treatment;

[0048] (6) Let the aluminum alloy liquid flow through a degassing box and a tubular filter box installed on the launder in sequence for on-line degassing and filtering treatment;

[0049] (7) Semi-continuously cast the aluminum alloy liquid into an aluminum alloy ingot at a temperature of 680 - 720 °C, a casting speed of 100 - 200 mm / minute, and a cooling water temperature of 20 - 40 °C;

[0050] (8) Heat the aluminum alloy ingot at 565 - 575 °C for 5 - 6 hours for homogenization treatment, and then spray water mist to cool it to room temperature;

[0051] (9) Heat the aluminum alloy casting rod to 480 - 500 °C, and then extrude it into aluminum profiles.

[0052] (10) Heat the aluminum profiles at 180 - 190 °C for 4 - 5 hours for aging treatment to obtain the aluminum profiles for rail transit current collectors.

[0053] Preferably, in step (1), the aluminum content of the aluminum ingot is ≥ 99.7 wt%, the magnesium content of the magnesium ingot is ≥ 99.8 wt%, the silicon content of the aluminum - silicon alloy is 25 wt%, the copper content of the aluminum - copper alloy is 20 wt%, the manganese content of the aluminum - manganese alloy is 10 wt%, the iron content of the aluminum - iron alloy is 15 wt%, the titanium content of the aluminum - titanium - boron alloy rod is 5 wt%, the boron content is 1 wt%, and the balance is aluminum.

[0054] Preferably, in step (3), the purity of the argon is ≥ 99.99%. Argon is mainly used for blowing the refining agent. For better dispersion of the refining agent, the pressure of argon is 0.3 - 0.5 MPa. The dosage of the refining agent is 0.1 - 0.2% of the weight of the aluminum alloy liquid, and the blowing refining time is 15 - 25 minutes. The refining agent consists of the following components by mass percentage: ZnCl₂ 40 - 50%, K₂CO₃ 20 - 30%, NaNO₃ 5 - 10%, KF 8 - 13%, K₂SO₄ 5 - 8%, Li₂SO₄ 3 - 5%. The production method of the refining agent includes the following steps in sequence: (i) Select ZnCl₂, K₂CO₃, NaNO₃, KF, K₂SO₄, Li₂SO₄ with a purity ≥ 99.8% as raw materials for batching; (ii) Under the protection of argon with a purity ≥ 99.99%, heat the raw materials to melt at 1150 °C, and then cool and solidify into a block - shaped refining agent; (iii) Crush the block - shaped refining agent into a powder with a particle size ≤ 2 mm to obtain the refining agent.

[0055] Stomata and inclusions not only reduce the strength of aluminum profiles, but also reduce their electrical conductivity. Removing the gases and inclusions inside the aluminum profiles and improving the purity of the aluminum profiles can simultaneously increase the strength and electrical conductivity of the aluminum profiles. Traditional refining agents are mainly made by directly crushing and mixing raw materials such as sodium salts, fluorides, chlorides, and hexachloroethane, without giving full play to the interaction between the raw materials, resulting in a high melting point of the refining agent and a low slag removal efficiency. In order to improve the purity of aluminum profiles, increase the strength and electrical conductivity of aluminum profiles, the inventor developed a highly efficient and environmentally friendly refining agent through a large number of experimental studies. The refining agent has ZnCl2 as the main component, and is further mixed with a small amount of K2CO3, NaNO3, KF, K2SO4, and Li2SO4. Under the protection of argon, the raw materials are first heated and melted at 1100 - 1200 °C, then cooled, solidified, and crushed into a powdered refining agent. The melting point of ZnCl2 is about 290 °C, the melting point of NaNO3 is 306.8 °C, the melting point of K2CO3 is 891 °C, the melting point of KF is 858 °C, the melting point of K2SO4 is 1069 °C, and the melting point of Li2SO4 is 859 °C. Although the melting points of K2CO3, KF, K2SO4, and Li2SO4 are relatively high, through melting and solidification crystallization, K2CO3 and KF form a KF·K2CO3 eutectic with a melting point of only 688 °C, and K2SO4 and Li2SO4 form a K2SO4·Li2SO4 eutectic with a melting point of only 716 °C, greatly reducing the melting point of the refining agent. The refining agent is more easily melted in the aluminum alloy liquid. ZnCl2 decomposes to produce Cl2, K2CO3 decomposes to produce CO2, and NaNO3 decomposes to produce N2, CO2, and NO gases. A large number of bubbles capture the inclusions in the aluminum alloy liquid during the upward floating process, achieving a slag removal effect. The K2SO4·Li2SO4 eutectic melts into a liquid molten salt, which has a good wetting and spheroidizing effect on inclusions such as alumina, promotes the separation of inclusions from the aluminum liquid, and improves the slag removal efficiency. In addition, this refining agent does not contain sodium salts and hexachloroethane, only contains a small amount of fluorides, and is also more environmentally friendly.

[0056] Preferably, in step (4), the purity of the argon ≥ 99.99%, the purity of the chlorine gas ≥ 99.9%, the volume percentage of chlorine gas in the mixed gas is 3 - 5%, the flow rate of the mixed gas is 0.3 - 0.6 cubic meters per minute, and the degassing time is 10 - 20 minutes.

[0057] Degassing with bottom porous bricks in the melting aluminum furnace is to install multiple porous bricks at the bottom of the melting aluminum furnace, and then introduce a mixed gas composed of argon and chlorine into the aluminum alloy liquid in the furnace through the porous bricks. The mixed gas is decomposed into small and uniform bubbles after passing through the porous bricks. During the upward floating process, the small bubbles capture the hydrogen in the aluminum alloy liquid and then float out of the aluminum alloy liquid, playing a role in degassing. Since multiple porous bricks are evenly installed at the bottom of the melting aluminum furnace, the bubbles are evenly distributed in the aluminum alloy liquid. At the same time, when the bubbles float upward, they also stir the aluminum alloy liquid, avoiding dead corners in degassing the aluminum alloy liquid in the furnace and improving the degassing efficiency of the aluminum alloy liquid. The greater the flow rate of the mixed gas and the longer the ventilation time, the better the degassing effect. Preferably, the flow rate of the mixed gas is 0.3 - 0.6 cubic meters per minute, and the degassing time is 10 - 20 minutes, which can reduce the hydrogen content in the aluminum alloy liquid in the furnace to less than 0.2 ml / 100gAl, greatly improving the purity of the aluminum alloy liquid in the furnace.

[0058] Preferably, in step (6), the rotational speed of the graphite rotor in the degassing tank is 400 - 500 revolutions per minute, the gas flow rate on the graphite rotor is 2 - 3 cubic meters per hour, the gas pressure is 0.4 - 0.6 MPa, the gas is a mixed gas composed of argon with a purity of ≥99.99% and chlorine with a purity of ≥99.9%, and the volume percentage of chlorine in the mixed gas is 5 - 10%.

[0059] The mixed gas composed of argon and chlorine is broken into small bubbles by the high-speed rotating graphite rotor in the degassing tank and enters the aluminum alloy liquid. Utilizing the partial pressure difference of hydrogen between the aluminum alloy liquid and the bubbles, the hydrogen atoms in the aluminum alloy liquid continuously diffuse into the bubbles and then float out of the aluminum alloy liquid with the bubbles, playing a role in degassing. After degassing in the degassing tank, the hydrogen content of the aluminum alloy liquid can be reduced to less than 0.08 ml / 100gAl, which can greatly improve the strength and conductivity of the aluminum profile.

[0060] The filtering medium of the tubular filter tank in step (6) is a ceramic filter tube, which is formed by high-temperature sintering of silicon nitride ceramic particles with a particle size of 3 - 6 mm and a binder, and has a large number of tortuous pores inside. When the aluminum alloy liquid flows through the ceramic filter tube, inclusions are adsorbed or blocked on the surface and inner wall of the pores of the ceramic filter tube, achieving the effect of filtering and removing impurities. The ceramic filter tube has high thermal strength, strong resistance to thermal shock and thermal erosion, large filtering capacity, and high filtering efficiency. The structure and usage method of the tubular filter tank can be found in publicly available literature materials and will not be elaborated here. Tubular filtration belongs to high-precision filtration. After tubular filtration, the removal rate of inclusions with a size of more than 5 μm in the aluminum alloy liquid can reach more than 98%, and the slag content in the aluminum profile can be reduced to 0.05 mm 2 / kg, thus greatly improving the cleanliness of the aluminum profile, and improving the strength and conductivity of the aluminum profile.

[0061] In step (8), the aluminum alloy ingot is heated at 565 - 575 °C for 5 - 6 hours for homogenization treatment. The purpose is to eliminate the macro and micro segregation of elements inside the aluminum alloy ingot, melt the coarse intermetallic compounds, eliminate the internal stress of the ingot, reduce the deformation resistance of the aluminum alloy ingot, and improve the uniformity of the ingot's tissue composition.

[0062] Preferably, in step (9), the extrusion ratio of the extrusion is 10 - 30, the extrusion speed is 5 - 15 mm / s, and the heating temperature of the extrusion die is 420 - 460 °C.

[0063] In summary, through the comprehensive adjustment of the above formula and process, an aluminum alloy profile for rail transit current collector with a tensile strength ≥ 250 MPa, a yield strength ≥ 210 MPa, an elongation after fracture ≥ 12%, a resistivity at 20 °C ≤ 0.03 Ω·mm 2 ·m -1 , and a conductivity ≥ 57.5% IACS can be obtained, meeting the requirements of the high-speed development of urban rail transit such as light rail, subway, and maglev trains.

[0064] The following further illustrates the present invention with specific examples:

[0065] Example 1

[0066] The aluminum profile is composed of the following components by mass percentage: Si 0.41%, Mg 0.51%, Cu 0.04%, Mn 0.03%, Ti 0.0125%, B 0.0025%, Fe 0.12%, and the balance is Al and inevitable impurity elements, with a single impurity ≤ 0.05% and the total impurity ≤ 0.15%.

[0067] The production method successively includes the following steps:

[0068] (1) According to the component composition and mass percentage of the aluminum profile, select aluminum ingots with an aluminum content ≥ 99.7%, magnesium ingots with a magnesium content ≥ 99.8%, aluminum-silicon alloys with a silicon content of 25%, aluminum-copper alloys with a copper content of 20%, aluminum-manganese alloys with a manganese content of 10%, aluminum-iron alloys with an iron content of 15%, and aluminum-titanium-boron alloy rods with a titanium content of 5% and a boron content of 1% as raw materials for batching;

[0069] (2) Add the aluminum ingot, magnesium ingot, aluminum-silicon alloy, aluminum-copper alloy, aluminum-manganese alloy, and aluminum-iron alloy into a melting furnace and heat them to melt into an aluminum alloy liquid at 750 °C;

[0070] (3) Use argon with a purity ≥ 99.99% and a pressure of 0.4 MPa and a refining agent accounting for 0.15% of the weight of the aluminum alloy liquid to blow and refine the aluminum alloy liquid in the furnace for 20 minutes for slag removal treatment, and then skim off the floating slag on the surface of the aluminum alloy liquid;

[0071] (4) The degassing treatment is carried out by introducing a mixed gas composed of argon with a purity of ≥99.99% and chlorine with a purity of ≥99.9% into the molten aluminum alloy in the furnace through the porous plug installed at the bottom of the furnace. The volume percentage of chlorine in the mixed gas is 4%, the flow rate of the mixed gas is 0.45 cubic meters per minute, and the degassing time is 15 minutes;

[0072] (5) The molten aluminum alloy is introduced into the launder, and then an aluminum-titanium-boron alloy rod accounting for 0.25% of the total weight of the raw materials is added for on-line grain refinement treatment;

[0073] (6) The molten aluminum alloy flows through the degassing box and the tubular filter box arranged on the launder in sequence for on-line degassing and filtering treatment. The rotation speed of the graphite rotor in the degassing box is 450 revolutions per minute, the gas flow rate on the graphite rotor is 2.5 cubic meters per hour, the gas pressure is 0.5 MPa, the gas is a mixed gas composed of argon with a purity of ≥99.99% and chlorine with a purity of ≥99.9%, and the volume percentage of chlorine in the mixed gas is 7%;

[0074] ((7) Under the conditions that the temperature of the molten aluminum alloy is 700 °C, the casting speed is 150 mm / minute, and the temperature of the cooling water is 30 °C, the molten aluminum alloy is semi-continuously cast into an aluminum alloy casting rod;

[0075] (8) The aluminum alloy casting rod is heated at 570 °C for 5.5 hours for homogenization treatment, and then cooled to room temperature by spraying water mist;

[0076] (9) The aluminum alloy casting rod is heated to 490 °C, and then extruded into aluminum profiles under the conditions that the extrusion ratio is 18, the extrusion speed is 11 mm / s, and the heating temperature of the extrusion die is 440 °C;

[0077] (10) The aluminum profiles are heated at 185 °C for 4.5 hours for aging treatment to obtain the aluminum profiles.

[0078] The refining agent described in this embodiment is composed of the following components by mass percentage: ZnCl2 45%, K2CO3 25%, NaNO3 8%, KF 11%, K2SO4 7%, Li2SO4 4%. The production method of the refining agent includes the following steps in sequence: (1) Selecting ZnCl2, K2CO3, NaNO3, KF, K2SO4, Li2SO4 with a purity of ≥99.8% as raw materials for batching; (2) Heating and melting the raw materials at 1150 °C under the protection of argon with a purity of ≥99.99%, and then cooling and solidifying into a massive refining agent; (3) Crushing the massive refining agent into powder with a particle size of ≤2 mm to obtain the refining agent.

[0079] Example 2

[0080] The aluminum profile consists of the following components by mass percentage: Si 0.38%, Mg 0.53%, Cu 0.05%, Mn 0.02%, Ti 0.01%, B 0.002%, Fe 0.1%, and the balance is Al and inevitable impurity elements, with a single impurity ≤ 0.05% and the total impurity ≤ 0.15%. The production method successively includes the following steps:

[0081] (1) According to the component composition and mass percentage of the aluminum profile, select aluminum ingots with an aluminum content ≥ 99.7%, magnesium ingots with a magnesium content ≥ 99.8%, aluminum-silicon alloy with a silicon content of 25%, aluminum-copper alloy with a copper content of 20%, aluminum-manganese alloy with a manganese content of 10%, aluminum-iron alloy with an iron content of 15%, and an aluminum-titanium-boron alloy rod with a titanium content of 5% and a boron content of 1% as raw materials for batching;

[0082] (2) Add the aluminum ingots, magnesium ingots, aluminum-silicon alloy, aluminum-copper alloy, aluminum-manganese alloy, and aluminum-iron alloy into a melting furnace and heat them to melt into aluminum alloy liquid at 760 °C;

[0083] (3) Use argon with a purity ≥ 99.99% and a pressure of 0.5 MPa and a refining agent accounting for 0.2% of the weight of the aluminum alloy liquid to spray and refine the aluminum alloy liquid in the furnace for 25 minutes for slag removal treatment, and then skim off the floating slag on the surface of the aluminum alloy liquid;

[0084] (4) Pass a mixed gas composed of argon with a purity ≥ 99.99% and chlorine with a purity ≥ 99.9% into the aluminum alloy liquid in the furnace through a porous plug installed at the bottom of the furnace for degassing treatment. The volume percentage of chlorine in the mixed gas is 5%, the flow rate of the mixed gas is 0.3 cubic meters per minute, and the degassing time is 20 minutes;

[0085] (5) Introduce the aluminum alloy liquid into a launder, and then add an aluminum-titanium-boron alloy rod accounting for 0.2% of the total weight of the raw materials for on-line grain refinement treatment;

[0086] (6) Let the aluminum alloy liquid flow successively through a degassing box and a tubular filter box installed on the launder for on-line degassing and filtration treatment. The rotation speed of the graphite rotor in the degassing box is 500 revolutions per minute, the gas flow rate on the graphite rotor is 2 cubic meters per hour, the gas pressure is 0.6 MPa, the gas is a mixed gas composed of argon with a purity ≥ 99.99% and chlorine with a purity ≥ 99.9%, and the volume percentage of chlorine in the mixed gas is 10%;

[0087] (7) Semi-continuously cast the aluminum alloy liquid into an aluminum alloy casting rod under the conditions of an aluminum alloy liquid temperature of 680 °C, a casting speed of 200 mm / minute, and a cooling water temperature of 20 °C;

[0088] (8) Heat the aluminum alloy casting rod at 575 °C for 5 hours for homogenization treatment, and then spray water mist to cool it to room temperature;

[0089] (9) Heat the aluminum alloy casting rod to 500 °C, and then extrude it into an aluminum profile under the conditions of an extrusion ratio of 30, an extrusion speed of 5 mm / s, and an extrusion die heating temperature of 460 °C;

[0090] (10) Age the aluminum profile by heating it at 190 °C for 4 hours to obtain the aluminum profile.

[0091] The refining agent described in this embodiment is composed of the following components by mass percentage: ZnCl2 50%, K2CO3 24%, NaNO3 5%, KF 8%, K2SO4 8%, Li2SO4 5%. The production method of the refining agent successively includes the following steps: (1) Select ZnCl2, K2CO3, NaNO3, KF, K2SO4, Li2SO4 with a purity ≥ 99.8% as raw materials for batching; (2) Under the protection of argon with a purity ≥ 99.99%, heat the raw materials to melt at 1150 °C, and then cool and solidify into a block refining agent; (3) Crush the block refining agent into a powder with a particle size ≤ 2 mm to obtain the refining agent.

[0092] Example 3

[0093] The aluminum profile is composed of the following components by mass percentage: Si 0.42%, Mg 0.49%, Cu 0.02%, Mn 0.05%, Ti 0.015%, B 0.003%, Fe 0.15%, and the balance is Al and inevitable impurity elements, with a single impurity ≤ 0.05% and a total impurity ≤ 0.15%. The production method successively includes the following steps:

[0094] (1) According to the component composition and mass percentage of the aluminum profile, select aluminum ingots with an aluminum content ≥ 99.7%, magnesium ingots with a magnesium content ≥ 99.8%, aluminum-silicon alloys with a silicon content of 25%, aluminum-copper alloys with a copper content of 20%, aluminum-manganese alloys with a manganese content of 10%, aluminum-iron alloys with an iron content of 15%, and aluminum-titanium-boron alloy rods with a titanium content of 5% and a boron content of 1% as raw materials for batching;

[0095] (2) Add the aluminum ingots, magnesium ingots, aluminum-silicon alloy, aluminum-copper alloy, aluminum-manganese alloy, and aluminum-iron alloy to a melting furnace and heat them to melt into an aluminum alloy liquid at 740 °C;

[0096] (3) Use argon with a purity ≥ 99.99% and a pressure of 0.3 MPa and a refining agent accounting for 0.1% of the weight of the aluminum alloy liquid to blow and refine the aluminum alloy liquid in the furnace for 15 minutes for slag removal treatment, and then skim the floating slag on the surface of the aluminum alloy liquid;

[0097] (4) The degassing treatment is carried out by introducing a mixed gas composed of argon with a purity of ≥99.99% and chlorine with a purity of ≥99.9% into the molten aluminum alloy in the furnace through the porous plug installed at the bottom of the furnace. The volume percentage of chlorine in the mixed gas is 3%, the flow rate of the mixed gas is 0.6 cubic meters per minute, and the degassing time is 10 minutes;

[0098] (5) The molten aluminum alloy is introduced into the launder, and then an aluminum-titanium-boron alloy rod accounting for 0.3% of the total weight of the raw materials is added for on-line grain refinement treatment;

[0099] (6) The molten aluminum alloy flows through the degassing box and the tubular filter box arranged on the launder in sequence for on-line degassing and filtering treatment. The rotation speed of the graphite rotor in the degassing box is 400 revolutions per minute, the gas flow rate on the graphite rotor is 3 cubic meters per hour, the gas pressure is 0.4 MPa, the gas is a mixed gas composed of argon with a purity of ≥99.99% and chlorine with a purity of ≥99.9%, and the volume percentage of chlorine in the mixed gas is 5%;

[0100] (7) The molten aluminum alloy is semi-continuously cast into an aluminum alloy casting rod under the conditions that the temperature of the molten aluminum alloy is 720 °C, the casting speed is 100 mm / minute, and the temperature of the cooling water is 40 °C;

[0101] (8) The aluminum alloy casting rod is heated at 565 °C for 6 hours for homogenization treatment, and then sprayed with water mist to cool to room temperature;

[0102] (9) The aluminum alloy casting rod is heated to 480 °C, and then extruded into aluminum profiles under the conditions that the extrusion ratio is 10, the extrusion speed is 15 mm / s, and the heating temperature of the extrusion die is 420 °C;

[0103] (10) The aluminum profiles are heated at 180 °C for 5 hours for aging treatment to obtain the aluminum profiles.

[0104] The refining agent described in this embodiment is composed of the following components by mass percentage: ZnCl2 40%, K2CO3 29%, NaNO3 10%, KF 13%, K2SO4 5%, Li2SO4 3%. The production method of the refining agent successively includes the following steps: (1) Selecting ZnCl2, K2CO3, NaNO3, KF, K2SO4, Li2SO4 with a purity of ≥99.8% as raw materials for batching; (2) Heating and melting the raw materials at 1150 °C under the protection of argon with a purity of ≥99.99%, and then cooling and solidifying into a block-shaped refining agent; (3) Crushing the block-shaped refining agent into powder with a particle size of ≤2 mm to obtain the refining agent.

[0105] Example 4

[0106] The aluminum profile consists of the following components by mass percentage: Si 0.39%, Mg 0.52%, Cu 0.04%, Mn 0.03%, Ti 0.0125%, B 0.0025%, Fe 0.14%, and the balance is Al and inevitable impurity elements, with individual impurities ≤ 0.05% and the total impurity content ≤ 0.15%. The production method successively includes the following steps:

[0107] (1) According to the component composition and mass percentage of the aluminum profile, select aluminum ingots with an aluminum content ≥ 99.7%, magnesium ingots with a magnesium content ≥ 99.8%, aluminum-silicon alloy with a silicon content of 25%, aluminum-copper alloy with a copper content of 20%, aluminum-manganese alloy with a manganese content of 10%, aluminum-iron alloy with an iron content of 15%, and an aluminum-titanium-boron alloy rod with a titanium content of 5% and a boron content of 1% as raw materials for batching;

[0108] (2) Add the aluminum ingots, magnesium ingots, aluminum-silicon alloy, aluminum-copper alloy, aluminum-manganese alloy, and aluminum-iron alloy to a melting furnace and heat them to melt into aluminum alloy liquid at 750 °C;

[0109] (3) Use argon with a purity ≥ 99.99% and a pressure of 0.4 MPa and a refining agent accounting for 0.5% of the weight of the aluminum alloy liquid to blow and refine the aluminum alloy liquid in the furnace for 20 minutes for slag removal treatment, and then skim off the floating slag on the surface of the aluminum alloy liquid;

[0110] (4) Pass a mixed gas composed of argon with a purity ≥ 99.99% and chlorine with a purity ≥ 99.9% into the aluminum alloy liquid in the furnace through a porous plug installed at the bottom of the furnace for degassing treatment. The volume percentage of chlorine in the mixed gas is 4%, the flow rate of the mixed gas is 0.4 cubic meters per minute, and the degassing time is 13 minutes;

[0111] (5) Introduce the aluminum alloy liquid into a launder, and then add an aluminum-titanium-boron alloy rod accounting for 0.25% of the total weight of the raw materials for on-line grain refinement treatment;

[0112] (6) Let the aluminum alloy liquid flow successively through a degassing box and a tubular filter box installed on the launder for on-line degassing and filtering treatment. The rotation speed of the graphite rotor in the degassing box is 480 revolutions per minute, the gas flow rate on the graphite rotor is 2.6 cubic meters per hour, the gas pressure is 0.5 MPa, and the gas is a mixed gas composed of argon with a purity ≥ 99.99% and chlorine with a purity ≥ 99.9%. The volume percentage of chlorine in the mixed gas is 7%;

[0113] (7) Semi-continuously cast the aluminum alloy liquid into an aluminum alloy casting rod under the conditions that the temperature of the aluminum alloy liquid is 690 °C, the casting speed is 170 mm / minute, and the cooling water temperature is 28 °C;

[0114] (8) Heat the aluminum alloy casting rod at 570 °C for 5.5 hours for homogenization treatment, and then spray water mist to cool it to room temperature;

[0115] (9) Heat the aluminum alloy casting rod to 490 °C, and then extrude it into aluminum profiles under the conditions of an extrusion ratio of 20, an extrusion speed of 13 mm / s, and an extrusion die heating temperature of 450 °C;

[0116] (10) Age the aluminum profiles by heating at 185 °C for 4.5 hours to obtain the aluminum profiles.

[0117] The refining agent described in this example is composed of the following components by mass percentage: 43% ZnCl2, 30% K2CO3, 7% NaNO3, 10% KF, 6% K2SO4, 4% Li2SO4. The production method of the refining agent includes the following steps in sequence: (1) Select ZnCl2, K2CO3, NaNO3, KF, K2SO4, and Li2SO4 with a purity ≥ 99.8% as raw materials for batching; (2) Under the protection of argon with a purity ≥ 99.99%, heat the raw materials to melt at 1150 °C, and then cool and solidify into massive refining agent; (3) Crush the massive refining agent into powder with a particle size ≤ 2 mm to obtain the refining agent.

[0118] Comparative Example 1

[0119] In this comparative example, the component composition and preparation process parameters of the aluminum profiles are the same as those in Example 1, except that the used refining agent is a commonly used commercially available refining agent. The refining agent is composed of the following components by mass percentage: 26.1% NaCl, 10.6% Na2SiF6, 17.1% Na2SO4, 6.9% CaF2, 9.3% C6Cl6, 14.3% Na2S2O3, and 15.7% NaF. The production method of this refining agent is to directly crush the raw materials into powder with a particle size ≤ 2 mm and then mix them.

[0120] Comparative Example 2

[0121] In this comparative example, the component composition and preparation process parameters of the aluminum profiles are the same as those in Example 2, except that a bottom blowing permeable brick is not used to introduce a mixed gas composed of argon and chlorine into the molten aluminum alloy in the furnace for degassing treatment.

[0122] Comparative Example 3

[0123] In this comparative example, the component composition and preparation process parameters of the aluminum profiles are the same as those in Example 3, except that a tubular filter box is not used to filter the molten aluminum alloy.

[0124] Comparative Example 4

[0125] In this comparative example, the component composition and preparation process parameters of the aluminum profiles are the same as those in Example 4, except that a degassing box is not used to degas the molten aluminum alloy in this comparative example.

[0126] Verification Example 1

[0127] Using an OXFORD-DSC500 differential scanning calorimeter, the melting points of the refining agents used in Example 1 and Comparative Example 1 were detected respectively. The results are shown in Table 1. As can be seen from Table 1, the initial melting temperature of the refining agent in Example 1 was 290 °C, and the final melting temperature was only 716 °C. The initial melting temperature of the refining agent in Comparative Example 1 was 564 °C, and the final melting temperature was 1249 °C. By comparison, it can be seen that the refining agent developed in the present invention has a lower initial melting temperature and final melting temperature, indicating that the refining agent developed in the present invention is more easily melted in the aluminum alloy liquid, which is beneficial to improving the slag removal effect.

[0128] Table 1 Melting Points of the Refining Agents in Example 1 and Comparative Example 1

[0129]

[0130]

[0131] Verification Example 2

[0132] Using an HDA-V hydrogen detector and an Analyze PoDFA slag detector, the hydrogen content and slag content of the aluminum alloy liquid before semi-continuous casting in Examples 1-4 and Comparative Examples 1-4 were detected on-site. The results are shown in Table 2. As can be seen from Table 2, the hydrogen content of the aluminum alloys in Examples 1-4 was less than 0.08 ml / 100 g Al, and the slag content was less than 0.05 mm 2 / kg. In Comparative Example 1, due to the use of a traditional commercially available refining agent for in-furnace injection refining, in Comparative Example 2, due to the absence of a bottom blowing permeable brick for degassing, in Comparative Example 3, due to the absence of tubular filtration, and in Comparative Example 4, due to the absence of a degassing box for degassing, the gas and slag contents of the aluminum alloy liquid before casting were higher than those of the aluminum alloy liquid before casting in the examples. By comparison, it can be seen that the use of the method of the present invention can greatly improve the cleanliness of aluminum profiles.

[0133] Table 2 Hydrogen Content and Slag Content of the Aluminum Alloy Liquid before Casting in Examples and Comparative Examples

[0134] Hydrogen content / (ml / 100gAl) <![CDATA[Sludge content / (mm 2 / kg)]]> Example 1 0.074 0.045 Example 2 0.068 0.048 Example 3 0.072 0.039 Example 4 0.075 0.046 Comparative Example 1 0.086 0.069 Comparative Example 2 0.091 0.053 Comparative Example 3 0.076 0.113 Comparative Example 4 0.084 0.045

[0135] Verification Example 3

[0136] Samples were taken from the aluminum profiles in Examples 1-4 and Comparative Examples 1-4, and then the room temperature tensile mechanical properties, 20 °C resistivity and conductivity of the aluminum profiles were detected respectively. The results are shown in Table 3. As can be seen from Table 3, the tensile strength of the aluminum profiles in Examples 1-4 was ≥250 MPa, the yield strength was ≥210 MPa, the elongation after fracture was ≥12%, and the 20 °C resistivity was ≤0.03 Ω·mm 2 ·m -1, the conductivity ≥ 57.5% IACS, and the mechanical and electrical conductivity data are relatively uniform and stable. For the aluminum profiles of Comparative Examples 1-4, the tensile strength ≤ 240 MPa, the yield strength ≤ 200 MPa, the elongation after fracture ≤ 12%, and the resistivity at 20°C ≥ 0.03 Ω·mm 2 ·m -1 , the conductivity ≤ 57% IACS. By comparison, it can be seen that by scientifically designing the composition of the aluminum profile, optimizing the production method of the aluminum profile, and improving the cleanliness of the aluminum profile liquid, the strength and conductivity of the aluminum profile are simultaneously greatly improved.

[0137] Table 3 Room temperature tensile mechanical properties, resistivity and conductivity at 20°C of the aluminum profiles in the examples and comparative examples

[0138]

[0139]

[0140] The above is the preferred embodiment of the invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

Claims

1. A production method of an aluminum profile for a conductive busbar of rail transit, characterized in that, The steps are as follows in sequence: (1) Select aluminum ingots, magnesium ingots, aluminum-silicon alloy, aluminum-copper alloy, aluminum-manganese alloy, aluminum-iron alloy and aluminum-titanium-boron alloy rods as raw materials for batching according to the composition and mass percentage of the aluminum profile; wherein, the aluminum profile is composed of the following components by mass percentage: Si 0.38 - 0.42%, Mg 0.49 - 0.53%, Cu 0.02 - 0.05%, Mn 0.02 - 0.05%, Ti 0.01 - 0.015%, B 0.002 - 0.003%, Fe 0.1 - 0.15%, the balance being Al and inevitable impurity elements, with individual impurity ≤ 0.05% and total impurity ≤ 0.15%; (2) Add the aluminum ingots, magnesium ingots, aluminum-silicon alloy, aluminum-copper alloy, aluminum-manganese alloy and aluminum-iron alloy into a melting furnace and heat to melt into aluminum alloy liquid at 740 - 760 °C; (3) Use argon gas and a refining agent to blow and refine the aluminum alloy liquid in the furnace for slag removal treatment, and then skim off the floating slag on the surface of the aluminum alloy liquid; the refining agent is composed of the following components by mass percentage: ZnCl2 40 - 50%, K2CO3 20 - 30%, NaNO3 5 - 10%, KF 8 - 13%, K2SO4 5 - 8%, Li2SO4 3 - 5%; (4) Pass a mixed gas composed of argon gas and chlorine gas into the aluminum alloy liquid in the furnace through a porous brick installed at the bottom of the furnace for degassing treatment; (5) Introduce the aluminum alloy liquid into a launder, and then add an aluminum-titanium-boron alloy rod accounting for 0.2 - 0.3% of the total weight of the raw materials for on-line grain refinement treatment; (6) Let the aluminum alloy liquid flow through a degassing box and a tubular filter box arranged on the launder in sequence for on-line degassing and filtering treatment; (7) Semi-continuously cast the aluminum alloy liquid into an aluminum alloy cast rod under the conditions that the temperature of the aluminum alloy liquid is 680 - 720 °C, the casting speed is 100 - 200 mm / minute, and the cooling water temperature is 20 - 40 °C; (8) Heat the aluminum alloy cast rod at 565 - 575 °C for 5 - 6 hours for homogenization treatment, and then spray water mist to cool it to room temperature; (9) Heat the aluminum alloy cast rod to 480 - 500 °C, and then extrude it into an aluminum profile; (10) Heat the aluminum profile at 180 - 190 °C for 4 - 5 hours for aging treatment to obtain the finished aluminum profile for rail transit current collector bars.

2. The production method of the aluminum profile for the conductive busbar of rail transit according to claim 1, characterized in that, In step (1), the aluminum content of the aluminum ingot ≥ 99.7 wt%, the magnesium content of the magnesium ingot ≥ 99.8 wt%, the silicon content of the aluminum-silicon alloy is 25 wt%, the copper content of the aluminum-copper alloy is 20 wt%, the manganese content of the aluminum-manganese alloy is 10 wt%, the iron content of the aluminum-iron alloy is 15 wt%, the titanium content of the aluminum-titanium-boron alloy rod is 5 wt%, the boron content is 1 wt%, and the balance is aluminum.

3. The production method of the aluminum profile for the rail transit current collector bar according to claim 1, characterized in that, In step (3), the purity of the argon gas ≥ 99.99%, the pressure of the argon gas is 0.3 - 0.5 MPa, the dosage of the refining agent is 0.1 - 0.2% of the weight of the aluminum alloy liquid, and the blowing and refining time is 15 - 25 minutes.

4. The production method of the aluminum profile for the rail transit current collector bar according to claim 1, characterized in that, The production method of the refining agent in step (3) includes the following steps in sequence: (i)Select ZnCl2, K2CO3, NaNO3, KF, K2SO4, Li2SO4 with a purity of ≥99.8% as raw materials for batching; (ii)Under the protection of argon with a purity of ≥99.99%, heat and melt the raw materials at 1150 °C, and then cool and solidify the bulk refining agent; (iii)Crush the bulk refining agent into powder with a particle size of ≤2 mm to obtain the refining agent.

5. The production method of the aluminum profile for the rail transit conductive busbar according to claim 1, characterized in that, In step (4), the purity of the argon is ≥99.99%, the purity of the chlorine gas is ≥99.9%, the volume percentage of chlorine gas in the mixed gas is 3-5%, the flow rate of the mixed gas is 0.3-0.6 cubic meters per minute, and the degassing time is 10-20 minutes.

6. The production method of the aluminum profile for the rail transit current collector bar according to claim 1, characterized in that, In step (6), the rotation speed of the graphite rotor in the degassing box is 400-500 revolutions per minute, the gas flow rate on the graphite rotor is 2-3 cubic meters per hour, the gas pressure is 0.4-0.6 MPa, the gas is a mixed gas composed of argon with a purity of ≥99.99% and chlorine gas with a purity of ≥99.9%, and the volume percentage of chlorine gas in the mixed gas is 5-10%.

7. The production method of the aluminum profile for the rail transit conductive busbar according to claim 1, characterized in that, In step (9), the extrusion ratio of the extrusion is 10-30, the extrusion speed is 5-15 mm / s, and the heating temperature of the extrusion die is 420-460 °C.

8. The production method of the aluminum profile for the rail transit conductive busbar according to claim 1, characterized in that, The tensile strength of the aluminum profile ≥ 250 MPa, the yield strength ≥ 210 MPa, the elongation after fracture ≥ 12%, and the resistivity at 20°C ≤ 0.03 Ω•mm 2 •m -1 , and the conductivity ≥ 57.5% IACS.

Images