A method for producing an aluminum alloy by a short process of electrolytic aluminum

Abstract

The application discloses a method for preparing aluminum alloy by electrolytic aluminum short process, and belongs to the technical field of aluminum alloy production. The method comprises the following preparation steps: injecting electrolytic aluminum liquid into a smelting furnace, adding high-purity aluminum ingot for temperature reduction, adding other components, and obtaining an aluminum alloy solution; using high-purity argon gas to spray and blow a refining solvent into the furnace for in-furnace refining; transferring the aluminum melt into a static furnace, continuously blowing high-purity argon gas into the melt through the air brick at the bottom of the furnace for degassing; adopting pulse type rotary spraying of high-purity argon gas for online deep degassing, adopting ultrasonic electromagnetic field assisted degassing, adding a grain refiner, and finally filtering through double-stage ceramic filter plates to obtain a refined aluminum alloy melt; and pouring the aluminum alloy melt into aluminum alloy products with a specified shape. The method reduces the grain size, improves the strength and elongation of the aluminum alloy, realizes short process and efficient preparation of high-performance aluminum alloy products from electrolytic aluminum liquid, and combines in-furnace refining, degassing and deslagging technologies.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy production technology, and specifically to a method for preparing aluminum alloys using a short process of electrolytic aluminum production. Background Technology

[0002] Aluminum alloys, due to their lightweight, high strength, and good machinability, are widely used in various fields such as automobiles, aerospace, and electronics. Currently, traditional methods for preparing aluminum alloys require ingot casting and remelting, resulting in a long production process. To shorten this process, electrolytic aluminum liquid is now used for a shorter process. However, when using this short process to prepare high-quality aluminum alloys, especially for products requiring high conductivity and porosity, the high temperature of the electrolytic aluminum liquid leads to severe hydrogen absorption and slag formation, which is difficult to completely remove with ordinary refining. This results in pinholes, porosity, and cracks in the castings. Summary of the Invention

[0003] To address the aforementioned problems, the present invention aims to provide a method for preparing aluminum alloys through a short process of electrolytic aluminum production. By controlling the composition and combining it with in-furnace refining, degassing, and slag removal technology, aluminum alloys can be directly produced from electrolytic aluminum liquid.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a method for preparing aluminum alloys through a short process of electrolytic aluminum, comprising the following preparation steps:

[0005] (1) The raw material formula includes the following components by mass percentage: Si 0.05-0.09%, Fe 0.12-0.18%, Cu 0.2-0.5%, Mg 0.02-0.05%, Zn 0.06-0.1%, Ti 0.01-0.02%, with the remainder being Al and unavoidable impurities;

[0006] Aluminum alloy melt was prepared according to the raw material formula: electrolytic aluminum liquid was injected into the melting furnace, high-purity aluminum ingots were added to cool down, the temperature was adjusted to 740-750℃, Al-Si master alloy, electrolytic copper and Al-Zn master alloy were added for melting, magnesium ingots were added and stirred evenly to obtain aluminum alloy melt.

[0007] (2) High-purity argon gas is used to inject refining solvent into the furnace for in-furnace refining. After refining, the furnace is allowed to stand and remove slag to remove some hydrogen and inclusions.

[0008] (3) Transfer the aluminum melt into a settling furnace and continuously blow high-purity argon into the melt through the permeable bricks installed at the bottom of the furnace for degassing;

[0009] (4) The melt is introduced into the online degassing device, and high-purity argon gas is pulsed and sprayed online for deep degassing. Ultrasonic electromagnetic field is used to assist in degassing. The melt is allowed to stand and slag is removed. Al-Ti5-1B grain refiner is added. Finally, the melt is filtered through a double-stage ceramic filter plate to obtain refined aluminum alloy melt.

[0010] (5) Cast the aluminum alloy melt into an aluminum alloy product of a specified shape.

[0011] Furthermore, the amount of high-purity aluminum ingot added is 25%-30% of the weight of the aluminum alloy melt.

[0012] Furthermore, the ultrasonic electromagnetic field-assisted degassing includes: first applying an ultrasonic wave with a frequency of 20 kHz and a power of 2000W for 60-90 seconds, and then applying an electromagnetic field with a frequency of 80 kHz and a current intensity of 60A for 40-60 seconds after the ultrasonic treatment is completed.

[0013] Furthermore, in step (2), the blowing pressure is 0.25-0.30 MPa, the blowing gas flow rate is 15-20 L / min, and the refining time is 15-20 min.

[0014] Furthermore, the amount of the refining flux is 0.1-0.2% of the weight of the aluminum alloy melt, and the refining solvent comprises the following components by mass percentage: MgCl2 50%, KCl 35%, Na3AlF6 10%, and CaF2 5%.

[0015] Furthermore, in step (3), the flow rate of the high-purity argon gas is 20-25 L / min, and the refining time is 20-25 min.

[0016] Furthermore, in step (4), the pulse frequency of the pulsed rotary jet is 30-50 Hz, the flow rate of the rotary jet gas is 20-25 L / min, the inlet pressure is 0.6-0.9 MPa, and the rotor speed is 400-450 rpm.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The melt of this invention is refined using a sprayed refining solvent, then degassed by blowing high-purity argon gas through permeable bricks at the bottom of the furnace. Finally, it undergoes online rotary spraying of high-purity argon gas combined with ultrasonic and electromagnetic composite physical fields for deep purification, forming a multi-stage degassing and impurity removal system. Ultrasonic waves utilize the cavitation effect to induce dissolved hydrogen precipitation and form microbubble nuclei, while the electromagnetic field promotes bubble merging and rapid floating. The synergistic effect of these two methods significantly improves degassing efficiency, thereby reducing impurity content. After treatment using this method, the aluminum alloy sheet and strip exhibit a tensile strength ≥125 MPa, elongation ≥11%, and conductivity ≥55% IACS. Its overall performance is superior to or equivalent to similar products prepared using traditional high-purity aluminum ingot remelting processes. This method solves the casting defects such as pinholes and porosity caused by high hydrogen content during direct casting of electrolytic aluminum liquid, refining the grain size of the aluminum alloy to below 30 μm, far superior to conventional casting and rolling processes, and providing good strength and elongation. Detailed Implementation

[0019] The specific embodiments of the present invention will be further described below with reference to examples.

[0020] Example 1

[0021] A method for preparing aluminum alloys via electrolytic aluminum short-process includes the following preparation steps:

[0022] (1) The raw material formula includes the following components by mass percentage: Si 0.05%, Fe 0.12%, Cu 0.2%, Mg 0.02%, Zn 0.06%, Ti 0.01%, with the remainder being Al and unavoidable impurities.

[0023] Aluminum alloy melt was prepared according to the raw material formula: electrolytic aluminum liquid was injected into the melting furnace, high-purity aluminum ingots were added to cool down, the temperature was adjusted to 740℃, Al-Si master alloy, electrolytic copper and Al-Zn master alloy were added for melting, magnesium ingots were added and stirred evenly to obtain aluminum alloy melt.

[0024] (2) In-furnace refining was performed by injecting high-purity argon gas into the furnace using a refining solvent. The amount of refining flux was 0.1% of the weight of the aluminum alloy melt, the injection pressure was 0.25 MPa, the gas flow rate was 15 L / min, the refining time was 15 min, and after refining, the furnace was allowed to stand for 10 min to remove slag and some hydrogen and inclusions. The refining solvent consisted of the following components by mass percentage: MgCl2 50%, KCl 35%, Na3AlF6 10%, and CaF2 5%.

[0025] (3) Transfer the aluminum alloy melt into a settling furnace and continuously blow high-purity argon into the melt through the permeable bricks installed at the bottom of the furnace for degassing. The gas flow rate of high-purity argon is 20L / min and the refining time is 20min.

[0026] (4) The melt is introduced into the online degassing device, and online deep degassing is performed by pulsed rotary jetting of high-purity argon gas. The pulse frequency is 30 Hz, the rotary jetting gas flow rate is 20 L / min, the inlet pressure is 0.6 MPa, the rotor speed is 400 rpm, and ultrasonic electromagnetic field-assisted degassing is used. After standing and removing slag, Al-Ti5-1B grain refiner is added. Finally, it is filtered through a double-stage ceramic filter plate to obtain refined aluminum alloy melt.

[0027] The ultrasonic electromagnetic field-assisted degassing process involves first applying an ultrasonic wave with a frequency of 20 kHz and a power of 2000W for 90 seconds, followed by an electromagnetic field treatment with a frequency of 80 kHz and a current intensity of 60A for another 60 seconds.

[0028] (5) Cast the aluminum alloy melt into aluminum alloy products of a specified shape. Specifically, the refined aluminum alloy melt is introduced into a double-belt continuous casting and rolling production line and cast into an aluminum alloy slab with a thickness of 15 mm. The casting temperature is 700℃ and the casting speed is 3 m / min. The slab is rolled into an aluminum alloy strip with a thickness of 4 mm in 3 passes. After rolling, it is cooled to room temperature by laminar flow and then coiled to obtain an aluminum alloy strip coil.

[0029] The aluminum alloy sheet and strip prepared in this embodiment has a grain size ≤30um, a tensile strength of 125 MPa, an elongation of 15%, and an electrical conductivity of 55.4% IACS, and can be directly used to manufacture high-performance aluminum alloys.

[0030] Example 2

[0031] Unlike Example 1, the raw material formulation included the following components by mass percentage: Si 0.07%, Fe 0.15%, Cu 0.35%, Mg 0.05%, Zn 0.1%, Ti 0.015%, with the remainder being Al and unavoidable impurities. Other steps were the same as in Example 1.

[0032] The aluminum alloy strip prepared in this embodiment has a hydrogen content ≤0.10 mL / 100g Al, a grain size ≤30 μm, a tensile strength of 130 MPa, an elongation of 13%, and an electrical conductivity of 55.3% IACS.

[0033] Example 3

[0034] A method for preparing aluminum alloys via electrolytic aluminum short-process includes the following preparation steps:

[0035] (1) The raw material formula includes the following components by mass percentage: Si 0.07%, Fe 0.15%, Cu 0.35%, Mg 0.05%, Zn 0.1%, Ti 0.02%, with the remainder being Al and unavoidable impurities.

[0036] Aluminum alloy melt was prepared according to the raw material formula: electrolytic aluminum liquid was injected into the melting furnace, high-purity aluminum ingots were added to cool down, the temperature was adjusted to 745℃, Al-Si master alloy, electrolytic copper and Al-Zn master alloy were added for melting, magnesium ingots were added and stirred evenly to obtain aluminum alloy melt.

[0037] (2) High-purity argon gas is used to inject refining solvent into the furnace for in-furnace refining. The injection pressure is 0.30 MPa, the gas flow rate is 20 L / min, and the refining time is 20 min. After refining, the furnace is allowed to stand and remove slag to remove some hydrogen and inclusions. The amount of refining flux is 0.2% of the weight of the aluminum alloy melt. The refining solvent consists of the following components by mass percentage: MgCl2 50%, KCl 35%, Na3AlF6 10%, and CaF2 5%.

[0038] (3) Transfer the aluminum melt into a settling furnace and continuously blow high-purity argon into the melt through the permeable bricks installed at the bottom of the furnace for degassing; the gas flow rate of the high-purity argon is 25 L / min and the refining time is 25 min.

[0039] (4) The melt is introduced into an online degassing device, and online deep degassing is performed by pulse-type rotary blowing of high-purity argon gas. Ultrasonic electromagnetic field is used to assist in degassing. After standing and removing slag, Al-Ti5-1B grain refiner is added. Finally, it is filtered through a double-stage ceramic filter plate to obtain refined aluminum alloy melt. The pulse frequency of the pulse-type rotary blowing is 50 Hz, the flow rate of the rotary blowing gas is 25 L / min, the inlet pressure is 0.9 MPa, and the rotor speed is 450 rpm.

[0040] The ultrasonic electromagnetic field-assisted degassing includes: first applying an ultrasonic wave with a frequency of 20 kHz and a power of 2000W for 90 seconds, and then applying an electromagnetic field with a frequency of 80 kHz and a current intensity of 60A for 60 seconds after the ultrasonic treatment is completed.

[0041] (5) Cast the aluminum alloy melt into aluminum alloy products of a specified shape. Specifically, the refined aluminum alloy melt is introduced into a double-belt continuous casting and rolling production line and cast into an aluminum alloy slab with a thickness of 15 mm. The casting temperature is 700℃ and the casting speed is 3 m / min. The slab is rolled into an aluminum alloy strip with a thickness of 4 mm in 3 passes. After rolling, it is cooled to room temperature by laminar flow and then coiled to obtain an aluminum alloy strip coil.

[0042] The aluminum alloy sheet and strip prepared in this embodiment has a grain size ≤30um, a tensile strength of 134MPa, an elongation of 12%, and an electrical conductivity of 55.1% IACS.

[0043] Example 4

[0044] A method for preparing aluminum alloys via electrolytic aluminum short-process includes the following preparation steps:

[0045] (1) The raw material formula includes the following components by mass percentage: Si 0.09%, Fe 0.18%, Cu 0.5%, Mg 0.05%, Zn 0.1%, Ti 0.02%, with the remainder being Al and unavoidable impurities.

[0046] Aluminum alloy melt was prepared according to the raw material formula: electrolytic aluminum liquid was injected into the melting furnace, high-purity aluminum ingots were added to cool down, the temperature was adjusted to 750℃, Al-Si master alloy, Al-Fe master alloy, electrolytic copper and Al-Zn master alloy were added for melting, magnesium ingots were added and stirred evenly to obtain aluminum alloy melt.

[0047] (2) High-purity argon gas is used to inject a refining solvent into the furnace for in-furnace refining. After refining, the furnace is allowed to stand and slag is removed to remove some hydrogen and inclusions. The injection pressure is 0.30 MPa, the injection gas flow rate is 20 L / min, and the refining time is 20 min. In step (2), as a further improvement of the present invention, the amount of the refining flux is 0.2% of the weight of the aluminum alloy melt, and the refining solvent comprises the following components by mass percentage: MgCl2 50%, KCl 35%, Na3AlF6 10%, and CaF25%.

[0048] (3) Transfer the aluminum melt into a settling furnace and continuously blow high-purity argon into the melt through the permeable bricks installed at the bottom of the furnace for degassing; the gas flow rate of the high-purity argon is 25 L / min and the refining time is 25 min.

[0049] (4) The melt is introduced into an online degassing device, and online deep degassing is performed by pulse-type rotary blowing of high-purity argon gas. Ultrasonic electromagnetic field is used to assist in degassing. After standing and removing slag, Al-Ti5-1B grain refiner is added. Finally, it is filtered through a double-stage ceramic filter plate to obtain refined aluminum alloy melt. The pulse frequency of the pulse-type rotary blowing is 50 Hz, the flow rate of the rotary blowing gas is 25 L / min, the inlet pressure is 0.9 MPa, and the rotor speed is 450 rpm.

[0050] The ultrasonic electromagnetic field-assisted degassing includes: first applying an ultrasonic wave with a frequency of 20 kHz and a power of 2000W for 60 seconds, and then applying an electromagnetic field with a frequency of 80 kHz and a current intensity of 60A for 40 seconds after the ultrasonic treatment is completed.

[0051] (5) Cast the aluminum alloy melt into aluminum alloy products of a specified shape. Specifically, the refined aluminum alloy melt is introduced into a double-belt continuous casting and rolling production line and cast into an aluminum alloy slab with a thickness of 15 mm. The casting temperature is 700℃ and the casting speed is 3 m / min. The slab is rolled into an aluminum alloy strip with a thickness of 4 mm in 3 passes. After rolling, it is cooled to room temperature by laminar flow and then coiled to obtain an aluminum alloy strip coil.

[0052] The aluminum alloy sheet and strip prepared in this embodiment has a grain size ≤30um, a tensile strength of 140MPa, an elongation of 11%, and an electrical conductivity of 55% IACS.

[0053] The above description is a detailed description of the preferred embodiments of the present invention. However, the embodiments are not intended to limit the scope of the patent application of the present invention. All equivalent changes or modifications made under the technical spirit of the present invention should be considered as patents covered by the present invention.

Claims

1. A method for preparing aluminum alloys via a short-process electrolytic aluminum process, characterized in that, The preparation steps include the following: (1) The raw material formula includes the following components by mass percentage: Si 0.05-0.09%, Fe 0.12-0.18%, Cu 0.2-0.5%, Mg 0.02-0.05%, Zn 0.06-0.1%, Ti 0.01-0.02%, with the remainder being Al and unavoidable impurities; Aluminum alloy melt was prepared according to the raw material formula: electrolytic aluminum liquid was injected into the melting furnace, high-purity aluminum ingots were added to cool down, the temperature was adjusted to 740-750℃, Al-Si master alloy, electrolytic copper and Al-Zn master alloy were added for melting, magnesium ingots were added and stirred evenly to obtain aluminum alloy melt. (2) High-purity argon gas is used to inject refining solvent into the furnace for in-furnace refining. After refining, the furnace is allowed to stand and remove slag to remove some hydrogen and inclusions. (3) Transfer the aluminum melt into a settling furnace and continuously blow high-purity argon into the melt through the permeable bricks installed at the bottom of the furnace for degassing; (4) The melt is introduced into the online degassing device, and high-purity argon gas is pulsed and sprayed online for deep degassing. Ultrasonic electromagnetic field is used to assist in degassing. The melt is allowed to stand and slag is removed. Al-Ti5-1B grain refiner is added. Finally, the melt is filtered through a double-stage ceramic filter plate to obtain refined aluminum alloy melt. (5) Cast the aluminum alloy melt into an aluminum alloy product of a specified shape.

2. The method for preparing aluminum alloys via a short-process electrolytic aluminum process as described in claim 1, characterized in that, The amount of high-purity aluminum ingot added is 25%-30% of the weight of the aluminum alloy melt.

3. The method for preparing aluminum alloys via a short-process electrolytic aluminum process as described in claim 1, characterized in that, The ultrasonic electromagnetic field-assisted degassing process includes: first, applying an ultrasonic wave with a frequency of 20 kHz and a power of 2000W for 60-90 seconds; after the ultrasonic treatment is completed, applying an electromagnetic field with a frequency of 80 kHz and a current intensity of 60A for 40-60 seconds.

4. The method for preparing aluminum alloys via a short-process electrolytic aluminum process as described in claim 1, characterized in that, In step (2), the blowing pressure is 0.25-0.30 MPa, the blowing gas flow rate is 15-20 L / min, and the refining time is 15-20 min.

5. The method for preparing aluminum alloys via a short-process electrolytic aluminum process as described in claim 1, characterized in that, The amount of the refining flux is 0.1-0.2% of the weight of the aluminum alloy melt, and the refining solvent comprises the following components by mass percentage: MgCl2 50%, KCl 35%, Na3AlF6 10%, CaF2 5%.

6. The method for preparing aluminum alloys via a short-process electrolytic aluminum process as described in claim 1, characterized in that, In step (3), the flow rate of the high-purity argon gas is 20-25 L / min, and the refining time is 20-25 min.

7. The method for preparing aluminum alloys via a short-process electrolytic aluminum process as described in claim 1, characterized in that, In step (4), the pulse frequency of the pulsed rotary jet is 30-50 Hz, the flow rate of the rotary jet gas is 20-25 L / min, the inlet pressure is 0.6-0.9 MPa, and the rotor speed is 400-450 rpm.