Al-Cu-Sc aluminum alloy wire for electric arc additive manufacturing and preparation method of Al-Cu-Sc aluminum alloy wire

Abstract

The invention discloses an Al-Cu-Sc aluminum alloy wire for electric arc additive manufacturing and a preparation method of the Al-Cu-Sc aluminum alloy wire. The preparation method comprises the steps that S1, molten aluminum is smelted; s2, electromagnetic stirring; s3, refining and degassing; s4, carrying out online filtration; s5, continuous casting is conducted, specifically, the aluminum melt is quantitatively guided into a crystallization wheel and cooled and solidified through the crystallization wheel, and an aluminum rod blank is obtained; and S6, continuous extrusion is conducted, specifically, the aluminum rod blank is transferred into continuous extrusion equipment, the aluminum rod blank is guided into an extrusion wheel groove to be subjected to radial extrusion after being straightened, subjected to oxide skin scraping and cleaned, and a wire blank is obtained. According to the preparation method disclosed by the invention, the structure of the wire rod blank subjected to a continuous extrusion process is fully crushed through violent shear deformation, the wire rod blank has a compact and fine shear deformation grain structure, the wire rod blank has good drawing machinability, and the wire rod blank can be drawn and scraped to the size of a finished product only through one-time intermediate annealing in the subsequent processing process; the production efficiency is improved, and the cost is reduced.

Description

Technical Field

[0001] The present invention relates to the field of 3D printing metal materials, and in particular to an Al-Cu-Sc aluminum alloy wire for arc additive manufacturing and a preparation method thereof, which is suitable for printing large and complex parts in the aerospace field. Background Art

[0002] Al-Cu aluminum alloys have high specific strength and good high and low temperature properties. Medium and large-sized metal structural parts printed by arc additive manufacturing technology are used in many fields such as aerospace and automobile manufacturing, and the market prospects are very broad. However, in the above-mentioned actual service process, Al-Cu alloy materials will face the test of temperature rise and stress, and catastrophic rapid softening will occur, which will lead to material failure. Many studies have shown that adding trace amounts of scandium elements to Al-Cu alloys can refine the grains, increase their recrystallization temperature, and enhance high-temperature mechanical properties.

[0003] With the continuous development of CMT arc additive manufacturing process, the 3D printing process of aluminum alloy has been greatly improved, making it possible to use Al-Cu alloy wire for arc additive manufacturing. In view of the excellent mechanical properties of Al-Cu aluminum alloy, it is very necessary to develop an Al-Cu-Sc aluminum alloy 3D printing wire for aerospace and automobile manufacturing fields in combination with market demand.

[0004] The Chinese patent with publication number CN113649415B discloses a high-strength aluminum alloy welding wire preparation process, which includes: aluminum liquid smelting, furnace refining, online refining, continuous casting, continuous rolling, wire drawing, scraping, ultrasonic cleaning and vacuum packaging; the online refining process controls the hydrogen content in the aluminum liquid to ≤0.1ml / 100g Al, and the electromagnetic filtration device is used for online filtration to effectively remove the inclusions with a size of more than 1μm in the aluminum liquid, which greatly improves the purity of the aluminum liquid, ensures that the internal structure of the alloy is uniform and dense, improves the wire breaking problem in the drawing process, and reduces the formation of inclusions and pore defects in the weld. The casting process adopts a liquid level automatic control system, and the crystallization wheel is cooled independently in different zones to ensure that the metallurgical structure of the cast alloy is uniform and stable. The high-strength aluminum alloy welding wire prepared by this method has stable mechanical properties, uniform and dense structure, and high surface quality, and is suitable for automated welding processes. 1. Equipment: Continuous rolling is a common production process for large aluminum processing enterprises. Compared with continuous extrusion, the equipment investment cost is high. 2. Process: Continuous casting, continuous rolling and drawing are adopted. First, a T-shaped billet (cross-sectional area 3000mm 2), and then transferred to the rolling mill for rolling reduction. The deformation of a single rolling process is small (10-15%), and multiple rolling passes (5-10 passes) are required. Multiple drawing (5-10 passes) are also required to reach φ1.6-1.65mm welding wire. Compared with continuous extrusion, the process route is long. Continuous rolling has a large cross-sectional area of ​​the continuous casting ingot, and the subsequent continuous rolling has many rolling passes, a large investment in rolling mill equipment, a long process route, and high production costs. Summary of the invention

[0005] The present invention aims to provide an Al-Cu-Sc aluminum alloy wire for arc additive manufacturing and a preparation method thereof, which has a short process route, low equipment investment cost and low production cost.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A method for preparing an Al-Cu-Sc aluminum alloy wire for arc additive manufacturing comprises the following steps:

[0008] S1. Aluminum liquid smelting: adding alloy raw materials into a medium frequency furnace, heating and melting, stirring and fully melting to obtain aluminum liquid, wherein the alloy raw materials include aluminum, copper and scandium;

[0009] S2, electromagnetic stirring: Turn on the electromagnetic stirring power supply to electromagnetically stir the aluminum liquid in S1;

[0010] S3, refining and degassing: the aluminum liquid is refined and degassed;

[0011] S4, online filtration: online degassing, deslagging and filtering of the aluminum melt;

[0012] S5, continuous casting: quantitatively introducing the aluminum melt obtained in S4 into a crystallization wheel, cooling and solidifying through the crystallization wheel to obtain an aluminum rod blank;

[0013] S6, continuous extrusion: the aluminum rod blank obtained in S5 is transferred to a continuous extrusion device, the aluminum rod blank is straightened, the oxide scale is scraped off, the aluminum rod blank is cleaned, and then introduced into the wheel groove of the extrusion wheel for radial extrusion to obtain a wire blank;

[0014] S7, intermediate annealing: annealing, drawing and scraping the wire blank;

[0015] S8, cleaning and layer winding: cleaning the surface of the wire blank, coating with a reagent, and layer winding and packaging to obtain a 3D printing wire;

[0016] Preferably, the speed of the extrusion wheel in the continuous extrusion in S6 is 7-8r\min and the torque is 7-8r / min; further preferably, a wire blank with a diameter of 2-4mm is obtained in S6; further preferably, the temperature in the extrusion wheel groove in S6 is 400-500℃.

[0017] The present invention adopts continuous casting and then continuous extrusion, has fewer processes, a short process, high production efficiency and material utilization rate; adds a process of scraping off surface oxide scale, improves the purity of the aluminum rod blank, and has better wire blank quality; utilizes friction heat, eliminates heating, and reduces energy consumption.

[0018] In the production process, the aluminum liquid is transformed into an aluminum rod blank through a continuous casting process. The aluminum rod is pressed into the groove of the extruder wheel and friction is established. The solid aluminum material and the surface of the extrusion wheel are rapidly heated to 400-500°C due to friction. The solid aluminum material is crushed into a semi-solid state and solidified through extrusion through the mold of the extrusion cavity. Therefore, the continuous extrusion process heats the aluminum rod by providing heat through its own friction, eliminating heating.

[0019] The S6 of the present invention does not need heating and pickling, has no pollutant emissions, and is green and environmentally friendly; the equipment has a high degree of automation and a low operating cost; the equipment is compact, occupies a small area, and requires little investment in equipment and plant construction; the product has uniform performance, high dimensional accuracy, and good finish.

[0020] First, an extrusion process (based on the principle of continuous extruder) can produce wire billets of φ1.6-2.5mm, which are characterized by large deformation (deformation of 95%), short process, and low equipment investment cost. Secondly, due to the large torque and low speed of the extrusion wheel of the continuous extruder (the continuous extrusion equipment is specially customized with the manufacturer when purchasing, which is opposite to the high speed and low torque of the equipment on the market. It has low speed and high torque, but the energy consumption is basically the same). The aluminum rod billet produced by continuous casting can be directly pressed into the wheel groove of the extrusion wheel without annealing, and the solid aluminum material is crushed into a semi-solid state. In general wire billet production, before the continuous extrusion process, the aluminum rod billet needs to be annealed first to soften the aluminum rod, and then pressed into the extrusion wheel. After the continuous extrusion process is completed, annealing is carried out again, which reduces one annealing, and this annealing can realize intermediate annealing and low-temperature annealing at the same time. The resulting short process route, low equipment investment cost, and low production cost.

[0021] The main improvement of this application is that the continuous extrusion equipment is specially customized to have a low speed of 0-12r / min and high torque according to the continuous extrusion process technology requirements. The speed of this application invention for continuous extrusion of Al-Cu-Sc aluminum rods is 7-8r / min. The continuous extrusion equipment on the market has a high speed, basically 0-30r / min, and low torque. Due to the characteristics of high torque, the aluminum rod billet produced by continuous casting can be pressed into the extrusion wheel to produce wire billets without annealing.

[0022] The continuous extrusion process parameter indicators are rotation speed, extrusion gap, cooling water, and the extrusion speed is determined by preparing wire billets at different rotation speeds. Through the accumulation of data from multiple tests, it is found that the metallographic quality, mechanical properties, and production efficiency of the wire billets prepared at 7-8r / min are relatively excellent. After analysis, it is found that this is the result obtained under the combined action of Al-Cu-Sc element formula, extrusion speed, extrusion gap, and cooling water. If a parameter indicator is changed at random, the aforementioned results cannot be obtained.

[0023] According to the embodiments of the present invention, the present invention can be further optimized. The following is the technical solution formed after optimization:

[0024] In one preferred embodiment, the casting temperature in S5 is in the range of 710°C to 720°C, the crystallization wheel has its own water cooling system, the cooling water temperature range is 10°C to 20°C, and the aluminum liquid is cooled and solidified by the crystallization wheel to obtain an aluminum rod blank; preferably, the cross-sectional area of ​​the crystallization wheel is 63.6-122.6mm 2 , further preferably, the diameter of the aluminum rod blank is Φ9-12.5 mm.

[0025] In one preferred embodiment, the alloy raw material includes the following components in mass percentage: Cu 5.3%-6.7%, Mn 0.2%-0.4%, Ti 0.12%-0.18%, Sc 0.1%-0.2%, Zr 0.12%-0.18%, V0.08%-0.16%, Fe≤0.15%, Si≤0.08%, and the rest are Al and other inevitable impurity elements, the content of each element in the inevitable impurity elements is ≤0.05%, and the total amount of other inevitable impurity elements is ≤0.15%.

[0026] The Chinese patent with publication number CN117926090A discloses a heat-resistant aluminum alloy material suitable for arc 3D printing and its preparation method, which belongs to the technical field of non-ferrous metal materials. Its chemical composition is: Cu: 5.7-7.0%, Mg: 0.11-0.35%, Ag: 0.7-1.5%, Mn: 0.2-0.6%, Ti: 0.10-0.35%, V: 0.1-0.4%, Zr: 0.01-0.10%, Cd: 0.1-0.3%, Ce: 0.01-0.1%, Cr: 0.1-0.35%, B: 0.01-0.05%, Fe≤0.06%, Si≤0.06%; Cu / Mg≥20; the balance is Al and unavoidable impurities. The aluminum alloy material has good room temperature mechanical properties and high temperature mechanical properties, and is suitable for the manufacture of aerospace aircraft components. This patent and this application are both aluminum-copper alloys, and the main element composition is basically the same. The main difference lies in the type and content of trace elements added. The idea of ​​microalloying in this patent is different from that of microalloying in this application. This patent introduces Mg, Ag, and Cd elements. One defect is that the Cd element will produce toxic oxide smoke. The second defect is that there are many types of trace alloys, with as many as 13 controlled elements. It is difficult to control the elements in actual production. This application has 8 types, and the element control is simple. The third defect is that the design of the alloy formula requires that the iron Fe element is ≤0.06%. In the aluminum processing industry, the iron Fe element is required to be ≤0.06%. Compared with the iron Fe element ≤0.15% in this application, it will inevitably increase the cost of raw material production and greatly increase the difficulty of industrialization.

[0027] The composition formula of this application is based on another design concept of microalloying. As we all know, Sc is the best modifier in aluminum alloys, which greatly improves the mechanical properties of wire and the performance of printed bodies. The preparation method of this application: adding trace amounts of Sc and Zr, innovatively optimizes the metallographic quality of the wire blank, thereby obtaining high-quality wire. This application adds trace amounts of Sc elements, and through the composite addition of Sc and Zr elements, the dispersed secondary Al3 (Sc, Zr) phase formed has a good fine grain strengthening and precipitation strengthening effect on the alloy structure, so that the printed body has excellent thermal stability.

[0028] In one preferred embodiment, the electromagnetic stirring frequency in S2 is 10 Hz to 20 Hz.

[0029] This electromagnetic stirring frequency is suitable for electromagnetic filtration of the five series aluminum-magnesium alloys in this application, and the functional attribute used is the aluminum liquid filtration process. The electromagnetic stirring used in this application is in the aluminum liquid stirring process, which is another functional attribute. Its principle is to form waves on the aluminum liquid by changing the frequency from 10Hz to 20Hz, and to make the aluminum liquid move irregularly through the emitted traveling wave magnetic field to achieve the effect of uniform stirring of the alloy elements, while the electromagnetic filtration is a single frequency (10Hz), which is an electromagnetic device that provides power for separating oxides and impurities in the aluminum liquid.

[0030] The existing electromagnetic stirring parameter range is often relatively large and is not suitable for specific alloy systems. Since the alloy formula of the present application adds the Sc element, the electromagnetic stirring frequency is best between 10 Hz and 20 Hz.

[0031] In one preferred embodiment, the temperature range of refining and degassing in S3 is 740° C. to 750° C., the refining time range is 20 minutes to 30 minutes, and the hydrogen content in the aluminum melt after refining and degassing is ≤0.1 ml / 100 g Al.

[0032] In one preferred embodiment, S7 is to keep the wire billet at a temperature range of 350° C. to 400° C. for 2 to 3 hours, and then keep the wire billet at a temperature range of 250° C. to 300° C. for 3 to 4 hours.

[0033] The annealing process of the national standard grade 2319 wire billet with similar alloy composition is to keep the temperature at 300℃-400℃ for 2-3 hours. The existing annealing temperature range is relatively large, 300-400℃, which belongs to complete annealing. The annealing temperature range of this application is a temperature range optimized according to the addition of Sc and Zr alloy elements and the arrangement of production process procedures. The first section belongs to intermediate annealing, the purpose is to obtain a balanced and uniform structure, which is 350-400℃. The second section belongs to low-temperature annealing to eliminate processing residual stress, which is 250-300℃. The purpose is to anneal through the temperature parameters in this range so that its various properties reach the best state.

[0034] In one preferred embodiment, the drawing and scraping in S7 is specifically to draw the annealed wire blank to a nearly finished product size, then remove surface scratches and fatigue layer through two consecutive scraping passes, and obtain Al-Cu-Sc aluminum alloy wire through cleaning layer winding.

[0035] In one preferred embodiment, degassing bricks are used in S4 for online degassing and slag removal, and a three-stage filtration system is used to control the removal rate of inclusions with a particle size greater than 5 μm in the aluminum melt to be greater than 90%.

[0036] Preferably, the diameter of the wire blank in S6 is 1.6-2.5 mm.

[0037] Preferably, the diameter of the Al-Cu-Sc aluminum alloy wire in S7 is 1.2-1.8 mm.

[0038] Preferably, the alloy raw materials in S1 include aluminum ingots, aluminum-copper alloys, aluminum-titanium alloys, aluminum-manganese alloys, aluminum-zirconium alloys, aluminum-scandium alloys, and aluminum-vanadium alloys.

[0039] Preferably, after S1 is heated and melted, the element composition is analyzed and adjusted for the first time in front of the furnace to obtain qualified aluminum liquid.

[0040] Preferably, after S2 electromagnetic stirring, the element composition is analyzed and adjusted for the second time before the furnace to obtain aluminum liquid with uniform element composition. The element composition is analyzed and adjusted before the furnace to obtain aluminum liquid with uniform element composition.

[0041] Preferably, S3 uses 99.999% Ar gas to fill the aluminum liquid for refining and degassing, and after refining and degassing, the aluminum liquid is allowed to stand and adjust the temperature.

[0042] Preferably, in S5, the aluminum melt is first introduced into a flow control box and then quantitatively introduced into a crystallization wheel.

[0043] Preferably, the present invention adopts a fixed rotary blowing device and uses 99.999% Ar as the degassing medium. Ar is an inert gas, and the production is safer and more reliable. The treatment time is 20-30 minutes with the refining agent, and the aluminum liquid can be purified. Subsequently, the scum on the surface of the aluminum liquid is scraped off, and the hydrogen content in the aluminum melt after treatment is ≤0.1ml / 100g Al.

[0044] The refining and degassing in the prior art uses a mobile rotary blowing device, with a 95% N2+5% Cl2 mixed gas as the degassing medium, and a sodium-free particle refining agent for treatment for 10 minutes. Among them, chlorine is a toxic gas, and safety protection measures must be taken during the production process.

[0045] The aluminum rod billet in S6 is transferred to the continuous extrusion equipment and is preheated to 50-70℃.

[0046] The invention also discloses an Al-Cu-Sc aluminum alloy wire material prepared by the preparation method.

[0047] The present invention also discloses an Al-Cu-Sc aluminum alloy wire material, which has a tensile strength of ≥420MPa, a yield strength of ≥300MPa, and an elongation of ≥12% after T6 heat treatment. The Al-Cu-Sc aluminum alloy wire material of the present invention has a uniform chemical composition distribution, good room temperature mechanical properties and high temperature stability, and no difference in anisotropic properties.

[0048] Compared with the Chinese patent with publication number CN113649415B, the present application improves the continuous casting crystallization wheel, Figure 1Crystallization wheel. Compared with the Chinese patent CN113649415B, the cross-sectional area of ​​the crystallization wheel groove is only 63.6-122.6mm 2 Φ9-12.5mm aluminum rod blanks can be cast through the rolling wheel. The crystallization wheel has its own cooling water system, which can ensure that the aluminum liquid is quickly cooled and solidified in the crystallization wheel groove, and the aluminum rod metallographic structure is uniform and delicate. 2 ) Aluminum rod blanks have a small cross-sectional area, and the subsequent diameter reduction process is greatly reduced.

[0049] The present application also improves the extrusion wheel of the continuous extruder. Figure 2 According to the technical requirements of the continuous extrusion process of this application, it is specially customized with low speed, 0-12r / min and high torque. The torque for continuous extrusion of Al-Cu-Sc aluminum rods invented in this application is 7-8r / min. The crystallization wheel has its own cooling water system, which can ensure that the temperature of the semi-solid aluminum material in the extrusion wheel groove is balanced and maintained at 400-500℃. There will be no overburning, and the metallographic structure of the wire blank is uniform and delicate. Only one extrusion process (based on the principle of continuous extruder) is required to produce φ1.6-2.5mm wire blanks, which are characterized by large deformation (deformation of 95%), short process, low energy consumption, and low equipment investment cost.

[0050] The main element of Al-Cu-Sc alloy is Cu, and research has found that Cu and Sc will form W (Al 3-8 Cu 2-4 Sc) phase will have an adverse effect on the properties of the alloy. Based on this characteristic, when the aluminum liquid is continuously cast, the crystallization wheel speed and cooling water are adjusted to quickly cool and solidify to obtain an aluminum rod billet to prevent the precipitation and growth of the W phase. When it is then transferred to continuous extrusion, the cooling water of the extrusion wheel is adjusted to maintain the temperature of the semi-solid aluminum material in the extrusion wheel groove at 400-500℃, which is also to prevent the precipitation and growth of the W phase. At the same time, the extrusion wheel speed and torque are adjusted, and the semi-solid structure in the extrusion wheel groove passes through a 90° angle position, undergoing severe shear deformation, which can also allow the precipitated and grown W phase to be fully broken, and obtain a dense and fine shear deformed grain structure.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] (1) The preparation method of Al-Cu-Sc aluminum alloy wire provided in the present application adopts a continuous casting process to directly obtain a wire rod blank from an aluminum melt. The process flow is short, the crystallization inside the rod blank is uniform and refined, there is no element segregation, the surface of the rod blank is smooth, and there are no scratches visible to the naked eye, oxide scale inclusions and other defects.

[0053] (2) The preparation method of Al-Cu-Sc aluminum alloy wire provided in the present application is that the wire rod blank produced by the continuous extrusion process has its structure fully broken after severe shear deformation, and has a dense and fine shear deformed grain structure. The wire rod blank has good drawing processability and only needs one intermediate annealing in the subsequent processing to be drawn and scraped to the finished product size, thereby improving production efficiency and reducing costs.

[0054] (3) The preparation method of the Al-Cu-Sc aluminum alloy wire provided in the present application adopts continuous casting and continuous extrusion technology, the manufacturing process is simple, and the yield rate is ≥80%.

[0055] (4) The Al-Cu-Sc aluminum alloy wire provided in the present application contains 0.1%-0.2% Sc element. The Sc, Zr, Ti, and V elements work together to refine the grains, thereby reducing structural defects and significantly improving the mechanical properties of the printed body of the Al-Cu-Sc aluminum alloy. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 It is a schematic structural diagram of a crystallization wheel of a continuous casting machine in one embodiment of the present invention.

[0057] Figure 2 It is a schematic structural diagram of an extrusion wheel of a continuous extruder in one embodiment of the present invention.

[0058] in,

[0059] 1-aluminum inlet, 2-aluminum liquid control flow box, 3-guide wheel, 4-steel belt, 5-cooling water guide hole, 6-crystallization wheel, 7-aluminum rod blank, 8-crystallization wheel groove, 9-tensioning wheel, 10-rolling wheel, 11-scraper;

[0060] 11-compacting wheel, 12-aluminum rod blank, 13-extrusion shoe, 14-extrusion wheel groove, 15-extrusion die, 16-cooling water guide hole, 17-extrusion wheel, 18-scraper, 19-wire blank. DETAILED DESCRIPTION

[0061] The present invention will be described in detail below in conjunction with the embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0062] Example:

[0063] Aluminum ingots, aluminum-copper alloys, aluminum-titanium alloys, aluminum-zirconium alloys, aluminum-scandium alloys, aluminum-manganese alloys, and aluminum-vanadium alloys were weighed, and alloys were smelted, and continuous casting, continuous extrusion, intermediate annealing, drawing and scraping, cleaning and layer winding, and sample printing were performed to obtain printed parts. Table 1 shows the chemical element contents in each printed part in Examples 1-3.

[0064] Table 1 Chemical element analysis sheet of printed parts of Examples 1-3

[0065]

[0066] The production process of aluminum alloy wire is:

[0067] (1) Aluminum liquid smelting: Add aluminum ingots, aluminum-copper alloy, aluminum-titanium alloy, aluminum-zirconium alloy, aluminum-scandium alloy, and aluminum-vanadium alloy into the medium frequency furnace and heat to melt. The aluminum liquid temperature is 740-750℃. Mechanical stirring is performed for 30 minutes at a speed of 300r / min. The element composition is adjusted for the first time before the furnace to obtain qualified aluminum liquid.

[0068] (2) Electromagnetic stirring: Turn on the electromagnetic stirring power supply, set the traveling wave frequency to vary from 10 Hz to 20 Hz, and stir the aluminum liquid electromagnetically for 20 minutes. Analyze and adjust the elemental composition for the second time before the furnace to obtain aluminum liquid with uniform elemental composition.

[0069] (3) Refining and degassing: The aluminum liquid is transferred to a refining furnace for refining and degassing. 99.999% Ar gas is filled into the aluminum liquid for refining and degassing. The Ar gas flow rate is 15L\min. The refining is performed for 25 minutes. After refining and degassing, the aluminum liquid is allowed to stand and the temperature is adjusted. The hydrogen content in the aluminum melt after treatment is ≤0.1ml / 100g Al.

[0070] (4) Online filtration: A three-stage filtration device is used to perform online degassing, deslagging and filtration on the aluminum melt; and the removal rate of inclusions with a particle size greater than 1 μm in the aluminum melt is controlled to be greater than 90%.

[0071] (5) Continuous casting: The casting temperature ranges from 710°C to 720°C. The crystallization wheel has its own water cooling system. The cooling water temperature ranges from 10°C to 20°C. The aluminum liquid is cooled and solidified by the crystallization wheel. The casting speed is 90-120kg / h to obtain the Φ9.5mm aluminum rod blank. The temperature range of the aluminum rod blank is 380°C to 430°C.

[0072] (6) Continuous extrusion: The wire rod blank is continuously extruded. The aluminum rod is scraped to remove the surface oxide scale, cleaned and preheated, and then pressed into the wheel groove of the extrusion wheel by a compacting wheel. The extrusion wheel speed is 8 rpm to obtain a wire rod blank with a diameter of 2.4 mm.

[0073] (7) Intermediate annealing: the wire rod blank is annealed, and the annealing process of the wire rod blank is as follows: heating to 350°C for 2 hours, keeping at 350°C for 2.5 hours, cooling to 280°C for 2 hours, keeping at 280°C for 3.5 hours, and air cooling after being taken out of the furnace.

[0074] (8) Drawing and scraping: The annealed wire blank is drawn to a nearly finished size at a speed of 3-5 m / s, and then the surface scratches and fatigue layer are scraped off by two consecutive stripping steps at a speed of 2-3 m / s.

[0075] (9) Cleaning and layer winding: The wire blank is subjected to surface cleaning, chemical coating, and layer winding packaging to obtain the finished Al-Cu-Sc aluminum alloy wire with a diameter of 1.8 mm and a single coil weight of 7 kg.

[0076] The wires prepared in Examples 1, 2, and 3 were printed using CMT arc additive manufacturing equipment, and processed into three groups of test pieces after T6 heat treatment. The mechanical properties of the printed parts were tested in accordance with GB / T 228.1-2021 standard, and the test results are shown in Table 2:

[0077] Table 2 Mechanical properties test results of printed parts

[0078] Example Average tensile strength (MPa) Average yield strength (MPa) Average elongation (%) Example 1 431 311 13.8 Example 2 438 312 13.5 Example 3 429 308 14.7

[0079] Comparative Example:

[0080] Aluminum ingots, aluminum-copper alloys, aluminum-titanium alloys, aluminum-zirconium alloys, aluminum-manganese alloys, and aluminum-vanadium alloys were weighed, and alloys were smelted, and continuous casting, continuous extrusion, intermediate annealing, drawing and scraping, cleaning and layer winding, and sample printing were performed to obtain printed parts. Table 3 shows the chemical element contents in each printed part in Comparative Examples 1-3.

[0081] Table 3 Chemical element analysis of the printouts of Comparative Examples 1-3

[0082]

[0083] The production process of aluminum alloy wire is:

[0084] (1) Aluminum liquid smelting: Add aluminum ingots, aluminum-copper alloy, aluminum-titanium alloy, aluminum-zirconium alloy, and aluminum-vanadium alloy into the medium frequency furnace and heat to melt. The aluminum liquid temperature is 740-750℃. Mechanical stirring is performed for 30 minutes at a speed of 300r / min. The element composition is adjusted for the first time before the furnace to obtain qualified aluminum liquid.

[0085] (2) Electromagnetic stirring: Turn on the electromagnetic stirring power supply, set the traveling wave frequency to vary from 10 Hz to 20 Hz, and stir the aluminum liquid electromagnetically for 20 minutes. Analyze and adjust the elemental composition for the second time before the furnace to obtain aluminum liquid with uniform elemental composition.

[0086] (3) Refining and degassing: The aluminum liquid is transferred to a refining furnace for refining and degassing. 99.999% Ar gas is filled into the aluminum liquid for refining and degassing. The Ar gas flow rate is 15L\min. The refining is performed for 25 minutes. After refining and degassing, the aluminum liquid is allowed to stand and the temperature is adjusted. The hydrogen content in the aluminum melt after treatment is ≤0.1ml / 100g Al.

[0087] (4) Online filtration: A three-stage filtration device is used to perform online degassing, deslagging and filtration on the aluminum melt; and the removal rate of inclusions with a particle size greater than 1 μm in the aluminum melt is controlled to be greater than 90%.

[0088] (5) Continuous casting: The casting temperature ranges from 710°C to 720°C. The crystallization wheel has its own water cooling system. The cooling water temperature ranges from 10°C to 20°C. The aluminum liquid is cooled and solidified by the crystallization wheel. The casting speed is 90-120kg / h to obtain the Φ9.5mm aluminum rod blank. The temperature range of the aluminum rod blank is 380°C to 430°C.

[0089] (6) Continuous extrusion: The wire rod blank is continuously extruded. The aluminum rod is scraped to remove the surface oxide scale, cleaned and preheated, and then pressed into the wheel groove of the extrusion wheel by a compacting wheel. The extrusion wheel speed is 8 rpm to obtain a wire rod blank with a diameter of 2.4 mm.

[0090] (7) Intermediate annealing: the wire rod blank is annealed, and the annealing process of the wire rod blank is as follows: heating to 350°C for 2 hours, keeping at 350°C for 2.5 hours, cooling to 280°C for 2 hours, keeping at 280°C for 3.5 hours, and air cooling after being taken out of the furnace.

[0091] (8) Drawing and scraping: The annealed wire blank is drawn to a nearly finished size at a speed of 3-5 m / s, and then the surface scratches and fatigue layer are scraped off by two consecutive stripping steps at a speed of 2-3 m / s.

[0092] (9) Cleaning and layer winding: The wire blank is subjected to surface cleaning, chemical coating, and layer winding packaging to obtain the finished Al-Cu-Sc aluminum alloy wire with a diameter of 1.8 mm and a single coil weight of 7 kg.

[0093] The wires prepared in Comparative Examples 1, 2, and 3 were printed using CMT arc additive manufacturing equipment and processed into three groups of test pieces after T6 heat treatment. The mechanical properties of the printed parts were tested in accordance with GB / T 228.1-2021 standard, and the test results are shown in Table 4:

[0094] Table 4 Mechanical properties test results of printed parts

[0095] Example Average tensile strength (MPa) Average yield strength (MPa) Average elongation (%) Comparative Example 1 357 285 6.3 Comparative Example 2 370 273 7.9 Comparative Example 3 378 288 8

[0096] The contents explained in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the present invention, and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the embodiments made by those skilled in the art fall within the scope defined by the claims attached to the present invention.

Claims

1. A method for preparing Al-Cu-Sc aluminum alloy wire for arc additive manufacturing, characterized in that The following steps are involved: S1. Aluminum liquid smelting: adding alloy raw materials into a medium frequency furnace, heating and melting, stirring and fully melting to obtain aluminum liquid, wherein the alloy raw materials include aluminum, copper and scandium; S2, electromagnetic stirring: Turn on the electromagnetic stirring power supply to electromagnetically stir the aluminum liquid in S1; S3, refining and degassing: the aluminum liquid is refined and degassed; S4, online filtration: online degassing, deslagging and filtering of the aluminum melt; S5, continuous casting: quantitatively introducing the aluminum melt obtained in S4 into a crystallization wheel, cooling and solidifying through the crystallization wheel to obtain an aluminum rod blank; S6, continuous extrusion: the aluminum rod blank obtained in S5 is transferred to a continuous extrusion device, the aluminum rod blank is straightened, the oxide scale is scraped off, the aluminum rod blank is cleaned, and then introduced into the wheel groove of the extrusion wheel for radial extrusion to obtain a wire blank; S7, intermediate annealing: annealing, drawing and scraping the wire blank; S8, cleaning and layer winding: cleaning the surface of the wire blank, coating with a reagent, and layer winding and packaging to obtain a 3D printing wire; Preferably, the speed of the extrusion wheel in the continuous extrusion in S6 is 7-8r\min and the torque is 7-8r / min; further preferably, a wire blank with a diameter of 2-4mm is obtained in S6; further preferably, the temperature in the extrusion wheel groove in S6 is 400-500℃.

2. The method for preparing the Al-Cu-Sc aluminum alloy wire according to claim 1, characterized in that: The casting temperature in S5 is in the range of 710°C to 720°C, the crystallization wheel has its own water cooling system, the cooling water temperature range is 10°C to 20°C, the aluminum liquid is cooled and solidified by the crystallization wheel to obtain an aluminum rod blank; preferably, the cross-sectional area of ​​the crystallization wheel is 63.6-122.6mm 2 , further preferably, the diameter of the aluminum rod blank is Φ9-12.5 mm.

3. The method for preparing the Al-Cu-Sc aluminum alloy wire according to claim 1, characterized in that: The alloy raw material includes the following components in mass percentage: Cu 5.3% to 6.7%, Mn 0.2% to 0.4%, Ti 0.12% to 0.18%, Sc0.1% to 0.2%, Zr 0.12% to 0.18%, V0.08% to 0.16%, Fe≤0.15%, Si≤0.08%, and the rest are Al and other inevitable impurity elements, the content of each element in the inevitable impurity elements is ≤0.05%, and the total amount of other inevitable impurity elements is ≤0.15%.

4. The method for preparing the Al-Cu-Sc aluminum alloy wire according to claim 1, characterized in that: The electromagnetic stirring frequency in S2 is 10 Hz to 20 Hz.

5. The method for preparing the Al-Cu-Sc aluminum alloy wire according to claim 1, characterized in that: The temperature range of refining and degassing in S3 is 740° C. to 750° C., the refining time range is 20 minutes to 30 minutes, and the hydrogen content in the aluminum melt after refining and degassing is ≤0.1 ml / 100 g Al.

6. The method for preparing the Al-Cu-Sc aluminum alloy wire according to claim 3, characterized in that: S7: keeping the wire billet at a temperature range of 350° C. to 400° C. for 2 to 3 hours, and then keeping the wire billet at a temperature range of 250° C. to 300° C. for 3 to 4 hours.

7. The method for preparing the Al-Cu-Sc aluminum alloy wire according to claim 1, characterized in that: The drawing and scraping in S7 specifically involves drawing the annealed wire billet to a nearly finished product size, then removing surface scratches and fatigue layers through two consecutive scraping passes, and obtaining the Al-Cu-Sc aluminum alloy wire through a cleaning layer winding.

8. The method for preparing the Al-Cu-Sc aluminum alloy wire according to claim 1, characterized in that: In S4, degassing bricks are used for online degassing and slag removal, and a three-stage filtration system is used to control the removal rate of inclusions with a particle size greater than 5 μm in the aluminum melt to be greater than 90%.

9. An Al-Cu-Sc aluminum alloy wire prepared according to the method for preparing an Al-Cu-Sc aluminum alloy wire according to any one of claims 1 to 8.

10. An Al-Cu-Sc aluminum alloy wire, characterized in that: After T6 heat treatment, the tensile strength is ≥420MPa, the yield strength is ≥300MPa, and the elongation is ≥12%.

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