Aluminum magnesium copper alloy wire for additive manufacturing and method of making the same

Abstract

This invention discloses an aluminum-magnesium-copper alloy wire for additive manufacturing and its preparation method, comprising the following components by mass percentage: Mg: 5.0-8.0 wt%, Cu: 0.5-1.5 wt%, Mg+Cu: 6.0-9.0 wt%, Ce: 0.5-1.0 wt%, Yb: 0.3-0.8 wt%, Ce+Yb: ≤1.5 wt%, Li+Ca+Na: ≤0.005 wt%, with the balance being Al, and other impurity elements individually ≤0.05 wt%, and H content ≤0.10 wt%. L / 100gAl; This invention abandons the expensive Sc and instead adopts a composite addition of Yb+Ce, while controlling the content of Mg and Cu. This not only reduces costs but also brings the following performance improvements: Yb and Ce elements can react with impurities such as hydrogen, oxygen, and nitrogen in the melt to form high-melting-point compounds, thereby purifying the melt and significantly reducing porosity defects in additively manufactured parts. At the same time, these elements can act as heterogeneous nucleation sites during solidification, effectively refining grains, inhibiting columnar crystal growth, promoting equiaxed crystal formation, and reducing the tendency for hot cracking.

Description

Technical Field

[0001] This invention relates to the field of metal materials technology, and in particular to an aluminum-magnesium-copper alloy wire for additive manufacturing and its preparation method. Background Technology

[0002] Additive manufacturing technology originated in the 1980s. Unlike traditional subtractive manufacturing processes, it allows for the direct construction of complex geometries without the need for molds, significantly reducing material waste. Early additive manufacturing technologies primarily relied on powder bed processes. After 2000, wire additive manufacturing (such as WAAM) emerged, rapidly gaining popularity in aerospace and automotive fields due to its high material utilization rate (greater than 95%) and low cost. Aluminum alloys, as the core material, have become the preferred choice for additive manufacturing wires due to their lightweight and high strength properties.

[0003] The development of aluminum alloy wire in additive manufacturing has gone through iterations from basic alloys to high-performance alloys. The current Al-Si system (such as AlSi10Mg / 12Mg) has good fluidity and low tendency to hot cracking, but its strength is limited. Other 2xxx, 5xxx and 7xxx series alloys are prone to oxidation, are sensitive to porosity, and their directional solidification leads to columnar crystal growth, which causes the mechanical properties to show directional differences. Rapid cooling generates thermal stress, which can cause cracks. It is difficult to balance strength and toughness, which limits their application in critical load-bearing components.

[0004] In recent years, microalloying innovations have emerged, such as Al-Mg-Sc alloys with added Sc, which improve performance by refining grains. However, the following problems exist: First, Sc, as a strategic rare earth element, is expensive, resulting in excessively high wire costs. Second, the evolution of wire is limited by traditional casting processes, making it difficult to effectively control the distribution of Sc and maintain good microstructure consistency in subsequent wire rolling, leading to unstable performance. Third, after Sc alloying, the process properties of the wire (such as hot cracking tendency, porosity sensitivity, and arc stability) do not match well with existing or desired additive manufacturing (such as WAAM) process parameters. Summary of the Invention

[0005] The purpose of this invention is to provide an aluminum-magnesium-copper alloy wire for additive manufacturing and a method for preparing the same, so as to solve the problems existing in the prior art.

[0006] An aluminum-magnesium-copper alloy wire for additive manufacturing is composed of the following components by mass percentage: Mg: 5.0-8.0 wt%, Cu: 0.5-1.5 wt%, Mg+Cu: 6.0-9.0 wt%, Ce: 0.5-1.0 wt%, Yb: 0.3-0.8 wt%, Ce+Yb: ≤1.5 wt%, Li+Ca+Na: ≤0.005 wt%, with the balance being Al, other impurity elements ≤0.05 wt% individually, and H content ≤0.10 mL / 100 g Al.

[0007] Preferably, when the mass content of Mg is 6.0-8.0 wt%, the mass content of Cu is 0.6-1.0 wt%.

[0008] Preferably, the mass content of Ce is 0.55-0.98 wt%, and the mass content of Yb is 0.33-0.65 wt%.

[0009] A method for preparing aluminum-magnesium-copper alloy wire for additive manufacturing includes the following steps: S1 Batching and Refining: Weigh pure metals or intermediate alloys according to mass percentages to obtain the prepared raw materials; S2 smelting: The prepared raw materials are placed into a smelting furnace for smelting. The melt temperature reaches 740-750℃ to obtain the smelted melt. S3 Gas Blowing Refining: The melt after smelting is refined by blowing a mixture of argon and chlorine gas; after refining, it is allowed to stand for 15-25 minutes to make the melt composition uniform and remove the surface slag, and the total content of Li+Ca+Na in the melt is controlled to be ≤0.005wt%, thus obtaining the purified melt. S4 Continuous Casting and Rolling: The purified melt is made into aluminum alloy wire rods using a continuous casting and rolling process, with a casting temperature of 700-720℃. S5 Low Temperature Aging: The aluminum alloy wire rod is placed in a liquid nitrogen environment for low temperature aging treatment. The low temperature aging treatment temperature is -196℃ to -180℃, and the holding time is 1-2 hours. Then it is restored to room temperature to obtain the low temperature aluminum alloy wire rod. S6 rolling: The aluminum alloy wire rod after low temperature is subjected to multiple passes of continuous cold rolling to obtain wire billet. The total rolling deformation of the obtained billet is not less than 90%, and the final diameter is 2.0mm. S7 Finishing and Cleaning: The wire blank is scraped, sized, and cleaned in sequence; scraping is done using a polycrystalline mold, with a single-sided scraping thickness of not less than 0.3mm; sizing process brings the wire diameter to 1.2-1.4mm; cleaning is done using ultrasonic cleaning to remove surface oil and impurities, finally obtaining aluminum-magnesium-copper alloy wire.

[0010] Preferably, the volume ratio of chlorine in the mixed gas in S3 is 10-20%, and the gas purity is not less than 99.8%.

[0011] Preferably, the diameter of the aluminum alloy rod in S4 is less than 6.5 mm, and the total deformation during rolling is not less than 95%.

[0012] Preferably, the temperature for the low-temperature aging treatment in S5 is -190℃, and the holding time is 1 hour.

[0013] Preferably, the diameter of the wire after sizing in S7 is 1.4 mm.

[0014] Compared with the prior art, the present invention provides an aluminum-magnesium-copper alloy wire for additive manufacturing and a method for preparing the same, which has the following beneficial effects: This invention abandons the expensive Sc and instead adopts a composite addition of Yb+Ce, while controlling the content of Mg and Cu. This is not only to reduce costs, but also brings the following performance improvements: Yb and Ce elements can react with impurities such as hydrogen, oxygen, and nitrogen in the melt to form high-melting-point compounds, thereby purifying the melt and significantly reducing porosity defects in additively manufactured parts. At the same time, these elements can act as heterogeneous nucleation sites during solidification, effectively refining grains, inhibiting columnar crystal growth, promoting equiaxed crystal formation, and reducing the tendency for hot cracking. Detailed Implementation

[0015] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0016] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to specific embodiments.

[0017] An aluminum-magnesium-copper alloy wire for additive manufacturing is composed of the following components by mass percentage: Mg: 5.0-8.0 wt%, Cu: 0.5-1.5 wt%, Mg+Cu: 6.0-9.0 wt%, Ce: 0.5-1.0 wt%, Yb: 0.3-0.8 wt%, Ce+Yb: ≤1.5 wt%, Li+Ca+Na: ≤0.005 wt%, with the balance being Al, other impurity elements ≤0.05 wt% individually, and H content ≤0.10 mL / 100 g Al.

[0018] A method for preparing aluminum-magnesium-copper alloy wire for additive manufacturing includes the following steps: S1 Batching and Refining: Weigh pure metals or intermediate alloys according to mass percentages to obtain the prepared raw materials; S2 smelting: The prepared raw materials are placed into a smelting furnace for smelting. The melt temperature reaches 740-750℃ to obtain the smelted melt. S3 Gas Blowing Refining: The smelted melt is refined by blowing a mixture of argon and chlorine gas; the volume ratio of chlorine in the mixture is 10-20%, and the gas purity is not less than 99.8%; after refining, the melt is allowed to stand for 15-25 minutes to make the melt composition uniform and remove the surface slag, and the total content of Li+Ca+Na in the melt is controlled to be ≤0.005wt%, thus obtaining a purified melt; S4 Continuous Casting and Rolling: The purified melt is continuously cast and rolled into aluminum alloy wire rods at a casting temperature of 700-720℃; the diameter of the aluminum alloy wire rods is less than 6.5mm, and the total rolling deformation is not less than 95%. S5 Low Temperature Aging: The aluminum alloy wire rod is placed in a liquid nitrogen environment for low temperature aging treatment. The low temperature aging treatment temperature is -196℃ to -180℃, and the holding time is 1-2 hours. Then it is restored to room temperature to obtain the low temperature aluminum alloy wire rod. S6 rolling: The aluminum alloy wire rod after low temperature is subjected to multiple passes of continuous cold rolling to obtain wire billet. The total rolling deformation of the obtained billet is not less than 90%, and the final diameter is 2.0mm. S7 Finishing and Cleaning: The wire blank is scraped, sized, and cleaned in sequence; scraping is done using a polycrystalline mold, with a single-sided scraping thickness of not less than 0.3mm; sizing process brings the wire diameter to 1.2-1.4mm; cleaning is done using ultrasonic cleaning to remove surface oil and impurities, finally obtaining aluminum-magnesium-copper alloy wire. Example

[0019] S1: Prepare the raw materials according to the following mass percentages: Mg: 5.6wt%, Cu: 1.45wt%, Ce: 0.5wt%, Yb: 0.36wt%, Li+Ca+Na: 0.001wt%, with the balance being Al; S2 smelting: The prepared raw materials are placed into a smelting furnace for smelting. The melt temperature reaches 745℃, and the smelted melt is obtained. S3 Gas Blowing Refining: Using 316 stainless steel round tubes, a mixture of argon and chlorine (argon to chlorine volume ratio of 80:20) is blown onto the molten material for refining. Under the premise of ensuring the blowing time and uniformity, the material is allowed to stand for 20 minutes after refining to make the composition of the melt uniform and remove the surface slag, thus obtaining a purified melt. S4 Continuous Casting and Rolling: The purified melt is produced into aluminum alloy wire rods with a diameter of less than 6.5mm using a continuous casting and rolling process, with a casting temperature of 710℃. S5 Low Temperature Aging: The aluminum alloy wire rod is placed in a liquid nitrogen device for low temperature aging treatment. It is kept at a low temperature of -190℃ for 1 hour, and then restored to room temperature to obtain the low temperature aluminum alloy wire rod. S6 rolling: The aluminum alloy wire rod after low temperature is subjected to multiple passes of continuous cold rolling to obtain wire blank. The final diameter of the obtained blank is 2.0mm. S7 finishing and cleaning: First, the wire blank is scraped with a polycrystalline die to a thickness of not less than 0.3mm on one side; then, the wire is sizing and polycrystalline scraping die is used to reduce the diameter to 1.4mm; finally, the wire is cleaned with ultrasonic waves to remove surface oil and impurities, and finally aluminum-magnesium-copper alloy wire is obtained. Example

[0020] S1: Prepare the raw materials according to the following mass percentages: Mg: 6.96wt%, Cu: 0.99wt%, Ce: 0.67wt%, Yb: 0.45wt%, Li+Ca+Na: 0.003wt%, with the balance being Al; S2 smelting: The prepared raw materials are placed into a smelting furnace for smelting. The melt temperature reaches 750℃ to obtain the smelted melt. S3 Gas Blowing Refining: Using 316 stainless steel round tubes, a mixture of argon and chlorine gas (argon to chlorine volume ratio of 85:15) is blown onto the molten material for refining. Under the premise of ensuring the blowing time and uniformity, the material is allowed to stand for 15 minutes after refining to make the composition of the melt uniform and remove the surface slag, thus obtaining a purified melt. S4 Continuous Casting and Rolling: The purified melt is produced into aluminum alloy wire rods with a diameter of less than 6.5mm using a continuous casting and rolling process, with a casting temperature of 700℃. S5 Low Temperature Aging: The aluminum alloy wire rod is placed in a liquid nitrogen device for low temperature aging treatment, and held at a low temperature of -185℃ for 1.5 hours, and then restored to room temperature to obtain the low temperature aluminum alloy wire rod. S6 rolling: The aluminum alloy wire rod after low temperature is subjected to multiple passes of continuous cold rolling to obtain wire blank. The final diameter of the obtained blank is 2.0mm. S7 finishing and cleaning: First, the wire blank is scraped with a polycrystalline die to a thickness of not less than 0.3mm on one side; second, the wire is sizing and polycrystalline scraping die is used to reduce the diameter to 1.2mm; finally, the wire is cleaned with ultrasonic waves to remove surface oil and impurities, and finally aluminum-magnesium-copper alloy wire is obtained. Example

[0021] S1: Prepare the raw materials according to the following mass percentages: Mg: 7.93wt%, Cu: 0.53wt%, Ce: 0.56wt%, Yb: 0.56wt%, Li+Ca+Na: 0.005wt%, with the balance being Al; S2 smelting: The prepared raw materials are placed into a smelting furnace for smelting. The melt temperature reaches 740℃, and the smelted melt is obtained. S3 Gas Blowing Refining: Using 316 stainless steel round tubes, a mixture of argon and chlorine gas (argon to chlorine volume ratio of 90:10) is blown onto the molten material for refining. Under the premise of ensuring the blowing time and uniformity, the material is allowed to stand for 25 minutes after refining to make the composition of the melt uniform and remove the surface slag, thus obtaining a purified melt. S4 Continuous Casting and Rolling: The purified melt is produced into aluminum alloy wire rods with a diameter of less than 6.5mm using a continuous casting and rolling process, with a casting temperature of 700℃. S5 Low Temperature Aging: The aluminum alloy wire rod is placed in a liquid nitrogen device for low temperature aging treatment. It is kept at a low temperature of -180℃ for 2 hours, and then restored to room temperature to obtain the low temperature aluminum alloy wire rod. S6 rolling: The aluminum alloy wire rod after low temperature is subjected to multiple passes of continuous cold rolling to obtain wire blank. The final diameter of the obtained blank is 2.0mm. S7 finishing and cleaning: First, the wire blank is scraped with a polycrystalline die to a thickness of not less than 0.3mm on one side; then, the wire is sizing and polycrystalline scraping die is used to reduce the diameter to 1.4mm; finally, the wire is cleaned with ultrasonic waves to remove surface oil and impurities, and finally aluminum-magnesium-copper alloy wire is obtained. Example

[0022] S1: Prepare the raw materials according to the following mass percentages: Mg: 5.65wt%, Cu: 1.03wt%, Ce: 0.98wt%, Yb: 0.33wt%, Li+Ca+Na: 0.001wt%, with the balance being Al; S2 smelting: The prepared raw materials are placed into a smelting furnace for smelting. The melt temperature reaches 745℃, and the smelted melt is obtained. S3 Gas Blowing Refining: Using 316 stainless steel round tubes, a mixture of argon and chlorine (argon to chlorine volume ratio of 80:20) is blown onto the molten material for refining. Under the premise of ensuring the blowing time and uniformity, the material is allowed to stand for 20 minutes after refining to make the composition of the melt uniform and remove the surface slag, thus obtaining a purified melt. S4 Continuous Casting and Rolling: The purified melt is produced into aluminum alloy wire rods with a diameter of less than 6.5mm using a continuous casting and rolling process, with a casting temperature of 710℃. S5 Low Temperature Aging: The aluminum alloy wire rod is placed in a liquid nitrogen device for low temperature aging treatment, and held at a low temperature of -196℃ for 1.5 hours, and then restored to room temperature to obtain the low temperature aluminum alloy wire rod. S6 rolling: The aluminum alloy wire rod after low temperature is subjected to multiple passes of continuous cold rolling to obtain wire blank. The final diameter of the obtained blank is 2.0mm. S7 finishing and cleaning: First, the wire blank is scraped with a polycrystalline die to a thickness of not less than 0.3mm on one side; second, the wire is sizing and polycrystalline scraping die is used to reduce the diameter to 1.3mm; finally, the wire is cleaned with ultrasonic waves to remove surface oil and impurities, and finally aluminum-magnesium-copper alloy wire is obtained. Example

[0023] S1: Prepare the raw materials according to the following mass percentages: Mg: 6.92wt%, Cu: 0.55wt%, Ce: 0.78wt%, Yb: 0.55wt%, Li+Ca+Na: 0.003wt%, with the balance being Al; S2 smelting: The prepared raw materials are placed into a smelting furnace for smelting. The melt temperature reaches 740℃, and the smelted melt is obtained. S3 Gas Blowing Refining: Using 316 stainless steel round tubes, a mixture of argon and chlorine (argon to chlorine volume ratio of 80:20) is blown onto the molten material for refining. Under the premise of ensuring the blowing time and uniformity, the material is allowed to stand for 20 minutes after refining to make the composition of the melt uniform and remove the surface slag, thus obtaining a purified melt. S4 Continuous Casting and Rolling: The purified melt is produced into aluminum alloy wire rods with a diameter of less than 6.5mm using a continuous casting and rolling process, with a casting temperature of 700℃. S5 Low Temperature Aging: The aluminum alloy wire rod is placed in a liquid nitrogen device for low temperature aging treatment, and held at a low temperature of -190℃ for 1.5 hours, and then restored to room temperature to obtain the low temperature aluminum alloy wire rod. S6 rolling: The aluminum alloy wire rod after low temperature is subjected to multiple passes of continuous cold rolling to obtain wire blank. The final diameter of the obtained blank is 2.0mm. S7 finishing and cleaning: First, the wire blank is scraped with a polycrystalline die to a thickness of not less than 0.3mm on one side; then, the wire is sizing and polycrystalline scraping die is used to reduce the diameter to 1.4mm; finally, the wire is cleaned with ultrasonic waves to remove surface oil and impurities, and finally aluminum-magnesium-copper alloy wire is obtained. Example

[0024] S1: Prepare the raw materials according to the following mass percentages: Mg: 7.99wt%, Cu: 0.82wt%, Ce: 0.88wt%, Yb: 0.38wt%, Li+Ca+Na: 0.005wt%, with the balance being Al; S2 smelting: The prepared raw materials are placed into a smelting furnace for smelting. The melt temperature reaches 745℃, and the smelted melt is obtained. S3 Gas Blowing Refining: Using 316 stainless steel round tubes, a mixture of argon and chlorine gas (argon to chlorine volume ratio of 80:20) is blown onto the molten material for refining. Under the premise of ensuring the blowing time and uniformity, the material is allowed to stand for 15 minutes after refining to make the composition of the melt uniform and remove the surface slag, thus obtaining a purified melt. S4 Continuous Casting and Rolling: The purified melt is produced into aluminum alloy wire rods with a diameter of less than 6.5mm using a continuous casting and rolling process, with a casting temperature of 715℃. S5 Low Temperature Aging: The aluminum alloy wire rod is placed in a liquid nitrogen device for low temperature aging treatment. It is kept at a low temperature of -190℃ for 2 hours, and then restored to room temperature to obtain the low temperature aluminum alloy wire rod. S6 rolling: The aluminum alloy wire rod after low temperature is subjected to multiple passes of continuous cold rolling to obtain wire blank. The final diameter of the obtained blank is 2.0mm. S7 finishing and cleaning: First, the wire blank is scraped with a polycrystalline die to a thickness of not less than 0.3mm on one side; then, the wire is sizing and polycrystalline scraping die is used to reduce the diameter to 1.4mm; finally, the wire is cleaned with ultrasonic waves to remove surface oil and impurities, and finally aluminum-magnesium-copper alloy wire is obtained. Example

[0025] S1: Prepare the raw materials according to the following mass percentages: Mg: 5.69wt%, Cu: 0.51wt%, Ce: 0.95wt%, Yb: 0.39wt%, Li+Ca+Na: 0.001wt%, with the balance being Al; S2 smelting: The prepared raw materials are placed into a smelting furnace for smelting. The melt temperature reaches 745℃, and the smelted melt is obtained. S3 Gas Blowing Refining: Using 316 stainless steel round tubes, a mixture of argon and chlorine (argon to chlorine volume ratio of 80:20) is blown onto the molten material for refining. Under the premise of ensuring the blowing time and uniformity, the material is allowed to stand for 20 minutes after refining to make the composition of the melt uniform and remove the surface slag, thus obtaining a purified melt. S4 Continuous Casting and Rolling: The purified melt is produced into aluminum alloy wire rods with a diameter of less than 6.5mm using a continuous casting and rolling process, with a casting temperature of 710℃. S5 Low Temperature Aging: The aluminum alloy wire rod is placed in a liquid nitrogen device for low temperature aging treatment, and held at a low temperature of -190℃ for 1.5 hours, and then restored to room temperature to obtain the low temperature aluminum alloy wire rod. S6 rolling: The aluminum alloy wire rod after low temperature is subjected to multiple passes of continuous cold rolling to obtain wire blank. The final diameter of the obtained blank is 2.0mm. S7 finishing and cleaning: First, the wire blank is scraped with a polycrystalline die to a thickness of not less than 0.3mm on one side; then, the wire is sizing and polycrystalline scraping die is used to reduce the diameter to 1.4mm; finally, the wire is cleaned with ultrasonic waves to remove surface oil and impurities, and finally aluminum-magnesium-copper alloy wire is obtained. Example

[0026] S1: Prepare the raw materials according to the following mass percentages: Mg: 6.95wt%, Cu: 1.47wt%, Ce: 0.55wt%, Yb: 0.55wt%, Li+Ca+Na: 0.003wt%, with the balance being Al; S2 smelting: The prepared raw materials are placed into a smelting furnace for smelting. The melt temperature reaches 745℃, and the smelted melt is obtained. S3 Gas Blowing Refining: Using 316 stainless steel round tubes, a mixture of argon and chlorine gas (argon to chlorine volume ratio of 80:20) is blown onto the molten material for refining. Under the premise of ensuring the blowing time and uniformity, the material is allowed to stand for 15 minutes after refining to make the composition of the melt uniform and remove the surface slag, thus obtaining a purified melt. S4 Continuous Casting and Rolling: The purified melt is produced into aluminum alloy wire rods with a diameter of less than 6.5mm using a continuous casting and rolling process, with a casting temperature of 705℃. S5 Low Temperature Aging: The aluminum alloy wire rod is placed in a liquid nitrogen device for low temperature aging treatment, and held at a low temperature of -190℃ for 1.5 hours, and then restored to room temperature to obtain the low temperature aluminum alloy wire rod. S6 rolling: The aluminum alloy wire rod after low temperature is subjected to multiple passes of continuous cold rolling to obtain wire blank. The final diameter of the obtained blank is 2.0mm. S7 finishing and cleaning: First, the wire blank is scraped with a polycrystalline die to a thickness of not less than 0.3mm on one side; then, the wire is sizing and polycrystalline scraping die is used to reduce the diameter to 1.4mm; finally, the wire is cleaned with ultrasonic waves to remove surface oil and impurities, and finally aluminum-magnesium-copper alloy wire is obtained. Example

[0027] S1: Prepare the raw materials according to the following mass percentages: Mg: 7.89wt%, Cu: 1.02wt%, Ce: 0.63wt%, Yb: 0.65wt%, Li+Ca+Na: 0.005wt%, with the balance being Al; S2 smelting: The prepared raw materials are placed into a smelting furnace for smelting. The melt temperature reaches 745℃, and the smelted melt is obtained. S3 Gas Blowing Refining: Using 316 stainless steel round tubes, a mixture of argon and chlorine gas (argon to chlorine volume ratio of 85:15) is blown onto the molten material for refining. Under the premise of ensuring the blowing time and uniformity, the material is allowed to stand for 20 minutes after refining to make the composition of the melt uniform and remove the surface scum, thus obtaining a purified melt. S4 Continuous Casting and Rolling: The purified melt is produced into aluminum alloy wire rods with a diameter of less than 6.5mm using a continuous casting and rolling process, with a casting temperature of 710℃. S5 Low Temperature Aging: The aluminum alloy wire rod is placed in a liquid nitrogen device for low temperature aging treatment, and held at a low temperature of -190℃ for 1.5 hours, and then restored to room temperature to obtain the low temperature aluminum alloy wire rod. S6 rolling: The aluminum alloy wire rod after low temperature is subjected to multiple passes of continuous cold rolling to obtain wire blank. The final diameter of the obtained blank is 2.0mm. S7 finishing and cleaning: First, the wire blank is scraped with a polycrystalline die to a thickness of not less than 0.3mm on one side; then, the wire is sizing and polycrystalline scraping die is used to reduce the diameter to 1.4mm; finally, the wire is cleaned with ultrasonic waves to remove surface oil and impurities, and finally aluminum-magnesium-copper alloy wire is obtained.

[0028] Comparative Example 1: The ingredients were prepared according to the following mass percentages: Mg: 5.56%, Cu: 1.02%, Mg+Cu: 6.58%, Ce: 0.00%, Yb: 0.56%, Li+Ca+Na: 0.009%, with the balance being Al. No Ce element was added to the raw materials, and no low-temperature aging was performed during the processing. The rest was the same as in Example 1.

[0029] Comparative Example 2: The ingredients were formulated according to the following mass percentages: Mg: 7.8%, Cu: 2.5%, Mg+Cu: 10.30%, Ce: 0.56%, Yb: 0%, Li+Ca+Na: 0.011%, with the balance being Al. No Yb was added to the raw materials, and the Cu content exceeded the scope of this invention. Low-temperature aging was not performed during processing; otherwise, it was the same as in Example 1.

[0030] Comparative Example 3: The ingredients were prepared according to the following mass percentages: Mg: 9%, Cu: 2%, Mg+Cu: 11.00%, Ce: 0.95%, Yb: 0%, Li+Ca+Na: 0.008%, with the balance being Al. No Yb was added, and the contents of Mg and Cu exceeded the limits of this invention. Low-temperature aging was not performed during processing; otherwise, the process was the same as in Example 1.

[0031] The aluminum alloy wires obtained in Examples 1-9 and Comparative Examples 1-3 were used for arc additive manufacturing. The mechanical properties of the arc additive manufacturing samples with aging heat treatment were tested. Simultaneously, samples with a length of 10 mm, a width of 8 mm, and a height of 6 mm were cut, ground, polished, and cleaned. The samples were then observed under an optical microscope, and the porosity was measured using Image-J software. The test results are shown in Table 1. Table 1 Mechanical properties and porosity of additive buildup samples from Examples 1-9 and Comparative Examples 1-3

[0032] Table 1 shows that, within the element range defined by this invention, the aluminum alloy wires obtained can achieve high strength when used in arc additive manufacturing, and the porosity is consistently below 2.1%. Among them, it can be seen from Comparative Examples 1-3 that when Ce and Yb are not added to the material, although the content of Mg and Cu is high, the yield strength and elongation of the tensile specimens are significantly lower, and the porosity is around 3%, which is significantly higher than that of Examples 1-9. It can be seen that by controlling the appropriate element content and ratio, this invention can obtain aluminum alloy wires with better comprehensive performance.

[0033] This invention lays the foundation for material processing through precise control of performance-enhancing elements, trace rare earth elements, and impurity elements, achieving a balance between cost and performance. The entire wire processing employs a rolling method combined with a low-temperature aging process, resulting in a uniform internal composition of the material. Unlike traditional material refinement methods, the material volume and lattice shrink under ultra-low temperature aging, leading to an increase in internal stress and the generation of numerous microscopic defects such as dislocations and subgrains. During the recovery process to room temperature after the low-temperature treatment, the grains rotate, and preferential orientation forms a recrystallization texture. On the other hand, the multi-grain boundary structure generated by grain refinement is more conducive to electron transport and transfer, which improves the material's conductivity and helps form a stable electric arc during subsequent use, reducing defect generation.

[0034] To address the issues of "porosity" and "cracking susceptibility" in traditional high-strength aluminum alloy additive manufacturing, and to improve the density and forming reliability of additive parts, a method is developed. By designing a high Mg content (5-8 wt%), a supersaturated solid solution is formed in the Al matrix, providing basic strength. By controlling an appropriate amount of Cu (0.5-1.5 wt%), an Al2Cu strengthening phase can be formed during aging. At the same time, the nanoparticles formed by Yb and Ce also play a precipitation strengthening role. Yb and Ce refine the grains, increase the grain boundary area, hinder dislocation movement, and improve strength and toughness. This achieves a synergistic effect of multiple strengthening mechanisms, obtaining high comprehensive mechanical properties (high tensile strength, yield strength, and good elongation) without over-reliance on a single expensive element (such as Sc).

[0035] By strictly limiting the total amount of alkali metal impurities such as Li, Ca, and Na (≤0.005wt%) and controlling the H content (≤0.10mL / 100gAl), the plastic deformation capacity of the material was optimized, and the tendency to crack during processing was reduced. This makes the wire rod more suitable for subsequent plastic processing steps such as continuous rolling and scraping, improves the stability of the preparation process and the material utilization rate, and overcomes the limitations of being "limited by traditional casting processes".

[0036] The preparation method of this invention adopts an integrated process of "continuous casting and rolling + low-temperature aging + finishing". The continuous casting and rolling process directly produces small-diameter (≤6.5mm) wire rods with a total deformation of ≥95%. This effectively breaks up casting dendrites, compensates for porosity and shrinkage cavities, and yields wire rod blanks with more uniform composition and microstructure, laying the foundation for subsequent processing and consistent final performance, thus improving the intrinsic quality of the material. The wire rods are then subjected to low-temperature aging at -196℃ to -180℃. This process introduces a large number of dislocations and substructures into the material through the "thermal expansion and contraction" effect, inducing recrystallization and grain refinement during the recovery to room temperature.

[0037] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An aluminum-magnesium-copper alloy wire for additive manufacturing, characterized in that, It is composed of the following components by mass percentage: Mg: 5.0-8.0 wt%, Cu: 0.5-1.5 wt%, Mg+Cu: 6.0-9.0 wt%, Ce: 0.5-1.0 wt%, Yb: 0.3-0.8 wt%, Ce+Yb: ≤1.5 wt%, Li+Ca+Na: ≤0.005 wt%, with the balance being Al, and other impurity elements ≤0.05 wt% individually, and H content ≤0.10 mL / 100 g Al.

2. The aluminum-magnesium-copper alloy wire for additive manufacturing according to claim 1, characterized in that, When the mass content of Mg is 6.0-8.0 wt%, the mass content of Cu is 0.6-1.0 wt%.

3. The aluminum-magnesium-copper alloy wire for additive manufacturing according to claim 1, characterized in that, The mass content of Ce is 0.55-0.98 wt%, and the mass content of Yb is 0.33-0.65 wt%.

4. A method for preparing an aluminum-magnesium-copper alloy wire for additive manufacturing according to any one of claims 1-3, characterized in that, Includes the following steps, S1 Batching and Refining: Weigh pure metals or intermediate alloys according to mass percentages to obtain the prepared raw materials; S2 smelting: The prepared raw materials are placed into a smelting furnace for smelting. The melt temperature reaches 740-750℃ to obtain the smelted melt. S3 Gas Blowing Refining: The melt after smelting is refined by blowing a mixture of argon and chlorine gas; after refining, it is allowed to stand for 15-25 minutes to make the melt composition uniform and remove the surface slag, and the total content of Li+Ca+Na in the melt is controlled to be ≤0.005wt%, thus obtaining the purified melt. S4 Continuous Casting and Rolling: The purified melt is made into aluminum alloy wire rods using a continuous casting and rolling process, with a casting temperature of 700-720℃. S5 Low Temperature Aging: The aluminum alloy wire rod is placed in a liquid nitrogen environment for low temperature aging treatment. The low temperature aging treatment temperature is -196℃ to -180℃, and the holding time is 1-2 hours. Then it is restored to room temperature to obtain the low temperature aluminum alloy wire rod. S6 rolling: The aluminum alloy wire rod after low temperature is subjected to multiple passes of continuous cold rolling to obtain wire billet. The total rolling deformation of the obtained billet is not less than 90%, and the final diameter is 2.0mm. S7 Finishing and Cleaning: The wire blank is scraped, sized, and cleaned in sequence; scraping is done using a polycrystalline mold, with a single-sided scraping thickness of not less than 0.3mm; sizing process brings the wire diameter to 1.2-1.4mm; cleaning is done using ultrasonic cleaning to remove surface oil and impurities, finally obtaining aluminum-magnesium-copper alloy wire.

5. The aluminum-magnesium-copper alloy wire for additive manufacturing and its preparation method according to claim 4, characterized in that, The volume ratio of chlorine in the S3 mixed gas is 10-20%, and the gas purity is not less than 99.8%.

6. The aluminum-magnesium-copper alloy wire for additive manufacturing and its preparation method according to claim 4, characterized in that, In S4, the diameter of the aluminum alloy rod is less than 6.5mm, and the total deformation during rolling is not less than 95%.

7. The aluminum-magnesium-copper alloy wire for additive manufacturing and its preparation method according to claim 4, characterized in that, The temperature for the S5 medium-low temperature aging treatment is -190℃, and the holding time is 1 hour.

8. The aluminum-magnesium-copper alloy wire for additive manufacturing and its preparation method according to claim 4, characterized in that, The diameter of the wire after sizing in S7 is 1.4mm.