Aluminum-magnesium alloy powder for additive manufacturing, preparation method and application

Abstract

The application provides an aluminum-magnesium alloy powder for additive manufacturing, a preparation method and application, and the alloy powder comprises the following components: Mg 5.0-6.0%, Sc 0.5-0.8%, Zr 0.35-0.6%, B 0.05-0.1%, V 0.05-0.1%, Fe <0.1%, Si <0.05%, and the balance is Al; the preparation process comprises the following steps: firstly, melting aluminum ingot, then adding aluminum-vanadium, aluminum-boron, aluminum-scandium and aluminum-zirconium intermediate alloys in sequence, finally adding magnesium ingot into the melt liquid surface, and then refining and low-temperature casting to obtain an Al-Mg mother ingot; then, the Al-Mg mother ingot is subjected to gas atomization treatment to form a powder; by adding Sc and Zr, the Al3(Sc, Zr) phase is introduced to refine the grains, a large number of equiaxed grains are generated to inhibit the generation of thermal cracks and pores, and B and V further play a role in refining the grains; the addition of Sc, Zr, B and V achieves a synergistic effect, solves the problems of high porosity and easy thermal cracking which limit the application of Al-Mg alloy, and high-performance aluminum-magnesium alloy is obtained after SLM printing.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of alloy powder, in particular to an aluminum-magnesium alloy powder for additive manufacturing, a preparation method and application.

BACKGROUND

[0002] Al-Mg alloy is widely used in vehicle manufacturing, electronics, aerospace and other fields due to its high specific strength, good plasticity and weldability. However, it is difficult to obtain complex shapes and high-strength and high-toughness Al-Mg alloy by traditional processing methods. Selective laser melting (SLM) technology, as one of metal 3D printing technologies, can not only quickly and accurately prepare metal components with complex geometric configurations to realize "free manufacturing", but also shorten the processing time and save the processing cost. The commercially available developed by Airbus, is an Al-Mg-Sc-Zr-based alloy powder, which is currently applied in the fields of aerospace, transportation, military and medical treatment. Airbus will be applied to the cabin isolation structure of an aircraft. The alloy has a small tendency of thermal cracking and better printing performance compared with the alloy added with Cu and Zn, and the tensile strength can reach 520 MPa and the yield strength can reach 480 MPa.

[0003] CN115354199A discloses a 3D printing high-strength Al-Mg-Mn-Sc-Zr alloy powder and a forming method thereof. The qualified Al-Mg-Mn-Sc-Zr alloy powder for printing is prepared by a gas atomization method, and a printing sample with internal density, no porosity and few forming defects is obtained. However, the tensile strength is only about 400 MPa, which is far from the product of Airbus. The Al-Mg-Sc-Zr alloy powder is prepared by the method disclosed in CN109909492A, and the product has a tensile strength of about 510 MPa.

SUMMARY

[0004] The application aims to provide an aluminum-magnesium alloy powder for additive manufacturing, a preparation method and application.

[0005] The application adopts the following technical scheme: an aluminum-magnesium alloy powder for additive manufacturing, by mass percentage, comprising Mg 5.0-6.0%, Sc 0.5-0.8%, Zr 0.35-0.6%, B 0.05-0.1%, V 0.05-0.1%, Fe <0.1%, Si <0.05%, and the balance of Al.

[0006] Preferably, the aluminum-magnesium alloy powder comprises, by mass percentage, Mg 5.0-5.5%, Sc 0.6-0.8%, Zr 0.4-0.6%, B 0.05-0.1%, V 0.05-0.1%, Fe <0.1%, Si <0.05%, and the balance of Al.

[0007] The second aspect of the present application provides a preparation method of the aluminum-magnesium alloy powder, comprising the following steps:

[0008] (1) heating in a resistance furnace, and placing an aluminum ingot into the resistance furnace;

[0009] (2) after the aluminum ingot is completely melted, heating, and sequentially adding aluminum-vanadium intermediate alloy and aluminum-boron intermediate alloy, and holding the melt for 10 min;

[0010] (3) continuing to heat in the resistance furnace, and then sequentially adding aluminum-scandium intermediate alloy and aluminum-zirconium intermediate alloy, and holding the melt for 30 min;

[0011] (4) quickly adding a magnesium ingot under the melt liquid surface, and performing electromagnetic stirring until the melt is homogenized;

[0012] (5) introducing argon and a refining agent into the resistance furnace for refining, and performing slagging treatment after holding for 5 min, and obtaining a refined melt;

[0013] (6) performing low-pressure casting on the melt obtained in step (5) to obtain an Al-Mg master ingot;

[0014] (7) performing gas atomization treatment on the Al-Mg master ingot obtained in step (6) to obtain the alloy powder.

[0015] Preferably, the temperature of the resistance furnace in step (1) is 420°C.

[0016] Preferably, the temperature of the resistance furnace in step (2) is 720-740°C.

[0017] Preferably, the temperature of the resistance furnace in step (3) is controlled to be 760°C.

[0018] Preferably, the temperature of the resistance furnace in step (4) is controlled to be 720-740°C.

[0019] Preferably, the amount of the refining agent in step (5) is 2-4 kg / ton, and the refining temperature is 720-740°C.

[0020] Preferably, the temperature of the low-pressure casting in step (6) is 690-720°C.

[0021] Preferably, the specific process of the gas atomization treatment in step (7) is as follows: the Al-Mg master ingot prepared in step (6) is added into a melting chamber, and then the sample is subjected to the gas atomization treatment, first, the melting chamber and the atomization chamber are subjected to vacuumizing treatment, so that the vacuum degree reaches 5*10 -3 ~1*10 -2 Pa, then high-purity argon gas is introduced into the chamber as a protective gas, and the gas pressure is kept at 1.0~1.5 Pa, then the temperature of the melting chamber is raised, and the alloy is melted at 760~860℃; the alloy melt is broken into droplets through a nozzle under the action of high pressure of 0.5~4.0 MPa, and the droplets are solidified after passing through a cooling liquid to form the powder.

[0022] The beneficial effects of the present application are as follows:

[0023] The present application optimizes each component of the alloy, introduces new alloying elements, and uses the micro-alloying method of multiple elements to improve the alloy structure aiming at the defects of the Al-Mg alloy such as thermal cracking and low density; Al3(Sc, Zr) phase is introduced by adding Sc and Zr, which can refine the grain and generate a large number of equiaxed grains to inhibit the generation of thermal cracks and pores; in the aluminum alloy with the composite addition of Sc and Zr, Zr also participates in the solute distribution of the formation of Al3Sc precipitates, in the intermetallic compound Al3Sc phase, Zr can replace up to half of Sc while retaining the L12 structure, but due to the small diffusion coefficient of Zr in Al, the concentration of Zr in the precipitate is much lower than its solubility; Zr acts as a barrier layer on the α-Al / Al3Sc heterogeneous interface, showing better precipitation stability and coarsening resistance. Similarly, the solubility of V in Al3Sc is similar to that of Zr, and V reduces the lattice parameters of Al3(Sc, V) phase to a greater extent, thereby reducing the interface energy and elastic strain energy, further improving the coarsening resistance of Al3(Sc, V) precipitates; alloy phases with similar structures will lead to more obvious aggregation and coarsening, and due to the unique thermal recycling process of additive manufacturing Al alloy, a unique thermal recasting effect is generated, so adding B element to generate Al-B-Mg phase different from Al3(Sc, Zr) can better balance the mechanical properties of the alloy; in summary, the addition of Sc, Zr, B and V in the Al-Mg alloy powder of the present application achieves a synergistic effect, greatly improving the mechanical properties of the alloy;

[0024] The aluminum-magnesium alloy powder is prepared by sequentially adding each component in order, which is beneficial to the melting of the intermediate alloy and the diffusion of solute elements, and can prevent burning loss; in addition, the raw materials are first placed in a resistance furnace for melting, which can accurately control the melting temperature, further reducing the burning loss of the raw materials, so that the content of each element in the alloy powder is accurately controllable; the alloy melt is subjected to refining treatment to reduce impurities therein;

[0025] The application solves the problems of high porosity and easy hot cracking which limit the application of Al-Mg alloy, and an Al-Mg alloy with high performance is obtained after SLM printing, thereby meeting the demand for lightweight.

CONCRETE EMBODIMENT

[0026] In order to make the purpose, technical scheme and advantages of the application more clear, the application is described in the following specific embodiments, but is not limited to this. The following description is a preferred embodiment of the application, which is only used to describe the application, and cannot be understood as a limitation of the application. Any modification, equivalent replacement and improvement made within the spirit and principle of the application shall be included in the protection scope of the application.

[0027] The alloy powder comprises the following alloy components in mass percentage: Mg 5.0-6.0%, Sc 0.5-0.8%, Zr 0.35-0.6%, B 0.05-0.1%, V 0.05-0.1%, Fe <0.1%, Si <0.05%, and the balance is Al.

[0028] Too high Mg element will bring higher hot cracking tendency to the alloy, and too low Mg element will reduce the specific strength of the material;

[0029] Zr and Sc elements are rare earth elements, and the cost is high. Excessive addition will bring high cost and reduce the ductility of the alloy due to excessive second phase coarsening. Too little addition cannot inhibit the hot cracking tendency of the Al-Mg alloy, resulting in a large reduction in performance. Therefore, the alloy composition needs to be in a suitable range, and each element can synergistically achieve a good strengthening effect.

[0030] B and V elements are trace elements that can improve the performance of the alloy, but excessive addition will form other large phase and affect the performance of the alloy.

[0031] In the following examples, the mass percentage of V element in Al-5V intermediate alloy is 5%, the mass percentage of B element in Al-5B intermediate alloy is 5%, the mass percentage of Sc element in Al-2Sc intermediate alloy is 2%, and the mass percentage of Zr element in Al-5Zr intermediate alloy is 5%.

[0032] Example 1

[0033] The mass percentage of each component in the aluminum-magnesium alloy powder is: Mg 5.0%, Sc 0.5%, Zr 0.35%, B 0.1%, V 0.1%, Fe <0.1%, Si <0.05%, and the balance is Al;

[0034] The powder is prepared according to the following method:

[0035] (1) When the resistance furnace is heated to 420℃, the aluminum ingot is loaded into the resistance furnace;

[0036] (2) After the aluminum ingot is completely melted, the temperature is raised to 720℃, and Al-5V intermediate alloy and Al-5B intermediate alloy are sequentially added, and the melt is kept for 10 min;

[0037] (3) After the furnace temperature is raised to 760℃, Al-2Sc and Al-5Zr intermediate alloy are sequentially added, and the melt is kept for 30 min;

[0038] (4) The magnesium ingot is quickly added to the melt below the liquid surface, and electromagnetic stirring is performed until the melt is homogenized;

[0039] (5) Argon gas and refining agent (Pyrone 6AB type powder) are introduced into the resistance furnace for refining, the amount is 2 kg / ton, and the refining temperature is 720℃; After keeping still for 5 min, the slag is removed, and the refined melt is obtained;

[0040] (6) The melt obtained in step (5) is subjected to low pressure casting at 690℃ to obtain an Al-Mg master ingot;

[0041] (7) The Al-Mg master ingot prepared in step (6) is added to the melting chamber, and then the sample is subjected to gas atomization treatment. First, the melting chamber and the atomization chamber are vacuumized to a vacuum degree of 5*10 -3 Pa, then high-purity argon gas is introduced as a protective gas, and the gas pressure is kept at 1.0 Pa, then the temperature of the melting chamber is raised, and the alloy is melted by heating to above 760℃. The alloy melt is broken into droplets by argon gas at a high pressure of 4.0 MPa through a nozzle, and the droplets are solidified after passing through a cooling liquid to form a powder.

[0042] Example 2

[0043] The mass percentage of each component in the aluminum-magnesium alloy powder is: Mg 5.0%, Sc 0.6%, Zr 0.4%, B 0.1%, V 0.1%, Fe <0.1%, Si <0.05%, and the balance is Al;

[0044] The powder is prepared according to the following method:

[0045] (1) When the resistance furnace is heated to 420℃, the aluminum ingot is loaded into the resistance furnace;

[0046] (2) After the aluminum ingot is completely melted, the temperature is raised to 730℃, and Al-5V intermediate alloy and Al-5B intermediate alloy are sequentially added, and the melt is kept for 10 min;

[0047] (3) After the furnace temperature is raised to 760℃, Al-2Sc and Al-5Zr intermediate alloys are added successively, and the melt is kept for 30 min;

[0048] (4) The magnesium ingot is quickly added to the melt below the liquid surface, and electromagnetic stirring is performed until the melt is homogenized;

[0049] (5) Argon gas and a refining agent (Pyrilox 6AB powder) are introduced into the resistance furnace for refining, and the amount is 2 kg / ton, and the refining temperature is 730℃; after keeping still for 5 min, slagging treatment is performed, and the refined melt is obtained;

[0050] (6) The melt obtained in step (5) is subjected to low-pressure casting at 700℃ to obtain an Al-Mg master ingot;

[0051] (7) The Al-Mg master ingot prepared in step (6) is added to the melting chamber, and then the sample is subjected to gas atomization treatment. First, the melting chamber and the atomization chamber are subjected to vacuum treatment, so that the vacuum degree reaches 8*10 -3 Pa, then high-purity argon gas is introduced as a protective gas, and the gas pressure is kept at 1.3 Pa, then the temperature of the melting chamber is raised, and the alloy is melted by heating to above 780℃. The alloy melt is broken into droplets by argon gas at a high pressure of 3.5 MPa through a nozzle, and the droplets are solidified after passing through a cooling liquid to form a powder.

[0052] Example 3

[0053] The mass percentage of each component in the aluminum-magnesium alloy powder is: Mg 5.0%, Sc 0.7%, Zr 0.45%, B 0.1%, V 0.1%, Fe <0.1%, Si <0.05%, and the balance is Al;

[0054] The powder is prepared according to the following method:

[0055] (1) When the resistance furnace is heated to 420℃, the aluminum ingot is loaded into the resistance furnace;

[0056] (2) After the aluminum ingot is completely melted, Al-5V intermediate alloy and Al-5B intermediate alloy are added successively under the condition of heating to 720℃, and the melt is kept for 10 min;

[0057] (3) After the furnace temperature is raised to 760℃, Al-2Sc and Al-5Zr intermediate alloys are added successively, and the melt is kept for 30 min;

[0058] (4) The magnesium ingot is quickly added to the melt below the liquid surface, and electromagnetic stirring is performed until the melt is homogenized;

[0059] (5) The argon gas and refining agent (Pyrilox 6AB powder) are introduced into the resistance furnace for refining, the amount is 4 kg / ton, and the refining temperature is 740 DEG C; after static heat preservation for 5 min, the slag is removed, and the refined melt is obtained from the furnace;

[0060] (6) The melt obtained in step (5) is subjected to low-pressure casting at 720 DEG C, and the Al-Mg master ingot is obtained;

[0061] (7) The Al-Mg master ingot prepared in step (6) is added into the melting chamber, and then the sample is subjected to gas atomization treatment; first, the melting chamber and the atomization chamber are vacuumized to a vacuum degree of 7*10 -3 Pa, then the high-purity argon gas is introduced into the chamber as the protective gas, the gas pressure is kept at 1.5 Pa, the temperature of the melting chamber is increased, the alloy is melted at 800 DEG C, the alloy melt is broken into liquid drops by the argon gas at a high pressure of 4.0 MPa through the nozzle, and the liquid drops are solidified into powder after passing through the cooling liquid.

[0062] Example 4

[0063] The mass percentage of each component in the aluminum-magnesium alloy powder is: Mg 5.0%, Sc 0.8%, Zr 0.5%, B 0.1%, V 0.1%, Fe <0.1%, Si <0.05%, and the balance is Al;

[0064] The powder is prepared by the following method:

[0065] (1) When the resistance furnace is heated to 420 DEG C, the aluminum ingot is loaded into the resistance furnace;

[0066] (2) After the aluminum ingot is completely melted, the Al-5V intermediate alloy and the Al-5B intermediate alloy are sequentially added under the condition that the temperature is increased to 740 DEG C, and the melt is heat preserved for 10 min;

[0067] (3) After the temperature of the furnace is increased to 760 DEG C, the Al-2Sc and Al-5Zr intermediate alloys are sequentially added, and the melt is heat preserved for 30 min;

[0068] (4) The magnesium ingot is quickly added below the liquid surface of the melt, and the electromagnetic stirring is performed until the melt is homogenized;

[0069] (5) The argon gas and refining agent (Pyrilox 6AB powder) are introduced into the resistance furnace for refining, the amount is 3 kg / ton, and the refining temperature is 720 DEG C; after static heat preservation for 5 min, the slag is removed, and the refined melt is obtained from the furnace;

[0070] (6) The melt obtained in step (5) is subjected to low-pressure casting at 710 DEG C, and the Al-Mg master ingot is obtained;

[0071] (7) The Al-Mg master ingot prepared in step (6) is added into a melting chamber, and then the sample is subjected to gas atomization treatment. First, the melting chamber and the atomization chamber are vacuumized to a vacuum degree of 6*10 -2 Pa, high-purity argon gas is introduced into the chamber as a protective gas, the gas pressure is kept at 1.5 Pa, the temperature of the melting chamber is raised, the alloy is melted at 820 ℃, the alloy melt is broken into droplets by argon gas at a high pressure of 4.0 MPa through a nozzle, and the droplets are solidified into powder after passing through a cooling liquid.

[0072] Example 5

[0073] The aluminum magnesium alloy powder contains, by mass percent, Mg 5.5%, Sc 0.8%, Zr 0.5%, B 0.1%, V 0.1%, Fe <0.1%, Si <0.05%, and the balance of Al;

[0074] The powder is prepared by the following method:

[0075] (1) When the temperature of the resistance furnace is raised to 420 ℃, an aluminum ingot is loaded into the resistance furnace;

[0076] (2) After the aluminum ingot is completely melted, Al-5V intermediate alloy and Al-5B intermediate alloy are sequentially added under the condition of a temperature of 740 ℃, and the melt is kept for 10 min;

[0077] (3) After the temperature of the furnace is raised to 760 ℃, Al-2Sc and Al-5Zr intermediate alloys are sequentially added, and the melt is kept for 30 min;

[0078] (4) A magnesium ingot is quickly added below the liquid surface of the melt, and electromagnetic stirring is performed until the melt is homogenized;

[0079] (5) Argon gas and a refining agent (Pyrilox 6AB powder) are introduced into the resistance furnace for refining, the amount of the refining agent is 2 kg / ton, and the refining temperature is 720 ℃; after keeping still for 5 min, slagging is performed, and a refined melt is obtained;

[0080] (6) The melt obtained in step (5) is subjected to low-pressure casting at 690 ℃, and an Al-Mg master ingot is obtained;

[0081] (7) The Al-Mg master ingot prepared in step (6) is added into a melting chamber, and then the sample is subjected to gas atomization treatment. First, the melting chamber and the atomization chamber are vacuumized to a vacuum degree of 6*10 -3Pa, then high-purity argon gas is introduced into it as a protective gas, and the gas pressure is kept at 1.1 Pa, then the temperature of the smelting chamber is raised, and the alloy is melted by heating to 800 ℃, the alloy melt is broken into liquid drops by argon gas at a high pressure of 3.0 MPa through a nozzle, and the liquid drops form powder after solidification in a cooling liquid.

[0082] Example 6

[0083] The mass percentage of each component in the aluminum-magnesium alloy powder is: Mg 6%, Sc 0.8%, Zr 0.5%, B 0.1%, V 0.1%, Fe <0.1%, Si <0.05%, and the balance is Al;

[0084] The powder is prepared by the following method:

[0085] (1) When the temperature of the resistance furnace is raised to 420 ℃, the aluminum ingot is loaded into the resistance furnace;

[0086] (2) After the aluminum ingot is completely melted, the temperature is raised to 730 ℃, and then Al-5V intermediate alloy and Al-5B intermediate alloy are sequentially added, and the melt is kept for 10 min;

[0087] (3) After the temperature of the furnace is raised to 760 ℃, Al-2Sc and Al-5Zr intermediate alloys are sequentially added, and the melt is kept for 30 min;

[0088] (4) The magnesium ingot is quickly added to the melt below the liquid surface, and electromagnetic stirring is performed until the melt is homogenized;

[0089] (5) Argon gas and a refining agent (Pyrilox 6AB type powder) are introduced into the resistance furnace for refining, and the amount of the refining agent is 3 kg / ton, and the refining temperature is 740 ℃; after keeping still for 5 min, slagging treatment is performed, and the refined melt is obtained;

[0090] (6) The melt obtained in step (5) is subjected to low-pressure casting at 710 ℃, and an Al-Mg master ingot is obtained;

[0091] (7) The Al-Mg master ingot prepared in step (6) is added to the smelting chamber, and then the sample is subjected to gas atomization treatment, first the smelting chamber and the atomization chamber are subjected to vacuum treatment, and the vacuum degree reaches 5*10 -3 Pa, then high-purity argon gas is introduced into it as a protective gas, and the gas pressure is kept at 1.5 Pa, then the temperature of the smelting chamber is raised, and the alloy is melted by heating to 760 ℃, the alloy melt is broken into liquid drops by argon gas at a high pressure of 2.5 MPa through a nozzle, and the liquid drops form powder after solidification in a cooling liquid.

[0092] Example 7

[0093] The aluminum magnesium alloy powder has the following mass percentages of components: Mg 5.0%, Sc 0.8%, Zr 0.5%, B 0.05%, V 0.05%, Fe <0.1%, Si <0.05%, and the balance of Al;

[0094] The powder is prepared according to the following method:

[0095] (1) When the resistance furnace is heated to 420℃, an aluminum ingot is loaded into the resistance furnace;

[0096] (2) After the aluminum ingot is completely melted, the temperature is raised to 740℃, and Al-5V intermediate alloy and Al-5B intermediate alloy are sequentially added, and the melt is kept for 10 min;

[0097] (3) After the temperature of the furnace is raised to 760℃, Al-2Sc and Al-5Zr intermediate alloys are sequentially added, and the melt is kept for 30 min;

[0098] (4) The magnesium ingot is quickly added to the melt below the liquid surface, and electromagnetic stirring is performed until the melt is homogenized;

[0099] (5) Argon gas and a refining agent (Pyrilox 6AB type powder) are introduced into the resistance furnace for refining, and the amount is 3 kg / ton, and the refining temperature is 720℃; after keeping still for 5 min, slagging treatment is performed, and the refined melt is obtained;

[0100] (6) The melt obtained in step (5) is subjected to low-pressure casting at 710℃, and an Al-Mg master ingot is obtained;

[0101] (7) The Al-Mg master ingot prepared in step (6) is added to the melting chamber, and then the sample is subjected to gas atomization treatment. First, the melting chamber and the atomization chamber are subjected to vacuum treatment, so that the vacuum degree reaches 1*10 -2 Pa, then high-purity argon gas is introduced as a protective gas, and the gas pressure is kept at 1.5 Pa, then the temperature of the melting chamber is raised, and the alloy is melted. The alloy melt is passed through a nozzle, and under the action of argon gas at a high pressure of 4.0 MPa, the liquid stream is broken into droplets, and the droplets are solidified after passing through a cooling liquid to form a powder.

[0102] Comparative Example 1

[0103] The same as Example 1, except that the alloy powder does not contain scandium and zirconium elements, and the mass percentages of the components are: Mg 5.0%, B 0.1%, V 0.1%, Fe <0.1%, Si <0.05%, and the balance of Al.

[0104] Comparative Example 2

[0105] The same as example 5, except that the mass percentage of each component in the alloy powder is: Mg 5.0%, Sc 0.9%, Zr 0.3%, B 0.1%, V 0.1%, Fe <0.1%, Si <0.05%, and the balance is Al.

[0106] Comparative example 3

[0107] The same as example 5, except that the mass percentage of each component in the alloy powder is: Mg 5.0%, Sc 0.4%, Zr 0.7%, B 0.1%, V 0.1%, Fe <0.1%, Si <0.05%, and the balance is Al.

[0108] Comparative example 4

[0109] The same as example 5, except that the mass percentage of each component in the alloy powder is: Mg 5.0%, Sc 0.9%, Zr 0.7%, B 0.1%, V 0.1%, Fe <0.1%, Si <0.05%, and the balance is Al.

[0110] Comparative example 5

[0111] The same as example 5, except that the mass percentage of each component in the alloy powder is: Mg 5.0%, Sc 0.8%, Zr 0.5%, B 0.04%, V 0.12%, Fe <0.1%, Si <0.05%, and the balance is Al.

[0112] Comparative example 6

[0113] The same as example 4, except that the mass percentage of each component in the alloy powder is: Mg 5.0%, Sc 0.8%, Zr 0.5%, B 0.15%, V 0.12%, Fe <0.1%, Si <0.05%, and the balance is Al.

[0114] Comparative example 7

[0115] This comparative example uses a product of Airbus Company—

[0116] The alloy powders prepared in the above examples 1-7 and comparative examples 1-7 are printed into alloy parts by using a 3D printing process (SLM), and the printed alloy parts are subjected to a tensile test according to the standard GB / T 228.1-2010, and the results are shown in Table 1.

[0117] Table 1 Mechanical properties of alloy parts prepared by using the alloy powders described in examples 1-7 and comparative examples 1-7

[0118]

[0119]

[0120] From the data of the above table, it can be seen that the alloy parts made by the 3D printing process of the alloy powder described in the application have good performance, the tensile strength is greater than 521 MPa, the yield strength is greater than 481 MPa, which is better than that of the comparative examples 1-7, and the elongation is equivalent to that of the comparative example 7; although the comparative example 4 increases the amount of Sc and Zr, the tensile strength and yield strength are improved, but more Al3Zr phases are produced, the elongation of the alloy is reduced, and the production cost is increased.

[0121] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application belong to the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. An aluminum magnesium alloy powder for additive manufacturing, characterized by, 5.0-6.0% of Mg, 0.5-0.8% of Sc, 0.35-0.6% of Zr, 0.05-0.1% of B, 0.05-0.1% of V, <0.1% of Fe, <0.05% of Si, and the balance of Al; The preparation method of the aluminum-magnesium alloy powder comprises the following steps: (1) heating the resistance furnace and placing aluminum ingots into the resistance furnace; (2) after the aluminum ingots are completely melted, heating, sequentially adding aluminum-vanadium intermediate alloy and aluminum-boron intermediate alloy, and keeping the melt for 10 min; (3) continuously heating the resistance furnace, then sequentially adding aluminum-scandium intermediate alloy and aluminum-zirconium intermediate alloy, and keeping the melt for 30 min; (4) quickly adding magnesium ingots under the melt liquid surface, and performing electromagnetic stirring until the melt is homogenized; (5) introducing argon and a refining agent into the resistance furnace for refining, performing slagging treatment after keeping still for 5 min, and discharging the refined melt; (6) performing low-pressure casting on the melt obtained in step (5) to obtain Al-Mg mother ingots; (7) performing gas atomization treatment on the Al-Mg mother ingots obtained in step (6) to obtain the alloy powder.

2. The aluminum magnesium alloy powder for additive manufacturing according to claim 1, characterized by 5.0-5.5% of Mg, 0.6-0.8% of Sc, 0.4-0.5% of Zr, 0.05-0.1% of B, 0.05-0.1% of V, <0.1% of Fe, <0.05% of Si, and the balance of Al.

3. A method of producing the aluminum-magnesium alloy powder according to claim 1 or 2, characterized by, The preparation method comprises the following steps: (1) heating the resistance furnace and placing aluminum ingots into the resistance furnace; (2) after the aluminum ingots are completely melted, heating, sequentially adding aluminum-vanadium intermediate alloy and aluminum-boron intermediate alloy, and keeping the melt for 10 min; (3) continuously heating the resistance furnace, then sequentially adding aluminum-scandium intermediate alloy and aluminum-zirconium intermediate alloy, and keeping the melt for 30 min; (4) quickly adding magnesium ingots under the melt liquid surface, and performing electromagnetic stirring until the melt is homogenized; (5) introducing argon and a refining agent into the resistance furnace for refining, performing slagging treatment after keeping still for 5 min, and discharging the refined melt; (6) performing low-pressure casting on the melt obtained in step (5) to obtain Al-Mg mother ingots; (7) performing gas atomization treatment on the Al-Mg mother ingots obtained in step (6) to obtain the alloy powder.

4. The method of producing an aluminum magnesium alloy powder according to claim 3, characterized by, The temperature of the resistance furnace in step (1) is 420 ℃; and the temperature of the resistance furnace in step (2) is 720-740 ℃.

5. The method of producing an aluminum magnesium alloy powder according to claim 3, characterized by, The temperature of the resistance furnace in step (3) is 760 ℃.

6. The method of producing an aluminum magnesium alloy powder according to claim 3, characterized by, The temperature of the resistance furnace in step (4) is 720-740 ℃.

7. The method of producing an aluminum magnesium alloy powder according to claim 3, characterized by, The amount of the refining agent in step (5) is 2-4 kg / ton, and the refining temperature is 720-740 ℃.

8. The method of producing an aluminum magnesium alloy powder according to claim 3, characterized by, The temperature of the low-pressure casting in step (6) is 690-720 ℃.

9. The method of producing an aluminum magnesium alloy powder according to claim 3, characterized by, The gas atomization treatment in step (7) is specifically as follows: the Al-Mg master ingot prepared in step (6) is added into a smelting chamber, and then the sample is subjected to gas atomization treatment. First, the smelting chamber and an atomization chamber are subjected to vacuumizing treatment, so that the vacuum degree reaches 5×10 -3 ~1×10 -2 Pa, then high-purity argon gas is introduced into the chamber as a protective gas, and the gas pressure is kept at 1.0~1.5 Pa, then the temperature of the smelting chamber is raised, and the alloy is heated to 760~860 ℃ to be melted; the alloy melt is broken into droplets through a nozzle under the action of high pressure of 0.5~4.0 MPa, and the droplets are solidified after passing through a cooling liquid to form a powder.

10. Use of the alloy powder of claim 1 or 2 in additive manufacturing.

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