Erbium-containing high-strength aluminum alloy powder suitable for selective laser melting forming and technological method of erbium-containing high-strength aluminum alloy powder

Abstract

The invention discloses erbium-containing high-strength aluminum alloy powder suitable for selective laser melting forming and a technological method of the erbium-containing high-strength aluminum alloy powder, and belongs to the technical field of additive manufacturing. The erbium-containing high-strength aluminum alloy powder prepared through specific component design is used for additive manufacturing, and according to the unique layered structure and stress distribution characteristics of an SLM forming part, the erbium-containing high-strength aluminum alloy powder is prepared; the spraying mode of the quenching liquid and the formed temperature gradient are designed in a targeted mode, and the specific quenching liquid is combined, so that precise regulation and efficient release of the internal stress of the SLM forming part are achieved, the mechanical strength of an additive forming product is effectively improved, meanwhile, the heat treatment process period is greatly shortened, and the production cost is reduced; and a new path is opened up for wide application of the high-strength aluminum alloy in the selective laser melting forming technology.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of additive manufacturing technology. Specifically, it is a kind of high-strength aluminum alloy powder containing erbium suitable for selective laser melting forming and its process method. BACKGROUND

[0002] Selective laser melting technology (SLM) breaks through the conventional mode of transformation forming and removal forming in traditional manufacturing process. This technology uses laser as energy source and metal powder as raw material. By means of high-density laser energy beam, the specific area of powder bed is melted and processed, and the required parts are manufactured by means of layer-by-layer stacking. It is the most commonly used technical means in additive manufacturing.

[0003] Aluminum alloy is widely used in industrial field due to its high specific strength, excellent thermal conductivity and strong corrosion resistance. However, the traditional Al-Cu, Al-Mg, Al-Zn-Mg-Cu and other high-strength aluminum alloys have poor casting performance, wide solidification interval, and are prone to generate thermal stress in the printing process, thereby affecting the printing quality and mechanical properties of the formed parts, and are difficult to meet the needs of harsh service scenarios such as aerospace. Chinese patent CN105734470A discloses a heat treatment method of as-deposited aluminum alloy. This method needs to uniformly treat the aluminum alloy obtained after additive manufacturing at 500℃ for 20h, and then quench in water at room temperature. After quenching, it is aged for 14-28h and cooled to room temperature. Although this method can improve the organization and performance of additive formed aluminum alloy to some extent, it cannot fundamentally eliminate the thermal stress generated in the printing process for high-strength aluminum alloy formed by selective laser melting, and cannot effectively solve the quality problems such as stress defects and crack sensitivity caused by poor solidification characteristics of high-strength aluminum alloy in SLM forming, so as to realize the ideal mechanical strength. At the same time, the heat treatment process cycle is relatively long, which leads to the decrease of production efficiency and the increase of energy consumption cost.

[0004] Therefore, it is a key problem to be solved in this field to develop a new type of high-strength aluminum alloy material with good SLM forming adaptability and the ability to improve production efficiency and mechanical strength in subsequent heat treatment process. SUMMARY

[0005] To solve the above technical problems, the present application provides the following technical solutions:

[0006] Therefore, the present application provides a kind of high-strength aluminum alloy powder containing erbium suitable for selective laser melting forming and its process method. By optimizing the composition design of aluminum alloy and the heat treatment process, the internal stress and crack sensitivity of high-strength aluminum alloy in additive manufacturing are effectively reduced, the mechanical strength of additive formed product is effectively improved, and the heat treatment process cycle is shortened, and the production cost is reduced.

[0007] In order to achieve the above-mentioned purpose, the present application provides the technical scheme as follows:

[0008] The present application also provides a process method suitable for selective laser melting forming, which uses the above-mentioned high-strength aluminum alloy powder containing erbium suitable for selective laser melting forming for additive manufacturing, and comprises the following steps:

[0009] In the above-mentioned scheme, the added magnesium (Mg) and manganese (Mn) mainly play a solid solution strengthening effect, and the manganese (Mn) can form Al6Mn precipitated phase in the printing process to play a precipitated strengthening effect. When the content of scandium (Sc), erbium (Er) and zirconium (Zr) is in the above-mentioned proportion range, Al3(Sc, Er, Zr) primary phase can be formed, which can play a heterogeneous nucleation effect, thereby realizing the effects of refining grains and reducing the tendency of thermal cracking. When there is no zirconium (Zr) or the content of zirconium (Zr) is low, the primary phase will not be formed, thereby obtaining an aluminum alloy powder with high strength.

[0010] The present application also provides a process method suitable for selective laser melting forming, which uses the above-mentioned high-strength aluminum alloy powder containing erbium suitable for selective laser melting forming for additive manufacturing, and comprises the following steps:

[0011] S1. Layered printing the high-strength aluminum alloy powder containing erbium suitable for selective laser melting forming to obtain an aluminum alloy preliminary product;

[0012] S2. Solid solution treatment of the aluminum alloy preliminary product at a solid solution temperature of 480-520 DEG C for 8-12 h to obtain a solid solution alloy piece;

[0013] S3. Quenching treatment of the solid solution alloy piece, in which a temperature gradient is formed between the top and bottom of the solid solution alloy piece in the quenching liquid, and the temperature of the top of the solid solution alloy piece is higher than that of the bottom, and then aging treatment is performed after the quenching is completed, the aging treatment temperature is 140-160 DEG C, the time is 4-8 h, and the aluminum alloy finished product is obtained after cooling to room temperature.

[0014] The aluminum alloy preliminary product is printed layer by layer from the bottom to the top in the forming process. The internal stress of the aluminum alloy workpiece obtained in this way is different at different heights, the internal stress of the bottom is large, the internal stress of the top is small, and a stress gradient is formed from bottom to top. In the above scheme, although the solid solution treatment eliminates part of the internal stress, due to the short solid solution time, there is still a certain stress and stress gradient in the solid solution alloy part. In the quenching process, the temperature of the quenching liquid at the top of the aluminum alloy workpiece is lower than that at the bottom, a temperature gradient is formed between the upper and lower parts of the aluminum alloy workpiece, which is adapted to the stress gradient after the solid solution treatment, the internal stress of different parts of the workpiece is balanced and adjusted, the generation of local stress defects is avoided, and the precipitation of erbium elements in the cooling process is inhibited. The solid solution time is shortened, and the mechanical strength of the aluminum alloy material is improved.

[0015] Further, in step S3, the solid solution alloy part is quenched by spraying the quenching liquid.

[0016] In the above scheme, by spraying the quenching liquid, the solid solution alloy part can be quenched as a whole, and the constant temperature gradient can be used to continuously cool the solid solution alloy part, ensuring the stability in the quenching process, thereby ensuring the continuous enhancement of the mechanical properties, and providing favorable conditions for the uniform precipitation of Al3Er and other nano phases in a small and dispersed manner in the subsequent aging process.

[0017] Further, in the operation process of spraying the quenching liquid, the bottom of the solid solution alloy part (i.e. the part printed earliest in the aluminum alloy preliminary product) is placed upward, and the spraying of the quenching liquid is performed at the bottom position of the solid solution alloy part, so that the quenching liquid flows from the bottom to the top (i.e. the part printed latest in the aluminum alloy preliminary product) of the solid solution alloy part under the action of gravity, realizing the overall quenching of the solid solution alloy part.

[0018] In the above scheme, the quenching liquid is sprayed from the bottom to the top of the solid solution alloy part for overall quenching, which can promote the quenching liquid to build a uniformly distributed temperature gradient at different heights of the workpiece to adapt to the stress gradient after the solid solution treatment, and then achieve uniform elimination of internal stress at different heights, effectively avoid the generation of cracks and crack tendency, and improve the mechanical strength of the aluminum alloy material.

[0019] Further, the quenching liquid is an aqueous solution of polyalkylene glycol, sodium chloride, polyethylene glycol and a gas generating agent.

[0020] In the above scheme, the polyalkylene glycol and the polyethylene glycol realize high coalescing ability and film forming performance through the reverse solution film forming mechanism, can improve the flowability of the quenching liquid, and after film forming, the aluminum alloy material surface is protected as a whole, the phenomenon of being eroded by oxygen, moisture and the like is reduced, and the quenching uniformity and mechanical properties of the aluminum alloy material are improved; the sodium chloride as a cooling accelerator can improve the hardenability of the quenching liquid; the gas generated by the gas generating agent has a stripping effect, prevents the quenching material and the film forming material from excessive accumulation at the spraying position, and can promote the liquid phase flow and uniform dispersion of the quenching liquid, prevent the occurrence of quenching dead angles, and promote the formation of uniformly distributed Al3Er and other strengthening phases in the subsequent aging treatment, thereby effectively improving the mechanical strength of the aluminum alloy material.

[0021] Further, the quenching liquid comprises the following substances in percentage by mass: 18-22% polyalkylene glycol, 0.8-1.2% sodium chloride, 3-5% polyethylene glycol, 0.4-0.6% gas generating agent, and the balance water.

[0022] In the above scheme, the specific content of each component is limited, which can make full use of the advantages of each component, overcome the shortcomings of a single medium, make the components synergize, obtain a quenching liquid with good flowability and uniform cooling property, and further improve the quenching effect.

[0023] Further, the gas generating agent is one or a mixture of both of sodium bicarbonate and potassium bicarbonate.

[0024] In the above scheme, the gas generating agent is sodium bicarbonate and potassium bicarbonate, and the carbonates generated after gas generation can adjust the cooling speed of the quenching liquid and improve the quenching effect, and at the same time, since the gas generating agent and its product (carbonate) are alkaline, the alkaline system formed can improve the compatibility and chemical stability of the polyethylene glycol, and further improve the quenching uniformity and mechanical properties of the aluminum alloy material.

[0025] Further, the temperature of the quenching liquid is 15-40℃.

[0026] In the above scheme, the temperature of the quenching liquid is controlled to be 15-40℃, which can not only ensure that the alloy grains are uniformly distributed and quenched completely, and the organizational stress is effectively released, but also can avoid the risk of inconsistent internal and external cooling and uneven internal organizational morphology, and ensure that the aluminum alloy material achieves the goal of rapid quenching. At the same time, this quenching temperature can ensure that the gas generating agent generates a large amount of gas in the instant of contacting with the workpiece, realizes rapid stripping, prevents the accumulation and aggregation of the quenching material and the film forming material at the spraying position, and further improves the quenching effect.

[0027] Further, the erbium-containing high-strength aluminum alloy powder suitable for selective laser melting is prepared by the following steps: taking pure aluminum, pure magnesium, pure manganese, Al-10Sc, Al-10Er, Al-5Zr and Al-Si as raw materials, feeding according to the element components, melting into an alloy liquid, obtaining an aluminum alloy powder through vacuum gas atomization treatment, sieving, and drying to obtain the erbium-containing high-strength aluminum alloy powder suitable for selective laser melting.

[0028] In the above scheme, the raw materials are fully melted in a melting furnace, and the core purpose is to achieve high homogenization of alloy elements; in the gas atomization process, the liquid droplets are cooled at a high speed to form microcrystalline or even amorphous structures, which can inhibit the segregation of alloy elements, so that Sc, Er, Zr and other elements are dissolved in the aluminum matrix in a supersaturated form or form extremely fine dispersed phases, thereby creating favorable conditions for the precipitation of strengthening phases in subsequent SLM forming and heat treatment.

[0029] Further, the particle size of the erbium-containing high-strength aluminum alloy powder suitable for selective laser melting is 3-80 μm.

[0030] In the above scheme, the powder with a particle size of 3-80 μm has moderate cohesion and good flowability, can form a uniform and dense powder layer, and achieves the best balance between flowability and bulk density, which is the premise of stabilizing the molten pool and reducing defects, and provides reliable raw material guarantee for finally obtaining aluminum alloy components with high strength, high density and stable performance.

[0031] The technical scheme of the present application has the following beneficial technical effects:

[0032] 1. The present application effectively reduces the internal stress and crack sensitivity of the erbium-containing high-strength aluminum alloy in additive manufacturing by designing the composition of the aluminum alloy and optimizing the heat treatment process, effectively improves the mechanical strength of the additive forming product, shortens the heat treatment process cycle, and reduces the production cost, thereby opening up a new path for the wide application of high-strength aluminum alloy in selective laser melting technology.

[0033] 2. Through the synergistic effect of the rare earth element erbium (Er) and the elements such as scandium (Sc) and zirconium (Zr) and its influence on formability and subsequent strengthening effect, not only the alloy grain is refined, but also the Al3(Sc, Er, Zr) primary phase and the subsequent aging precipitated Al3Er nano-strengthening phase are formed, which fundamentally improves the solidification characteristics of the aluminum alloy, reduces the tendency of hot cracking, and in the subsequent optimized heat treatment process, the Er element in the supersaturated solid solution is uniformly dispersed and precipitated in the form of Al3Er nano-phase, which significantly improves the mechanical strength of the alloy.

[0034] 3. According to the unique layered structure and stress distribution characteristics of the SLM formed part, the quenching liquid spraying mode and temperature gradient are innovatively designed in the heat treatment process, combined with the quenching liquid with a specific formula, to realize the accurate regulation and efficient release of the internal stress of the additive formed part, avoid the generation of defects such as cracks, further optimize the precipitation behavior of the strengthening phase, significantly improve the mechanical strength of the aluminum alloy material, and greatly shorten the long period required by the traditional heat treatment, effectively reduce the production energy consumption and cost on the basis of improving the mechanical strength. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 A scanning electron microscope (SEM) picture of the erbium-containing high-strength aluminum alloy powder prepared for example 1 of the present application and suitable for selective laser melting forming;

[0036] Figure 2 A scanning electron microscope (SEM) picture of the apparent organizational morphology of the aluminum alloy finished product prepared for example 1 of the present application. DETAILED DESCRIPTION

[0037] Example 1

[0038] An erbium-containing high-strength aluminum alloy powder suitable for selective laser melting forming, comprising the following components in terms of mass percentage: 4.1% Mg, 0.52% Mn, 0.68% Er, 0.26% Sc, 0.48% Zr, 0.18% Si, and the balance being Al; pure aluminum, pure magnesium, pure manganese, Al-10Sc, Al-10Er, Al-5Zr and Al-Si are used as raw materials, the elements are fed according to the element components, the alloy liquid is melted, the aluminum alloy powder is obtained by vacuum gas atomization treatment, sieved and dried in a vacuum environment to obtain the erbium-containing high-strength aluminum alloy powder suitable for selective laser melting forming.

[0039] The above-mentioned erbium-containing high-strength aluminum alloy powder is used for selective laser melting forming for additive manufacturing, comprising the following steps:

[0040] S1. Pour the erbium-containing high-strength aluminum alloy powder into the powder supply chamber of the 3D printing equipment, flush in inert gas to reduce the oxygen content to below 0.1%, import the three-dimensional digital model of the designed printed part, perform slicing processing, set the process parameters: laser power is 300W, scanning speed is 1000mm / s, scanning layer thickness is 0.03mm, scanning spacing is 0.10mm, then perform layer-by-layer printing, after printing, obtain the aluminum alloy preliminary product;

[0041] S2. Solid solution treatment of the aluminum alloy preliminary product, solid solution temperature is 500℃, treatment time is 10h, to obtain the solid solution alloy part;

[0042] S3. Adopting the way of spraying quenching liquid, quenching the solid solution alloy piece, during the quenching process, placing the bottom of the solid solution alloy piece (i.e. the earliest printed part in the aluminum alloy preliminary product) upward, spraying the quenching liquid at the bottom position of the solid solution alloy piece, making the quenching liquid flow from the bottom to the top (i.e. the latest printed part in the aluminum alloy preliminary product) of the solid solution alloy piece under the action of gravity, realizing the overall quenching of the solid solution alloy piece, when the temperature of the solid solution alloy piece drops below 80℃, aging treatment is carried out, the aging treatment temperature is 150℃, the time is 6h, and the aluminum alloy finished product is obtained after cooling to room temperature;

[0043] In step S3, the temperature of the quenching liquid is 30℃, and the quenching liquid includes the following substances in mass percentage: 20% polyalkylene glycol, 1.0% sodium chloride, 4% polyethylene glycol, 0.5% sodium bicarbonate, and the balance is water.

[0044] Example 2

[0045] An erbium-containing high-strength aluminum alloy powder suitable for selective laser melting forming, comprising the following components in mass percentage: 3.41% Mg, 0.58% Mn, 0.62% Er, 0.2% Sc, 0.4% Zr, 0.05% Si, and the balance is Al; pure aluminum, pure magnesium, pure manganese, Al-10Sc, Al-10Er, Al-5Zr and Al-Si are used as raw materials, the elements are fed according to the component, the alloy liquid is melted, the aluminum alloy powder is obtained by vacuum gas atomization treatment, sieved and dried in a vacuum environment to obtain the erbium-containing high-strength aluminum alloy powder suitable for selective laser melting forming.

[0046] The above-mentioned erbium-containing high-strength aluminum alloy powder is used for selective laser melting forming and additive manufacturing, including the following steps:

[0047] S1. Layered printing the erbium-containing high-strength aluminum alloy powder to obtain an aluminum alloy preliminary product;

[0048] S2. Solid solution treatment of the aluminum alloy preliminary product at a solid solution temperature of 480℃ for 12h to obtain a solid solution alloy piece;

[0049] S3. Adopting the way of spraying quenching liquid, quenching the solid solution alloy piece, during the quenching process, placing the bottom of the solid solution alloy piece (i.e. the earliest printed part in the aluminum alloy preliminary product) upward, spraying the quenching liquid at the bottom position of the solid solution alloy piece, making the quenching liquid flow from the bottom to the top (i.e. the latest printed part in the aluminum alloy preliminary product) of the solid solution alloy piece under the action of gravity, realizing the overall quenching of the solid solution alloy piece, when the temperature of the solid solution alloy piece drops below 80℃, aging treatment is carried out, the aging treatment temperature is 140℃, the time is 8h, and the aluminum alloy finished product is obtained after cooling to room temperature;

[0050] The temperature of the quenching liquid in step S3 is 15℃, and the quenching liquid comprises the following substances in percentage by mass: 18% polyalkylene glycol, 0.8% sodium chloride, 3% polyethylene glycol, 0.4% sodium bicarbonate, and the balance water.

[0051] Example 3

[0052] An erbium-containing high-strength aluminum alloy powder suitable for selective laser melting forming, comprising the following components in percentage by mass: 4.58% Mg, 0.43% Mn, 0.79% Er, 0.3% Sc, 0.59% Zr, 0.3% Si, and the balance Al; pure aluminum, pure magnesium, pure manganese, Al-10Sc, Al-10Er, Al-5Zr, and Al-Si are used as raw materials, the elements are fed according to the component, the alloy liquid is melted, the aluminum alloy powder is obtained by vacuum gas atomization treatment, is sieved, and is dried in a vacuum environment to obtain the erbium-containing high-strength aluminum alloy powder suitable for selective laser melting forming.

[0053] The above erbium-containing high-strength aluminum alloy powder is used for selective laser melting forming and additive manufacturing, comprising the following steps:

[0054] S1. Layered printing the erbium-containing high-strength aluminum alloy powder to obtain an aluminum alloy preliminary product;

[0055] S2. Solid solution treatment of the aluminum alloy preliminary product at a solid solution temperature of 520℃ for 8h to obtain a solid solution alloy piece;

[0056] S3. Quenching treatment of the solid solution alloy piece by spraying a quenching liquid, wherein the bottom of the solid solution alloy piece (i.e. the earliest printed part of the aluminum alloy preliminary product) is placed upward, the quenching liquid is sprayed at the bottom of the solid solution alloy piece, and the quenching liquid flows from the bottom to the top of the solid solution alloy piece (i.e. the latest printed part of the aluminum alloy preliminary product) under the action of gravity to realize the overall quenching of the solid solution alloy piece, and when the temperature of the solid solution alloy piece is reduced to below 80℃, aging treatment is performed at a temperature of 160℃ for 4h, and then cooled to room temperature to obtain an aluminum alloy finished product;

[0057] The temperature of the quenching liquid in step S3 is 40℃, and the quenching liquid comprises the following substances in percentage by mass: 22% polyalkylene glycol, 1.2% sodium chloride, 5% polyethylene glycol, 0.6% sodium bicarbonate, and the balance water.

[0058] Example 4

[0059] The difference between the present comparative example and Example 1 is that the quenching liquid in step S3 is water.

[0060] Example 5

[0061] The difference between the present embodiment and embodiment 1 is that no sodium bicarbonate is added in the quenching liquid, specifically, the quenching liquid comprises the following substances in percentage by mass: 20% polyalkylene glycol, 1.0% sodium chloride, 4% polyethylene glycol, and the balance water.

[0062] Embodiment 6

[0063] The difference between the present embodiment and embodiment 1 is that no polyethylene glycol is added in the quenching liquid, specifically, the quenching liquid comprises the following substances in percentage by mass: 20% polyalkylene glycol, 1.0% sodium chloride, 0.5% sodium bicarbonate, and the balance water.

[0064] Embodiment 7

[0065] The difference between the present embodiment and embodiment 1 is that neither sodium bicarbonate nor sodium bicarbonate is added in the quenching liquid, specifically, the quenching liquid comprises the following substances in percentage by mass: 20% polyalkylene glycol, 1.0% sodium chloride, and the balance water.

[0066] Comparative Example 1

[0067] In the present comparative example, no erbium is added in the element composition of the erbium-containing high-strength aluminum alloy powder suitable for selective laser melting forming, specifically as follows:

[0068] An erbium-containing high-strength aluminum alloy powder suitable for selective laser melting forming comprises the following components in percentage by mass: 4.0% Mg, 0.54% Mn, 0.27% Sc, 0.51% Zr, 0.15% Si, and the balance Al.

[0069] The rest of the process and parameter control are completely consistent with embodiment 1.

[0070] Comparative Example 2

[0071] The difference between the present comparative example and embodiment 1 is that in step S3, the spray quenching is changed to immersion quenching, that is, the solid solution alloy part is directly immersed in the quenching liquid, specifically as follows:

[0072] S3. The solid solution alloy part is directly immersed in the quenching liquid, and when the temperature of the solid solution alloy part is reduced to below 80℃, aging treatment is performed, the aging treatment temperature is 150℃, the time is 6h, and the temperature is cooled to room temperature to obtain the aluminum alloy finished product;

[0073] The temperature of the quenching liquid in step S3 is 30℃, and the quenching liquid comprises the following substances in percentage by mass: 20% polyalkylene glycol, 1.0% sodium chloride, 4% polyethylene glycol, 0.5% sodium bicarbonate, and the balance water.

[0074] Comparative Example 3

[0075] The difference between the present comparative example and Example 1 is only that in step S3, the top of the solution-treated alloy piece (i.e. the part printed last in the aluminum alloy preliminary product) is placed upward, and the spraying operation of the quenching liquid is performed at the top position, specifically as follows:

[0076] S3. The solution-treated alloy piece is quenched by spraying the quenching liquid, and during the quenching process, the top of the solution-treated alloy piece (i.e. the part printed last in the aluminum alloy preliminary product) is placed upward, and the spraying operation of the quenching liquid is performed at the top position of the solution-treated alloy piece, so that the quenching liquid flows from the top to the bottom (i.e. the part printed first in the aluminum alloy preliminary product) of the solution-treated alloy piece under the action of gravity, thereby realizing the overall quenching of the solution-treated alloy piece. When the temperature of the solution-treated alloy piece drops to below 80℃, the aging treatment is performed, the aging treatment temperature is 150℃, and the aging treatment time is 6h. After cooling to room temperature, the aluminum alloy finished product is obtained.

[0077] Performance characterization and testing

[0078] The appearance morphology of the erbium-containing high-strength aluminum alloy powder suitable for selective laser melting forming obtained in Example 1 and the aluminum alloy finished product was observed, and the scanning electron microscope (SEM) is shown in FIGS. 1 and 2. Figure 1 and Figure 2 The aluminum alloy finished products obtained in Examples 1-7 and Comparative Examples 1-3 were made into samples, and the tensile strength was detected, and the specific test results are shown in Table 1.

[0079] Table 1

[0080]

[0081] Result analysis

[0082] As can be seen from Examples 1-7 and Comparative Examples 1-3 and in combination with the data in Table 1, the tensile strength of the aluminum alloy finished product (Examples 1-7) prepared by the present application is 424-483MPa, which has a relatively high mechanical strength.

[0083] Obviously, the above examples are only examples for clearly illustrating, and do not limit the embodiments. For those skilled in the art, other different forms of changes or variations can be made on the basis of the above description. Here, it is not necessary and impossible to exhaust all the embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the claims of the present patent application.

Claims

1. An erbium-containing high-strength aluminum alloy powder suitable for selective laser melting forming, characterized in that, The alloy comprises the following components by mass percentage: 3.4-4.6% Mg, 0.4-0.6% Mn, 0.6-0.8% Er, 0.2-0.3% Sc, 0.4-0.6% Zr, 0.05-0.3% Si, with the balance being Al. The alloy is fed according to the alloy composition to prepare erbium-containing high-strength aluminum alloy powder suitable for selective laser melting forming.

2. A process method suitable for selective laser melting forming, characterized in that, Using the erbium-containing high-strength aluminum alloy powder of claim 1, suitable for selective laser melting forming, for additive manufacturing, includes the following steps: S1. Erbium-containing high-strength aluminum alloy powder suitable for selective laser melting forming is used for layer printing to obtain a preliminary aluminum alloy product; S2. Solution treatment of the aluminum alloy raw product at a temperature of 480-520℃ for 8-12 hours to obtain solution alloy parts; S3. Quenching the solid solution alloy parts. During the quenching process, a temperature gradient is formed between the top and bottom of the solid solution alloy parts by the quenching liquid. At the same time, the temperature of the quenching liquid at the top of the solid solution alloy parts is higher than that at the bottom. After quenching, aging treatment is performed at a temperature of 140-160℃ for 4-8 hours. After cooling to room temperature, the finished aluminum alloy parts are obtained.

3. The process method for selective laser melting forming according to claim 2, characterized in that, In step S3, the solid solution alloy parts are quenched by spraying quenching liquid.

4. The process method for selective laser melting forming according to claim 3, characterized in that, During the spraying of quenching fluid, the bottom of the solution-treated alloy part is placed upwards, and the quenching fluid is sprayed at the bottom of the solution-treated alloy part. Under the action of gravity, the quenching fluid flows from the bottom to the top of the solution-treated alloy part, thereby achieving overall quenching of the solution-treated alloy part.

5. A process method for selective laser melting forming according to claim 2, characterized in that, The quenching fluid is an aqueous solution of polyalkylene glycol, sodium chloride, polyethylene glycol, and a gas-generating agent.

6. The process method for selective laser melting forming according to claim 2, characterized in that, The quenching fluid comprises the following substances by mass percentage: 18-22% polyalkylene glycol, 0.8-1.2% sodium chloride, 3-5% polyethylene glycol, 0.4-0.6% gas-generating agent, and the balance water.

7. A process method for selective laser melting forming according to claim 6, characterized in that, The gas-generating agent is one or a mixture of sodium bicarbonate and potassium bicarbonate.

8. A process method for selective laser melting forming according to claim 7, characterized in that, The temperature of the quenching fluid is 15-40℃.

9. A process method for selective laser melting forming according to claim 2, characterized in that, Erbium-containing high-strength aluminum alloy powder suitable for selective laser melting is prepared by the following steps: using pure aluminum, pure magnesium, pure manganese, Al-10Sc, Al-10Er, Al-5Zr and Al-Si as raw materials, the raw materials are fed according to the elemental composition, melted into an alloy liquid, and then subjected to vacuum atomization treatment to obtain aluminum alloy powder. The powder is then sieved and dried to obtain erbium-containing high-strength aluminum alloy powder suitable for selective laser melting.

10. A process method for selective laser melting forming according to claim 2, characterized in that, The particle size range of erbium-containing high-strength aluminum alloy powder suitable for selective laser melting forming is 3-80μm.

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