Method for printing Zn-Mg alloy through binder and Zn-Mg alloy

Abstract

The invention discloses a method for printing a Zn-Mg alloy through a binder and the Zn-Mg alloy, and relates to the technical field of zinc alloys. The zinc-magnesium alloy is prepared through the binder jet 3D printing technology (BJAM), uniform powder bonding can be achieved by regulating and controlling the composition of a binder, and the high density of a printed piece is ensured; the microhardness of the alloy can be improved through the processes of printing-thermocuring and degreasing sintering. According to the method provided by the invention, the zinc alloy part with a complex shape can be produced, and the cost can be obviously reduced and the production efficiency can be obviously improved while the performance is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of zinc alloys, and in particular, to a method for printing Zn-Mg alloys with a binder and Zn-Mg alloys. Background Art

[0002] In the field of medical metallic materials, Zn-Mg alloys have received extensive attention due to their good degradability and show great potential in implants. Traditional bone implants are generally made of titanium alloys and need to be removed by a second operation after bone healing. However, Zn-Mg alloy implants will gradually degrade in the human body over time and will not cause harm to the human body, having good application prospects. However, orthopedic implants also require good biocorrosion properties and physical properties, and how to prepare high-performance Zn-Mg alloys has become a difficult problem.

[0003] Currently, in the preparation of high-performance zinc alloys, density and microhardness are the key indicators for evaluating their performance. Traditional methods for preparing zinc alloys mainly rely on casting and powder metallurgy techniques. However, these methods have certain limitations in improving density and microhardness. For example, pores and defects may be introduced during the casting process, resulting in a decrease in the density of the material. While powder metallurgy can improve the density of the material, during the sintering process, due to high temperature and long-term heat treatment, the microhardness of the material may be affected. In recent years, with the development of 3D printing technology, a new approach has been provided for the preparation of Zn-Mg alloys. Such as selective laser melting technology (SLM), which has made some progress in improving the density and microhardness of zinc alloys, but there are still some challenges. For example, thermal stress and deformation problems may occur during the SLM printing process, affecting the final performance of the material. In addition, the cost of vacuum sintering equipment is relatively high, limiting its application in large-scale production.

[0004] Currently, the preparation of Zn-Mg alloys mainly relies on traditional melting and casting techniques and selective laser printing, and the research on 3D printing of magnesium-based composites mainly focuses on selective laser melting technology. Traditional melting and casting techniques and selective laser printing technology have many limitations in practical applications:

[0005] (1) A large amount of waste gas is generated during the melting process. These waste gases not only cause serious environmental pollution but also may pose a hazard to human health, increasing the environmental and health risks during the production process.

[0006] (2) The processing procedures of the melting and casting technology are cumbersome. The entire process involves dozens of procedures, with complex operations and long time consumption, and the obtained alloy has a low density.

[0007] (3) Since the shape of human implants varies among individuals, traditional casting techniques are difficult to meet personalized needs. Although selective laser melting technology has certain advantages over traditional methods, the metal or plastic powder materials required are relatively expensive and the selection is relatively limited, further increasing the production cost.

[0008] (4) The point-by-point melting method of laser printing results in a slow printing speed. Especially when dealing with complex structures or large-sized components, the printing time is long, the efficiency is low, and it is difficult to obtain high-performance Zn-Mg alloy materials with a high relative density.

[0009] (5) Components after laser printing usually require complex post-processing steps such as heat treatment and removal of support structures, increasing the time and labor costs. During the printing process, defects such as splashing, balling, and porosity may also occur, affecting the microhardness of the material and reducing the relative density of the material.

[0010] Therefore, there is an urgent need to improve the preparation process of zinc alloys to reduce the process cost while preparing Zn-Mg alloys with high density and microhardness.

[0011] In view of this, the present invention is specifically proposed. Summary of the Invention

[0012] The purpose of the present invention is to provide a method for printing Zn-Mg alloys with a binder and Zn-Mg alloys, aiming to reduce the process cost while preparing Zn-Mg alloys with high density and microhardness.

[0013] The present invention is implemented as follows:

[0014] In the first aspect, the present invention provides a method for printing Zn-Mg alloys with a binder, including:

[0015] Spreading Zn-Mg mixed powder on a substrate and starting 3D printing. During the printing process, after laying a layer of Zn-Mg mixed powder, a binder is sprayed, and the process of spraying Zn-Mg mixed powder and spraying the binder is cycled;

[0016] After printing is completed, heat curing and debinding sintering are carried out;

[0017] Among them, the binder is a water-based binder. By mass percentage, the water-based binder contains 2%-20% of acetylene diol and 2%-20% of 2-butoxyethanol.

[0018] In an optional embodiment, by mass percentage, the water-based binder contains 2%-5% of acetylene diol and 13%-18% of 2-butoxyethanol.

[0019] In an optional embodiment, the temperature of heat curing is 100°C - 200°C, and the heat curing time is 3h - 6h;

[0020] Preferably, the temperature of thermal curing is 150°C - 200°C, and the thermal curing time is 3h - 5h.

[0021] In an alternative embodiment, the process of debinding and sintering includes: first, holding at 365°C - 375°C for 20min - 30min, then holding at 388°C - 393°C for 20min - 30min, and finally holding at 395°C - 405°C for 20min - 30min;

[0022] and / or, the heating rate of debinding and sintering is 3°C / min - 8°C / min;

[0023] and / or, debinding and sintering is carried out under vacuum conditions, and the vacuum degree is controlled to be (0.5 - 2.0)×10 -3 Pa.

[0024] In an alternative embodiment, during the printing process, the thickness of each powder spreading is controlled to be 0.04mm - 0.08mm, and the binder saturation is controlled to be 60% - 90% after each injection of the binder.

[0025] In an alternative embodiment, during the printing process, the running speed of the powder spreading roller is controlled to be 25mm / s - 60mm / s, the roller rotation speed is 30rpm - 100rpm, and the powder bed temperature is 20°C - 30°C.

[0026] In an alternative embodiment, before printing, three-dimensional modeling of the product is completed according to the product drawing, and the model is imported into the printing device to complete the identification and slicing work.

[0027] In an alternative embodiment, the preparation process of the Zn - Mg mixed powder includes: under an inert atmosphere, zinc powder and magnesium powder are mixed by ball milling, and then sieved and vacuum dried.

[0028] In an alternative embodiment, the ball milling time is 6h - 10h, and the mesh aperture of the sieve is 300 mesh - 400 mesh;

[0029] and / or, the vacuum drying temperature is 70°C - 90°C, and the drying time is 3h - 5h.

[0030] In a second aspect, the present invention provides a Zn - Mg alloy prepared by the method according to any one of the foregoing embodiments.

[0031] The present invention has the following beneficial effects: The zinc-magnesium alloy is prepared by binder jet additive manufacturing (BJAM). By regulating the composition of the binder, uniform powder bonding can be achieved, ensuring a high density of the printed parts. Through the processes of printing-thermal curing and debinding sintering, the microhardness of the alloy can be improved. The method provided by the present invention can not only produce zinc alloy parts with complex shapes, but also significantly reduce costs and improve production efficiency while ensuring performance. Description of the Drawings

[0032] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0033] Figure 1 Scanning electron microscope image of the Zn-10Mg alloy prepared in Example 2;

[0034] Figure 2 Scanning electron microscope image of the Zn-10Mg alloy prepared in Example 4;

[0035] Figure 3 Scanning electron microscope image of the Zn-10Mg alloy prepared in Example 8;

[0036] Figure 4 Scanning electron microscope image of the Zn-10Mg alloy prepared in Example 11;

[0037] Figure 5 Scanning electron microscope image of the Zn-10Mg alloy prepared in Comparative Example 1;

[0038] Figure 6 Scanning electron microscope image of the Zn-10Mg alloy prepared in Comparative Example 3. Detailed Embodiments

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. For those conditions not specified in the embodiments, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. For the reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchases.

[0040] The embodiments of the present invention provide a method for printing Zn-Mg alloy with a binder, including:

[0041] S1. Prepare the Zn-Mg mixed powder

[0042] The Zn-Mg mixed powder is prepared by mixing zinc powder and magnesium powder. The zinc powder and magnesium powder can be commercially available materials. For example, near-spherical zinc powder and magnesium powder produced by gas atomization can be purchased. The powder particle size of the zinc powder and magnesium powder is 5 μm - 20 μm, and the purity is 99.4%.

[0043] In some embodiments, the preparation process of the Zn-Mg mixed powder includes: under an inert atmosphere, the zinc powder and magnesium powder are mixed by ball milling, and then sieved and vacuum dried. By means of ball milling, the zinc powder and magnesium powder are uniformly mixed. The materials with too large particles are removed by sieving, and then water is removed by vacuum drying to ensure the fluidity of the 3D printed Zn-Mg mixed powder. Specifically, the type of inert atmosphere is not limited, such as nitrogen, argon, etc.

[0044] Furthermore, the ball milling time can be 6 h - 10 h, such as 6 h, 7 h, 8 h, 9 h, 10 h, etc.; the mesh aperture of the sieve is 300 mesh - 400 mesh, such as 300 mesh, 350 mesh, 400 mesh, etc. The vacuum drying temperature is 70 °C - 90 °C, such as 70 °C, 80 °C, 90 °C, etc.; the drying time is 3 h - 5 h, such as 3 h, 4 h, 5 h, etc.

[0045] S2. 3D printing

[0046] The Zn-Mg mixed powder is spread on the substrate, and 3D printing is started. During the printing process, after laying a layer of Zn-Mg mixed powder, the binder is sprayed, and the process of spraying the Zn-Mg mixed powder and spraying the binder is cycled, so that the binder is evenly loaded on the powder layer. The number of cycles is not limited until the size meets the requirements of the target product.

[0047] Furthermore, the binder is a water-based binder. By mass percentage, the water-based binder contains 2% - 20% of acetylene diol and 2% - 20% of 2-butoxyethanol. Preferably, by mass percentage, the water-based binder contains 2% - 5% of acetylene diol and 13% - 18% of 2-butoxyethanol. The inventors creatively select acetylene diol and 2-butoxyethanol as the effective components of the binder, and through the dual action mechanism of synergistically regulating the surface tension and the evaporation rate, the density of the printed parts can be significantly improved.

[0048] Specifically, most of the binder is water. The mass fraction of acetylene diol can be 2%, 3%, 4%, 5%, 8%, 10%, 13%, 15%, 18%, 20%, etc.; the mass fraction of 2-butoxyethanol can be 2%, 5%, 8%, 10%, 13%, 15%, 18%, 20%, etc.

[0049] The working principle of 3D printing refers to the prior art. Before printing, three-dimensional modeling of the product is completed according to the product drawing, the model is imported into the printing device, identification and slicing are completed, printing parameters are set, and printing starts. The entire printing process can be carried out in an argon atmosphere.

[0050] In some embodiments, during the printing process, the thickness of each powder spreading is controlled to be 0.04 mm - 0.08 mm, such as 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, etc.; after each injection of the binder, the binder saturation is controlled to be 60% - 90%, such as 60%, 70%, 80%, 90%, etc. The binder saturation refers to the mass ratio of the injected binder in the total mass of this layer. Since most of the binder is water, it will be removed in the subsequent treatment, and only the effective components of the binder are retained. It is appropriate that the dosage of the binder is within the above range to further improve the density of the printed part.

[0051] Furthermore, during the printing process, the running speed of the powder spreading roller is controlled to be 25 mm / s - 60 mm / s, such as 25 mm / s, 30 mm / s, 40 mm / s, 50 mm / s, 60 mm / s, etc.; the roller rotation speed is 30 rpm - 100 rpm, such as 30 rpm, 40 rpm, 50 rpm, 60 rpm, 70 rpm, 75 rpm, 80 rpm, 90 rpm, 100 rpm, etc.; the powder bed temperature is 20°C - 30°C, such as 20°C, 25°C, 30°C, etc. By optimizing printing parameters such as the powder spreading layer thickness, binder saturation, roller speed and rotation speed, the stability of the printing process and the uniformity of the product are ensured; the control of the powder bed temperature can avoid the oxidation and caking of the powder during the printing process.

[0052] S3. Thermal curing

[0053] After printing is completed, thermal curing is carried out to dry the binder.

[0054] In some embodiments, the temperature of thermal curing is 100°C - 200°C, such as 100°C, 120°C, 150°C, 180°C, 200°C, etc., preferably 150°C - 200°C; the thermal curing time is 3 h - 6 h, such as 3 h, 4 h, 5 h, 6 h, etc., preferably 3 h - 5 h.

[0055] S4. Debinding and sintering

[0056] The cured product is subjected to debinding and sintering, and the Zn-Mg mixed powder is melted to form an alloy state through debinding and sintering.

[0057] In some embodiments, the process of degreasing and sintering includes: first, heat preservation is carried out at 365°C - 375°C for 20 min - 30 min, then heat preservation is carried out at 388°C - 393°C for 20 min - 30 min, and finally heat preservation is carried out at 395°C - 405°C for 20 min - 30 min. Sintering is carried out in three stages. Through the path of "zinc melting → structure stabilization → slow participation of magnesium", uniform mutual dissolution of the two phases is achieved, forming a uniform alloy structure. If the temperature is too high, it will cause both to melt simultaneously, which is not conducive to the uniformity of the final alloy structure. Specifically, the temperature of the first-stage sintering can be 365°C, 370°C, 375°C, etc., and the heat preservation time can be 20 min, 25 min, 30 min, etc.; the temperature of the second-stage sintering can be 388°C, 390°C, 393°C, etc., and the heat preservation time can be 20 min, 25 min, 30 min, etc.; the temperature of the third-stage sintering can be 395°C, 400°C, 405°C, etc., and the heat preservation time can be 20 min, 25 min, 30 min, etc. By regulating the temperature and heat preservation time of degreasing and sintering, the density and physical properties of the Zn-Mg alloy can be significantly improved, and the content of pores and impurities can be reduced.

[0058] The heating rate of degreasing and sintering is 3°C / min - 8°C / min, such as 3°C / min, 4°C / min, 5°C / min, 6°C / min, 7°C / min, 8°C / min, etc. Degreasing and sintering are carried out under vacuum conditions, and the vacuum degree is controlled to be (0.5 - 2.0)×10 - 3 Pa, such as 0.5×10 -3 Pa, 1.0×10 -3 Pa, 2.0×10 -3 Pa, etc.

[0059] It should be noted that the present invention adopts binder jet 3D printing technology, combines three-dimensional modeling and slicing technology, realizes the precise forming of complex structures, further improves the printing accuracy and efficiency, and solves the problems of complex processes and difficulty in meeting personalized needs in traditional processes. By layer-by-layer bonding of metal powders and subsequent sintering post-treatment, the rapid forming of complex structures is realized, and the forming efficiency and material utilization rate of the Zn-Mg alloy are significantly improved.

[0060] An embodiment of the present invention also provides a Zn-Mg alloy, which is prepared by the method provided in the embodiment of the present invention and has a Zn-Mg alloy with high density and high microhardness.

[0061] The features and properties of the present invention will be further described in detail below in conjunction with embodiments.

[0062] Example 1

[0063] This embodiment provides a method for printing Zn-Mg alloy with a binder, and the steps are as follows:

[0064] Mix Zn powder and Mg powder with a powder particle size of 5-20 μm and a purity of 99.4% (the mass ratio of Zn powder to Mg powder is 9:1), mix and ball-mill them under argon for 8 h, then sieve through a 350-mesh sieve, and dry the obtained Zn-Mg mixed powder in a vacuum at 80 °C for 4 h. At the same time, set the parameters of the BJAM printing equipment. The powder spreading layer thickness is D = 0.04 mm, the speed of the powder spreading roller is 50 mm / s, the roller rotation speed is 75 rpm, the powder bed temperature is 25 °C, the water-based binder selects 3% acetylene diol and 15% 2-butoxyethanol, and the binder saturation is 80%. Spread the dried Zn-10Mg powder evenly on the substrate and start printing until the printing is completed. Cure the printed blank at 180 °C for 4 h, and carry out debinding and sintering on the cured blank. The sintering atmosphere is vacuum, and the vacuum degree is 10 -3 Pa, set the heating rate to 5 °C / min, and the heating temperatures are 370, 390, and 400 °C, and keep them warm for 20 min, 30 min, and 30 min respectively. After the sintering is completed, wait for the temperature in the furnace to drop to room temperature, take out the product, and obtain a Zn-10Mg alloy sample.

[0065] After testing: The relative density of the alloy sample prepared in this embodiment is 78.13%, and the average microhardness is 295.5 HV.

[0066] It should be added that the test method for relative density refers to GB / T 4472-2011, and the test method for average microhardness refers to GB / T 9097-2016.

[0067] Example 2

[0068] The difference from Example 1 is only that when setting the parameters of the BJAM printing equipment, the powder spreading layer thickness is set to D = 0.06 mm.

[0069] The scanning electron microscope photo of the Zn-10Mg alloy sample obtained in this embodiment is shown in Figure 1 . After testing: The relative density of the alloy sample prepared in this embodiment is 79.65%, the crystal grains are extremely fine, the structure is uniform, and the average microhardness is 323.6 HV.

[0070] Example 3

[0071] The difference from Example 1 is only that when setting the parameters of the BJAM printing equipment, the powder spreading layer thickness is set to D = 0.08 mm.

[0072] After testing: The relative density of the alloy sample prepared in this embodiment is 77.83%, and the average microhardness is 287.5 HV.

[0073] Example 4

[0074] The difference from Example 2 is only that the holding time during the sintering process is different. The heating temperature is controlled at 370 °C, 390 °C, and 400 °C, and the holding time is 20 min, 20 min, and 20 min respectively.

[0075] The scanning electron microscope photos of the Zn-10Mg alloy sample prepared in this example are shown in Figure 2 . After testing: The relative density of the alloy sample prepared in this example is 77.97%, and the average microhardness is 288.5 HV.

[0076] Example 5

[0077] The difference from Example 2 is only that the holding time during the sintering process is different. The heating temperature is controlled at 370 °C, 390 °C, and 400 °C, and the holding time is 20 min, 20 min, and 30 min respectively.

[0078] After testing: The relative density of the alloy sample prepared in this example is 78.17%, and the average microhardness is 289.7 HV.

[0079] Example 6

[0080] The difference from Example 2 is only that the holding time during the sintering process is different. The heating temperature is controlled at 370 °C, 390 °C, and 400 °C, and the holding time is 30 min, 20 min, and 30 min respectively.

[0081] After testing: The relative density of the alloy sample prepared in this example is 78.72%, and the average microhardness is 305.5 HV.

[0082] Example 7

[0083] The difference from Example 2 is only that the holding time during the sintering process is different. The heating temperature is controlled at 370 °C, 390 °C, and 400 °C, and the holding time is 30 min, 30 min, and 20 min respectively.

[0084] After testing: The relative density of the alloy sample prepared in this example is 78.44%, and the average microhardness is 295.6 HV.

[0085] Example 8

[0086] The difference from Example 2 is only that the holding time during the sintering process is different. The heating temperature is controlled at 370 °C, 390 °C, and 400 °C, and the holding time is 30 min, 30 min, and 30 min respectively.

[0087] The scanning electron microscope images of the alloy sample prepared in this example are shown in Figure 3After testing: The relative density of the alloy sample prepared in this example is 77.32%, and the average microhardness is 283.8 HV.

[0088] Example 9

[0089] The difference from Example 2 is only that the water-based binder is 5% ethylene glycol and 10% 2-butoxyethanol.

[0090] After testing: The relative density of the alloy sample prepared in this example is 78.55%, and the average microhardness is 302.4 HV.

[0091] Example 10

[0092] The difference from Example 2 is only that the water-based binder is 10% ethylene glycol and 10% 2-butoxyethanol.

[0093] After testing: The relative density of the alloy sample prepared in this example is 77.65%, and the average microhardness is 285.4 HV.

[0094] Example 11

[0095] The difference from Example 2 is only that the water-based binder is 3% ethylene glycol and 20% 2-butoxyethanol.

[0096] The scanning electron microscope image of the Zn-10Mg alloy sample obtained in this example is shown in Figure 4 After testing: The average microhardness of the alloy sample prepared in this example is 308.9 HV.

[0097] Example 12

[0098] The difference from Example 2 is only that the water-based binder is 15% ethylene glycol and 5% 2-butoxyethanol.

[0099] After testing: The relative density of the alloy sample prepared in this example is 78.27%, and the average microhardness is 292.9 HV.

[0100] Example 13

[0101] The difference from Example 2 is only that the heating temperature during the sintering process is different. The heating temperature is controlled at 390 °C and 400 °C, and kept warm for 45 min and 45 min respectively.

[0102] Example 14

[0103] The difference from Example 2 is only that the heating temperature during the sintering process is different. The heating temperature is controlled at 370 °C and 400 °C, and kept warm for 45 min and 45 min respectively.

[0104] Comparative Example 1

[0105] The difference from Example 2 is only that: the water-based binder is 18% polyacrylic acid.

[0106] The scanning electron microscope photograph of the Zn-10Mg alloy sample obtained in this comparative example is shown in Figure 5 . After testing: There are many pores and impurities in the alloy sample prepared in this comparative example, the relative density is 60.76%, and the average microhardness is 237.8 HV.

[0107] Comparative Example 2

[0108] The difference from Example 2 is only that: the water-based binder is 5% polyvinyl alcohol.

[0109] After testing: The relative density of the alloy sample prepared in this comparative example is 58.15%, and the average microhardness is 234.5 HV.

[0110] Comparative Example 3

[0111] The difference from Example 2 is only that: the water-based binder is 15% polyacrylic acid and 5% polyvinyl alcohol.

[0112] The scanning electron microscope photograph of the Zn-10Mg alloy sample prepared in this comparative example is shown in Figure 6 . After testing: There are a large number of pores and impurities in the alloy sample prepared in this comparative example, the relative density is 55.24%, and the average microhardness is 231.5 HV.

[0113] Comparative Example 4

[0114] The difference from Example 2 is only that: the water-based binder is 3% polyacrylic acid and 15% polyvinyl alcohol.

[0115] After testing: The relative density of the alloy sample prepared in this comparative example is 59.64%, and the average microhardness is 236.7 HV.

[0116] In summary, the present invention provides a method for printing Zn-Mg alloy with a binder and a Zn-Mg alloy, which has the following advantages and effects compared with the prior art:

[0117] (1) Improve the product density

[0118] Through the binder jet 3D printing technology, combined with the optimized binder formula and printing process parameters, the density of the product can be effectively improved. Specifically, the present invention controls parameters such as powder layer thickness, binder saturation, and powder roller speed to ensure good bonding effect between powder particles, reduce the generation of pores and defects. In addition, by precisely controlling the sintering temperature and vacuum degree, the shrinkage rate during the sintering process is further reduced, and the dimensional accuracy of the product is improved.

[0119] (2) Improve the physical properties of the alloy

[0120] Through the optimized binder formulation and appropriate debinding and sintering temperature curves, the non-equilibrium phases in the alloy are reduced, grain refinement is promoted, and the microhardness of the alloy is improved.

[0121] (3) Simplify the production process and reduce production costs

[0122] Binder jetting 3D printing technology can achieve rapid prototyping of complex structures without additional supports, greatly simplifying the production process. In addition, the water-based binder formulation used in the present invention has a low cost, and the printing process is carried out in an argon atmosphere, avoiding waste gas emissions during the melting process, reducing environmental protection pressure and production costs.

[0123] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for printing Zn-Mg alloy with a binder, characterized in that, Including: Spread the Zn-Mg mixed powder on a substrate and start 3D printing. During the printing process, after laying one layer of the Zn-Mg mixed powder, spray the binder, and cycle the processes of spraying the Zn-Mg mixed powder and spraying the binder; After printing is completed, perform thermal curing and debinding sintering; Among them, the binder is a water-based binder. By mass percentage, the water-based binder contains 2%-20% of acetylenediol and 2%-20% of 2-butoxyethanol.

2. The method according to claim 1, wherein By mass percentage, the water-based binder contains 2%-5% of acetylenediol and 13%-18% of 2-butoxyethanol.

3. The method according to claim 1, wherein The temperature of thermal curing is 100°C - 200°C, and the thermal curing time is 3h - 6h; Preferably, the temperature of thermal curing is 150°C - 200°C, and the thermal curing time is 3h - 5h.

4. The method according to claim 1 or 3, characterized in that, The process of the debinding sintering includes: first keep warm at 365°C - 375°C for 20min - 30min, then keep warm at 388°C - 393°C for 20min - 30min, and finally keep warm at 395°C - 405°C for 20min - 30min; And / or, the heating rate of the debinding sintering is 3°C / min - 8°C / min; And / or, degreasing and sintering are carried out under vacuum conditions, and the vacuum degree is controlled to be (0.5 - 2.0)×10 -3 Pa.

5. The method according to claim 1, characterized in that, During the printing process, control the thickness of each powder laying to be 0.04mm - 0.08mm, and control the binder saturation to be 60% - 90% after each spraying of the binder.

6. The method according to claim 5, characterized in that, During the printing process, control the running speed of the powder laying roller to be 25mm / s - 60mm / s, the roller rotation speed to be 30rpm - 100rpm, and the powder bed temperature to be 20°C - 30°C.

7. The method according to claim 5 or 6, characterized in that, Before printing, complete the three-dimensional modeling of the product according to the product drawing, import the model into the printing device, and complete the recognition and slicing work.

8. The method according to claim 1, wherein The preparation process of the Zn-Mg mixed powder includes: under an inert atmosphere, mix zinc powder and magnesium powder by ball milling, and then screen and vacuum dry.

9. The method according to claim 8, wherein The ball milling time is 6h - 10h, and the screen aperture is 300 mesh - 400 mesh; And / or, the vacuum drying temperature is 70°C - 90°C, and the drying time is 3h - 5h.

10. A Zn-Mg alloy, characterized in that, Prepared by the method according to any one of claims 1 - 9.

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