A kind of additive and preparation method thereof

Abstract

The present application relates to the field of additive manufacturing technology, and in particular to an additive and a method for preparing the same. The additive preparation method of the present application includes the following steps: dispersing metal powder in a hot-melt organic material to obtain a paste; drying the paste to obtain a powder; using the powder as a raw material and adopting a three-dimensional model printing method to construct an additive with a cavity; degreasing the material of the additive with a cavity, and then filling the cavity with a melt of a semi-solid metal slurry; after the additive is cooled, heat-treating the additive. The present application improves the production efficiency of additives, reduces the production cost of additives, and improves the mechanical properties of additives.

Description

Technical Field

[0001] The present application relates to the field of additive manufacturing technology, and in particular to an additive manufacturing method and a preparation method thereof. Background Art

[0002] Additive Manufacturing (AM) is a technology that manufactures products by accumulating materials. In contrast to traditional subtractive manufacturing (such as removing materials from a blank by cutting, milling, etc. to obtain the final shape), additive manufacturing builds a three-dimensional object from scratch by adding materials layer by layer. For example, in traditional machining, to make a metal additive, you may start with a piece of raw metal, remove excess material by turning, grinding, etc., and finally form the shape of the additive. Additive manufacturing, on the other hand, is to stack materials (which can be metal powder, plastic filaments, etc.) layer by layer according to the designed three-dimensional model data until a complete additive is formed.

[0003] Additive manufacturing has a high material utilization rate, which can reduce material waste. Products prepared by additive manufacturing have high precision and good surface quality. It can manufacture products with high requirements for precision and appearance. Additive manufacturing has a high degree of design freedom and can manufacture objects with complex geometric shapes. The above advantages of additive manufacturing have enabled it to exert great application potential in many fields such as aerospace, medical, and automotive fields, which also poses new challenges to metal additive manufacturing technology.

[0004] Traditional methods of preparing metal additives include powder sintering and wire melting welding. The powder sintering method uses energy sources such as lasers and electron beams to irradiate metal powders, allowing the powders to absorb energy, heat up and sinter. The powders are then piled up layer by layer through a cycle of spreading, sintering and then spreading again to form additives. This method is capable of manufacturing complex structures, but its manufacturing efficiency is relatively low, and it is difficult to apply to the production of large-volume additive billets. The wire melting welding method (such as arc additive method) uses heat sources such as electric arcs and lasers to melt metal wires, and then accumulates droplets along a preset path to form additives. This method has high deposition efficiency, but limited manufacturing precision, high energy consumption and the tendency to produce oxide scale that affects additive performance. Fused Deposition Modeling (FDM) is an emerging metal additive manufacturing technology. Its consumables are a mixture of metal powder and organic binder. An intermediate is produced through a similar plastic fused deposition modeling technology, and then the organic binder is removed and further heat-processed to obtain the final product. Because the organic binder occupies a certain volume in the intermediate, a certain amount of voids will be generated after the organic binder is removed. During the heat processing, the intermediate shrinks uniformly to obtain the final product, and the mechanical properties are significantly lower than those of castings produced by conventional casting processes. Existing additive manufacturing technologies have low production efficiency and poor mechanical properties.

[0005] Based on this, it is necessary to provide an additive manufacturing method with high efficiency and high mechanical properties. Summary of the invention

[0006] Based on this, one or more embodiments of the present application provide an additive manufacturing method, which has high manufacturing efficiency and can manufacture high-performance additives.

[0007] The technical solution of this application includes the following contents:

[0008] An additive manufacturing method comprises the following steps:

[0009] Dispersing metal powder in a hot-melt organic material to obtain a paste;

[0010] The paste is dried to obtain powder;

[0011] Using the powder as a raw material and adopting a three-dimensional model printing method to construct an additive material with a cavity;

[0012] Degreasing the additive material having the cavity, and then filling the cavity with a semi-solid metal melt;

[0013] After the additive material is cooled, heat treating the additive material;

[0014] Wherein, the material of the metal powder is the same as the material of the semi-solid metal melt;

[0015] The solid phase fraction of the semi-solid metal melt is 40% to 60%, and the weight percentage of the metal powder in the paste is 80% to 90%.

[0016] In one embodiment, during the step of degreasing the additive material having the cavity and then filling the cavity with the melt of the semi-solid metal slurry, a protective gas is introduced into the cavity.

[0017] In one embodiment, metal powder is dispersed in a hot-melt organic material to obtain a paste, comprising:

[0018] The metal powder and the hot-melt organic material are mixed and kneaded for 1 h to 3 h to obtain the paste.

[0019] In one embodiment, degreasing the additive material having the cavity comprises:

[0020] Heating the additive having a cavity at a first temperature and in the presence of a first catalyst for a first time;

[0021] Wherein, the first temperature is 100° C. to 120° C., the first catalyst includes HNO 3 , and the first time is 5 h to 7 h.

[0022] In one embodiment, the solid phase fraction of the semi-solid metal melt is 50%.

[0023] In one embodiment, the metal powder includes A356.2 metal powder.

[0024] In one embodiment, the hot-melt organic material comprises polylactic acid.

[0025] In one embodiment, the heat treatment is a T6 heat treatment.

[0026] In one embodiment, the metal powder includes 6061 metal powder.

[0027] An additive material manufactured by the additive material manufacturing method described above.

[0028] The additive preparation method of the embodiment of the present application first improves the efficiency of additive production by printing the shell of the three-dimensional model and filling the semi-solid metal slurry into the cavity of the shell. Further, the additive with the cavity is manufactured by fused deposition molding. During degreasing, the hot-melt organic matter on the surface of the metal particles volatilizes to produce tiny pores on the surface of the additive. When the semi-solid metal slurry enters the cavity, on the one hand, the liquid phase component in the semi-solid metal slurry can enter the pores to form a physical interlocking effect, enhancing the interface bonding strength between the filler in the cavity and the inner wall of the cavity, and the filler and the additive shell have similar thermal expansion coefficients, which can prevent the additive from breaking after being stressed. On the other hand, the liquid phase component entering the pores can fill the gaps caused by the volatilization of organic matter, thereby avoiding the large shrinkage of the additive shell in the subsequent heat treatment, solving the problem that fused deposition molding is difficult to apply to high-precision additive manufacturing. The present application improves the efficiency of additive production, reduces the cost of additive production, and improves the mechanical properties of additives.

[0029] The additive material produced by the additive production method of the embodiment of the present application has the advantages of high precision, high strength and high production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 Flow chart of preparing additive materials by the additive manufacturing process of an embodiment of the present application.

[0032] Figure 2It is a comparison chart of the room temperature tensile stress-strain curves of the additives of Example 1 of the present application and Comparative Examples 1-4. DETAILED DESCRIPTION

[0033] The present application will be further described below in conjunction with the embodiments and examples. It should be understood that these examples are only used to illustrate the present application and are not intended to limit the scope of the present application. In addition, it should be understood that after reading the content taught in the present application, those skilled in the art may make various changes or modifications to the present application, and these equivalent forms also fall within the protection scope of the claims attached to the present application.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0035] the term

[0036] Unless otherwise specified or incompatible herewith, the terms and phrases used herein shall have the following meanings:

[0037] The term "and / or" used in this article includes any one of two or more related listed items, and also includes any and all combinations of the related listed items, wherein any and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items.

[0038] In this application, "optionally" and the like are used for descriptive purposes to indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0039] In this application, the terms "first", "second", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", etc. only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity.

[0040] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0041] In this application, when it comes to numerical intervals (i.e., numerical ranges), unless otherwise specified, the optional numerical distribution is considered continuous within the above numerical interval, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical range, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to integers within the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints. In addition, when multiple ranges are provided to describe features or characteristics, these ranges can be combined. In other words, unless otherwise specified, the ranges disclosed herein should be understood to include any and all subranges included therein.

[0042] The temperature parameters in this application, unless otherwise specified, are allowed to be either constant temperature treatment or to vary within a certain temperature range. It should be understood that the constant temperature treatment allows the temperature to fluctuate within the accuracy range controlled by the instrument. Fluctuations within the range of ±5°C, ±4°C, ±3°C, ±2°C, and ±1°C are allowed.

[0043] In the present application, weight may be μg, mg, g, kg or other mass units known in the chemical industry.

[0044] In the present application, unless otherwise specified, the size, particle size and diameter generally refer to the average value.

[0045] One or more embodiments of the present application provide a method for preparing an additive material, comprising:

[0046] S10: dispersing metal powder in a hot-melt organic material to obtain a paste;

[0047] S20: The paste is dried to obtain powder;

[0048] S30: Using powder as raw material and three-dimensional model printing to build additive materials with cavities;

[0049] S40: degreasing the additive material having the cavity, and then filling the cavity with a semi-solid metal melt;

[0050] S50: After the additive material is cooled, the additive material is subjected to T6 heat treatment;

[0051] Wherein, the material of the metal powder is the same as that of the semi-solid metal melt;

[0052] The solid phase fraction of the semi-solid metal melt is 40% to 60%.

[0053] The metal powder in the present application is a common metal powder that can be used for additive manufacturing in the art, preferably an aluminum alloy powder, such as 6061 aluminum alloy, 7075 aluminum alloy, A356.2 aluminum alloy, etc.

[0054] In one embodiment, the metal powder includes A356.2 metal powder.

[0055] The A356.2 metal powder in this application is mainly composed of aluminum alloy. The percentages of alloy components involved in this application are all mass fractions, wherein the silicon content is 6.5% to 7.5%, the magnesium content is 0.30% to 0.45%, the titanium content does not exceed 0.20%, the iron content does not exceed 0.12%, the copper content does not exceed 0.10%, the manganese content does not exceed 0.05%, the zinc content does not exceed 0.05%, and the balance is aluminum.

[0056] In one embodiment, the metal powder includes 6061 aluminum alloy powder.

[0057] The main component of the 6061 aluminum alloy powder in the present application is aluminum-magnesium-silicon alloy, wherein the magnesium content is 0.8% to 1.2%, the silicon content is 0.4% to 0.8%, the copper content is 0.15~0.4%, the titanium content is 0.1-0.15%, the zinc content is 0.15-0.25%, and the balance is aluminum.

[0058] In one embodiment, the metal powder includes 7075 aluminum alloy powder.

[0059] The main components of the 7075 aluminum alloy powder in this application include aluminum, zinc, copper, magnesium and chromium (aluminum is the main component, accounting for about 90%, the zinc content is 5.1%-6.1%, the copper content is 1.2%-2.0%, the magnesium content is 2.1%-2.9%, and the chromium content is 0.18%-0.28%), as well as a small amount of titanium (not exceeding 0.2%) and other impurities (not exceeding 0.05% individually and not exceeding 0.15% in total).

[0060] The hot-melt organic material in this application refers to a class of high molecular organic compounds that can melt when heated and resolidify into a solid after cooling, such as ethylene-vinyl acetate copolymer (EVA), polyamide (PA), polyolefin, polylactic acid (PLA), etc.

[0061] In one embodiment, the hot-melt organic material includes polylactic acid.

[0062] The polylactic acid in this application is a high molecular weight polymer formed by a polycondensation reaction or a ring-opening polymerization reaction of lactic acid monomers, and has a molecular weight range of 10,000~300,000g / mol, preferably 10,000~50,000g / mol. Low molecular weight polylactic acid (generally 10,000~50,000g / mol) usually has good fluidity and processing properties, and is more suitable for some application scenarios that require rapid prototyping or have high requirements for material fluidity, such as certain 3D printing materials. This low molecular weight polylactic acid is easier to soften and flow when heated, and can pass smoothly through molding equipment such as printing nozzles.

[0063] In one embodiment, the additive material having the cavity is degreased, and in the step of filling the cavity with the melt of the semi-solid metal slurry, a protective gas is introduced into the cavity.

[0064] In one embodiment, metal powder is dispersed in a hot-melt organic material to obtain a paste, comprising:

[0065] The metal powder and the hot-melt organic material are mixed and kneaded for 1 h to 3 h to obtain a paste.

[0066] In the present application, after a suitable amount of metal powder and hot-melt organic material are mixed and kneaded, metal powder coated with hot-melt organic material is obtained, so that during degreasing, a suitable amount of tiny pores can be generated on the surface of the additive through the volatilization of the hot-melt organic matter on the surface, so that the liquid phase components of the semi-solid metal slurry can enter the pores to form a physical interlocking effect, thereby enhancing the interface bonding strength between the filler in the cavity and the inner wall of the cavity.

[0067] In one embodiment, the weight percentage of the metal powder in the paste is 80%-90%.

[0068] Optionally, the weight percentage of the metal powder in the paste can be selected from 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, etc.

[0069] Mixing and kneading in this application refers to the process of fully mixing, stirring and kneading two or more different raw materials, such as polymers (such as PLA in the scheme) and metal powders (such as A356.2 metal powders) in a specific device (internal mixer).

[0070] Optionally, the mixing and kneading time can be selected from 1 h, 1.5 h, 2 h, 2.5 h, 3 h, etc.

[0071] In one embodiment, degreasing the additive material having the cavity comprises:

[0072] Heating the additive having a cavity at a first temperature and in the presence of a first catalyst for a first time;

[0073] Wherein, the first temperature is 100° C. to 120° C., the first catalyst includes HNO 3 , and the first time is 5 h to 7 h.

[0074] The HNO3 (nitric acid) used in this application is in a liquid state. When it is at a first temperature, it will decompose to produce nitrogen oxide (such as NO2, etc.) gas, which can be used as an actual catalytic gas to participate in the degreasing process. Nitric acid itself is a strong oxidant, which can react with PLA (polylactic acid) coated on the metal surface to undergo an oxidation reaction. PLA is an organic polymer material, and nitric acid can decompose it into small molecular organic matter and carbon dioxide, etc. These decomposition products are easier to remove from the metal surface, thereby achieving the purpose of degreasing. At the same time, the nitrogen oxide gas produced by the decomposition of nitric acid can continue to participate in the oxidation reaction in the atmosphere of the degreasing furnace, accelerating the degreasing process.

[0075] Alternatively, the first temperature may be selected from 100°C, 102°C, 105°C, 108°C, 110°C, 112°C, 115°C, 118°C, 120°C, and the like.

[0076] Optionally, the first heating time can be selected from 5h, 5.5h, 6h, 6.5h, 7h and the like.

[0077] In one embodiment, the solid fraction of the semi-solid metal melt is 40% to 60%.

[0078] Optionally, the solid phase fraction of the semisolid metal melt can be selected from 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, etc.

[0079] An additive material manufactured by the additive material manufacturing method described above.

[0080] The additive preparation method of the embodiment of the present application manufactures an additive with a cavity through fused deposition molding. During degreasing, the hot-melt organic matter on the surface of the metal particles volatilizes to produce tiny pores on the surface of the additive. When the semi-solid metal slurry enters the cavity, on the one hand, the liquid phase components in the semi-solid metal slurry can enter the pores to form a physical interlocking result, thereby enhancing the interface bonding strength between the filler in the cavity and the inner wall of the cavity. The filler and the additive shell have similar thermal expansion coefficients, which can prevent the additive from breaking after being subjected to force. On the other hand, the liquid phase components entering the pores can fill the gaps caused by the volatilization of organic matter, thereby avoiding a large shrinkage of the additive shell in subsequent heat treatment, thereby solving the problem that fused deposition molding is difficult to apply to high-precision additive manufacturing.

[0081] The additive material prepared by the additive preparation method of the embodiment of the present application has the advantages of high precision, high strength and high preparation efficiency, good application prospects and high economic value.

[0082] The following are some specific embodiments.

[0083] For experimental parameters not specified in the following specific embodiments, reference is made to the instructions given in the present application document, and reference may also be made to experimental manuals in the art or other experimental methods known in the art, or to experimental conditions recommended by manufacturers.

[0084] The raw materials and reagents involved in the following specific examples can be obtained from commercial sources, or can be prepared by those skilled in the art according to known methods.

[0085] 1. Additive preparation part

[0086] The composition of the following A356.2 metal powder is: silicon 6.5%, magnesium 0.4%, titanium 0.1%, iron 0.08%, copper 0.05%, manganese 0.02%, zinc 0.04%, and the balance is aluminum.

[0087] The composition of the following 6061 aluminum alloy is: 1% magnesium, 0.6% silicon, 0.25% copper, 0.15% titanium, 0.25% zinc, and the balance is aluminum.

[0088] Embodiment 1: This embodiment provides an additive material S1 of the present application, which is prepared by the additive material preparation method of the present application, comprising the following steps:

[0089] (1) A356.2 aluminum alloy metal powder was dried and mixed with PLA for 2 hours to obtain a paste, wherein the average particle size of the metal powder was 50 μm; the metal powder accounted for 85% of the weight of the paste;

[0090] (2) drying the cooled paste to obtain powder, i.e., A356.2 aluminum alloy metal powder coated with PLA;

[0091] (3) Using powder as raw material, a 3D printer is used to print an additive material with a cavity of a preset shape;

[0092] (4) The additive with the cavity is placed in a debinding furnace, catalytic gas HNO3 is introduced and heated at 110 °C for 6 h to complete the debinding;

[0093] (5) preparing a semi-solid A356.2 aluminum alloy melt with a solid phase fraction of 50%, and injecting the melt into the cavity of the additive material having a cavity after degreasing to fill the cavity;

[0094] (6) After the additive material is cooled, it is subjected to T6 heat treatment.

[0095] Example 2: This example provides an additive material S2 of the present application, which is prepared in the same manner as Example 1, except that 6061 aluminum alloy is used as metal powder in step (1) and a semi-solid 6061 aluminum alloy melt with a solid phase fraction of 50% is used in step (5).

[0096] Example 3: This example provides an additive material S3 of the present application, which is prepared in the same manner as in Example 1, except that in step (5), the solid phase fraction of the semi-solid A356.2 melt is 40%.

[0097] Example 4: This example provides an additive material S4 of the present application, which is prepared in the same manner as in Example 1, except that in step (5), the solid phase fraction of the semi-solid A356.2 melt is 60%.

[0098] Comparative Example 1: This comparative example provides another additive preparation method, which prepares additive D1, comprising the following steps:

[0099] (1) Using A356.2 metal wire as raw material (the composition is the same as that in Example 1), an additive arc manufacturing method is used to manufacture an additive with a cavity of a preset shape. The parameters of the additive arc additive manufacturing are: current 120A, voltage 12V, deposition speed 500mm / min, argon atmosphere;

[0100] (2) preparing a semi-solid A356.2 melt with a solid phase fraction of 50%, and injecting the melt into the cavity of the additive with a cavity to fill the cavity;

[0101] (3) After the additive material is cooled, it is subjected to T6 heat treatment.

[0102] Comparative Example 2: This comparative example provides another additive preparation method to prepare additive D2, which is prepared in a manner similar to Example 1, except that 6061 aluminum alloy is used as metal powder in step (1).

[0103] Comparative Example 3: This comparative example provides another additive preparation method to prepare additive D4, which is prepared in a manner similar to Example 1, except that the solid phase fraction of the semi-solid A356.2 melt in step (5) is 80%.

[0104] Comparative Example 4

[0105] This comparative example provides another additive preparation method to prepare additive D5, which is prepared in a manner similar to that of Example 1, except that in step (1), the weight percentage of metal powder in the paste is 95%.

[0106] 2. Performance testing part

[0107] Mechanical properties test

[0108] The mechanical properties of the additives of various embodiments and comparative examples at room temperature were tested with reference to standard GB / T 228.1-2010 “Tensile test of metallic materials Part 1: Room temperature test method”.

[0109] Table 1 Yield strength and tensile strength of the additives of various embodiments and comparative examples.

[0110]

[0111] According to Table 1: The additive materials S1~S4 of the embodiments of the present application have relatively high yield strength and tensile strength, with the yield strength being ≥230 MPa and the tensile strength being ≥290 MPa.

[0112] According to Table 1, the yield strength and tensile strength of Examples 1, 3, and 4 are better than those of Comparative Examples 1-4. This is because the additive preparation method of the embodiments of the present application manufactures additives with cavities through fused deposition molding. During degreasing, the hot-melt organic matter on the surface of the metal particles volatilizes to produce tiny pores on the surface of the additive. When the semi-solid metal slurry enters the cavity, on the one hand, the liquid phase components in the semi-solid metal slurry can enter the pores to form a physical interlocking effect, thereby enhancing the interface bonding strength between the filler in the cavity and the inner wall of the cavity, and the filler and the additive shell have similar thermal expansion coefficients, which can prevent the additive from breaking after being subjected to force. On the other hand, the liquid phase components entering the pores can fill the gaps caused by the volatilization of organic matter, thereby avoiding a large shrinkage of the additive shell in subsequent heat treatment, thereby solving the problem that fused deposition molding is difficult to apply to high-precision additive manufacturing.

[0113] According to Table 1 and Figure 2 The results (from top to bottom, respectively, are Example 1, Comparative Example 4, Comparative Example 3, Comparative Example 2 and Comparative Example 1) show that the tensile strength, yield strength and elongation of the material of Comparative Example 1 are relatively low, and the tensile curve drops rapidly after reaching the maximum stress, and brittle fracture occurs, which indicates that the interface bonding strength between the shell material of the additive in Example 1 and the material in the cavity is weak, and damage occurs after receiving a relatively low stress. Compared with Comparative Example 1, the tensile strength, yield strength and elongation of Example 1 are significantly improved, and it has a longer plastic section, which indicates that the inner and outer materials of the additive in Example 1 form a better interface bonding effect. Comparative Example 2 uses two materials with a large difference in thermal expansion coefficients, which are prone to shrinkage cracking after heat treatment, resulting in a decrease in the mechanical properties of the additive. Comparative Example 3 uses a semi-solid melt with a high solid phase fraction, which has poor fluidity, is difficult to fully fill the cavity, is prone to pores, and has a low content of liquid phase components, making it difficult to produce sufficient physical fit with the shell. Comparative Example 4 uses a paste with a higher proportion of metal powder, which results in a reduction in the number of pores in the shell. The liquid phase components in the semi-solid melt are difficult to enter the pores of the shell to form a physical embedding effect, resulting in a decrease in the mechanical properties of the additive.

[0114] All documents mentioned in this application are cited as references in this application, just as each document is cited as reference separately. Unless they conflict with the application purpose and / or technical solution of this application, the cited documents involved in this application are cited with all contents and all purposes. When the cited documents are involved in this application, the definitions of relevant technical features, terms, nouns, phrases, etc. in the cited documents are also cited. When the cited documents are involved in this application, the examples and preferred methods of the cited relevant technical features can also be incorporated into this application as references, but are limited to the implementation of this application. It should be understood that when the cited content conflicts with the description in this application, the present application shall prevail or be modified adaptively according to the description of this application.

[0115] The technical features of the above-mentioned implementation modes and examples can be combined in any appropriate manner. To make the description concise, not all possible combinations of the technical features in the above-mentioned implementation modes and examples are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0116] The above-described embodiments only express several implementation methods of the present application, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for those of ordinary skill in the art, without departing from the concept of the present application, several variations and improvements can also be made, which all belong to the protection scope of the present application. In addition, it should be understood that after reading the above-mentioned teaching content of the present application, those skilled in the art can make various changes or modifications to the present application, and the equivalent forms obtained also fall within the protection scope of the present application. It should also be understood that the technical solutions obtained by those skilled in the art on the basis of the technical solutions provided in the present application through logical analysis, reasoning or limited experiments are all within the protection scope of the claims attached to the present application. Therefore, the protection scope of the patent of the present application shall be based on the attached claims, and the description can be used to interpret the content of the claims.

Claims

1. An additive manufacturing method, characterized in that: The steps include: Dispersing metal powder in a hot-melt organic material to obtain a paste; The paste is dried to obtain powder; Using the powder as a raw material and adopting a three-dimensional model printing method to construct an additive material with a cavity; Degreasing the additive material having the cavity, and then filling the cavity with a semi-solid metal melt; After the additive material is cooled, heat treating the additive material; The solid phase fraction of the semi-solid metal melt is 40% to 60%, the material of the metal powder is the same as that of the semi-solid metal melt, and the weight percentage of the metal powder in the paste is 80% to 90%.

2. The additive manufacturing method according to claim 1, characterized in that: The metal powder includes 6061 metal powder.

3. The additive manufacturing method according to claim 1, characterized in that: In the step of degreasing the additive material having the cavity and then filling the cavity with a semi-solid metal melt, a protective gas is introduced into the cavity.

4. The additive manufacturing method according to any one of claims 1 to 3, characterized in that: The heat treatment is T6 heat treatment.

5. The additive manufacturing method according to any one of claims 1 to 3, characterized in that: The metal powder is dispersed in a hot-melt organic material to obtain a paste, comprising: The metal powder and the hot-melt organic material are mixed and kneaded for 1 h to 3 h to obtain the paste.

6. The additive manufacturing method according to any one of claims 1 to 3, characterized in that: The degreasing process of the additive material having the cavity comprises: Heating the additive having a cavity at a first temperature and in the presence of a first catalyst for a first time; Wherein, the first temperature is 100-120° C., the first catalyst includes HNO 3 , and the first time is 5 h-7 h.

7. The additive manufacturing method according to any one of claims 1 to 3, characterized in that: The solid phase fraction of the semi-solid metal melt is 50%.

8. The additive manufacturing method according to claim 1, characterized in that: The metal powder includes A356.2 metal powder.

9. The additive manufacturing method according to any one of claims 1 to 3, characterized in that: The heat-fusible organic material includes polylactic acid.

10. An additive material obtained by the additive preparation method according to any one of claims 1 to 8.

Images