SLM metal multi-material additive manufacturing equipment based on liquid metal suspended powder bed technology

Abstract

The invention provides SLM metal multi-material additive manufacturing equipment based on a liquid metal suspended powder bed technology. Liquid metal is adopted to replace a conventional powder pile and serve as supporting filler of a forming bin, metal powder is made to suspend on the liquid metal, layer-by-layer laying and melting forming of the metal powder are conducted, meanwhile, after one material is machined, layer-by-layer powder recycling can be conducted, and therefore mutual pollution of various kinds of powder can be effectively avoided, and the production efficiency is improved. And the recycling rate of the powder can be greatly increased, and practical application and popularization of the SLM multi-material additive manufacturing technology are facilitated.

Description

Technical Field

[0001] The present application relates to a metal multi-material additive manufacturing device based on liquid metal suspended powder bed technology SLM, which belongs to the field of additive manufacturing technology. Background Art

[0002] Currently, metal multi-material additive manufacturing technology is rapidly becoming the forefront of industrial research. By integrating the superior properties of multiple metals, metal multi-material additive manufacturing technology can produce high-performance complex components with material-structure integration that is difficult to achieve with traditional processes. It shows great potential in improving product functionality and performance. This field has not yet reached a comprehensive and systematic development stage.

[0003] SLM (Selective Laser Melting) is a common additive manufacturing technology. However, the current multi-material SLM additive manufacturing faces problems such as multi-material powder contamination and low material powder recovery efficiency that need to be solved. Summary of the invention

[0004] The present application provides a metal multi-material additive manufacturing device based on liquid metal suspended powder bed technology SLM to solve the problems of multi-material powder pollution and low material powder recovery efficiency in the existing multi-material SLM additive manufacturing technology.

[0005] In a first aspect, an embodiment of the present application provides a metal multi-material additive manufacturing device based on liquid metal suspended powder bed technology SLM, including a molding bin, a powder feeding assembly, a scraper assembly, a laser assembly, a metal powder recovery bin and a control module;

[0006] The upper end of the molding chamber is open, and liquid metal is contained therein; a substrate for carrying the molding is also provided in the molding chamber, and the substrate can drive the molding to move in a vertical direction so that the molding is immersed in the liquid metal or exposed from the liquid metal;

[0007] The powder feeding assembly is used to lay metal powder on the upper surface of the liquid metal so that the metal powder covers the molding surface of the molded part;

[0008] The scraper assembly is used to scrape the metal powder on the upper surface of the liquid metal to make its thickness uniform;

[0009] The laser assembly is used to irradiate the metal powder in a set area on the upper surface of the liquid metal so that the metal powder is formed on the molding surface of the molded part;

[0010] The scraper assembly is also used to scrape the remaining metal powder on the upper surface of the liquid metal;

[0011] The metal powder recovery bin is used to recover the metal powder scraped by the scraper assembly;

[0012] The control module is used to control the operation of other components.

[0013] Based on the above SLM metal multi-material additive manufacturing equipment based on liquid metal suspended powder bed technology, optionally, the molding chamber also includes a liquid level adjustment component for adjusting the liquid level of the liquid metal in the molding chamber.

[0014] Based on the above liquid metal suspended powder bed technology SLM metal multi-material additive manufacturing equipment, optionally, also includes a temperature regulating component for regulating the temperature of the liquid metal in the molding chamber.

[0015] Based on the above-mentioned SLM metal multi-material additive manufacturing equipment based on liquid metal suspended powder bed technology, optionally, the powder feeding assembly includes a plurality of powder feeding bins for storing different types of metal powders.

[0016] Based on the above-mentioned SLM metal multi-material additive manufacturing equipment based on liquid metal suspended powder bed technology, optionally, it also includes a powder separation and recovery module for separating and recovering the metal powder in the metal powder recovery bin.

[0017] Based on the above-mentioned SLM metal multi-material additive manufacturing equipment based on liquid metal suspended powder bed technology, optionally, there are multiple metal powder recovery bins, each of which is used to recover different metal powders.

[0018] Based on the above SLM metal multi-material additive manufacturing equipment based on liquid metal suspended powder bed technology, optionally, the liquid metal is a metal element or alloy.

[0019] Based on the above-mentioned SLM metal multi-material additive manufacturing equipment based on liquid metal suspended powder bed technology, optionally, when in use, after completing the laying, molding and recycling of one metal powder, the laying, molding and recycling of the next metal powder can be carried out.

[0020] The above technical solution provided by this application has at least the following beneficial effects:

[0021] The present application provides a metal multi-material additive manufacturing device based on liquid metal suspended powder bed technology SLM, in which liquid metal is used instead of conventional powder piles as a supporting filler in a molding bin, so that metal powder is suspended on the liquid metal, and the metal powder is laid layer by layer and melt-molded. At the same time, after completing the processing of one material, the powder can be recovered layer by layer. In this way, mutual contamination of multiple powders can be effectively avoided, and the recycling rate of powders can be greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings herein are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application. In addition, these drawings and text descriptions are not intended to limit the scope of the concept of the present application in any way, but to illustrate the concept of the present application for those skilled in the art by referring to specific embodiments.

[0023] Figure 1 A schematic diagram of a module of a metal multi-material additive manufacturing device based on liquid metal suspended powder bed technology SLM provided in one embodiment of the present application;

[0024] Figure 2 A schematic cross-sectional view of a metal multi-material additive manufacturing device based on liquid metal suspended powder bed technology SLM provided in an embodiment of the present application;

[0025] Figure 3 A cross-sectional schematic diagram of another state of a metal multi-material additive manufacturing device based on liquid metal suspended powder bed technology SLM provided in an embodiment of the present application;

[0026] Figure 4 A cross-sectional schematic diagram of another state of a metal multi-material additive manufacturing device based on liquid metal suspended powder bed technology SLM provided in an embodiment of the present application;

[0027] Figure 5 A cross-sectional schematic diagram of another state of a metal multi-material additive manufacturing device based on liquid metal suspended powder bed technology SLM provided in an embodiment of the present application;

[0028] Figure 6 A cross-sectional schematic diagram of another state of a metal multi-material additive manufacturing device based on liquid metal suspended powder bed technology SLM provided in an embodiment of the present application;

[0029] Figure 7 A cross-sectional schematic diagram of another state of a metal multi-material additive manufacturing device based on liquid metal suspended powder bed technology SLM provided in an embodiment of the present application;

[0030] Figure 8 A cross-sectional schematic diagram of another state of a metal multi-material additive manufacturing device based on liquid metal suspended powder bed technology SLM provided in an embodiment of the present application;

[0031] Fig. 9 A cross-sectional schematic diagram of another state of a metal multi-material additive manufacturing device based on liquid metal suspended powder bed technology SLM provided in an embodiment of the present application;

[0032] Fig.10 This is a schematic diagram of the top view of the structure of a metal multi-material additive manufacturing device based on the liquid metal suspended powder bed technology SLM provided in an embodiment of the present application.

[0033] Description of reference numerals:

[0034] 1-molding chamber; 11-liquid metal; 12-substrate; 13-molded part; 2-powder feeding assembly; 3-scraper assembly; 4-laser assembly; 5-metal powder recovery chamber; 6-control module; 7-metal powder. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0036] Reference Figure 1-3 , Figure 1 A schematic diagram of a module of a metal multi-material additive manufacturing device based on liquid metal suspended powder bed technology SLM provided in an embodiment of the present application, Figure 2 A schematic cross-sectional view of a metal multi-material additive manufacturing device based on liquid metal suspended powder bed technology SLM provided in an embodiment of the present application, Figure 3 A cross-sectional schematic diagram of another state of the liquid metal suspended powder bed technology SLM metal multi-material additive manufacturing equipment provided in an embodiment of the present application.

[0037] like Figure 1-2 As shown, in some embodiments, a metal multi-material additive manufacturing device based on liquid metal suspended powder bed technology SLM is provided, which includes: a molding bin 1, a powder feeding assembly 2, a scraper assembly 3, a laser assembly 4, a metal powder recovery bin 5 and a control module 6.

[0038] The upper end of the molding chamber 1 is open, in which liquid metal 11 is contained; a substrate 12 for supporting a molded part 13 is also provided in the molding chamber 1, and the substrate 12 can drive the molded part 13 to move in a vertical direction so that the molded part 13 is immersed in the liquid metal 11 or exposed from the liquid metal 11.

[0039] The powder feeding assembly 2 is used to lay the metal powder 7 on the upper surface of the liquid metal 11 so that the metal powder 7 covers the molding surface of the molding 13;

[0040] The scraper assembly 3 is used to scrape the metal powder 7 on the upper surface of the liquid metal 11 to make its thickness uniform;

[0041] The laser assembly 4 is used to irradiate the metal powder 7 in a set area on the upper surface of the liquid metal 11 so that it is formed on the molding surface of the molded part 13;

[0042] The scraper assembly 3 is also used to scrape the remaining metal powder 7 on the upper surface of the liquid metal 11;

[0043] The metal powder recovery bin 5 is used to recover the metal powder 7 scraped by the scraper assembly 3;

[0044] The control module 6 is used to control the operation of other components.

[0045] Specifically, in each of the above modules or components, the molding chamber 1 is a component for processing the molded part 13 , and the molded part 13 to be processed is processed into a target product or structure by metal powder 7 in the molding chamber 1 .

[0046] The powder feeding component 2 is a functional module for transferring metal powder 7 to the molding bin 1, and includes a powder feeding bin in which the metal powder 7 to be processed is stored. Furthermore, the powder feeding component 2 may include multiple powder feeding bins for storing different types of metal powder 7, so as to realize printing molding of multiple metal materials. The specific number can be designed according to actual needs, for example, 2 to 4.

[0047] In the existing scheme, a powder pile is pre-set in the molding bin 1 as a supporting filler, the molded part 13 is placed in the molding bin 1, and the metal powder 7 transferred by the powder feeding assembly 2 falls on the supporting filler and the upper surface of the molded part 13, and then the subsequent printing process is carried out. In this method, the excess metal powder 7 will be mixed with the powder pile as the supporting filler, causing mutual contamination of multiple powders, making it difficult to recover the powder, requiring more processes, and having low efficiency.

[0048] In the solution of the present application, liquid metal 11 is used to replace the powder pile as the supporting filler of the molding bin 1. The liquid metal 11 is selected from low melting point and high density materials, which can be metal elements or alloys. The specific material of the liquid metal 11 can be selected according to actual needs. It is necessary to ensure that it is liquid when the equipment is operating normally, and the metal powder 7 transferred to the molding bin 1 can be suspended on the upper surface of the liquid metal 11 (of course, it cannot affect the normal printing process, for example, it cannot react with the transferred metal powder 7).

[0049] During operation, when the powder feeding assembly 2 transfers the metal powder 7 to the molding chamber 1, the metal powder 7 floats on the upper surface of the liquid metal 11, and it is necessary to adjust the position of the substrate 12 so that the molding surface (i.e., the upper surface) of the molded part 13 is exposed outside the liquid surface of the liquid metal 11, so that the metal powder 7 can fully contact the molding surface of the molded part 13.

[0050] Afterwards, in order to ensure the forming effect, the scraper assembly 3 is controlled to scrape the excess metal material on the upper surface of the liquid metal 11 into the metal powder recovery bin 5 on one side, so that the thickness of the remaining metal powder 7 is uniform, which is more conducive to subsequent processing.

[0051] After that, the laser assembly 4 is controlled to irradiate the metal powder 7 in the set area (the area corresponding to the molding surface of the molded part 13) to make it molten and finally molded on the molding surface of the molded part 13. In this way, the printing molding of the metal material is completed. After completion, the scraper assembly 3 is controlled to scrape the remaining metal material on the upper surface of the liquid metal 11 into the metal powder recovery bin 5, so that the remaining metal material can be recovered. Among them, the number of metal powder recovery bins 5 can be multiple, each used to recover different metal powders 7, so as to better realize recycling and reuse.

[0052] After that, if other types of metal materials need to be printed, the above steps can be repeated. That is, when in use, after completing the laying, molding and recycling of one type of metal powder 7, the laying, molding and recycling of the next type of metal powder 7 can be carried out. The processing of multiple types of metal powders 7 does not interfere with each other, which is conducive to the orderly progress of each process.

[0053] It should be noted that the components such as the powder feeding component 2 and the laser component 4 that achieve the same function as the existing solution can directly adopt the existing design, and the specific details are not described in detail. In addition, it can be understood that the scraper component 3 includes a scraper and a power component that drives the scraper to move, such as a motor, etc. This function is also relatively easy to achieve, so the specific structure is not described in detail.

[0054] In addition, the control module 6 can adopt a combination of a software-based controller or control components. The functions of the software include the control of other modules or components (including the molding bin 1, the powder feeding component 2, the scraper component 3, the laser component 4 and the metal powder recovery bin 5), and the processing of data collected by the collection board, the sensor and other detection components. The specific design can be based on actual needs.

[0055] Based on the above scheme, liquid metal 11 is used to replace the conventional powder pile as the supporting filler of the molding bin 1, so that the metal powder 7 is suspended on the liquid metal 11, and the metal powder 7 is laid layer by layer and melt-molded. At the same time, after completing the processing of one material, the metal powder 7 can be recovered layer by layer. In this way, the mutual contamination of multiple powders can be effectively avoided, and the recycling rate of the powder can be greatly improved (without the need to separate the multiple powders).

[0056] In addition, when the laser assembly 4 is working, a large amount of heat will be generated in the printing area of ​​the molded part 13. Excessive heat accumulation may affect the molding accuracy. However, due to the fluidity and high thermal conductivity of the liquid metal 11 itself, the heat of the molded part 13 immersed in the liquid metal 11 can be quickly conducted away, thereby achieving a more uniform heat distribution, which is conducive to improving the molding accuracy.

[0057] Furthermore, since the residual metal powder 7 can be cleaned up after sintering a metal material, a very obvious heterogeneous material boundary can be formed at the processing boundary, thereby achieving the effect of improving the material control accuracy of the heterogeneous boundary.

[0058] Furthermore, as a preferred solution, the molding chamber 1 may also include a liquid level adjustment component for adjusting the liquid level of the liquid metal 11 in the molding chamber 1 .

[0059] Specifically, in practice, in order to facilitate the laying of metal powder 7 in the molding bin 1, during the laying stage, the liquid level of the liquid metal 11 is preferably lower than the upper opening of the molding bin 1, and after the metal powder 7 is processed by the laser assembly 4, when the metal powder 7 remaining on the liquid metal 11 needs to be recovered, the liquid level of the liquid metal 11 is preferably consistent with the upper opening of the molding bin 1, so that the scraper assembly 3 can more conveniently scrape the remaining metal powder 7 to the metal powder recovery bin 5. In view of this, the molding bin 1 may include a liquid level adjustment assembly, through which the liquid level height of the liquid metal 11 in the molding bin 1 is adjusted, thereby making it more convenient to efficiently execute each process.

[0060] Furthermore, as a preferred solution, the molding chamber 1 may also include a temperature regulating component for regulating the temperature of the liquid metal 11 in the molding chamber 1 .

[0061] Specifically, due to the fluidity and high thermal conductivity of the liquid metal 11 , by adjusting the temperature of the liquid metal 11 , the temperature of the molded part 13 therein can be indirectly adjusted, thereby further improving the molding accuracy.

[0062] The temperature regulating component can detect the actual temperature of the liquid metal 11 through a sensor, and regulate the temperature according to the set target temperature, so that the actual temperature of the liquid metal 11 is maintained at or approximately maintained at the target temperature.

[0063] In addition, in some embodiments, the printing device may further include a powder separation and recovery module for separating and recovering the metal powder 7 in the metal powder recovery bin 5 .

[0064] Specifically, during the laying stage of the metal powder 7 and the recovery stage after laser processing, the scraper assembly 3 will inevitably bring a small amount of liquid metal 11 into the metal powder recovery bin 5 when scraping the excess metal powder 7 to the metal powder recovery bin 5. Therefore, in this embodiment, a powder separation and recovery module can be designed to separate the metal powder 7 from the liquid metal 11 in the metal powder recovery bin 5 for recycling and reuse.

[0065] In order to make the above solution easier to understand, a specific printing process is exemplarily described with reference to the accompanying drawings.

[0066] Reference Figure 4-7 , Figure 4-7 It is a schematic cross-sectional diagram of the printing device at different times during the processing.

[0067] In this example, two different metal materials, denoted as powder A and powder B, are printed on the molding surface of the molded part 13 .

[0068] The specific process is as follows:

[0069] Step S1: Figure 2 On the basis of the control substrate 12 rising, the molded part 13 arranged on the substrate 12 rises accordingly, and the result is as follows Figure 4 As shown, the molding surface of the molded part 13 is slightly higher than the liquid surface of the liquid metal 11 (the specific height difference is preset according to actual conditions), that is, the molding surface is exposed outside the liquid surface.

[0070] Step S2: Powder A is transferred to the molding bin 1 through the powder feeding assembly 2, such as Figure 5 As shown, due to the large density and large surface tension of the liquid metal, the metal powder 7 will cover the liquid surface and the molding surface due to buoyancy.

[0071] Step S3: Figure 6 As shown, the scraper assembly 3 is controlled to operate, and the excess metal powder 7 at the upper opening of the molding bin 1 is pushed into the metal powder recovery bin 5, and the thickness of the metal powder 7 on the molding surface is made uniform.

[0072] Step S4: Control the laser assembly 4 to operate and irradiate the metal powder 7 in the set area. Figure 7 As shown, it is turned into a molten state and formed on the forming surface. In addition, during this process, the temperature of the liquid metal 11 can be adjusted by the temperature adjustment component. Due to the fluidity and high thermal conductivity of the liquid metal, the temperature of the molded part can be quickly and dynamically controlled.

[0073] Step S5: Control the substrate 12 to drive the molded part 13 to descend and completely immerse it in the liquid metal 11. The remaining metal powder 7 on the upper side of the molding surface is also suspended on the upper surface of the liquid metal 11. At the same time, the liquid level is raised by the liquid level adjustment component so that the remaining metal powder 7 is located outside the opening of the molding chamber 1. Figure 8 shown.

[0074] Step S6: Fig. 9 As shown, the scraper assembly 3 is controlled to operate again to scrape all the metal powder 7 remaining on the upper surface of the liquid metal 11 to the metal powder recovery bin 5. At this point, the printing of powder A is completed, and the printing of powder B is started next.

[0075] Step S7: Control the substrate 12 to rise and the liquid metal 11 to fall, respectively, to restore to a state similar to Figure 4 state, that is, the liquid level of the liquid metal 11 is lower than the opening of the molding chamber 1, and the molding surface of the molded part 13 is exposed outside the liquid surface.

[0076] Step S8: Powder B is transferred to the molding chamber 1 through the powder feeding assembly 2, and the metal powder 7 covers the liquid surface and the molding surface. Figure 5 similar.

[0077] Step S9: Control the scraper assembly 3 to operate, push the excess metal powder 7 at the upper opening of the molding bin 1 into the metal powder recovery bin 5, and make the thickness of the metal powder 7 on the molding surface uniform. Figure 6 It should be noted that, in practice, two metal powder recovery bins 5 may be provided, one for recovering powder A and the other for recovering powder B. Fig.10 As shown in the top view of FIG. 1 , when powder A needs to be recovered, the metal powder recovery bin 5 corresponding to powder A is controlled by the control component to align with the molding bin 1. Similarly, when powder B needs to be recovered, the metal powder recovery bin 5 corresponding to powder B is controlled by the control component to align with the molding bin 1 (with Fig.10 For example, the two metal powder recovery bins 5 can be controlled to move in the direction of the arrow).

[0078] Step S10: Control the laser assembly 4 to operate, irradiate the metal powder 7 in the set area, make it molten, and form it on the forming surface. Figure 7 similar.

[0079] Step S11: Control the substrate 12 to drive the molded part 13 to descend and completely immerse it in the liquid metal 11; at the same time, the liquid level is raised by the liquid level adjustment component so that the remaining metal powder 7 is located outside the opening of the molding chamber 1. Figure 8 similar.

[0080] Step S12: Control the scraper assembly 3 to operate again, and scrape all the metal powder 7 remaining on the upper surface of the liquid metal 11 to the metal powder recovery bin 5. At this point, the printing of powder B is completed.

[0081] From the above process, it can be seen that this solution has obvious advantages over the existing solutions in avoiding mutual contamination of multiple powders, improving powder recovery efficiency, temperature control of molded parts, and improving heterogeneous boundary accuracy, which is conducive to the practical application and promotion of SLM multi-material additive manufacturing technology.

[0082] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0083] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0084] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A metal multi-material additive manufacturing device based on liquid metal suspended powder bed technology SLM, characterized in that: It includes a molding bin, a powder feeding assembly, a scraper assembly, a laser assembly, a metal powder recovery bin and a control module; The upper end of the molding chamber is open, and liquid metal is contained therein; a substrate for carrying the molding is also provided in the molding chamber, and the substrate can drive the molding to move in a vertical direction so that the molding is immersed in the liquid metal or exposed from the liquid metal; The powder feeding assembly is used to lay metal powder on the upper surface of the liquid metal so that the metal powder covers the molding surface of the molded part; The scraper assembly is used to scrape the metal powder on the upper surface of the liquid metal to make its thickness uniform; The laser assembly is used to irradiate the metal powder in a set area on the upper surface of the liquid metal so that the metal powder is formed on the molding surface of the molded part; The scraper assembly is also used to scrape the remaining metal powder on the upper surface of the liquid metal; The metal powder recovery bin is used to recover the metal powder scraped by the scraper assembly; The control module is used to control the operation of other components.

2. The SLM metal multi-material additive manufacturing equipment based on liquid metal suspended powder bed technology according to claim 1 is characterized in that: The molding bin also includes a liquid level adjustment component for adjusting the liquid level of the liquid metal in the molding bin.

3. The SLM metal multi-material additive manufacturing equipment based on liquid metal suspended powder bed technology according to claim 1 is characterized in that: It also includes a temperature regulating component for regulating the temperature of the liquid metal in the molding bin.

4. The SLM metal multi-material additive manufacturing equipment based on liquid metal suspended powder bed technology according to claim 1 is characterized in that: The powder feeding assembly includes a plurality of powder feeding bins for storing different types of metal powders.

5. The metal multi-material additive manufacturing equipment based on liquid metal suspended powder bed technology SLM according to claim 1 is characterized in that: It also includes a powder separation and recovery module, which is used to separate and recover the metal powder in the metal powder recovery bin.

6. The metal multi-material additive manufacturing equipment based on liquid metal suspended powder bed technology SLM according to claim 5 is characterized in that: There are multiple metal powder recovery bins, each used to recover different metal powders.

7. The SLM metal multi-material additive manufacturing equipment based on liquid metal suspended powder bed technology according to claim 1 is characterized in that: The liquid metal is a metal element or an alloy.

8. The metal multi-material additive manufacturing equipment based on liquid metal suspended powder bed technology SLM according to claim 1 is characterized in that: When in use, after completing the laying, molding and recycling of one metal powder, the laying, molding and recycling of the next metal powder will be carried out.

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