Powder dropping device for metal composite material, binder jet printing method, and metal composite material

Abstract

The present invention provides a powder drop device for metal composite materials, a binder jet printing method, and a metal composite material. [Solution] The powder dropping device for metal composite materials includes a movable powder cylinder, a powder hopper, and a planar moving device. The powder cylinder is provided with at least one powder hopper, which is used to mix two different metal powders. The two different metal powders are mixed in a gradient manner by controlling the powder hopper's feed rate. The powder hopper is provided with a planar moving device for moving the plane of the powder outlet of the powder mixer. The movement of the powder layer is controlled, and the planar moving device changes the position of the powder outlet of the powder mixer, thereby achieving a spatial gradient change of the mixed metal powder. The present invention enables the production of metal composite parts with component gradients and structural gradients for binder jet printing.

Description

[Technical Field]

[0001] The present invention relates to the technical field of 3D printing of metal powder beds, and in particular to a powder drop device for metal composites, a binder jet printing method and a metal composite. [Background technology]

[0002] Binder injection molding technology uses an inkjet printhead to spray a binder onto the powder, bonding layers of powder together in predetermined areas. Each powder layer bonds with the previous one, becoming integrated through the infiltration of the binder, and is built up layer by layer to produce a three-dimensional object. Such technology is suitable for the production of polymeric, metal, and ceramic materials. In the case of metal and ceramic manufacturing, the prototype is sintered at high temperatures to remove the binder, resulting in a finished product with the required density and strength.

[0003] However, existing technologies do not allow for the laying of heterogeneous powder beds, and there are limitations to binder jet printing molding of heterogeneous and composite materials.

[0004] Prior art discloses a multi-material, adjustable-surface powder feeder and powder feeding method suitable for binder jet additive manufacturing. However, because the powder cylinder is divided by a baffle, material composition changes in the X direction cannot be achieved. Only multi-layer dissimilar metal composites can be produced. There is no composition gradient in the printing direction (Z), meaning there is no composition gradient between layers. The powder falls from the powder storage bin onto the powder receiving shaft, then falls back onto the powder scattering shaft, and then falls back onto the molding cylinder. The powder is transported three times, and the different powders are mixed during these three transports to form a mixed powder. This makes it difficult to accurately control the composition of the printed product at a specific location. This results in poor operability and practicality. Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the shortcomings of the prior art, the present invention provides a powder dropping device for metal composite materials, a binder jet printing method, and a metal composite material, in which the position of the powder hopper is controlled by a planar moving device to ensure that the powder is dispersed at a predetermined position on the printing molding surface, and the mixing function of the powder hopper enables gradient mixing of different powders, thereby enabling the production of metal composite parts with component gradients and structural gradients. [Means for solving the problem]

[0006] The present invention achieves the above technical object by the following technical means.

[0007] The powder dropping device for metal composite materials includes a movable powder cylinder, a powder hopper, an ultrasonic vibration device and a planar moving device. The powder cylinder is provided with a screen at its powder outlet, and at least one powder hopper is provided within the powder cylinder. The powder hopper is used to mix two different metal powders, and the two different metal powders are mixed in a gradient manner by controlling the feeding speed of the powder hopper. The powder outlet of the powder hopper extends to the screen and is in close contact with the screen. The powder hopper is provided with a planar moving device for moving the plane of the powder outlet of the powder mixer. The ultrasonic vibration device contacts the screen and vibrates the screen to uniformly distribute the powder throughout the powder cylinder and the powder hopper, forming a powder layer of metal composite material within the cylinder. The movement of the powder layer is controlled, and the planar moving device is used to change the position of the powder hopper powder outlet, thereby achieving spatial variations in the composition and structure gradient of the mixed metal powder.

[0008] Furthermore, the powder hopper includes a powder mixer, a powder conveying pipe, and a powder feeding pipe. The powder feeders for two different metal powders are connected to the inlets of the powder mixer via the powder feeding pipes, respectively, and are used to mix the metal powders in the powder mixer. A powder conveying pipe is provided at the outlet of the powder mixer, and one end of the powder conveying pipe is in close contact with a screen.

[0009] Furthermore, by controlling the conveying speed of the powder feeders of the two different metal powders respectively, the amount of the two different metal powders entering the powder mixer is controlled, and the component gradient of the two different material metal powders is controlled, and the above component gradient range is 10% to 90%.

[0010] Furthermore, the mesh size of the screen is 200 to 1000 mesh, and the ultrasonic vibration frequency of the ultrasonic vibration device is 80 to 2000 Hz.

[0011] The binder jet printing method using powder drop equipment for metal composite materials is a step of moving a powder hopper to a set position by a planar moving device, mixing powders of different metal materials and dropping them into the set position, placing a base powder in the powder cylinder, laying a powder layer, and compressing the powder layer to print the current layer; changing at least one of the set position, the powder mixing gradient of the different metal materials, and the base powder material, forming a modified powder layer, compressing the powder layer, and printing a next layer; and printing the next layer. This involves changing the height of the powder layer and repeating the printing of the next layer.

[0012] Furthermore, in printing the next layer, the set position and the powder mixing gradient of the different metal materials are changed, the spatial position of the different metal materials in the molded base is gradually changed, and the component gradient of the different metal materials is changed.

[0013] A metal composite material having a component gradient and a structural gradient, the metal composite material being printed by a binder jet printing method.

[0014] Furthermore, each layer of the above metal composite material includes a base region and a reinforcement region, the base region has at least one reinforcement region, the reinforcement region is formed from a mixed powder of different metal materials, and the position and / or material composition of the reinforcement region in adjacent layers of the above metal composite material are different.

[0015] Additionally, the material of the base region in adjacent layers of the metal composite material alternates. [Effects of the Invention]

[0016] 1. In the powder dropping device for metal composite materials according to the present invention, the powder outlet of the powder hopper extends to the screen and is in close contact with it, preventing the metal powder in the powder conveying pipe from mixing with the base powder and preventing powder leakage from the sides due to the close contact with the screen. The metal powder falls directly onto the powder layer in the forming cylinder, simplifying the process path, eliminating the need for a powder transfer process, and preventing the mixing of different types of powders and cross-contamination between different types of powders.

[0017] 2. In the powder dropping device for metal composite materials of the present invention, the amount of powder dropping on the screen is controlled by an ultrasonic vibration device, and the position of the powder hopper is controlled by a planar movement device, so that the powder is scattered at a predetermined position on the surface.

[0018] 3. The binder jet printing method of the present invention utilizes the powder mixing function of the powder hopper to achieve gradient mixing of different powders, enabling the production of metal composite parts with component and structural gradients. Plane movement of the powder hopper and movement of the powder layer allow for free movement of different alloy powders in three directions (X, Y, and Z), thereby realizing printing of different materials at predetermined locations. By changing the set position in the printing layer, the powder mixing gradient of the different metal materials, and the base powder material, a composite can be formed with varying gradients in the spatial position of the different metal materials in the base and varying component gradients of the different metal materials.

[0019] 4. The metal composite material with component gradients and structural gradients of the present invention can solve three-dimensional structural and component changes, making it possible to prepare composite materials with reinforcing ribs made of different materials, lattice-structured composite parts with component and structural gradients, etc.

[0020] In order to more clearly describe the embodiments of the present invention or the technical solutions in the prior art, the drawings that need to be used in the description of the embodiments or the prior art are briefly introduced below. The drawings in the following description are some embodiments of the present invention, and it is obvious that those skilled in the art can obtain other drawings based on these drawings without any creative work. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a schematic diagram of a powder drop apparatus for producing a metal composite material having a component gradient and a structure gradient by binder injection molding according to the present invention. [Figure 2] 1 is a schematic diagram of powder laying of a single layer powder bed of the present invention. [Figure 3] This is a printed product of a 316L stainless steel composite material using H13 mold steel / 420 stainless steel as reinforcing ribs according to the present invention. [Figure 4] 1 is a printed product of a multi-material lattice structure having a component gradient and a structural gradient according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The following detailed description of the preferred embodiments of the present invention is illustrated in the accompanying drawings, in which the same or similar reference numerals throughout the drawings represent the same or similar elements, or elements having the same or similar functions. The preferred embodiments described below with reference to the accompanying drawings are illustrative and are intended to explain the present invention, but not to limit it.

[0023] In describing the present invention, terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "axial," "diametric," "vertical," "horizontal," "inner," and "outer" indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings. These terms are intended to facilitate and simplify the description of the present invention and do not suggest or imply that the devices or elements referred to must have a specific orientation, be configured, or operate in a specific orientation, and should not be understood as limitations of the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to suggest or imply relative importance or the number of technical features depicted. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In this specification, "plurality" means two or more, unless expressly defined otherwise.

[0024] In the present invention, unless otherwise clearly defined and limited, the terms "provide," "couple," "connect," "fix," etc. should be understood in a broad sense, including, for example, a fixed connection, a detachable connection, an integral connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection via an intermediate medium, or an internal connection between two components. Those skilled in the art can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0025] 1, the powder dropping device for a metal composite material according to the present invention includes a powder cylinder 5 movable along a guide rail 8, a powder hopper, an ultrasonic vibration device 6, and a planar movement device 3, and the powder cylinder 5 is positioned 5 to 15 mm above a molding cylinder 7, and after dropping the powder, the powder cylinder 5 can move in and out from above the molding cylinder 7 along the guide rail 8. A screen 4 is provided at the powder outlet of the powder cylinder 5, and the powder cylinder 5 is filled with composite material base powder M.

[0026] At least one powder hopper is provided within the powder cylinder 5, and is used to mix two different metal powders. The mixing speed of the powder hopper is controlled to control the gradient mixing of the two different metal powders. The powder outlet of the powder hopper extends to and is in close contact with the screen 4, i.e., the powder outlet of the powder hopper is inserted into the composite material base powder M and extends to the screen 4, so that the metal powder in the powder mixer does not mix with the base powder M. The close contact with the screen 4 prevents powder leakage from the sides. The screen 4 and powder conveying pipes 1-2 are made of metal, ensuring close contact and preventing deformation of the screen. The powder hopper is equipped with a planar movement device 3 for moving the powder hopper's powder outlet plane. The ultrasonic vibration device 6 is installed outside the powder outlet of the powder cylinder 5 and contacts the metal screen 4, vibrating it to allow the powder to fall. The vibration frequency and vibration time are controlled to control the powder output. The powder is then compressed by a roller to form a metal composite powder layer inside the forming cylinder 7. The planar movement device 3 is controlled to change the position of the powder hopper's powder outlet, thereby achieving a spatial gradient variation of the mixed metal powder on the single-layer printing surface. By controlling the up-and-down movement of the powder bed and combining it with the planar movement of the powder hopper above the single-layer printing surface, the continuous composition and structural gradient variation of the metal powder can be controlled in three dimensions on the multi-layer printing surface.

[0027] The powder hopper includes a powder mixer 1-1, a powder conveying pipe 1-2, and a powder supply pipe 1-3. The two powder supply pipes 1-3 are connected to the inlet of the powder mixer 1-1, and the two powder supply pipes 1-3 are connected to supply pipes into which different powder materials are fed. A rotating track is provided within the powder mixer 1-1, and a powder conveying gas is used to flow the mixed powder through the spiral track, thereby thoroughly mixing the metal powder and uniformly mixing it. A powder conveying pipe 1-2 is provided at the outlet of the powder mixer 1-1, one end of which is in close contact with a screen 4. The mixed powder is temporarily stored in the powder conveying pipe 1-2 according to the gradient of the components, and the screen 4 is vibrated to scatter it above the powder bed. In the embodiment, a first powder feeder 9 holding metal powder A and a second powder feeder 10 holding metal powder B are each connected to the inlet of a powder mixer 1-1 via a powder feed pipe 1-3, and the powder feed pipe 1-3 may be provided with a flow controller for controlling the mass entering the powder mixer 1-1. By controlling the rolling speeds of the first powder feeder and the second powder feeder 10, respectively, the conveying speeds of metal powder A and metal powder B are controlled, and the component gradient of the mixed powder is controlled. The component gradient range of metal powder A and metal powder B is 10% to 90%, and the gradient range is the mass percentage or molar ratio of the mixture. The mixed powder A and B is placed in a powder conveying pipe 1-2. The powder conveying pipe 1-2 can be replaced according to the shape and size requirements of the reinforcing ribs of the printed product. The powder conveying pipe 1-2 is threadedly connected to the powder mixer 1-1. For example, the outlet shape of the powder conveying pipe 1-2 can be round, square, or other irregular shapes. The powder outlet area of ​​the powder conveying pipe 1-2 is 0.25 cm 2 ~2cm 2 Here, the reinforcing rib is a material molded structure made of a mixed powder of metal powder A and metal powder B.

[0028] The first powder feeder 9 and the second powder feeder 10 are both pneumatic powder feeders. The operating principle of pneumatic powder feeders is to store powder in a storage tank and transport it as a fluid via a carrier gas. During transportation, the air flow rate is controlled to keep the powder suspended in the pipeline. A scraper is installed at the bottom of the powder storage tank. Its function is to scrape the powder from the storage tank into the powder feed pipe 1-3. During operation, the scraper is attached to the surface of the turntable. As the turntable rotates, the scraper continuously scrapes the powder, which is then sent to the powder mixer 1-1 through the powder feed pipe 1-3 by the action of the carrier gas. The powder discharge rate from the storage tank can be controlled by adjusting the rotation speed of the turntable. The method for calculating the molar ratio in the gradient range is described in detail below.

[0029] Based on the component gradients of metal powder A and metal powder B, the powder discharge speed of each powder feeder is calculated, and the powder discharge speed, powder discharge pressure, and gas flow rate of each storage tank are set, so that metal powder A and metal powder B enter powder mixer 1-1 successively and are mixed.

[0030] The calculation of the component gradient satisfies the following equation:

number

[0031] where n1 is the mass of metal powder A, n2 is the mass of metal powder B, a is a correction parameter in the range of 0.8 to 1.2, ρ1 is the density of metal powder A, ρ2 is the density of metal powder B, P1 is the conveying gas pressure of the first powder feeder 9, P2 is the conveying gas pressure of the second powder feeder 10, and v ガス1 is the flow rate of the carrier gas of the first powder feeder 9, and v ガス2 is the carrier gas flow rate of the second powder feeder 10, and ν 転1 is the rotation speed of the scraper of the first powder feeder 9, and υ 転2 is the rotation speed of the scraper of the second powder feeder 10.

[0032] The planar movement device 3 consists of two independent displacement devices, an X-direction displacement device and a Y-direction displacement device, which are respectively installed on the powder cylinder 5 and realize the relative movement of the powder mixer with respect to the powder cylinder 5. Both the X-direction displacement device and the Y-direction displacement device are electric push rods. The displacement devices are connected to a computer and their movement is controlled by the computer's instructions, with an interlayer displacement accuracy of 50 microns and a displacement range of less than 15 cm. The planar movement device 3 is controlled by the computer. Based on the position information indicated by a slice of the 3D actual object of the printed part, the final position is determined by controlling the X-direction and Y-direction electric push rods of the displacement device respectively.

[0033] The powder outlet of the powder cylinder 5 is closely attached to the screen 4, and its size is equivalent to the width of the forming cylinder 7, so that the powder dropping from the screen 4 can be guaranteed to completely cover the entire width of the forming cylinder 7. The mesh size of the screen 4 is generally selected according to the particle size of the powder, which is generally 10 to 75 microns, and the mesh size is generally selected to be 200 to 1000 mesh.

[0034] By controlling the frequency and amplitude of the ultrasonic vibration device 6, the amount and speed of powder falling from the powder outlet of the powder cylinder 5 can be controlled. Generally, the objective is to achieve a single powder layer thickness of 25 to 120 microns, and the ultrasonic vibration frequency is 80 to 2000 Hz.

[0035] In the embodiment shown in FIG. 1, two powder hoppers, a first powder hopper 1 and a second powder hopper 2, are installed inside the powder cylinder 5. The first powder hopper 1 mixes metal powder A and metal powder B, and the second powder hopper 2 mixes metal powder C and metal powder D. As shown in the cross-sectional view of the powder outlet of the powder cylinder 5 in FIG. 2, the first powder hopper 1 and the second powder hopper 2 mix four types of metal powder in pairs.

[0036] The binder jet printing method using the powder drop device for metal composite materials of the present invention includes the following steps.

[0037] In the process of printing the current layer, the planar moving device 3 moves the powder hopper to a set position, mixes powders of different metal materials and drops them into the set position, places the base powder in the powder cylinder 5, lays a powder layer, and compresses the powder layer to print the current layer, where the set position is determined according to the molding material.

[0038] The height of the powder layer is moved downward, and at least one of the setting position, the powder mixing gradient of the different metal material, and the base powder material is changed to form an altered powder layer, and the powder layer is compressed to print the next layer. In printing the next layer, the setting position of the reinforcing rib and the powder mixing gradient of the different metal material are changed, thereby changing the spatial position gradient at the base of the formed reinforcing rib and changing the gradient of the metal material components in the reinforcing rib of the different layer. In printing the next layer, the base powder material is changed to change the base powder of the formed different printed layer.

[0039] The powder bed in the forming cylinder 7 is moved down one printing thickness and the printing process for the next layer is repeated.

[0040] Example 1 As shown in FIG. 3, in a printed composite material based on a reinforcing rib M, the binder jet printing method using the powder dropping device for metal composite material according to the present invention includes the following steps.

[0041] One end of the powder conveying pipe 1-2 of the first powder hopper 1 is in close contact with the screen, and the powder conveying pipe 1-2 of the first powder hopper 1 is moved to a corresponding set position by the planar movement device 3. By controlling the conveying speeds of the first powder feeder 9 and the second powder feeder 10, metal powder A and metal powder B are mixed at a desired ratio and dropped to the bottom of the powder conveying pipe 1-2. Similarly, one end of the powder conveying pipe 1-2 of the second powder hopper 2 is in close contact with the screen, and the powder conveying pipe 1-2 of the second powder hopper 2 is moved to a corresponding set position, and metal powder C and metal powder D are mixed at a desired ratio and dropped to the bottom of the powder conveying pipe 1-2. The set positions and desired ratios are determined according to the needs of the molding materials.

[0042] Composite material base powder M is placed in powder cylinder 5 located outside powder conveying pipe 1-2. Powder cylinder 5 moves to the top of forming cylinder 7 via a guide rail, and the amount of powder that falls is controlled by an ultrasonic vibration screen. As a result, the powder is evenly distributed over the entire surface of forming cylinder 7, and a powder layer containing powder M, a mixture of powder A and powder B, and a mixture of powder C and powder D is formed, as shown in Figure 2.

[0043] After the powder falls onto the surface of the forming cylinder 7, a two-stage roller is used to compress the powder layer. The first stage roller has a large diameter and rotates quickly, allowing the powder layer to be roughly smoothed and roughly compressed. The second stage roller has a slightly smaller diameter, rotates slowly, and has a less rough roller surface, allowing the powder bed surface to be finely smoothed and the powder layer to be compressed into a denser, smoother surface.

[0044] The binder nozzle moves to the top of the forming cylinder 7 and jets the binder into place, and the infrared lamp pre-dries the binder of the previous layer and completes the printing of the current layer.

[0045] During the printing of the next layer, the position of the powder delivery pipe 1-2 within the powder cylinder 5 is changed by the planar movement device 3 according to the molding material needs, and the mixing ratio of metal powder A and metal powder B within the powder delivery pipe 1-2 is simultaneously changed to complete the powder layer laying, powder layer compression, and binder injection. In this way, the position of the powder delivery pipe 1-2 can be gradually changed during the printing process, so that the spatial positions of different metal materials in the molded base change gradually, and the composition of the different metal materials also changes gradually. The height of the powder layer needs to be adjusted during printing. In this embodiment, during printing of the next layer, only the mixing ratio of metal powder A and metal powder B in the first powder hopper 1 can be changed, or only the mixing ratio of metal powder C and metal powder D in the second powder hopper 2 can be changed, or the mixing ratios of metal powder A and metal powder B and metal powder C and metal powder D can be changed simultaneously.

[0046] Example 2 The printing method of the powder dropping device with component gradient and structure gradient produced by binder injection molding according to the present invention is used to produce printed products of H13 mold steel / 420 stainless steel / 316L stainless steel composite material, using 316L stainless steel as the base material, and H13 mold steel and 420 stainless steel as the reinforcing rib materials due to their high strength, i.e., alloy powder material A is H13 mold steel, and alloy powder material B is 420 stainless steel, specifically comprising the following steps:

[0047] One end of the powder conveying tube 1-2 of the first powder hopper 1 is in close contact with the screen, and the powder conveying tube 1-2 of the first powder hopper 1 is moved to a set position by the planar moving device 3. By controlling the conveying speeds of the first powder feeder 9 and the second powder feeder 10, the alloy powder H13 mold steel and 420 stainless steel are mixed in the required ratio, and the mass percentage of H13 mold steel during the entire printing process gradually changes from 10% to 90% and falls to the bottom of the powder conveying tube 1-2.

[0048] The powder cylinder 5 outside the powder conveying pipe 1-2 is filled with composite-based powder 316L stainless steel. The powder cylinder 5 moves to the top of the forming cylinder 7 via a guide rail, and the amount of powder that falls is controlled by an ultrasonic vibration screen. As a result, the powder is evenly distributed over the entire surface of the forming cylinder 7, forming a powder layer containing a mixed powder of 316L stainless steel, H13 mold steel, and 420 stainless steel over the entire surface. After the powder falls onto the surface of the forming cylinder 7, a two-stage roller is used to compress the powder layer. The first stage roller has a large diameter and a fast rotation speed, which allows the powder layer to be roughly smoothed and roughly compressed. The second stage roller has a slightly smaller diameter, a slower rotation speed, and a smaller roller surface roughness, which allows the surface of the powder bed to be finely smoothed, resulting in a higher compression density and a flatter surface.

[0049] The binder nozzle moves above the forming cylinder 7 and jets the binder at a predetermined position, and an infrared lamp pre-dries the binder of the previous layer, completing the printing of the current layer.

[0050] During the printing process for the next layer, the position of the powder delivery pipe 1-2 within the powder cylinder 5 is changed by the planar movement device 3, and the mixture ratio of H13 mold steel and 420 stainless steel within the powder delivery pipe 1-2 is simultaneously changed to complete the powder layer laying, powder layer compression, and binder injection. In this way, the position of the powder delivery pipe 1-2 can be gradually changed during the printing process, and the mixture ratio within it also gradually changes. The height of the powder layer within the molding cylinder 7 changes during printing.

[0051] Example 3 Figure 4 shows a multi-material lattice structure printed product with a component gradient and a structural gradient. Based on Example 1, the powder cylinder 5 has six powder hoppers, the composite material base of the upper layer of the powder cylinder 5 is powder M, and the composite material base of the lower layer of the powder cylinder 5 is powder N, with powder M and powder N distributed alternately in the printing direction.

[0052] The metal composite material with component gradients and structural gradients according to the present invention is printed using the binder jet printing method. The metal composite material can be sliced ​​and stacked according to the printing direction, with each layer including a base region 11 and a reinforced region 12. The base region 11 is formed from a base powder, and at least one reinforced region 12 is present within the base region 11. The reinforced regions 12 are formed from mixed powders of different metal materials, and the positions and / or material compositions of the reinforced regions 12 differ between adjacent layers of the metal composite material.

[0053] In the metal composite printed by the process of Example 2, the base region 11 is made of 316L stainless steel, and the base region 11 contains reinforced regions 12 made of a mixture of H13 mold steel and 420 stainless steel. Generally, the reinforced regions 12 made of a mixture of H13 mold steel and 420 stainless steel in adjacent layers at least partially overlap. However, in special cases, the reinforced regions 12 made of a mixture of H13 mold steel and 420 stainless steel in adjacent layers do not overlap.

[0054] The metal composite printed by the process of Example 3 has alternating materials in the base region 11 in adjacent layers of the metal composite.

[0055] The additive manufacturing method of the powder drop device for metal composite materials with component gradients and structural gradients using the binder injection molding method of the present invention can resolve three-dimensional structural and component changes and produce composite materials with reinforcing ribs made of different materials, lattice-structured composite material parts with component and structural gradients, etc.

[0056] This specification is described according to each embodiment, but it should be understood that each embodiment does not include only one independent technical solution, and such expressions in this specification are provided only for clarity, and those skilled in the art should interpret this specification as a whole, and the technical solutions in each embodiment can also be appropriately combined with other embodiments that can be understood by those skilled in the art.

[0057] The above series of detailed descriptions are merely specific descriptions of possible embodiments of the present invention, and do not limit the protection scope of the present invention; all equivalent embodiments or modifications that do not deviate from the technical idea of ​​the present invention should be included in the protection scope of the present invention. [Explanation of symbols]

[0058] 1. First powder hopper 1-1 Powder mixer 1-2 Powder transport tube 1-3 Powder supply tube 2. Second powder mixer 3 Plane moving device 4 screens 5 powder cylinders 6. Ultrasonic vibration device 7. Forming cylinder 8 guide rails 9. First Powder Feeder 10 Second powder feeder 11 Base Area 12 Strengthening areas

Claims

1. The device includes a movable powder cylinder (5), a powder hopper, an ultrasonic vibration device (6), and a planar moving device (3), A screen (4) is provided at the powder outlet of the powder cylinder (5), and at least one powder hopper is provided within the powder cylinder (5). The powder hopper is used to mix two different types of metal powders, and the two different types of metal powders are mixed in a gradient manner by controlling the supply speed of the powder hopper. The powder outlet of the powder hopper extends to the screen (4) and is in close contact with the screen (4). The powder hopper is provided with a planar movement device (3) for moving the plane of the powder outlet of the powder mixer. The ultrasonic vibration device (6) is in contact with the screen (4). By vibrating the screen (4), the powder in the powder cylinder and the powder hopper is uniformly dispersed within the molding cylinder (7), and a powder layer of metal composite material is formed. The movement of the powder layer is controlled, and the position of the powder outlet of the powder hopper is changed by the planar movement device (3), so that the components and position of the mixed metal powder in space are changed in a gradient manner. A powder dropping device for preparing a metal composite material, characterized in that:

2. 2. The powder dropping device for preparing a metal composite material according to claim 1, wherein the powder hopper comprises a powder mixer (1-1), a powder conveying pipe (1-2) and a powder supply pipe (1-3), the powder feeders of two different metal powders are respectively connected to the inlet of the powder mixer (1-1) via the powder supply pipe (1-3), the powder mixer (1-1) is used to mix the metal powders, the outlet of the powder mixer (1-1) is provided with a powder conveying pipe (1-2), one end of the powder conveying pipe (1-2) is in close contact with a screen (4).

3. The powder dropping device for preparing metal composite materials according to claim 2, characterized in that the amount of the two different metal powders entering the powder mixer (1-1) is controlled by respectively controlling the conveying speeds of the powder feeders of the two different metal powders, and the component gradient of the metal powders of the two different materials is controlled, the component gradient range being 10%-90%, and the component gradient is the mass percentage or molar ratio of the two different materials.

4. 2. The powder dropping device for preparing a metal composite material according to claim 1, wherein the mesh size of the screen (4) is 200 to 1000 mesh, and the ultrasonic vibration frequency of the ultrasonic vibration device (6) is 80 to 2000 Hz.

5. A binder jet printing method using a powder drop device for preparing the metal composite material according to any one of claims 1 to 4, comprising: a step of printing the current layer by moving the powder hopper to a set position by the plane moving device (3), mixing powders of different metal materials and dropping them into the set position, disposing the base powder in the powder cylinder (5), laying a powder layer, and compressing the powder layer to print the current layer; changing at least one of the set position, the powder mixing gradient of the different metal materials, and the base powder material, forming a modified powder layer, compressing the powder layer, and printing a next layer; and printing the next layer. The process of changing the height of the powder layer and printing the next layer is repeated A binder jet printing method comprising:

6. 6. The binder jet printing method of claim 5, wherein in printing the next layer, the set position and powder mixing gradient of the different metal materials are changed, the spatial position of the different metal materials in the used molded base is gradually changed, and the component gradient of the different metal materials is changed.

Images