3D printing method capable of accurately arranging various powder materials and 3D printing device thereof

Abstract

The invention relates to a 3D printing method capable of accurately arranging various powder materials and a printing device thereof. The 3D printing method comprises the following steps that at least two kinds of powder are placed in powder material bins with the corresponding number; each material in the same layer is arranged and formed after the former material is arranged and formed; the material arranging and forming method comprises the following steps that a powder distributing plate is moved to a powder material bin, the top face of the powder distributing plate is covered with an area where powder needs to be arranged through electrons, materials are adsorbed to the corresponding position of the bottom face of the powder distributing plate through charge polarization, and the powder distributing plate is moved to the position above a forming bin; electrons on the top surface of the powder distribution plate are removed to enable the powder to fall into a forming area, and the powder distribution plate is moved away for forming; thus, part forming is achieved by printing layer by layer in areas. Powder is adsorbed in a designated area through charge polarization, when the powder distribution plate moves to the corresponding position of the forming bin, adsorption of the powder distribution plate to the powder is eliminated, and multiple materials are accurately arranged on the same layer.

Description

Technical Field

[0001] The present invention relates to the field of additive manufacturing, and in particular to a 3D printing method and a 3D printing device capable of accurately arranging a variety of powder materials. Background Art

[0002] Selective Laser Melting (SLM) and Selective Laser Sintering (SLS) are both additive manufacturing methods based on the principle of powder bed fusion. Generally, a scraper or roller is used to spread the powder layer by layer onto a molding lifting platform to achieve powder arrangement, and then a laser beam is used to selectively melt (SLM) or sinter (SLS) the powder in the molding lifting platform area. In this way, the powder is spread and melted (SLM) or sintered (SLS) layer by layer to form parts.

[0003] The inventors have found through extensive practice that, due to the use of scrapers or rollers to lay powder layer by layer on the molding lifting platform, the SLM or SLS process can generally only use the same material powder to mold single-material parts, and it is difficult to arrange different types of materials between different layers of parts and at different positions on the same layer. A few multi-material additive manufacturing methods based on the SLM process can generally only print a certain material area in the same layer, first remove (negative pressure suction or flexible scraper sweeping) the excess powder in the layer, and then spread another powder to achieve the arrangement of different types of materials in the same layer, but this type of process will be accompanied by a large amount of different types of powders mixed, which must be separated and purified before they can be used again, and the step of removing excess powder in the layer is prone to cross-contamination of powders and consumes a lot of process time. Summary of the invention

[0004] Based on this, the purpose of the present invention is to provide a 3D printing method that can accurately arrange a variety of powder materials, by arranging electrons on the top surface of a non-metallic and non-conductive powder distribution board, so that the bottom surface of the powder distribution board is charge polarized, and then the powder material close to the bottom surface of the powder distribution board is charge polarized, and the powder at the corresponding position is adsorbed on the bottom surface of the powder distribution board to achieve the adsorption of powder in the designated area. When the powder distribution board moves to the corresponding position of the molding bin, all the electrons on the top surface of the powder distribution board are cleared to eliminate the adsorption effect of the powder distribution board on the powder, so that the powder falls to the designated position of the molding bin; thereby achieving the accurate arrangement of a variety of powder materials on the same layer. It has the advantages of accurate arrangement, convenient operation and simple process.

[0005] A 3D printing method for accurately arranging a plurality of powder materials comprises the following steps:

[0006] At least two powder material bins arranged in a straight line and a molding bin are arranged in a molding chamber, and powders of at least two materials are placed in corresponding numbers of powder material bins and leveled; a powder distribution plate made of non-metallic and non-conductive material is arranged above the powder material bins, and the powder distribution plate has two position states, namely, a powder suction position and a powder distribution position. The powder suction position refers to the position where the powder distribution plate is located directly above the powder material bin closest to the molding bin, and the powder distribution position refers to the position where the powder distribution plate is located directly above the molding bin;

[0007] Divide the 3D printing model of the product to be printed into multiple layers, and print them layer by layer from bottom to top until the product is printed;

[0008] Among them, the method for arranging and forming any layer of materials includes the following steps: moving the powder distribution board to the powder absorption position, moving the powder material bin where the first material to be arranged is located to the position closest to the forming bin, raising the surface of the material to be arranged in the powder material bin until it is just in close contact with the bottom surface of the powder distribution board, arranging a number of electrons on the top surface of the powder distribution board and making a number of electrons just cover the area where the current material needs to be arranged, so as to obtain a powder distribution board with the material adsorbed at the corresponding position on the bottom surface, moving the powder distribution board to the powder distribution position, and before the powder distribution board is moved above the forming bin, the bottom surface of the powder distribution board is The thickness of the adsorbed material is scraped flat to the preset layer thickness. After the powder distribution board reaches the powder distribution position, all electrons on the top surface of the powder distribution board are cleared to make the material adsorbed by the powder distribution board fall to the area where the material needs to be arranged above the bottom plate of the forming bin, and the powder distribution board is moved to the powder absorption position to complete the arrangement of the first material that needs to be arranged in the current layer; if the current material needs to be formed, then after forming by melting or sintering, the arrangement and forming of the next material in the current layer are carried out; if the current material does not need to be formed, the arrangement and forming of the next material in the current layer are directly carried out until all materials in the current layer are arranged and formed;

[0009] The above description can be further explained as follows: On the horizontal plane, a coordinate system is established with the center of the powder distribution board as the coordinate origin, and a certain point (x1, y1) on the bottom surface of the powder distribution board adsorbs powder. When the powder at this point is transferred to the molding platform, it should accurately fall on the corresponding point (j1, k1) in another coordinate system on the horizontal plane with the center of the molding bin bottom plate as the coordinate origin, and satisfy (x1, y1) = (j1, k1). These two points respectively identify the location of the area where the material needs to be arranged on the powder distribution board and the molding bin bottom plate. More generally, any point (x, y) in the area where the material needs to be arranged on the powder distribution board has a one-to-one corresponding point (j, k) on the molding bin bottom plate, and the area composed of these corresponding points is called the area where the material needs to be arranged above the molding bin bottom plate. When arranging electrons on a certain area on the top surface of the powder distribution board, the area with the same horizontal plane coordinates on the bottom surface of the powder distribution board is called the corresponding position on the bottom surface of the powder distribution board.

[0010] The method of printing layer by layer from bottom to top includes the following steps: after all materials of any layer are arranged and formed, the height of the bottom plate of the forming bin is lowered, the lowered height = the preset layer thickness, and then the next layer of materials is arranged and formed in the same way until all layers of materials are arranged and formed.

[0011] The 3D printing method for accurately arranging various powder materials described in the present invention arranges electrons on the top surface of a non-metallic and non-conductive powder distribution board, so that the bottom surface of the powder distribution board is charge polarized, and then the powder material close to the bottom surface of the powder distribution board is charge polarized, and the powder at the corresponding position is adsorbed on the bottom surface of the powder distribution board to achieve the adsorption of powder in the designated area. When the powder distribution board moves to the corresponding position of the molding bin, all the electrons on the top surface of the powder distribution board are cleared to eliminate the adsorption effect of the powder distribution board on the powder, so that the powder falls to the designated position of the molding bin; thereby achieving the accurate arrangement of various powder materials on the same layer. It has the advantages of accurate arrangement, convenient operation and simple process.

[0012] Furthermore, the material arrangement and molding method further includes the following steps: after the powder distribution board that has adsorbed the material at the corresponding position on the bottom surface is moved to the powder distribution position, the surface of the powder material bin corresponding to the material adsorbed by the powder distribution board is scraped flat. Specifically, the action of scraping the powder surface in the powder material bin can occur at any time during the process of the powder distribution board that has adsorbed the material being moved to the top of the molding bin and the powder arrangement being completed; the scraping of the surface of the material adsorbed on the bottom surface of the powder distribution board occurs during the process of the powder distribution board that has adsorbed the material being moved to the top of the molding bin. The excess powder generated by these two types of scraping actions is recovered into the recovery bin corresponding to the powder material bin. In the process of the powder distribution board being moved to the top of the molding bin, the surface of the material adsorbed on the bottom surface of the powder distribution board is scraped flat, and the free time of the powder distribution board being moved to the top of the molding bin for powder arrangement is used to scrape the surface of the material in the powder material bin and recover the excess powder, which are both conducive to shortening the process time, improving the utilization rate of powder materials, and improving production efficiency.

[0013] Furthermore, the material arrangement and molding method also includes the following steps: after smoothing the surface of the powder material bin corresponding to the material adsorbed by the powder distribution board, before moving the powder distribution board to the powder absorption position, first move the powder material bin corresponding to the next material to be arranged to the position closest to the molding bin. Before the powder distribution board adsorbs the powder of the next material, first move the corresponding powder material bin to a position close to the molding bin. On the one hand, it can avoid extending the production time due to waiting for the powder material bin to move, shorten the process time, and improve production efficiency. On the other hand, it can reduce the moving distance of the powder distribution board, reduce the loss of powder adsorbed by the powder distribution board due to movement, and also simplify the design of the drive device of multiple powder material bins.

[0014] Furthermore, the method of arranging a plurality of electrons on the top surface of the powder distribution plate includes the following steps: generating and emitting electrons through an electron beam generator, and adjusting the movement trajectory of the electrons through a focusing coil and a magnetic deflection coil, so that the electrons accurately fall at a designated position on the top surface of the powder distribution plate until the designated area is covered. The focusing coil is set to prevent the electrons from diverging, and the magnetic deflection coil is set to control the landing point of the electrons, so that the electrons accurately fall into the target position, which is conducive to the accurate transfer of powder.

[0015] Furthermore, the method for removing all electrons from the top surface of the powder distribution board includes the following steps: completely sweeping the top surface of the powder distribution board with a conductive and grounded de-static brush to remove all electrons from the top surface of the powder distribution board in a grounded manner.

[0016] Furthermore, the 3D printing method capable of accurately arranging a variety of powder materials is performed in a vacuum environment with a pressure of less than 10 Pa. In this way, on the one hand, the powder molding process can be protected from oxidation, and on the other hand, the electron beam is more easily not disturbed by gas molecules and is transmitted to the powder distribution board almost losslessly and accurately.

[0017] The present invention also provides a 3D printing device capable of accurately arranging a variety of powder materials, which is applicable to any of the above-mentioned 3D printing methods capable of accurately arranging a variety of powder materials, comprising a molding chamber and at least two powder material bins located in the molding chamber, a molding bin, a plurality of lifting bottom plates, a first driving unit, a powder distribution plate, a second driving unit, a leveling portion and a third driving unit, and a telescopic de-static brush fixed to the molding chamber, an electron beam generator, an electron beam controller, a laser scanning head and a vacuum joint;

[0018] The plurality of powder material bins are arranged in a row and fixed to each other, the plurality of lifting bottom plates are respectively located in the plurality of powder material bins and the forming bins, and the outer peripheries of the plurality of lifting bottom plates are respectively sealed against the inner walls of the plurality of powder material bins and the inner walls of the forming bins; the first driving unit is fixed to the outer side surface of the powder material bin, and the first driving unit drives the plurality of powder material bins to slide along the direction in which they are arranged and extended;

[0019] The top side of the powder distribution plate is fixed to the second driving unit, and the bottom surface of the powder distribution plate is arranged parallel to the horizontal plane. The powder distribution plate has two position states: a powder suction position and a powder distribution position. The powder suction position refers to the position where the powder distribution plate is located directly above the powder material bin closest to the forming bin, and the powder distribution position refers to the position where the powder distribution plate is located directly above the forming bin. In the powder suction position, the distance between the bottom surface of the powder distribution plate and the upper end surface of the powder material bin is equal to the preset layer thickness; the second driving unit drives the powder distribution plate to slide between the powder suction position and the powder distribution position;

[0020] The top side of the leveling portion is fixed to the third driving unit, and the lower end of the leveling portion extends below the bottom surface of the powder distribution plate, and the distance between the lower end of the leveling portion and the bottom side of the powder distribution plate = preset layer thickness + scraping thickness, the extending direction of the leveling portion is parallel to the extending direction of the plurality of powder material bins, and the extending length of the leveling portion is equal to the maximum width of the inner cavity of the powder material bin, and the leveling portion has two position states: a to-be-scraped position and a scraped position. When the powder material bin is located between the leveling portion and the forming bin, the position corresponding to the leveling portion is the to-be-scraped position, and the scraped position refers to the position of the leveling portion between the powder material bin and the forming bin, and the third driving unit drives the leveling portion to slide between the scraped position and the to-be-scraped position, and the sliding direction of the leveling portion is parallel to the sliding direction of the powder distribution plate;

[0021] One end of the telescopic de-staticizing brush is fixed to the molding chamber, and the other end of the telescopic de-staticizing brush is telescoped in the sliding direction of the powder distribution plate, and the telescopic de-staticizing brush includes a first state and a second state. In the first state, the telescopic de-staticizing brush is fully retracted, and the other end of the telescopic de-staticizing brush is located between the powder distribution plate in the powder distribution position and one end of the telescopic de-staticizing brush, and a gap is provided between the other end of the telescopic de-staticizing brush and the powder distribution plate, and in the telescopic direction of the telescopic de-staticizing brush, the projection of the other end of the telescopic de-staticizing brush covers the projection of the powder distribution plate, and in the second state, the telescopic de-staticizing brush is fully extended, and the telescopic de-staticizing brush is located between the powder distribution plate in the powder distribution position and the powder material bin; in the first state and the second state, the other end of the telescopic de-staticizing brush extends downward to below the top surface of the powder distribution plate, and when the other end of the telescopic de-staticizing brush is located above the powder distribution plate in the powder distribution position, the other end of the telescopic de-staticizing brush abuts against the top surface of the powder distribution plate;

[0022] The electron beam generator and the electron beam controller are both fixed to the molding chamber and located directly above the powder distribution plate at the powder suction position, and the electron beam controller is located below the electron beam generator; the laser scanning head is fixed to the molding chamber and located directly above the molding bin.

[0023] Furthermore, it also includes a plurality of lifting parts, which are located in the molding chamber, and the driving ends of the lifting parts are located outside the powder material bin and the molding bin, the driving ends of the plurality of lifting parts are respectively fixed to the bottom of the plurality of powder material bins and the molding bin, and the lifting ends of the plurality of lifting parts respectively penetrate the bottom of the plurality of powder material bins and the molding bin and are fixed to the bottom of the corresponding lifting bottom plate.

[0024] Furthermore, the electron beam controller comprises a focusing coil and a magnetic deflection coil which are sequentially arranged from top to bottom, and the electrons emitted by the electron beam generator sequentially pass through the focusing coil and the magnetic deflection coil.

[0025] Furthermore, it also includes several pairs of recovery bins, and several pairs of the recovery bins are respectively fixed to the outer sides of several powder material bins, and any pair of the recovery bins includes an outer recovery bin and an inner recovery bin fixed on both sides of the corresponding powder recovery bin. In the sliding direction of the leveling part, the outer recovery bin, the powder recovery bin, the inner recovery bin, and the molding bin are arranged in sequence, and the outer recovery bin is located directly below the leveling part in the to-be-scraped position, and the inner recovery bin is located directly below the leveling part in the scraped position. The inner recovery bin is arranged to collect the material scraped off by the side wall of the powder material bin or the side wall of the inner recovery bin during the movement of the powder distribution plate that absorbs the material toward the molding bin, and the material scraped off when the leveling part moves from the to-be-scraped position to the scraped position. The outer recovery bin is arranged to collect the material scraped off when the leveling part moves from the scraped position to the to-be-scraped position, and a recovery bin is arranged separately for each powder material to avoid mixing of different materials, which is beneficial to improving the recovery rate of the material and simplifying the recycling process of the powder material.

[0026] The beneficial effects of this application are:

[0027] 1. By arranging electrons on the top surface of the non-metallic and non-conductive powder distribution board, the bottom surface of the powder distribution board is polarized, and then the powder material close to the bottom surface of the powder distribution board is polarized, and the powder at the corresponding position is adsorbed on the bottom surface of the powder distribution board to achieve the adsorption of powder in the designated area. When the powder distribution board moves to the corresponding position of the forming bin, all the electrons on the top surface of the powder distribution board are cleared to eliminate the adsorption effect of the powder distribution board on the powder, so that the powder falls to the designated position of the forming bin; thereby achieving the precise arrangement of multiple powder materials on the same layer.

[0028] 2. In the process of moving the powder distribution board to the top of the molding bin, the surface of the material adsorbed on the bottom of the powder distribution board is scraped flat. In addition, the space when the powder distribution board is moved to the top of the molding bin for arrangement and molding is used to scrape the surface of the material in the powder material bin flat, which is conducive to shortening the process time and improving production efficiency.

[0029] 3. Multiple powder material bins are fixedly connected and share a set of driving devices. Before the powder distribution plate absorbs the next material powder, the corresponding powder material bin is first moved to a position close to the molding bin. On the one hand, this can avoid extending the production time due to waiting for the powder material bin to move, shorten the process time and improve production efficiency. On the other hand, it can reduce the moving distance of the powder distribution plate, reduce the loss of powder absorbed by the powder distribution plate due to movement, and also simplify the design of the driving device of multiple powder material bins.

[0030] 4. Setting a focusing coil to prevent electron divergence and setting a magnetic deflection coil to control the landing point of electrons, so that the electrons can accurately fall into the target position, which is conducive to the precise transfer of powder.

[0031] 5. An inner recovery bin is provided to collect materials scraped off by the side wall of the powder material bin or the side wall of the inner recovery bin when the powder distribution plate that absorbs the materials moves toward the forming bin, and materials scraped off when the collecting and leveling part moves from the to-be-scraped position to the scraped position. An outer recovery bin is provided to collect materials scraped off when the leveling part moves from the scraped position to the to-be-scraped position, and a recovery bin is separately provided for each powder material to avoid mixing of different materials, which is beneficial to improving the recovery rate of materials and simplifying the recycling process of powder materials.

[0032] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram of a cross-sectional structure of a product according to an embodiment;

[0034] Figure 2 This is a schematic diagram of the structure of a 3D printing device capable of accurately arranging a variety of powder materials according to an embodiment;

[0035] Figure 3 This is a schematic diagram of the structure of a 3D printing device capable of accurately arranging a variety of powder materials according to an embodiment;

[0036] Figure 4 It is a schematic diagram of a partial structure of a 3D printing device capable of accurately arranging a variety of powder materials according to an embodiment;

[0037] Figure 5 It is a partial structural schematic diagram of a 3D printing method capable of accurately arranging a variety of powder materials according to an embodiment;

[0038] Among them, the first powder 101, the second powder 102, the third powder 103, the filling powder 104, the first powder material warehouse 201, the second powder material warehouse 202, the third powder material warehouse 203, the filling powder material warehouse 204, the molding warehouse 3, the recovery warehouse 4, the lifting base plate 5, the lifting part 6, the first rack 7, the first drive motor 801, the first drive gear 802, the fixing plate 9, the second rack 10, the powder distribution plate 11, the second drive motor 1201, the second drive gear 1202, the leveling part 13, the third drive motor 1401, the third drive gear 1402, the telescopic drive part 1501, the telescopic part 1502, the brush head 1503, the electron beam generator 16, the focusing coil 1701, the magnetic deflection coil 1702, the laser scanning head 18, and the vacuum joint 19. DETAILED DESCRIPTION

[0039] It should be clear that the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the embodiments of the present application.

[0040] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present application. The singular forms of "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0041] When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims. In the description of the present application, it should be understood that the terms "first", "second", "third", etc. are only used to distinguish similar objects, and do not have to be used to describe a specific order or sequence, nor can they be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0042] In addition, in the description of this application, unless otherwise specified, "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0043] It should be understood that the embodiments of the present application are not limited to the precise structures described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the embodiments of the present application is limited only by the appended claims.

[0044] The embodiment of the present invention provides a 3D printing method that can accurately arrange multiple powder materials, which is used for additive manufacturing of products that need to arrange four powder materials (including a powder material for filling support) in the same layer based on the principle of powder bed fusion. It should be noted that the types of powder materials are not limited to the four types listed in the embodiment of the present invention. In other embodiments, the number of types of powder materials that can be accurately arranged by the 3D printing method of the present invention can be adjusted according to the needs of actual products. Among them, the 3D printing method that can accurately arrange multiple powder materials in the embodiment of the present invention includes the following steps:

[0045] Four powder material bins and a molding bin are arranged in a straight line and can slide along the straight line. The upper end faces of the powder material bin and the molding bin in the embodiment of the present invention are rectangular and coplanar. The rectangular upper end faces of the four powder material bins and the molding bin include two pairs of parallel sides with equal lengths. For any powder material bin or molding bin, the line connecting the midpoints of the two parallel sides forms two mutually perpendicular X-direction center lines and Y-direction center lines of the upper end face of the powder material bin or the upper end face of the molding bin. The Y-direction center lines of the four powder material bins are colinear (the Y-direction center line of the powder material bin in the embodiment of the present invention is used as the Y-axis), the Y-direction center line of the powder material bin is parallel to the straight line, and the Y-direction center line of the molding bin is parallel to the straight line. The powder material bin is parallel to the Y-axis centerline (the X-axis of the molding bin is used as the X-axis in the embodiment of the present invention); when the X-axis centerline of any powder material bin is collinear with the X-axis centerline of the molding bin, the powder material bin is considered to be moved to the position closest to the molding bin; three kinds of material powders (first powder, second powder, third powder) and one kind of filling powder are placed in four powder material bins (first powder material bin, second powder material bin, third powder material bin and filling powder material bin), and the surface of the powder in each powder material bin is leveled; the molding bin is used for molding the product; the three-dimensional printing model of the product is divided into multiple layers, and is printed layer by layer from bottom to top until the product is printed; please refer to Figure 1 , the product printed by the embodiment of the present invention needs to be arranged at least three kinds of powder materials in the same layer.

[0046] A rectangular powder distribution plate parallel to the horizontal plane and slidable along the X-axis is arranged directly above the X-axis. The powder distribution plate is made of non-metallic and non-conductive material. The powder distribution plate has two position states, namely, a powder suction position and a powder distribution position, during sliding along the X-axis. The powder suction position of the powder distribution plate refers to the position where the powder distribution plate is directly above the powder material bin located closest to the molding bin. The powder distribution position of the powder distribution plate refers to the position where the powder distribution plate is directly above the molding bin. In the initial state, the powder distribution plate is in the powder suction position. The electron beam generator, the focusing coil and the magnetic deflection coil are arranged in sequence from top to bottom above the powder distribution plate in the powder suction position, and the molding chamber is evacuated to a vacuum state inside the molding chamber. The pressure does not exceed 10Pa, and then the first layer of the product (i.e. the bottom layer) is printed; the first layer of the product includes four materials. First, the filling powder is arranged, and the filling powder material bin is moved to the position closest to the forming bin. At this time, the filling powder material bin is located directly below the powder distribution board, and then the powder plane of the filling powder material bin is raised to be close to the bottom surface of the powder distribution board, so that the electron beam generator emits electrons to the top surface of the powder distribution board. After focusing by the focusing coil and deflection by the magnetic deflection coil, the electrons fall on the specified position on the powder distribution board until the electrons on the top surface of the powder distribution board just cover the area where the first layer of filling powder material needs to be arranged. The electrons on the top surface of the powder distribution board will cause the powder distribution board to Charge polarization occurs, so that the top and bottom surfaces of the powder distribution board are respectively positively charged and negatively charged. Since the powder distribution board is made of non-metallic and non-conductive materials, no electron migration will occur between the powder distribution board and the filling powder. Since the powder distribution board is set close to the flat surface of the filling powder, the filling powder particles around the powder distribution board will be induced to be polarized by the electric field. The end surface of the powder particles close to one end of the powder distribution board is positively charged, and the end surface of the powder particles far away from the powder distribution board is negatively charged. Therefore, the filling powder close to the powder distribution board and corresponding to the position of the electrons is adsorbed on the bottom surface of the powder distribution board, resulting in a powder distribution board with material adsorbed at the corresponding position of the bottom surface; the powder distribution board with material adsorbed at the corresponding position of the bottom surface is Move from the powder suction position to the powder distribution position, and before the powder distribution plate moves to the top of the molding bin, scrape the thickness of the powder on the bottom surface of the powder distribution plate to the preset layer thickness. At the same time, scrape the surface of the powder filled in the powder material bin. The preset layer thickness of the embodiment of the present invention is 20μm. The preset layer thickness of the present invention can be selected between 10μm and 100μm according to the needs of the product process. After the powder distribution plate reaches the powder distribution position, use a conductive and grounded de-electrification brush to completely sweep the top surface of the powder distribution plate, remove all electrons on the top surface of the powder distribution plate in a grounded manner, so that the filling powder adsorbed on the bottom surface of the powder distribution plate falls into the molding bin under the action of gravity, completing the arrangement of the current layer of filling powder. Finally, move the powder distribution plate to the powder suction position.

[0047] After the surface of the filled powder in the filling powder material bin is scraped flat, the first powder material bin is moved to the position closest to the molding bin. After the powder distribution plate completes the arrangement of the filling powder and returns to the powder suction position, the first powder is arranged on the molding bin in the same manner as the arrangement of the filling powder, and the molding of the arranged first powder is completed by laser selective melting (SLM). It should be noted that in the process of arranging the first powder, it is necessary to scrape the surface of the first powder in the first powder material bin flat, and then move the second powder material bin to the position closest to the molding bin. After the powder distribution plate completes the arrangement of the first powder and returns to the powder suction position, after the molding of the first powder is completed, the second powder and the third powder are arranged and molded in the same manner as the arrangement of the first powder and molding of the first powder. After the filling powder is arranged and the first powder, the second powder and the third powder are arranged and formed, all the materials of the first layer are arranged and formed, and the height of the materials in the forming bin is lowered, and the lowered height = the preset layer thickness, so that there is just enough space above the first layer to arrange and form the second layer. The subsequent layers of materials are arranged and formed in the same way as the first layer until all the materials of all layers of the product are arranged and formed.

[0048] A 3D printing method for accurately arranging a variety of powder materials described in an embodiment of the present invention arranges electrons on the top surface of a non-metallic and non-conductive powder distribution board to polarize the charge on the bottom surface of the powder distribution board, thereby polarizing the charge on the powder material close to the bottom surface of the powder distribution board, and adsorbing the powder at the corresponding position on the bottom surface of the powder distribution board to achieve adsorption of powder in a designated area. When the powder distribution board moves to the corresponding position of a molding bin, the adsorption effect of the powder distribution board on the powder is eliminated by clearing all electrons on the top surface of the powder distribution board, so that the powder falls to the designated position of the molding bin; thereby achieving accurate arrangement of a variety of powder materials on the same layer; having the advantages of accurate arrangement, convenient operation, and simple process.

[0049] On the other hand, the present invention provides an embodiment of the invention, specifically providing a 3D printing device that can accurately arrange a variety of powder materials, see Figure 2-5 , including a molding chamber and a powder material bin located in the molding chamber, a molding bin 3, a recovery bin 4, a lifting bottom plate 5, a lifting part 6, a first rack 7, a first driving unit, a fixing plate 9, a second rack 10, a first bracket, a powder distribution plate 11, a second driving unit, a second bracket, a leveling part 13 and a third driving unit, and a telescopic destaticizing brush fixed to the molding chamber, an electron beam generator 16, an electron beam controller, a laser scanning head 18 and a vacuum joint 19;

[0050] The powder material bin includes a first powder material bin 201, a second powder material bin 202, a third powder material bin 203 and a filling powder material bin 204. The first powder material bin 201, the second powder material bin 202, the third powder material bin 203 and the filling powder material bin 204 are arranged in a row and fixed to each other. The cross-section and end faces of the powder material bin and the forming bin 3 in the embodiment of the present invention are square and the side lengths of each square are the same. The upper end faces of each powder material bin are coplanar with the upper end face of the forming bin 3 and are arranged parallel to the horizontal plane. The rectangular upper end surface of each powder material bin and the forming bin 3 includes two pairs of parallel sides. For any powder material bin, the line connecting the midpoints of the two parallel sides forms the X-direction center line of the upper end surface of the powder material bin, and the line connecting the midpoints of the other two parallel sides forms the Y-direction center line of the upper end surface of the powder material bin; for the forming bin 3, the line connecting the midpoints of the two parallel sides forms the X-direction center line of the upper end surface of the forming bin 3, and the line connecting the midpoints of the other two parallel sides forms the Y-direction center line of the upper end surface of the forming bin 3; the Y-direction center line of the upper end surface of the forming bin 3 is parallel to the Y-direction center line of the upper end surface of the powder material bin, and the X-direction center line of the upper end surface of the forming bin 3 is parallel to the X-direction center line of the upper end surface of the powder material bin. The Y-direction centerlines of the four powder material bins are collinear (the embodiment of the present invention takes the Y-direction centerline of the powder material bin as the Y-axis), the Y-direction centerline of the powder material bin is parallel to the direction in which the powder material bin extends, and the Y-direction centerline of the molding bin 3 is parallel to the Y-direction centerline of the powder material bin (the embodiment of the present invention takes the X-direction centerline of the molding bin 3 as the X-axis); the bottoms of the first powder material bin 201, the second powder material bin 202, the third powder material bin 203 and the filling powder material bin 204 are all slidably connected to the molding chamber through the same pair of slide grooves and slide rails, and the sliding direction of each powder material bin is parallel to the Y-direction centerline of the powder material bin. During the sliding process of the powder material bin, when the X-direction centerline of any powder material bin is collinear with the X-direction centerline of the molding bin 3, it is considered that the powder material bin is moved to the position closest to the molding bin 3. The first powder material bin 201, the second powder material bin 202, the third powder material bin 203 and the filling powder material bin 204 are respectively used to load the first powder 101 (pure titanium in this embodiment), the second powder 102 (pure titanium and 316L stainless steel in a mass ratio of 1:1 in this embodiment), the third powder 103 (316L stainless steel in this embodiment) and the filling powder 104 (fine sand in this embodiment, which is not melted or sintered) required for producing the product. The powder material bin closest to the forming bin 3 can be changed by sliding, which facilitates the use of materials and improves production efficiency. Specifically, if the X-axis center line of the first powder material bin 201 is collinear with the X-axis center line of the forming bin 3 by movement, it is considered that the first powder material bin 201 is moved to the position closest to the forming bin 3.

[0051] The recycling bin 4 includes a first outer recycling bin, a first inner recycling bin, a second outer recycling bin, a second inner recycling bin, a third outer recycling bin, a third inner recycling bin, an outer recycling bin for filling powder, and an inner recycling bin for filling powder; on the X-direction centerline of the first powder material bin 201, the first outer recycling bin, the first powder material bin 201, the first inner recycling bin, and the molding bin 3 are sequentially arranged, and the first outer recycling bin and the first inner recycling bin are both fixed to the first powder material bin 201; on the X-direction centerline of the second powder material bin 202, the second outer recycling bin, the second powder material bin 202, the second inner recycling bin, and the molding bin 3 are sequentially arranged, and the second outer recycling bin and the second inner recycling bin are both fixed to the second powder material bin The third powder material bin 202 is fixed; on the X-direction midline of the third powder material bin 203, the third outer recovery bin, the third powder material bin 203, the third inner recovery bin and the molding bin 3 are sequentially arranged, and the third outer recovery bin and the third inner recovery bin are both fixed to the third powder material bin 203; on the X-direction midline of the filling powder material bin 204, the filling powder outer recovery bin, the filling powder material bin 204, the filling powder inner recovery bin and the molding bin 3 are sequentially arranged, and the filling powder outer recovery bin and the filling powder inner recovery bin are both fixed to the filling powder material bin 204; different recovery bins are arranged to collect different types of materials, simplify the subsequent material recovery work, and reduce the difficulty and cost of material recycling;

[0052] The lifting bottom plate 5 includes a first lifting bottom plate, a second lifting bottom plate, a third lifting bottom plate, a filling lifting bottom plate and a molding lifting bottom plate. The first lifting bottom plate, the second lifting bottom plate, the third lifting bottom plate, the filling lifting bottom plate and the molding lifting bottom plate are respectively located in the first powder material bin 201, the second powder material bin 202, the third powder material bin 203, the filling powder material bin 204 and the molding bin 3. The outer periphery of the first lifting bottom plate is sealed against the inner wall of the first powder material bin 201, the outer periphery of the second lifting bottom plate is sealed against the inner wall of the second powder material bin 202, and the outer periphery of the third lifting bottom plate is sealed against the inner wall of the second powder material bin 202. The outer periphery is sealed against the inner wall of the third powder material bin 203, the outer periphery of the filling lifting bottom plate is sealed against the inner wall of the filling powder material bin 204, and the outer periphery of the molding lifting bottom plate is sealed against the inner wall of the molding bin 3; in the initial state, the lifting bottom plate located in the powder material bin is arranged close to the bottom of the powder material bin, and the lifting bottom plate located in the molding bin 3 is arranged close to the top of the molding bin 3, so that the powder material bin continuously raises the powder in the bin as the material in the bin is consumed, and the molding bin 3 continuously descends according to the degree of completion of the product after a certain layer of the product in the bin is molded;

[0053] The lifting part 6 includes a first lifting part, a second lifting part, a third lifting part, a filling lifting part and a molding lifting part. The driving ends of the first lifting part, the second lifting part, the third lifting part, the filling lifting part and the molding lifting part are all located outside the powder material bin and the molding bin 3. The driving ends of the first lifting part, the second lifting part, the third lifting part, the filling lifting part and the molding lifting part are respectively fixed to the bottom of the first powder material bin 201, the second powder material bin 202, the third powder material bin 203, the filling powder material bin 204 and the molding bin 3. The lifting ends of the descending part, the third lifting part, the filling lifting part and the molding lifting part are respectively arranged through the bottom of the first powder material bin 201, the second powder material bin 202, the third powder material bin 203, the filling powder material bin 204 and the molding bin 3 and are respectively fixed to the bottom side of the first lifting bottom plate, the bottom side of the second lifting bottom plate, the bottom side of the third lifting bottom plate, the bottom side of the filling lifting bottom plate and the bottom side of the molding lifting bottom plate. When the lifting end of the lifting part 6 is lifted relative to its driving end, it will drive the corresponding lifting bottom plate 5 to lift in the corresponding powder material bin;

[0054] The first rack 7 is fixed to the molding chamber and arranged parallel to the Y axis; the first driving unit includes a first driving motor 801 and a first driving gear 802 sleeved on the driving shaft of the first driving motor 801, the first driving motor 801 is fixed to the outer side of the powder material bin, the first driving gear 802 meshes with the first rack 7, the first driving motor 801 can rotate forward and reverse, when the first driving motor 801 is running, the first driving gear 802 rolls along the first rack 7, driving the first driving motor 801 to move along the first rack 7, and then driving the powder material bin to slide along the Y axis;

[0055] The fixed plate 9 is located above the powder material bin and the molding bin 3 and is fixed to the molding chamber. The direction in which the fixed plate 9 extends is parallel to the X-axis. The fixed plate 9 is provided with a long sliding hole extending along the X-axis. The second rack 10 is fixed on the fixed plate 9. The direction in which the second rack 10 extends is parallel to the X-axis.

[0056] The first bracket includes a first sliding portion and a first mounting portion, the upper end of the first sliding portion passes through the sliding hole and slides with the fixing plate 9, the first sliding portion slides along the direction in which the sliding hole extends, the lower end of the first sliding portion is fixed to the top side of the first mounting portion, the first mounting portion is provided with an avoidance hole and the projection of the first sliding portion on the first mounting portion is separated from the avoidance hole to ensure that the first sliding portion does not block the electrons falling into the area where the avoidance hole is located; the avoidance hole in the embodiment of the present invention is square, and the side length of the square avoidance hole is the same as the side length of the inner cavity of the powder material bin; in other embodiments, the shape of the avoidance hole can be determined according to the shape of the powder material bin, the shape of the forming bin 3, the size and shape of the product, etc. The selection and adjustment shall be based on the ability to meet the production requirements of the product; the top side of the powder distribution plate 11 is fixed to the bottom side of the first mounting portion and covers the avoidance hole setting, the bottom surface of the powder distribution plate 11 is parallel to the horizontal plane, and the distance between the bottom surface of the powder distribution plate 11 and the upper end surface of the powder material bin = the preset layer thickness. The preset layer thickness of the embodiment of the present invention is 20 μm. In other embodiments, the preset layer thickness can be reasonably adjusted between 0.01-0.1 mm. Within this range, the adsorption of the material by the powder distribution plate 11 is relatively stable; the powder distribution plate 11 is made of non-metallic and non-conductive material (glass is used in this embodiment. Preferably, in order to enhance the electrostatic induction effect, the thickness of the powder distribution plate 11 is between 0.1 and 2 mm), the powder distribution plate 11 has two position states: the powder suction position and the powder distribution position. In the initial state, the powder distribution plate 11 is located in the powder suction position, at which time the powder distribution plate 11 is located directly above the powder material bin closest to the forming bin 3. When the powder distribution plate 11 moves to the powder distribution position, the powder distribution plate 11 is located directly above the forming bin 3; when the powder distribution plate 11 is in the powder suction position, the avoidance hole just covers the inner cavity setting of the powder material bin closest to the forming bin 3, so as to ensure that the powder distribution plate can absorb powder at any position on the upper end of the powder material bin, and when the powder distribution plate 11 is in the powder distribution position, the avoidance hole just covers the inner cavity setting of the forming bin 3, so as to ensure that the powder absorbed by the powder distribution plate can be placed in the forming bin 3. The second driving unit is used to drive the powder distribution plate 11 to move between the powder suction position and the powder distribution position, and the second driving unit includes a second driving motor 1201 and a second driving gear 1202. The second driving motor 1201 is a forward and reverse motor. The second driving motor 1201 is fixed to the first sliding part, and the second driving gear 1202 is sleeved on the rotating shaft of the second driving motor 1201 and meshes with the second rack 10. When the second driving motor 1201 is running, the second driving gear 1202 rolls along the second rack 10, driving the second driving motor 1201 to move along the second rack 10, thereby driving the first bracket and the powder distribution plate 11 to slide along the X-axis direction.

[0057] The second bracket includes a second sliding portion and a second mounting portion, the upper end of the second sliding portion passes through the sliding hole and slides with the fixed plate 9, the second sliding portion slides in the direction in which the sliding hole extends, the lower end of the second sliding portion is fixed to the top side of the second mounting portion, the direction in which the second mounting portion extends is parallel to the Y axis and is detachably fixed to the upper end of the leveling portion 13, the lower end of the leveling portion 13 extends downward to below the bottom surface of the powder distribution plate 11, and the distance between the lower end surface of the leveling portion 13 and the lower end surface of the powder distribution plate 11 = preset layer thickness + scraping thickness, the scraping thickness of this embodiment is 10μm, and the direction in which the leveling portion 13 extends is parallel to the Y axis; the leveling portion 13 is to be There are two position states, namely, the scraping position and the scraped position. In the initial state, the flattening portion 13 is located in the position to be scraped. At this time, the flattening portion 13 is located in the outer recovery bin corresponding to the powder material bin closest to the forming bin 3 in the X-axis direction. After the flattening portion 13 moves to the scraped position, the flattening portion 13 is located in the inner recovery bin corresponding to the powder material bin closest to the forming bin 3 in the X-axis direction. When the flattening portion 13 is working, it will move from the position to be scraped to the scraped position, first pass through the outer recovery bin and enter the corresponding powder material bin closest to the forming bin 3, and then scrape the powder on the surface of the powder material bin flat, and then pass through the powder material bin closest to the forming bin 3 and enter the corresponding In the process of the leveling part 3 leaving the powder material bin and entering the corresponding inner recovery bin, the leveling part 13 will bring the powder particles scraped up when leveling the surface of the powder material bin to the inner recovery bin for collection, and finally the leveling part 13 will return to the outer recovery bin from the inner recovery bin through the powder material bin; when the leveling part 13 is directly above the powder material bin located closest to the forming bin 3, the length of the leveling part 13 extending in the Y-axis direction is the same as the side length of the inner circumference of the square of the powder material bin, so that the leveling part 13 can just extend into the inner cavity of the powder material bin located closest to the forming bin 3 and cover the powder material bin along the Y-axis direction. The side length of the flattening portion 13 can ensure that the entire upper surface of the powder material bin can be completely flattened during the movement of the flattening portion 13 from the to-be-scraped position to the scraped position. In other embodiments, the length of the flattening portion 13 extending in the Y-axis direction can also be slightly smaller than the side length of the square inner circumference of the powder material bin, so as to ensure that the bottom end of the flattening portion can smoothly extend into the powder material bin when deformed; the flattening portion 13 is made of a flexible material, specifically, it can be formed by a splint clamping an elastic flexible wire. The flattening portion 13 of this embodiment is formed by a splint clamping a metal wire. In other embodiments, it can also be formed by a splint clamping a wire such as a carbon fiber wire or a nylon wire;The third driving unit is used to drive the leveling part 13 to move between the to-be-scraped position and the scraped position. The third driving unit includes a third driving motor 1401 and a third driving gear 1402. The third driving motor 1401 is a forward and reverse motor. The third driving motor 1401 is fixed to the second sliding part. The third driving gear 1402 is sleeved on the rotating shaft of the third driving motor 1401 and meshes with the second rack 10. When the third driving motor 1401 is running, the third driving gear 1402 rolls along the second rack 10, driving the third driving motor 1401 to move along the second rack 10, thereby driving the second bracket and the leveling part 13 to slide along the X-axis direction. ;

[0058] The telescopic anti-static brush includes a telescopic drive unit 1501, a telescopic unit 1502 and a brush head 1503. The telescopic drive unit 1501 is located outside the molding chamber and is sealed and connected to the molding chamber. The telescopic drive unit 1501 is used to drive the telescopic unit 1502 to telescope. One end of the telescopic unit 1502 is fixed to the telescopic drive unit 1501, and the other end of the telescopic unit 1502 passes through the housing and extends and telescopes in a direction parallel to the X-axis. The brush head 1503 is located in the housing, and the upper end of the brush head is connected to the other end of the telescopic unit 1502. The brush head 1503 extends in a direction parallel to the Y-axis. The brush head is in the Y-axis The projection on the top covers the projection of the powder distribution board 11 on the Y axis to ensure that the brush head 1503 can completely brush the top surface of the powder distribution board 11. The brush head 1503 is grounded by a wire, so that when the lower end of the brush head 1503 contacts the top surface of the powder distribution board 11, the electrons on the top surface of the powder distribution board 11 can be removed by grounding; the brush head is made of a bundle of conductive flexible wires, which can be metal wires or carbon fiber wires; the telescopic de-static brush includes a first state and a second state. In the initial state, the telescopic de-static brush is in the first state, at which time the telescopic de-static brush is completely retracted, and the brush head 1503 is located at the molding position in the x-axis direction. In the second state, the telescopic de-static brush is fully extended. At this time, in the x-axis direction, the forming bin 3 is located between the brush head 1503 and the telescopic driving part 1501, and the lower end of the brush head 1503 extends downward to below the top surface of the powder distribution plate 11, but has no contact with the powder distribution plate 11 which is in the powder distribution position; the working process of the telescopic de-static brush is related to the working process of the powder distribution plate. Specifically, when the powder distribution plate 11 is in the powder absorption position, the telescopic de-static brush is fully extended. The brush is in the first state. When the powder distribution plate 11 moves from the powder absorption position to the powder distribution position, the telescopic driving unit 1502 drives the telescopic de-static brush to enter the second state. In this process, when the brush head 1503 moves to the top of the powder distribution plate 11 in a partial position, the brush head 1503 is deformed, so that the lower end of the brush head 1503 is against the top surface of the powder distribution plate 11, and driven by the telescopic driving unit 1502, the brush head 1503 completely brushes over the top surface of the powder distribution plate 11, completely removes the electrons on the top surface of the powder distribution plate 11, and makes the powder material adsorbed on the bottom surface of the powder distribution plate 11 fall to the specified position in the molding bin 3;

[0059] The electron beam generator 16 and the electron beam controller are both fixed to the molding chamber and are located directly above the powder distribution plate 11 in the powder suction position. The electron beam controller is located below the electron beam generator 16. The electron beam controller includes a focusing coil 1701 and a magnetic deflection coil 1702 arranged in sequence from top to bottom. The electrons emitted by the electron beam generator 16 are focused by the focusing coil 1701 and then deflected by the magnetic deflection coil 1702, so as to fall on the preset position on the top surface of the powder distribution plate 11; the laser scanning head 18 is fixed to the molding chamber and is located directly above the molding chamber 3. The laser scanning head 18 is used to melt or sinter the powder in the specified area of ​​the specified layer of the molding chamber 3; the vacuum joint 19 is fixed to the molding chamber and is arranged through the outer wall of the molding chamber;

[0060] The use process of a 3D printing device capable of accurately arranging a variety of powder materials according to an embodiment of the present invention is as follows:

[0061] Before starting printing, the first lifting bottom plate, the second lifting bottom plate, the third lifting bottom plate and the filling lifting bottom plate are lowered to the lowest point of the corresponding powder material bin, and a sufficient amount of the first powder 101, the second powder 102, the third powder 103 and the filling powder 104 are respectively loaded into the corresponding powder material bin, and the surface of the powder in each powder material bin is scraped flat and the distance between the upper end surface of the material in each powder material bin and the upper end surface of the powder material bin is 10 μm. This distance is related to the rising distance of the lifting bottom plate. In other embodiments, it can be reasonably adjusted according to different production needs. In this embodiment, it is set to 10 μm to ensure that the subsequent leveling unit 13 can use enough powder The surface of the material in the powder material bin was not smoothly scraped flat; then the powder distribution plate 11 was placed in the powder absorption position, the telescopic static removal brush was placed in the first state, and the leveling part 13 was placed in the scraping position, and a vacuum pump was used to evacuate the interior of the molding chamber through the vacuum joint 19 until the pressure inside the molding chamber did not exceed 10Pa. The slicing scanning path data of the molding layer of the multi-material part was imported into the 3D printing control system (the scanning path includes the geometric scanning data and material information of each printing area, as well as the powder filling scanning path data and material information of each molding layer), and after determining the number of layers of the product and the distribution areas of different materials in each layer, the product was printed layer by layer from bottom to top.

[0062] In the process of layer-by-layer printing, the printing process of the first layer is as follows:

[0063] Move the filling powder material bin 204 to the position closest to the forming bin 3. At this time, the filling powder material bin 204 is located directly below the powder distribution plate 11. Then, the filling lifting part drives the filling lifting bottom plate to rise by 30μm, so that the surface of the filling powder 104 is just in close contact with the bottom surface of the powder distribution plate 11. Then, the electron beam generator 16 and the electron beam controller use electrons to draw the area where the filling powder 104 is to be arranged on the forming bin 3 on the top surface of the powder distribution plate 11. Then, the powder distribution plate 11 is moved to the powder distribution position and when the powder distribution plate 11 reaches the powder distribution position, the leveling part 13 is moved from the to-be-scraped position to the scraped position, and then from the scraped position to the to-be-scraped position. In this process, first, the material that is adsorbed on the bottom surface of the powder distribution plate 11 and has a thickness greater than the preset layer thickness (20μm) and does not belong to the current layer will be scraped off by the top of the side wall of the filling powder material bin 204 and the top of the side wall of the filling powder recovery bin and fall into the filling powder material bin. 204 and the filling powder in the recovery bin, so that the thickness of the material adsorbed on the bottom surface of the powder distribution plate 11 is equal to the preset layer thickness and becomes flat, and secondly, the leveling part 13 can scrape the excess filling powder 104 scraped during leveling to the inner recovery bin during the movement from the to-be-scraped position to the scraped position, and the leveling part 13 can also scrape the excess filling powder 104 scraped during leveling to the outer recovery bin during the movement from the scraped position to the to-be-scraped position. After the powder distribution plate 11 moves to the powder distribution position, the telescopic de-static brush moves from the first state to the second state, and then moves from the second state to the first state. In this process, the brush head 1503 completely brushes over the top surface of the powder distribution plate 11, and completely removes the electrons on the top surface of the powder distribution plate 11 in a grounded manner, so that the powder on the bottom surface of the powder distribution plate 11 falls onto the molding bin 3 due to the elimination of the electrons on the top surface, and then the powder distribution plate 11 is moved back to the powder absorption position to complete the arrangement process of the filling powder 104. (The filling powder 104 of this embodiment does not need to be formed, so laser melting printing is not performed).

[0064] After the leveling unit 13 scrapes the filling powder 104 in the filling powder material bin 204 flat and returns to the scraping position, the first powder material bin 201 is moved to the position closest to the molding bin 3, and then after the powder distribution plate 11 completes the arrangement of the filling powder 104 and returns to the powder suction position, the first powder 101 is arranged on the molding bin in the same manner as the arrangement of the filling powder material 104, and then the molding of the arranged first powder 101 is completed by laser selective melting (SLM), and the molding of the first powder 101 of the current layer is completed. In the process of arranging the first powder 101, after the leveling part 13 scrapes the surface of the first powder 101 in the first powder material bin 201 flat and returns to the position to be scraped, the second powder material bin 202 can be moved to the position closest to the molding bin 3. After the powder distribution plate 11 completes the arrangement of the first powder 101 and returns to the powder suction position, after the molding of the first powder 101 is completed, the second powder 102 and the third powder 103 are arranged and molded in the same way as the arrangement of the first powder 101 and the molding of the first powder 101. After the filling powder 104, the first powder 101, the second powder 102 and the third powder 103 are arranged and molded (the filling powder 104 does not need to be molded), all the materials of the first layer are arranged and molded, and the height of the materials in the molding bin 3 is lowered, and the lowering height = the preset layer thickness (20μm in this embodiment) so that the space above the first layer is just enough to arrange and mold the second layer, and the arrangement and molding of the subsequent layers of materials are carried out in the same way as the first layer, until the materials of all layers of the product are arranged and molded.

[0065] The beneficial effects of this application are:

[0066] 1. By arranging electrons on the top surface of the non-metallic and non-conductive powder distribution board 11, the bottom surface of the powder distribution board 11 is polarized, and then the powder material close to the bottom surface of the powder distribution board 11 is polarized, and the powder at the corresponding position is adsorbed on the bottom surface of the powder distribution board 11, so as to achieve the adsorption of powder in the designated area. When the powder distribution board 11 moves to the corresponding position of the forming bin 3, all the electrons on the top surface of the powder distribution board 11 are cleared to eliminate the adsorption effect of the powder distribution board 11 on the powder, so that the powder falls to the designated position of the forming bin 3, thereby achieving the precise arrangement of various powder materials on the same layer.

[0067] 2. In the process of the powder distribution board 11 being moved to the top of the molding bin 3, the surface of the material adsorbed on the bottom of the powder distribution board 11 is scraped flat. The gap when the powder distribution board 11 is moved to the top of the molding bin 3 for arrangement and molding is used to scrape the surface of the material in the powder material bin flat, which is conducive to shortening the process time and improving production efficiency.

[0068] 3. Multiple powder material bins are fixedly connected and share a set of driving devices. Before the powder distribution plate 11 needs to adsorb powder materials, the powder material bin is first moved to the position closest to the forming bin 3. On the one hand, this can avoid extending the production time due to waiting for the powder distribution plate 11 to move or waiting for the powder material bin to move, shorten the process time and improve production efficiency. On the other hand, it can reduce the moving distance of the powder distribution plate 11, reduce the loss of powder adsorbed by the powder distribution plate 11 due to movement, and also simplify the design of the driving device of multiple powder material bins.

[0069] 4. A focusing coil 1701 is set to prevent electron divergence, and a magnetic deflection coil 1702 is set to control the landing point of the electrons, so that the electrons fall accurately into the target position, which is conducive to the accurate transfer of powder.

[0070] 5. An internal recovery bin 4 is provided to collect materials scraped off by the side wall of the powder material bin or the side wall of the internal recovery bin when the powder distribution plate that adsorbs the materials moves toward the forming bin, and materials scraped off when the collecting and leveling part moves from the to-be-scraped position to the scraped position. An external recovery bin is provided to collect materials scraped off when the leveling part moves from the scraped position to the to-be-scraped position, and a recovery bin is separately provided for each powder material to avoid mixing of different materials, which is beneficial to improving the recovery rate of materials and simplifying the recycling process of powder materials.

[0071] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, and the present invention is also intended to include these modifications and modifications.

Claims

1. A 3D printing method capable of accurately arranging a variety of powder materials, characterized in that: The following steps are involved: At least two powder material bins arranged in a straight line and a molding bin are arranged in a molding chamber, and powders of at least two materials are placed in corresponding numbers of powder material bins and leveled; a powder distribution plate made of non-metallic and non-conductive material is arranged above the powder material bins, and the powder distribution plate has two position states, namely, a powder suction position and a powder distribution position. The powder suction position refers to the position where the powder distribution plate is located directly above the powder material bin closest to the molding bin, and the powder distribution position refers to the position where the powder distribution plate is located directly above the molding bin; Divide the 3D printing model of the product to be printed into multiple layers, and print them layer by layer from bottom to top until the product is printed; Among them, the method for arranging and forming any layer of materials includes the following steps: moving the powder distribution board to the powder absorption position, moving the powder material bin where the first material to be arranged is located to the position closest to the forming bin, raising the surface of the material to be arranged in the powder material bin until it is just in close contact with the bottom surface of the powder distribution board, arranging a number of electrons on the top surface of the powder distribution board and making a number of electrons just cover the area where the current material needs to be arranged, so as to obtain a powder distribution board with the material adsorbed at the corresponding position on the bottom surface, moving the powder distribution board to the powder distribution position, and before the powder distribution board is moved above the forming bin, the bottom surface of the powder distribution board is The thickness of the adsorbed material is scraped flat to the preset layer thickness. After the powder distribution board reaches the powder distribution position, all electrons on the top surface of the powder distribution board are cleared to make the material adsorbed by the powder distribution board fall to the area where the material needs to be arranged above the bottom plate of the forming bin, and the powder distribution board is moved to the powder absorption position to complete the arrangement of the first material that needs to be arranged in the current layer; if the current material needs to be formed, then after forming by melting or sintering, the arrangement and forming of the next material in the current layer are carried out; if the current material does not need to be formed, the arrangement and forming of the next material in the current layer are directly carried out until all materials in the current layer are arranged and formed; The method of printing layer by layer from bottom to top includes the following steps: after all materials of any layer are arranged and formed, the height of the bottom plate of the forming bin is lowered, and the lowered height is equal to the preset layer thickness, and then the next layer of materials is arranged and formed in the same way until all layers of materials are arranged and formed.

2. The 3D printing method capable of accurately arranging a plurality of powder materials according to claim 1, characterized in that: The material arrangement and forming method also includes the following steps: after the powder distribution plate that has adsorbed the material at the corresponding position on the bottom surface is moved to the powder distribution position, the surface of the powder material bin corresponding to the material adsorbed by the powder distribution plate is scraped flat.

3. The 3D printing method capable of accurately arranging a plurality of powder materials according to claim 2, characterized in that: The material arrangement and molding method also includes the following steps: after scraping the surface of the powder material bin corresponding to the material adsorbed by the powder distribution plate flat, before moving the powder distribution plate to the powder absorption position, first move the powder material bin corresponding to the next material to be arranged to the position closest to the molding bin.

4. The 3D printing method capable of accurately arranging a plurality of powder materials according to claim 1, characterized in that: The method for arranging a number of electrons on the top surface of the powder distribution board includes the following steps: generating and emitting electrons through an electron beam generator, and then adjusting the movement trajectory of the electrons through a focusing coil and a magnetic deflection coil so that the electrons accurately fall at a designated position on the top surface of the powder distribution board until the designated area is covered.

5. The 3D printing method capable of accurately arranging a plurality of powder materials according to claim 1, characterized in that: The method for removing all electrons from the top surface of the powder distribution board comprises the following steps: completely sweeping the top surface of the powder distribution board with a conductive and grounded de-electrification brush to remove all electrons from the top surface of the powder distribution board in a grounded manner.

6. The 3D printing method capable of accurately arranging a plurality of powder materials according to claim 1, characterized in that: The 3D printing method capable of accurately arranging a variety of powder materials is carried out in a vacuum environment with a pressure less than 10Pa.

7. A 3D printing device capable of accurately arranging a variety of powder materials, applicable to the 3D printing method capable of accurately arranging a variety of powder materials as claimed in any one of claims 1 to 6, characterized in that: The invention comprises a molding chamber and at least two powder material bins located in the molding chamber, a molding bin, a plurality of lifting bottom plates, a first driving unit, a powder distribution plate, a second driving unit, a leveling unit and a third driving unit, as well as a telescopic static removal brush fixed to the molding chamber, an electron beam generator, an electron beam controller, a laser scanning head and a vacuum joint; The plurality of powder material bins are arranged in a row and fixed to each other, the plurality of lifting bottom plates are respectively located in the plurality of powder material bins and the forming bins, and the outer peripheries of the plurality of lifting bottom plates are respectively sealed against the inner walls of the plurality of powder material bins and the inner walls of the forming bins; the first driving unit is fixed to the outer side surface of the powder material bin, and the first driving unit drives the plurality of powder material bins to slide along the direction in which they are arranged and extended; The top side of the powder distribution plate is fixed to the second driving unit, and the bottom surface of the powder distribution plate is arranged parallel to the horizontal plane. The powder distribution plate has two position states: a powder suction position and a powder distribution position. The powder suction position refers to the position where the powder distribution plate is located directly above the powder material bin closest to the forming bin, and the powder distribution position refers to the position where the powder distribution plate is located directly above the forming bin. In the powder suction position, the distance between the bottom surface of the powder distribution plate and the upper end surface of the powder material bin is equal to the preset layer thickness; the second driving unit drives the powder distribution plate to slide between the powder suction position and the powder distribution position; The top side of the leveling portion is fixed to the third driving unit, and the lower end of the leveling portion extends below the bottom surface of the powder distribution plate, and the distance between the lower end of the leveling portion and the bottom side of the powder distribution plate = preset layer thickness + scraping thickness, the extending direction of the leveling portion is parallel to the extending direction of the plurality of powder material bins, and the extending length of the leveling portion is equal to the maximum width of the inner cavity of the powder material bin, and the leveling portion has two position states: a to-be-scraped position and a scraped position. When the powder material bin is located between the leveling portion and the forming bin, the position corresponding to the leveling portion is the to-be-scraped position, and the scraped position refers to the position of the leveling portion between the powder material bin and the forming bin, and the third driving unit drives the leveling portion to slide between the scraped position and the to-be-scraped position, and the sliding direction of the leveling portion is parallel to the sliding direction of the powder distribution plate; One end of the telescopic de-staticizing brush is fixed to the molding chamber, and the other end of the telescopic de-staticizing brush is telescoped in the sliding direction of the powder distribution plate, and the telescopic de-staticizing brush includes a first state and a second state. In the first state, the telescopic de-staticizing brush is fully retracted, and the other end of the telescopic de-staticizing brush is located between the powder distribution plate in the powder distribution position and one end of the telescopic de-staticizing brush, and a gap is provided between the other end of the telescopic de-staticizing brush and the powder distribution plate, and in the telescopic direction of the telescopic de-staticizing brush, the projection of the other end of the telescopic de-staticizing brush covers the projection of the powder distribution plate, and in the second state, the telescopic de-staticizing brush is fully extended, and the telescopic de-staticizing brush is located between the powder distribution plate in the powder distribution position and the powder material bin; in the first state and the second state, the other end of the telescopic de-staticizing brush extends downward to below the top surface of the powder distribution plate, and when the other end of the telescopic de-staticizing brush is located above the powder distribution plate in the powder distribution position, the other end of the telescopic de-staticizing brush abuts against the top surface of the powder distribution plate; The electron beam generator and the electron beam controller are both fixed to the molding chamber and located directly above the powder distribution plate at the powder suction position, and the electron beam controller is located below the electron beam generator; the laser scanning head is fixed to the molding chamber and located directly above the molding bin.

8. The 3D printing device capable of accurately arranging a variety of powder materials according to claim 7, characterized in that: It also includes a plurality of lifting parts, which are located in the molding chamber, and the driving ends of the lifting parts are located outside the powder material bin and the molding bin, the driving ends of the plurality of lifting parts are respectively fixed to the bottom of the plurality of powder material bins and the molding bin, and the lifting ends of the plurality of lifting parts respectively penetrate the bottom of the plurality of powder material bins and the molding bin and are fixed to the bottom of the corresponding lifting bottom plate.

9. The 3D printing device capable of accurately arranging a variety of powder materials according to claim 7, characterized in that: The electron beam controller comprises a focusing coil and a magnetic deflection coil arranged in sequence from top to bottom, and the electrons emitted by the electron beam generator pass through the focusing coil and the magnetic deflection coil in sequence.

10. The 3D printing device capable of accurately arranging a variety of powder materials according to claim 7, characterized in that: It also includes a plurality of pairs of recovery bins, which are respectively fixed to the outer sides of a plurality of powder material bins, and any pair of the recovery bins includes an outer recovery bin and an inner recovery bin fixed on both sides of the corresponding powder recovery bin. In the sliding direction of the leveling part, the outer recovery bin, the powder recovery bin, the inner recovery bin and the forming bin are arranged in sequence, the outer recovery bin is located directly below the leveling part in the to-be-scraped position, and the inner recovery bin is located directly below the leveling part in the scraped position.

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