Multi-material electron beam additive manufacturing apparatus

Abstract

The present application relates to a kind of multi-material electron beam additive manufacturing device.Multi-material electron beam additive manufacturing device includes sealed shell, first powder storage unit, second powder storage unit, forming unit, falling powder laying unit, single-arm powder laying unit, electron beam gun, first powder recycling unit and powder suction device.Sealed shell has working chamber and mounting chamber inside.Falling powder laying device is used to lay A powder material in first powder storage unit to forming cavity.Single-arm powder laying device is used to lay B powder material in second powder storage unit to forming cavity, and also used to push the excess B powder material outside forming cavity to second opening after B powder material laying is completed.Powder suction device is used to extract the powder dispersed in working chamber out of sealed shell after 3D printing of each material is completed.Multi-material electron beam additive manufacturing device realizes the overall forming of multi-material component, and solves the problems of multi-material cross contamination and material mixing that cannot be reused.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of additive manufacturing technology, in particular to a multi-material electron beam additive manufacturing device. BACKGROUND

[0002] The powder bed electron beam additive manufacturing technology has stronger penetration ability than laser, which makes the powder melting more uniform; it can melt high reflectivity materials without causing the surface of the powder particles to overheat and evaporate; it can adapt to a wider layer thickness range, and under the same conditions, the printing efficiency and density are better than laser; during the entire forming process, the powder bed maintains vacuum and high temperature, which plays a real-time heat treatment role and reduces the subsequent heat treatment requirements. Therefore, at present, the powder bed electron beam additive manufacturing technology is gradually replacing the powder bed laser additive manufacturing technology in some specific fields.

[0003] With the development of technology, the demand for multi-material integral forming in the fields of aerospace, national defense industry, automobile, etc. is becoming more and more urgent, and it is difficult to meet the demand by using the powder bed additive manufacturing technology. The biggest difficulty lies in the problem of powder cross-contamination during multi-material forming and the huge waste caused by the inability to reuse the mixed powder after forming. Therefore, it is urgent to develop a multi-material additive manufacturing device to realize the integral forming of multi-material components and solve the problems of powder cross-contamination and the inability to reuse the mixed powder. SUMMARY

[0004] Therefore, it is necessary to provide a multi-material electron beam additive manufacturing device which can realize multi-material integral forming and reduce the probability of powder cross-contamination and the inability to reuse the mixed powder.

[0005] A multi-material electron beam additive manufacturing device for manufacturing a multi-material 3D printing structure, the multi-material electron beam additive manufacturing device comprising:

[0006] A sealed shell having a working plate inside to divide the internal space of the sealed shell into a working chamber and a mounting chamber; the working plate is provided with a first opening and a second opening at intervals; a suction port is provided in the side wall of the sealed shell and communicates with the working chamber;

[0007] A first powder storage unit for storing A powder material;

[0008] A second powder storage unit for storing B powder material;

[0009] A forming unit arranged in the mounting chamber; the forming unit has a forming cavity communicating with the first opening;

[0010] A falling powder spreader for spreading the A powder material in the first powder storage unit into the forming cavity;

[0011] A first powder recycling unit is arranged in the installation chamber and has a first powder recycling tank in communication with the second opening;

[0012] A single-arm powder spreader is arranged to spread the B powder material in the second powder storage unit into the forming cavity and to push the excess B powder material outside the forming cavity into the second opening after the B powder material is spread;

[0013] An electron beam gun is arranged to melt the A powder material in the forming cavity layer by layer to form the A material part of the multi-material 3D printed structure and to melt the B powder material in the forming cavity layer by layer to form the B material part of the multi-material 3D printed structure.

[0014] A powder suction device is arranged in the suction port and is arranged to suck the powder dispersed in the working chamber out of the sealed shell after the 3D printing of one material is completed.

[0015] The multi-material electron beam additive manufacturing device can realize the one-step forming of a whole part of two different materials. The use of the electron beam additive manufacturing technology causes the phenomenon of "false sintering" of the powder, so that the excess powder in the forming cavity will be false sintered during the electron beam sintering process. After the 3D printing is completed, the A powder material and the B powder material after false sintering are not easy to cross-contaminate and mix with each other, which reduces the probability of cross-contamination of the powder and the secondary use of the mixed powder during the multi-material printing. Further, after the 3D printing of one material is completed, the powder suction device will suck the powder dispersed in the working chamber out of the sealed shell, and the single-arm powder spreader will push the excess B powder material outside the forming cavity into the powder recycling unit for recycling, which further reduces the probability of cross-contamination of the powder and the secondary use of the mixed powder during the multi-material printing. Therefore, the multi-material electron beam additive manufacturing device realizes the one-step forming of a whole part of two different materials and solves the problems of cross-contamination of the multi-material and the secondary use of the mixed material. BRIEF DESCRIPTION OF DRAWINGS

[0016] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The detailed description is made with reference to the accompanying drawings.

[0017] Figure 1 FIG. 1 is a structural schematic diagram of a multi-material electron beam additive manufacturing device according to an embodiment of the present application;

[0018] Figure 2 FIG. 2 is a structural schematic diagram of a multi-material electron beam additive manufacturing device according to another embodiment of the present application;Figure 1 A-A sectional view of the multi-material electron beam additive manufacturing device shown.

[0019] Explanation of reference numerals in the detailed description: 100, multi-material electron beam additive manufacturing device; 110, sealed housing; 111, workboard; 1111, first opening; 1112, second opening; 1113, third opening; 1114, fourth opening; 112, work chamber; 1121, first inner cavity; 1122, second inner cavity; 113, mounting chamber; 120, first powder storage unit; 130, second powder storage unit; 131, powder cavity; 132, first side plate; 133, first sliding plate; 134, first lifting driving member; 140, forming unit; 141, forming cavity; 142, second side plate; 143, second sliding plate; 144, second lifting driving member; 150, falling powder spreader; 160, single-arm powder spreader; 170, electron beam gun; 180, powder recycling unit; 181, powder recycling tank; 182, powder recycling channel; 190, powder suction device; 201, telescopic isolation door. DETAILED DESCRIPTION

[0020] In order to facilitate the understanding of the present application, a more complete understanding of the present application can be had by reference to the following description and the accompanying drawings. The figures in the drawings show preferred embodiments of the application. However, the application can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete. It is therefore to be understood that no limitation in the scope of the application is intended by the description of the preferred embodiments.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0022] In describing a position relationship, unless otherwise defined, when an element is referred to as being "on" another element, it can be directly on the other element or there can be an intermediate element. It can also be understood that when an element is referred to as being "between" two elements, it can be the only one between the two elements, or there can be one or more intermediate elements.

[0023] In the case of using "include", "have", and "contain" described herein, unless an explicit limiting term is used, such as "only", "consisting of", etc., another component can be added. Unless otherwise mentioned, the singular form of the term can include the plural form, and it cannot be understood as the number of one.

[0024] Figure 1and Figure 2 The structure of a multi-material electron beam additive manufacturing device in an embodiment of the present application is shown. For ease of illustration, the drawing only shows the structure related to the embodiment of the present application.

[0025] Referring to Figure 1 and Figure 2 The multi-material electron beam additive manufacturing device 100 in the preferred embodiment of the present application is used for manufacturing a multi-material 3D printing structure. The multi-material electron beam additive manufacturing device 100 comprises a sealed housing 110, a first powder storage unit 120, a second powder storage unit 130, a forming unit 140, a falling powder spreader 150, a single-arm powder spreader 160, an electron beam gun 170, a first powder recycling unit 180, and a powder suction device 190.

[0026] The sealed housing 110 is internally provided with a working plate 111 to divide the internal space of the sealed housing 110 into a working chamber 112 and a mounting chamber 113. The working plate 111 is provided with a first opening 1111 and a second opening 1112 at intervals. The sidewall of the sealed housing 110 is provided with a suction port (not marked in the drawing) in communication with the working chamber 112. The mounting chamber 113 can be a closed space or a semi-closed space.

[0027] Specifically, when the multi-material electron beam additive manufacturing device 100 is in a horizontal plane, the working plate 111 is transversely arranged in the interior of the sealed housing 110 to divide the internal space of the sealed housing 110 into the working chamber 112 and the mounting chamber 113 distributed in an upper and lower manner.

[0028] The first powder storage unit 120 is used for storing A powder material. The second powder storage unit 130 is used for storing B powder material. Therefore, the multi-material 3D printing structure is made of two materials of A material and B material.

[0029] The forming unit 140 is arranged in the mounting chamber 113. The forming unit 140 is internally provided with a forming cavity 141 in communication with the first opening 1111. Specifically, the forming cavity 141 is located directly below the first opening 1111.

[0030] The falling powder spreader 150 is used for spreading the A powder material in the first powder storage unit 120 into the forming cavity 141. In actual application, the A powder material in the first powder storage unit 120 falls into the falling powder spreader 150 under the action of gravity, and then the A powder material is uniformly spread in the forming cavity 141 by the falling powder spreader 150 to facilitate the subsequent forming of the multi-material 3D printing structure.

[0031] The first powder recycling unit 180 is arranged in the installation chamber 113 and has a first powder recycling tank 181 in communication with the second opening 1112. Specifically, the first powder recycling tank 181 is in communication with the second opening 1112 through a first powder recycling channel 182. The arrangement of the first powder recycling unit 180 facilitates the recycling and reuse of the powder after printing.

[0032] The single-arm powder spreader 160 is used to spread the B powder material in the second powder storage unit 130 into the forming cavity 141 and to push the excess B powder material outside the forming cavity 141 into the second opening 1112 after the spreading of the B powder material is completed. In this way, the single-arm powder spreader 160 has two functions, one of which is to spread the B powder material into the forming cavity 141, and the other of which is to recycle the excess B powder material that falls outside the forming cavity 141 into the first powder recycling unit 180 after the spreading of the B powder material is completed.

[0033] The electron beam gun 170 is used to melt the A powder material in the forming cavity 141 layer by layer to form the A material part of the multi-material 3D printed structure, and to melt the B powder material in the forming cavity 141 layer by layer to form the B material part of the multi-material 3D printed structure. Thus, the electron beam gun 170 is mainly used to melt the material powder in the forming cavity 141 layer by layer according to a preset trajectory after the forming cavity 141 is spread with powder material, so as to obtain a multi-material 3D printed structure.

[0034] The powder suction device 190 is installed at the suction port and is used to suck the powder dispersed in the working chamber 112 out of the sealed shell 110 after the 3D printing of each material is completed. The powder suction device 190 can be a mechanical pump or the like

[0035] Therefore, the multi-material electron beam additive manufacturing device 100 can realize the one-time forming of the whole part of two different materials. The use of electron beam additive manufacturing technology causes the phenomenon of "false sintering" of the powder. Therefore, during the electron beam sintering process, the excess powder in the forming cavity 141 will be false sintered. After the 3D printing is completed, when the excess A powder material and B powder material in the forming cavity 141 are recycled, the A powder material and the B powder material after false sintering are not easy to cross-contaminate and mix with each other. Even if there is some mixing of materials at the critical point between the A powder material and the B powder material after clumping, the mixed material at the critical point can be cut off, and the A powder material clumps and the B powder material clumps can be recycled separately, thereby reducing the probability of cross-contamination of the powder and the difficulty of recycling the mixed powder after the multi-material printing process. Further, after each 3D printing of a material is completed, the powder suction device 190 will suck the powder dispersed in the working chamber 112 out of the sealed shell 110, thereby reducing the probability of contamination of the subsequent printing work by splashed dust. At the same time, the single-arm powder spreader 160 will push the excess B powder material outside the forming cavity 141 to the first powder recycling unit 180 for recycling, thereby further reducing the probability of cross-contamination of the powder and the difficulty of recycling the mixed powder after the multi-material printing process. Therefore, the multi-material electron beam additive manufacturing device 100 can realize the one-time forming of the whole part of two different materials, and also solve the problems of cross-contamination of the multi-material and the difficulty of recycling the mixed material after the multi-material printing process.

[0036] Further, in the multi-material electron beam additive manufacturing device 100, the gravity falling type powder spreading and the single-arm powder spreading are combined. The gravity falling type powder spreading can add materials at any time and can be used as the main material for forming, so that the printing process will not be interrupted due to insufficient materials. The single-arm powder spreading can be used for the powder forming of the secondary material (less required material).

[0037] In some embodiments, the multi-material electron beam additive manufacturing device 100 further comprises a vacuum pumping device (not shown in the figure). The vacuum pumping device is used to pump the working chamber 112 to a pressure less than 1.67 x 10 -3 Pa. In this way, a low-oxygen and pressure-stable printing environment can be provided, which reduces the probability of material oxidation during the printing process and the probability of defects such as air holes in the structure after the printing forming, and is beneficial to the improvement of the yield and product quality of the multi-material 3D printed structure.

[0038] In some embodiments, a third opening 1113 is further formed in the working plate 111. The first opening 1111 is located between the third opening 1113 and the second opening 1112 in the spacing direction of the first opening 1111 and the second opening 1112. In this way, the third opening 1113, the first opening 1111, and the second opening 1112 are arranged in a straight line direction.

[0039] The second powder storage unit 130 is arranged in the installation chamber 113. The second powder storage unit 130 has a powder cavity 131 which is in communication with the third opening 1113. The single-arm spreader is configured to push the B powder at the third opening 1113 into the forming cavity 141 and push the excess powder in the forming cavity 141 into the second opening 1112 after 3D printing of each material.

[0040] In this way, the single-arm spreader is configured to reciprocally push the material in the direction between the first opening 1111 and the second opening 1112, so as to achieve the purpose of pushing the B powder material in the second powder storage unit 130 from the third opening 1113 into the forming cavity 141 for powder spreading, and pushing the excess powder in the forming cavity 141 into the second opening 1112 for recycling after printing of each material.

[0041] Further, in some embodiments, in the direction perpendicular to the direction between the first opening 1111 and the second opening 1112, the width of the third opening 1113 is greater than or equal to the width of the first opening 1111 and less than the width of the second opening 1112, and the pushing width of the single-arm spreader 160 is greater than the width of the third opening 1113.

[0042] It should be noted that the width of all openings herein refers to the linear dimension of the opening in the direction perpendicular to the direction between the first opening 1111 and the second opening 1112.

[0043] The pushing direction of the single-arm spreader 160 is consistent with the direction between the first opening 1111 and the second opening 1112, so the pushing width of the single-arm spreader 160 is set to be greater than the width of the third opening 1113, the width of the first opening 1111 and the width of the second opening 1112, respectively, to ensure that the single-arm spreader 160 can push all the B powder material at the third opening 1113 to the first opening 1111 and push all the excess B powder material outside the forming cavity 141 to the second opening 1112; and the width of the third opening 1113 is set to be greater than or equal to the width of the first opening 1111, so as to ensure that the B powder material pushed from the third opening 1113 can enter the first opening 1111 and fill the forming cavity 141; and the width of the second opening 1112 is set to be greater than the width of the first opening 1111 and the width of the third opening 1113, respectively, so as to ensure that all the excess B powder material outside the forming cavity 141 is pushed into the second opening 1112 for easy recycling.

[0044] Further, in some embodiments, the multi-material electron beam additive manufacturing device 100 further comprises a retractable isolation door 201. The retractable isolation door 201 is installed in the working chamber 112 and is configured to retract along a direction perpendicular to the working plate 111 to separate the working chamber 112 into a first inner chamber 1121 and a second inner chamber 1122. The third opening 1113 is located in the first inner chamber 1121, and the second opening 1112 and the first opening 1111 are both located in the second inner chamber 1122.

[0045] Thus, when the multi-material electron beam additive manufacturing device 100 is in a horizontal plane, the retractable isolation door 201 is vertically arranged and retractable along a vertical direction. When the retractable isolation door 201 is in an extended state, the retractable isolation door 201 is closed to isolate the working chamber 112 into the first inner chamber 1121 and the second inner chamber 1122; when the retractable isolation door 201 is in a retracted state, the retractable isolation door 201 is opened, and the first inner chamber 1121 and the second inner chamber 1122 are in a communicating state.

[0046] In actual applications, when printing of the A material part of the multi-material 3D printed structure is needed, the retractable isolation door 201 is closed to isolate the B powder material in the first inner chamber 1121, and the printing of the A powder material is performed in the second inner chamber 1122, so as to avoid the situation that the B powder material in the second powder storage unit 130 enters the forming cavity 141 due to various reasons; when printing of the B material part of the multi-material 3D printed structure is needed, the retractable isolation door 201 is opened to facilitate pushing of the B powder material in the second powder storage unit from the third opening 1113 to the first opening 1111 and performing powder laying work in the forming cavity 141. Therefore, the arrangement of the retractable isolation door 201 not only ensures one-time integral forming of the multi-material 3D printed structure, but also further reduces the probability of powder cross-contamination and the situation that the mixed powder cannot be used again in the multi-material printing process.

[0047] Further, in some embodiments, the drop-on-demand powder layering device 150 is configured to move between an initial position (not labeled in the figure) and a working position (not labeled in the figure). When the drop-on-demand powder layering device 150 is in the initial position, the interval direction between the drop-on-demand powder layering device 150 and the first opening 1111 is arranged transversely to the interval direction between the first opening 1111 and the second opening 1112. When the drop-on-demand powder layering device 150 is in the working position, the powder layering port of the drop-on-demand powder layering device 150 is located above the first opening 1111.

[0048] It should be noted that the interval direction between the initial position and the working position is arranged transversely to the interval direction between the first opening 1111 and the second opening 1112, which means that the two directions are perpendicular to each other or the included angle between them is less than 90 degrees.

[0049] When the A powder material needs to be laid into the forming cavity 141, the falling powder distributor 150 is controlled to move to the working position and make the powder laying opening above the first opening 1111, so that the falling powder distributor 150 can lay the A powder material in the first powder storage unit 120 into the forming cavity 141; when the powder laying work of the A powder material is completed, the falling powder distributor 150 is controlled to leave the working position and move to the initial position, so as to avoid interference with the work of the subsequent electron beam gun 170 and the single-arm powder distributor 160.

[0050] Specifically, when the telescopic isolation door 201 is in the contracted state, the telescopic isolation door 201 is opened, and the falling powder distributor 150 is located at the initial position, so that the single-arm powder distributor 160 can push the B powder material from the third opening 1113 into the first opening 1111.

[0051] Further, in some embodiments, the working plate 111 is further provided with a fourth opening 1114 spaced from the first opening 1111. The spacing direction between the first opening 1111 and the fourth opening 1114 is consistent with the spacing direction between the initial position and the working position.

[0052] The multi-material electron beam additive manufacturing device 100 further comprises a second powder recovery unit (not shown in the figure). The second powder recovery unit is installed in the installation cavity 113 and has a second powder recovery tank (not shown in the figure) in communication with the fourth opening 1114. The falling powder distributor 150 is further used to push the excess A powder material outside the forming cavity 141 into the fourth opening 1114 after the A powder material laying is completed. Specifically, the second powder recovery tank is in communication with the fourth opening 1114 through a second powder recovery channel, so as to facilitate the recovery of the A powder material.

[0053] Therefore, after the A powder material laying is completed, the falling powder distributor 150 can be used to push the excess A powder material outside the forming cavity 141 into the fourth opening 1114 and collect it in the second powder recovery tank, further reducing the probability of powder cross-contamination and the mixed powder being unable to be reused in the multi-material printing process.

[0054] Further, in some embodiments, the second powder storage unit 130 comprises a first side plate 132, a first sliding plate 133 and a first lifting driving member 134. The first side plate 132 is arranged along the circumference of the third opening 1113 and connected with the circumference of the third opening 1113. The first sliding plate 133 is slidably installed in the first side plate 132. The inner wall of the first side plate 132 and the side surface of the first sliding plate 133 facing the third opening 1113 form a powder cavity 131 therebetween. The first lifting driving member 134 is in transmission connection with the first sliding plate 133 and is used to drive the first sliding plate 133 to slide in the direction towards or away from the third opening 1113, so as to adjust the size of the powder cavity 131.

[0055] When the multi-material electron beam additive manufacturing device 100 is located on a horizontal plane, the third opening 1113 is located above the first sliding plate 133. In actual application, when the first sliding plate 133 is driven by the first lifting driving member 134 to slide upward, the B powder material in the powder cavity 131 can be pushed out of the third opening 1113, so as to facilitate the single-arm powder spreader 160 to push the B powder material to the first opening 1111 for powder spreading work of the B powder material; the first sliding plate 133 can also be driven by the first lifting driving member 134 to slide in the vertical direction, so as to adjust the powder storage amount of the powder cavity 131.

[0056] In some embodiments, the forming unit 140 comprises a second side plate 142 arranged along the circumference of the first opening 1111 and connected with the circumference of the first opening 1111, a second sliding plate 143 slidably installed in the second side plate 142, and a second lifting driving member 144 in driving connection with the second sliding plate 143. The inner wall of the second side plate 142 and the surface of the second sliding plate 143 on the side facing the first opening 1111 form a forming cavity 141 therebetween. The second lifting driving member 144 is used to drive the second sliding plate 143 to slide in the direction towards or away from the first opening 1111, so as to adjust the size of the forming cavity 141.

[0057] When the multi-material electron beam additive manufacturing device 100 is located on a horizontal plane, the first opening 1111 is located above the second sliding plate 143. In actual use, the second lifting driving member 144 can cooperate with the electron beam gun 170 to drive the second sliding plate 143 to gradually rise when the electron beam gun 170 melts the powder laid in the forming cavity 141 layer by layer, so as to ensure the electron beam melting forming effect and improve the yield and product quality of the multi-material 3D printed structure.

[0058] When the 3D printing is completed, and the excess powder in the forming cavity 141 needs to be pushed into the first powder recovery tank 181 for recovery, the second lifting driving member 144 can be used to drive the second sliding plate 143 to rise, so as to push the excess powder in the forming cavity 141 out of the first opening 1111, and facilitate the single-arm powder spreader 160 to push the excess powder in the forming cavity 141 into the second opening 1112 for recovery.

[0059] In some embodiments, a mounting hole (not labeled in the figure) is formed at the position opposite to the forming cavity 141 of the sealing shell 110. One end of the electron beam gun 170 is mounted in the mounting hole, and the other end is located outside the sealing shell 110. A powder passing hole (not labeled in the figure) is formed at the top of the sealing shell 110. The first powder storage unit 120 is mounted outside the sealing shell 110 and communicates with the falling powder spreader 150 through the powder passing hole.

[0060] Therefore, the first powder storage unit 120 and the electron beam gun 170 are arranged outside the sealed shell 110, and the A powder material is laid by using the gravity falling type powder laying method, so that the overall size of the working chamber 112 is greatly reduced, the integration of the multi-material electron beam additive manufacturing device 100 is higher, and the time and cost of vacuumizing the working chamber 112 are significantly reduced.

[0061] In some embodiments, the multi-material electron beam additive manufacturing device 100 further comprises a control unit (not shown in the figure). The control unit is electrically connected with the falling powder layering device 150, the single-arm powder layering device 160 and the electron beam gun 170, and is used to control the falling powder layering device 150, the single-arm powder layering device 160 and the electron beam gun 170 to operate according to the preset instructions, so as to form the multi-material 3D printing structure which is alternately printed and formed by the A powder material and the B powder material in the forming cavity 141.

[0062] Therefore, under the action of the control unit, the falling powder layering device 150, the single-arm powder layering device 160 and the electron beam gun 170 cooperate with each other to realize the multi-material 3D printing structure which is alternately printed and formed by the A powder material and the B powder material. Of course, when the number of times of alternately printing is 1, the A material part and the B material part in the multi-material 3D printing structure are both one; if the number of times of alternately printing is greater than 1, the A material part and the B material part in the multi-material 3D printing structure are both multiple.

[0063] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description simple, all possible combinations of the technical features in the above-mentioned embodiments are not described, but as long as the combinations of the technical features do not exist, they should be considered as the scope of the description.

[0064] The above-mentioned embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, some modifications and improvements can be made, which are all within the scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A multi-material electron beam additive manufacturing apparatus for manufacturing multi-material 3D printed structures, characterized in that, The multi-material electron beam additive manufacturing apparatus includes: A sealed housing has a working plate inside, which divides the internal space of the sealed housing into a working chamber and an installation chamber; the working plate has a first opening and a second opening spaced apart; the side wall of the sealed housing has a suction port communicating with the working chamber; the working plate also has a third opening; in the direction of the interval between the first opening and the second opening, the first opening is located between the third opening and the second opening. The first powder storage unit is used to store powder material A. The second powder storage unit is used to store powder material B; the second powder storage unit is located in the mounting cavity; the second powder storage unit has a powder cavity that communicates with the third opening; A molding unit is disposed within the mounting cavity; the molding unit has a molding cavity communicating with the first opening; A powder dropper is used to spread powder A material from the first powder storage unit into the molding cavity. The first powder recovery unit is located in the installation chamber and has a first powder recovery tank communicating with the second opening; A single-arm powder spreader is used to spread B powder material from the second powder storage unit into the molding cavity, and also to push excess B powder material outside the molding cavity into the second opening after the B powder material is spread; the single-arm powder spreader is configured to push B powder at the third opening into the molding cavity and push excess powder in the molding cavity into the second opening after 3D printing of each material. An electron beam gun is used to melt the A powder material in the molding cavity layer by layer to form the A material part of a multi-material 3D printed structure, and to melt the B powder material in the molding cavity layer by layer to form the B material part of a multi-material 3D printed structure. A powder suction device is installed at the suction port and is used to extract the powder dispersed in the working chamber from the sealed housing after the electron beam melting of each material is completed. A telescopic isolation door is installed inside the working chamber and is configured to extend and retract in a direction perpendicular to the working plate to divide the working chamber into a sealed first inner cavity and a second inner cavity; the third opening is located inside the first inner cavity, and both the second opening and the first opening are located inside the second inner cavity.

2. The multi-material electron beam additive manufacturing apparatus according to claim 1, characterized in that, It also includes a vacuum pumping device for evacuating the working chamber until the pressure inside the working chamber is less than 1.67 × 10⁻⁶. -3 Pa.

3. The multi-material electron beam additive manufacturing apparatus according to claim 1, characterized in that, In a direction perpendicular to the spacing direction of the first opening and the second opening, the width of the third opening is greater than or equal to the width of the first opening and less than the width of the second opening, and the pushing width of the single-arm powder spreader is greater than the width of the second opening.

4. The multi-material electron beam additive manufacturing apparatus according to claim 1, characterized in that, The falling powder spreader is configured to move in a controlled manner between an initial position and a working position; when the falling powder spreader is in the initial position, the spacing direction between the falling powder spreader and the first opening is intersected with the spacing direction between the first opening and the second opening; when the falling powder spreader is in the working position, the powder spreading port of the falling powder spreader is located above the first opening.

5. The multi-material electron beam additive manufacturing apparatus according to claim 4, characterized in that, The work plate is also provided with a fourth opening spaced apart from the first opening; the spacing direction between the first opening and the fourth opening is consistent with the spacing direction between the initial position and the working position. The multi-material electron beam additive manufacturing apparatus further includes a second powder recovery unit; the second powder recovery unit is installed in the mounting cavity and has a second powder recovery tank communicating with the fourth opening; the falling powder spreader is also used to push excess A powder material outside the forming cavity into the fourth opening after the A powder material is laid.

6. The multi-material electron beam additive manufacturing apparatus according to claim 1, characterized in that, The second powder storage unit includes a first side plate, a first sliding plate, and a first lifting drive; the first side plate is arranged circumferentially along the third opening and connected to the periphery of the third opening; the first sliding plate is slidably installed in the first side plate; a powder cavity is formed between the inner wall of the first side plate and the side surface of the first sliding plate facing the third opening; the first lifting drive is drivenly connected to the first sliding plate and is used to drive the first sliding plate to slide in a direction toward or away from the third opening to adjust the size of the powder cavity.

7. The multi-material electron beam additive manufacturing apparatus according to claim 1, characterized in that, The molding unit includes a second side plate arranged circumferentially along the first opening and connected to the periphery of the first opening, a second slide plate slidably installed in the second side plate, and a second lifting drive member pulsatorically connected to the second slide plate; the molding cavity is formed between the inner wall of the second side plate and the surface of the second slide plate facing the first opening; the second lifting drive member is used to drive the second slide plate to slide in a direction toward or away from the first opening to adjust the size of the molding cavity.

8. The multi-material electron beam additive manufacturing apparatus according to claim 1, characterized in that, The sealing housing has an installation hole at a position opposite to the forming cavity; one end of the electron beam gun is installed in the installation hole, and the other end is located outside the sealing housing; a powder passage hole is opened on the top of the sealing housing; the first powder storage unit is installed outside the sealing housing and communicates with the falling powder spreader through the powder passage hole.

9. The multi-material electron beam additive manufacturing apparatus according to claim 1, characterized in that, It also includes a control unit; the control unit is electrically connected to the falling powder spreader, the single-arm powder spreader and the electron beam gun respectively, and is used to control the falling powder spreader, the single-arm powder spreader and the electron beam gun to operate according to preset instructions, so as to form a multi-material 3D printed structure in the forming cavity by alternating printing of powder material A and powder material B.

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