Integrated electron beam powder bed fusion forming device and method for dissimilar metal

Abstract

The invention discloses a dissimilar metal integrated electron beam powder bed fusion forming device and method. The dissimilar metal integrated electron beam powder bed fusion forming device comprises an electron gun above a shell and a working platform formed in the shell, a forming cylinder is arranged below the working platform, two charging barrels are arranged on the uppermost portion of the working platform, and a stepping motor is used for controlling a rotating shaft to move and controlling the output amount of powder; a mixed powder rotating cylinder device is arranged below the charging barrel, a stepping motor drives a gear to rotate, then a mixed powder rotating shaft is controlled, a blade is driven, metal powder falling from the upper portion is mixed, and finally the charged powder is tightly adsorbed to an electrode rotating shaft in an electrostatic attraction mode. After electrostatic powder is laid on a working platform, the electrostatic powder is compacted and flattened through a scraper below the electrostatic powder, finally, an electron gun emits electron beams to melt the powder, and the method can achieve two effects that after dissimilar metal is mixed, printing of mixed powder of different gradient layers is completed layer by layer from bottom to top in a forming chamber; and the sequence of powder falling of the dissimilar metal is controlled, so that any design pattern can be produced on the powder bed.

Description

Technical Field

[0001] The present invention belongs to the technical field of additive manufacturing, and in particular relates to heterogeneous metal integrated electron beam powder bed fusion molding, and specifically is an electrostatic scraper system device, a mixed metal powder mechanism device and a method thereof. Background Art

[0002] Additive manufacturing (AM) technology is commonly known as 3D printing technology, among which electron beam powder bed fusion technology (EB-PBF for short) is one of the current mainstream development forms. EB-PBF technology is that after the electron beam is emitted from the anode hole, it is converged and deflected by the magnetic field generated by the current in the focusing coil and deflection coil below, and finally the powder is heated or melted on the forming plane of the electron beam powder bed fusion to form a three-dimensional part layer by layer.

[0003] At present, electron beam powder bed melting technology is mainly based on a single material. On the same component, traditional electron beam powder bed melting additive manufacturing equipment is difficult to achieve precise control of the organization, structure and performance of multiple materials, and it is difficult to meet the use requirements of aerospace for large, high-performance complex parts with functional coupling and multi-environment adaptation. In addition, a single material and structure cannot meet the special needs in the aerospace or medical fields. For example, in the aviation or medical fields, it is necessary to have high temperature, high load, high corrosion and other requirements in a specific part, that is, it is impossible for the equipment to change the material at a specified position to obtain different properties to meet the use requirements. In order to solve the above problems, some personnel have redesigned and transformed the structure and process of additive manufacturing technology to maximize the comprehensive performance; in addition to the improvement of process and structure, some personnel have also improved the equipment, using electrostatic or ultrasonic methods to spread heterogeneous metal powders, but the single electrostatic spreading method has no external pressure, making the powder layer loose, high and porous, and the processing efficiency of ultrasonic spreading is extremely low, affecting the molding speed. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide an integrated electron beam powder bed fusion molding device and method for dissimilar metals, so as to solve the problems raised in the above-mentioned background technology, realize the mixing of dissimilar metals, and complete the printing of mixed powders of different gradient layers from bottom to top in the molding chamber; or the order in which the dissimilar metal powders fall can be controlled, so that the ability to produce any design pattern on the powder bed can be achieved to meet the special needs of designated parts; the density of the powder bed can be increased and the molding quality can be improved through the electrostatic scraper mechanism.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A device and method for integrated electron beam powder bed melting molding of heterogeneous metals, characterized in that it includes a barrel device, a mixed powder drum device, an electrostatic-scraper system device, a working platform, a molding cylinder, an electron gun, and a shell; the barrel device includes a rotating shaft controlled by a stepper motor; the mixed powder drum device includes a stepper motor driving a driving wheel and a driven wheel to rotate, thereby driving a deep groove ball bearing to rotate, thereby controlling the rotation of blades on the mixed powder shaft, the electrostatic-scraper system device includes scraper baffles on both sides above a scraper support plate and a scraper under a middle scraper connector, an electrode shaft fixed by an electrode shaft fixing seat on both sides of the scraper connector, and a slider and a slide rail protrusion connecting the scraper support plate to reciprocate along the slide rail guide rail and the slide rail.

[0007] In the improved solution, a groove is provided in the rotating shaft in the barrel device, and the rotation of the groove is controlled by a stepper motor to deliver the powder into the groove, thereby accurately controlling the powder delivery ratio.

[0008] In the improved solution, after the mixing powder drum device conveys a certain proportion of powder through the barrels on the left and right sides of the upper barrel device through the rotating shaft, the heterogeneous metal powders are mixed by rotating the blades on the mixing powder rotating shaft.

[0009] In the improved solution, the mixed powder drum device controls the order in which the heterogeneous metal powders in the drum fall through the rotating shafts on the left and right sides of the upper drum device, so that the two different powders fall onto the left and right electrode rotating shafts of the electrostatic scraper system device respectively.

[0010] In the improved solution, the blades on the mixing powder shaft are distributed in a circle, and the blades are rectangular. The input powder is mixed by rotation and output to the lower mechanism.

[0011] In the improved solution, the scraper support plate in the electrostatic scraper system device is connected to the slide rail protrusion, the slide rail protrusion is connected to the slider.

[0012] In the improved solution, the electrode shaft in the electrostatic scraper system is located on the left and right sides of the scraper connecting part, and the electrode shaft is connected to a high-voltage power supply. The statically charged powder is adsorbed on the electrode shaft. The powder is mainly spread in the forming cylinder of the working platform by mainly utilizing the polarity of the electrode shaft being opposite to the polarity of the charge carried by the powder.

[0013] In the improved solution, the electrode shaft is connected to a high-voltage power supply, the statically charged powder is adsorbed on the electrode shaft, the powder is spread in the forming cylinder, and the powder adsorbed on the electrode shaft is compacted and flattened by a scraper connected under the scraper connector.

[0014] In the improved solution, two grooves are provided under the scraper connecting piece to facilitate the scraper to be embedded therein and connected by screws.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. The scheme of the present invention adopts a mixed powder drum device to mix dissimilar metal powders in the chamber, and the forming chamber completes the printing of mixed powders of different gradient layers from bottom to top layer by layer; it solves the current use of mainly single materials, and meets the use requirements of high-performance complex parts with functional coupling and multi-environment adaptation. The mixed powders of different gradient layers are printed layer by layer from bottom to top in the forming chamber, realizing the control of the organization, structure and performance of multiple materials.

[0017] 2. The scheme of the present invention adopts the barrels on the left and right sides of the barrel device to control the order of the heterogeneous metal powders in the barrel to fall in sequence, so that the two different powders fall onto the left and right electrode shafts of the electrostatic scraper system device respectively, and then the powder is laid, so that the ability to produce any design pattern can be achieved on the powder bed, thereby meeting the requirements of different properties in a certain specific part in the aerospace field or medical field.

[0018] 3. The present invention adopts an electrostatic-scraper system device, connects the electrode shaft to a high-voltage power supply, so that the statically charged powder is adsorbed on the electrode shaft, and the powder is spread in the forming cylinder of the working platform. Finally, the scraper flattens and compacts the powder to increase the density of the powder bed and improve the forming quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the three-dimensional structure of the system of the present invention;

[0020] Figure 2 It is a schematic diagram of a front cross-sectional view of the barrel of the present invention;

[0021] Figure 3 It is a schematic diagram of the three-dimensional structure of the powder mixing drum device of the present invention;

[0022] Figure 4 It is a schematic cross-sectional view of the powder mixing drum device of the present invention;

[0023] Figure 5 It is a three-dimensional structural schematic diagram of the electrostatic scraper system device of the present invention;

[0024] Figure 6 It is a front schematic diagram of the electrostatic scraper system device of the present invention;

[0025] Figure 7 This is a schematic diagram of a mixed heterogeneous metal gradient layer of the present invention;

[0026] Figure 8 Schematic diagram of powder spreading-melting-molding of the system of the present invention.

[0027] In the figure: 1. barrel device; 11. rotating shaft; 2. mixed powder drum device; 21. drum end cover; 22. slave gear; 23. mixed powder rotating shaft; 24. main gear; 25. stepper motor; 26. deep groove ball bearing; 27. blade; 3. electrostatic-scraper system device; 31. scraper baffle; 32. electrode rotating shaft; 33. scraper connecting part; 34. slide rail guide; 35. slide rail; 36. scraper support plate; 37. slider; 38. slide rail protrusion; 39. scraper; 40. electrode rotating shaft fixing seat; 4. working platform; 5. forming cylinder; 6. electron gun; 7. casing. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] See also Figure 1-Figure 6 As shown, the present invention provides a technical solution: a heterogeneous metal integrated electron beam powder bed melting molding device and method includes a barrel device 1, a mixed powder drum device 2, an electrostatic-scraper system device 3, a working platform 4, a molding cylinder 5, an electron gun 6, and a shell 7.

[0030] A groove is provided in the rotating shaft 11 in the barrel device 1, and the rotation of the rotating shaft 11 is controlled by a stepping motor to feed the powder into the groove, thereby accurately controlling the powder delivery ratio.

[0031] The mixed powder drum device 2 conveys a certain proportion of powder through the barrels on the left and right sides of the upper barrel device 1 through the rotating shaft 11, and then mixes the heterogeneous metal powders through the rotation of the blades 27 on the mixed powder rotating shaft 23. The blades 27 on the mixed powder rotating shaft 23 are distributed in a circle, and the blades are rectangular. In order to realize the rotation of the blades 27 on the mixed powder rotating shaft 23, the stepping motor 25 drives the driving wheel 24 and the driven wheel 22 to rotate, and then drives the deep groove ball bearing 26 to rotate, so that the mixed powder drum device 2 rotates to achieve the purpose of mixing heterogeneous metal powders.

[0032] The scraper support plate 36 in the electrostatic scraper system device 3 is connected to the slide rail protrusion 38, the slide rail protrusion 38 is connected to the slider 37, and the electrode shaft 32 above it is located on the left and right sides of the scraper connecting member 33, surrounded by the scraper baffle 31, and the electrode shaft 32 is connected to a high-voltage power supply to adsorb the statically charged powder on the electrode shaft 32. The powder is mainly spread in the forming cylinder 5 of the working platform 4 by mainly utilizing the polarity of the electrode shaft 32 being opposite to the polarity of the charge carried by the powder. Finally, the scraper 39 connected below the scraper connecting member 33 compacts and flattens the powder spread on the electrode shaft 32, and the electron gun 6 emits an electron beam to melt the powder to complete the printing process.

[0033] In the working method of the device and method for integrated electron beam powder bed melting molding of heterogeneous metals of the present invention, two different powders with static electricity are placed in the barrels on the left and right sides of the barrel device 1; the powders are transported to the mixed powder rotating barrel device 2 below through the control of the rotating shaft 11 in the barrel device 1, and the blades 27 on the mixed powder rotating shaft 23 rotate to achieve the mixing of heterogeneous metal powders; a high-voltage power supply is connected to the electrode rotating shaft 32 through the electrostatic scraper system device 3 below, and the polarity of the electrode rotating shaft 32 and the polarity of the charge carried by the powder are used to mix the heterogeneous metal powders. On the contrary, the electrostatic powder is adsorbed on the electrode shaft 32; the slider 37 and the slide rail protrusion 38 connect the scraper support plate 36 together along the slide rail guide 34 and the slide rail 35 to spread the mixed powder on the forming cylinder 5, and the scraper flattens and compacts the powder; the electrostatic-scraper system device 3 returns to the starting point, and finally the electron gun 6 emits an electron beam to scan and melt the laid layer of powder; the forming cylinder 5 descends a distance of the thickness of one layer, and then lays a layer of powder for scanning and melting; the cycle is repeated layer by layer until the entire part is formed.

[0034] like Figure 7-Figure 8 As shown, in the working method of the device and method for integrated electron beam powder bed fusion molding of heterogeneous metals of the present invention, the powder drum device 2 mixes heterogeneous metal powders in the chamber, and the forming cylinder 5 completes the printing of mixed powders of different gradient layers from bottom to top layer by layer; the barrels on the left and right sides of the barrel device 1 control the order of powder falling of heterogeneous metal powders in the barrel through the rotating shaft 11, so that two different powders fall onto the left and right electrode rotating shafts 32 of the electrostatic scraper system device 3 respectively, and then the powder is laid, so that the ability to produce any design pattern on the powder bed can be achieved, thereby meeting the requirements of having different properties in a specific part in the aerospace field or the medical field.

Claims

1. A device and method for integrated electron beam powder bed fusion molding of heterogeneous metals, characterized in that: The invention comprises a barrel device (1), a mixed powder drum device (2), an electrostatic-scraper system device (3), a working platform (4), a forming cylinder (5), an electron gun (6), and a housing (7); the barrel device (1) comprises a rotating shaft (11) controlled by a stepping motor; the mixed powder drum device (2) comprises a stepping motor (25) driving a driving wheel (24) and a driven wheel (22) to rotate, thereby driving a deep groove ball bearing (26) to rotate, thereby controlling the mixed powder rotating shaft (23) The blade (27) on the scraper rotates, and the electrostatic scraper system device (3) includes scraper baffles (31) on both sides above the scraper support plate (36) and a scraper (39) below the middle scraper connecting member (33). The electrode shaft (32) is fixed by an electrode shaft fixing seat (40) on both sides of the scraper connecting member (33). At the same time, the scraper support plate (36) is connected by a slider (37) and a slide rail protrusion (38) to reciprocate along the slide rail guide rail (34) and the slide rail (35).

2. The device and method for integrated electron beam powder bed fusion molding of heterogeneous metals according to claim 1, characterized in that: A groove is provided in the rotating shaft (11) in the barrel device (1), and the rotation of the rotating shaft (11) is controlled by a stepping motor to feed the powder into the groove, thereby accurately controlling the powder delivery ratio.

3. The device and method for integrated electron beam powder bed fusion molding of heterogeneous metals according to claim 1, characterized in that: After a certain proportion of powder is conveyed from the material barrels on the left and right sides of the upper material barrel device (1) via the rotating shaft (11), the mixing powder rotating drum device (2) drives the driving wheel (24) and the driven wheel (22) to rotate through the stepping motor (25), thereby driving the deep groove ball bearing (26) to rotate, thereby controlling the blades (27) on the mixing powder rotating shaft (23) to rotate and mix the heterogeneous metal powders.

4. The device and method for integrated electron beam powder bed fusion molding of heterogeneous metals according to claim 1, characterized in that: The mixing powder drum device (2) passes through the drums on the left and right sides of the upper drum device (1) through the rotating shafts (11), and the order in which the heterogeneous metal powders in the drums fall is controlled, so that the two different powders fall respectively onto the left and right electrode rotating shafts (32) of the electrostatic scraper system device (3).

5. The device and method for integrated electron beam powder bed fusion molding of heterogeneous metals according to claim 1, characterized in that: In the electrostatic scraper system device (3), the scraper support plate (36) is connected to the slide rail protrusion (38), the slide rail protrusion (38) is connected and then connected to the slider (37).

6. The device and method for integrated electron beam powder bed fusion molding of heterogeneous metals according to claim 1, characterized in that: In the electrostatic-scraper system device (3), the electrode shaft (32) is located on the left and right sides of the scraper connecting member (33), and the electrode shaft (32) is connected to a high-voltage power supply. The powder with static electricity is adsorbed on the electrode shaft (32). The powder is mainly spread in the forming cylinder (5) of the working platform (4) by mainly utilizing the polarity of the electrode shaft (32) being opposite to the polarity of the charge carried by the powder.

7. The device and method for integrated electron beam powder bed fusion molding of heterogeneous metals according to claim 1, characterized in that: The electrode shaft (32) is connected to a high-voltage power source, and powder with static electricity is adsorbed on the electrode shaft (32). The powder is spread in a forming cylinder (5) of a working platform (4), and a scraper (39) connected below a scraper connector (33) compacts and flattens the powder adsorbed on the electrode shaft (32).

8. The device and method for integrated electron beam powder bed fusion molding of heterogeneous metals according to claim 1, characterized in that: The scraper connecting piece (33) has two grooves below for the scraper (39) to be embedded therein and connected by screws.

9. The device and method for integrated electron beam powder bed fusion molding of heterogeneous metals according to claim 1, characterized in that: After the different types of metals are mixed by the mixed powder drum device (2), the forming cylinder (5) prints the mixed powders of different gradient layers layer by layer from bottom to top.

10. The device and method for integrated electron beam powder bed fusion molding of heterogeneous metals according to claim 1, characterized in that: The barrels on the left and right sides of the upper barrel device (1) are rotated by shafts (11) to control the heterogeneous metal powders in the barrels to fall in a certain order and adsorb them on the left and right electrode shafts (32), so that any design pattern can be produced on the powder bed.

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