Vacuum laser additive and subtractive material device capable of dynamically shaping light beams and additive and subtractive material manufacturing method of vacuum laser additive and subtractive material device

Abstract

The invention provides a vacuum laser additive and subtractive material device capable of dynamic beam shaping and an additive and subtractive material manufacturing method thereof.The vacuum laser additive and subtractive material device comprises a forming chamber and an optical set, the optical set is arranged above the forming chamber, and a forming cylinder is arranged in the forming chamber and used for bearing a printing material and a printing piece; the optical group emits laser to solidify the printing material and forms the printing material on a forming plane at the top of the forming cylinder; a protective mirror for preventing dust and returned slag from entering the optical set through the forming chamber is arranged on the forming chamber in a penetrating mode, a powder cylinder and a powder recycling cylinder which are distributed on the two sides of a forming cylinder are arranged in the forming chamber, and a first guide rail and a second guide rail which are parallel to the forming plane are further arranged in the forming chamber. According to the vacuum laser additive and subtractive material device capable of dynamically shaping the light beams and the additive and subtractive material manufacturing method of the vacuum laser additive and subtractive material device, through the arrangement of the milling cutter head and the milling cutter disc, the device can machine a printed piece after a printing material is formed, and the surface quality and the mechanical property of the printed piece are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing, and in particular to a vacuum laser additive and subtractive material device capable of dynamic beam shaping and an additive and subtractive material manufacturing method thereof. Background Art

[0002] Laser powder bed fusion additive manufacturing technology (LPBF for short), as an advanced metal additive manufacturing technology, is widely used in medical devices, automotive industry, aerospace and other fields due to its design flexibility and high material utilization rate. LPBF technology uses a high-energy-density laser beam to scan and melt metal powder layer by layer to construct a three-dimensional entity. This technology can not only achieve high-precision forming of complex structures, but also has high density and excellent mechanical properties of printed parts. However, the surface accuracy of the prints directly formed by LPBF technology is often not high enough, and there are defects such as unfused and porosity, which will reduce the surface quality and mechanical properties of the prints. In addition, the surface of the LPBF-formed print may have a rough surface caused by incomplete melting of powder particles, as well as oxide inclusions and pores caused by spattering. These factors reduce the density of the prints and have an adverse effect on the performance of the prints. Summary of the invention

[0003] The embodiment of the present invention provides a vacuum laser additive and subtractive material device capable of dynamic beam shaping and an additive and subtractive material manufacturing method thereof, so as to solve the problem that the surface accuracy of parts directly formed by the laser powder bed fusion additive manufacturing technology in the prior art is not high enough.

[0004] To achieve the above-mentioned purpose, the embodiment of the present invention adopts the following technical scheme: a vacuum laser additive and subtractive device capable of dynamic beam shaping, comprising a forming chamber and an optical group, wherein the optical group is arranged above the forming chamber, a forming cylinder is arranged in the forming chamber, the forming cylinder is used to carry printing materials and printed parts, and the optical group emits laser to solidify the printing materials and form them on the forming plane at the top of the forming cylinder;

[0005] A protective mirror is provided through the forming chamber to prevent dust and slag from entering the optical group through the forming chamber, a powder cylinder and a powder recovery cylinder are provided on both sides of the forming cylinder, a first guide rail and a second guide rail parallel to the forming plane are provided in the forming chamber, a scraper driven by the second guide rail and moving along the length direction of the second guide rail is provided on the second guide rail, and the bottom of the scraper can pass through the surfaces of the powder cylinder and the forming cylinder, the scraper has an initial position and a working position on the second guide rail, when the scraper is in the initial position, the bottom of the scraper is arranged between the powder cylinder and the forming chamber frame, when the scraper is in the working position, the bottom of the scraper is arranged between the powder recovery cylinder and the forming chamber frame, a flexible brush driven by the first guide rail and moving along the length direction of the first guide rail and a third guide rail are provided on the first guide rail, and the bottom of the flexible brush can pass through the surface of the protective mirror, a milling cutter head driven by the third guide rail and moving along the length direction of the third guide rail is provided on the third guide rail, and a milling cutter disc for placing multiple groups of milling cutters of different models is provided in the forming chamber, so that the milling cutter head can clamp different milling cutters in the milling cutter disc;

[0006] The forming chamber is provided with a vacuum pump for removing the gas in the forming chamber.

[0007] Furthermore, the optical group includes a laser, a collimator, a galvanometer and a focusing mirror. The laser emits Gaussian light which passes through the collimator, the galvanometer and the focusing mirror in sequence and is projected onto the forming plane of the forming cylinder. The optical group also includes a diffraction optical element which is arranged between the collimator and the galvanometer and is used to convert the Gaussian light emitted by the laser into a flat top light or an annular light.

[0008] The optical group also includes a controller, which is electrically connected to the diffractive optical element and is used to control the diffractive optical element so that the laser emitted by the optical group can be switched to annular light, flat-top light or Gaussian light.

[0009] Furthermore, a pressure gauge for monitoring the pressure in the forming chamber is provided on the forming chamber.

[0010] Furthermore, a ventilation valve is provided on the forming chamber.

[0011] Furthermore, a screen is provided on the powder recovery cylinder.

[0012] Furthermore, a cooling water channel is provided in the forming cylinder.

[0013] Furthermore, a temperature monitoring device is provided in the cooling water circuit. The vacuum laser material adding and subtracting device also includes an industrial computer, which is electrically connected to the temperature monitoring device and the cooling water circuit respectively. The temperature monitoring device transmits the temperature information in the cooling water circuit to the industrial computer.

[0014] A method for additive and subtractive material manufacturing using a vacuum laser additive and subtractive material device capable of dynamic beam shaping, using the vacuum laser additive and subtractive material device capable of dynamic beam shaping according to the above, has the following operating steps:

[0015] S1: After adding sufficient metal powder into the powder tank, turn on the vacuum pump to remove the gas in the forming chamber;

[0016] S2: Start the laser;

[0017] S3: After the powder cylinder rises one layer, the scraper moves from the initial position to the working position, brings enough powder to the forming plane and ensures the flatness of the forming plane, and then returns to the initial position;

[0018] S4: After the laser solidifies the design area in the forming plane according to the set cross section, the forming cylinder descends one layer;

[0019] S5: Repeat steps S3 and S4. After completing the multi-layer solid forming of the part, first start the flexible brush, which moves left and right on the first guide rail to clean the protective mirror; then start the milling cutter head, which moves to the top of the milling cutter disc, and after clamping a suitable milling cutter in the milling cutter disc, moves to the top of the formed part for subtractive processing, and then returns to its original position;

[0020] S6: Start the scraper, move the scraper from the initial position to the working position and then return to the initial position, and this process brings the chips on the forming plane to the powder recovery cylinder;

[0021] S7: Repeat steps S3 to S6 until the entire part is manufactured.

[0022] The beneficial effects of the present invention are:

[0023] The vacuum laser additive and subtractive material device capable of dynamic beam shaping and the additive and subtractive material manufacturing method provided by the present invention enable the device to process the printed part after the printed material is formed by providing a milling cutter head and a milling cutter disc, thereby improving the surface quality and mechanical properties of the printed part. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the present invention;

[0025] Figure 2 Schematic diagram of the scraper's working state.

[0026] Description of reference numerals:

[0027] 1. Optical group; 101. Laser; 102. Collimating mirror; 103. Galvanometer; 104. Focusing mirror; 105. Diffractive optical element; 106. Controller; 2. Forming chamber; 3. Forming cylinder; 4. Protective mirror; 5. Powder cylinder; 6. Powder recovery cylinder; 7. First guide rail; 8. Second guide rail; 9. Scraper; 91. Initial position; 92. Working position; 10. Flexible brush; 11. Third guide rail; 12. Milling head; 13. Milling disc; 14. Vacuum pump; 15. Pressure gauge; 16. Vent valve; 17. Screen; 18. Cooling water circuit. DETAILED DESCRIPTION

[0028] The specific implementation of the present application is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present application, and is not used to limit the present application.

[0029] like Figure 1-2 As shown, an embodiment of the present invention provides a vacuum laser additive and subtractive device capable of dynamic beam shaping, comprising a forming chamber 2 and an optical group 1, wherein the optical group 1 is arranged above the forming chamber 2, a forming cylinder 3 is arranged in the forming chamber 2, and the forming cylinder 3 is used to carry printing materials and printed parts, and the optical group 1 emits laser to solidify the printing materials and form them on a forming plane at the top of the forming cylinder 3 (the forming plane refers to a plane formed by the model being stacked layer by layer during the printing process);

[0030] The optical group 1 includes a laser 101, a collimator 102, a galvanometer 103 and a focusing mirror 104 (the laser 101 is a device for generating a laser beam such as Gaussian light. The laser 101 in the present invention generates Gaussian light with a laser wavelength of about 1064 nm and a laser power of 100 to 500 W; the collimator 102 is used to adjust the shape of the laser beam so that the laser beam emitted by the laser 101 is more parallel; the galvanometer 103 is a pair of high-speed rotating reflectors used to control the lateral movement of the laser beam on the forming plane of the forming cylinder 3; the focusing mirror 104 is used to focus the laser beam to a very small point to ensure that the laser can accurately solidify the material. The laser 101, the collimator 102, the galvanometer 103 and the focusing mirror 104 all have multiple embodiments in the prior art. The laser 10 1. The specific structures of the collimator 102, the galvanometer 103 and the focusing mirror 104 are not described in detail here. The laser 101 emits Gaussian light which passes through the collimator 102, the galvanometer 103 and the focusing mirror 104 in sequence and is projected onto the forming plane of the forming cylinder 3. The optical group 1 also includes a diffractive optical element 105, which is arranged between the collimator 102 and the galvanometer 103 and is used to convert the Gaussian light emitted by the laser 101 into a flat top light or an annular light (a beam shaping system for metal SLM printing is disclosed in the patent document with the document number CN111796429B, which discloses in detail the detailed process of converting the Gaussian light emitted by the laser beam into a flat top light by passing through the diffractive optical element 105, so the specific structure of the diffractive optical element 105 is not described in detail here);

[0031] The optical group 1 further includes a controller 106, which is electrically connected to the diffractive optical element 105 and is used to control the diffractive optical element 105 so that the laser emitted by the optical group 1 can be switched to annular light, flat top light or Gaussian light.

[0032] A protective mirror 4 is provided through the forming chamber 2 to prevent dust and slag from entering the optical group 1 through the forming chamber 2 (the protective mirror 4 has multiple embodiments in the prior art, and the specific structure of the protective mirror 4 is not repeated here). A powder cylinder 5 and a powder recovery cylinder 6 distributed on both sides of the forming cylinder 3 are provided in the forming chamber 2. A first guide rail 7 and a second guide rail 8 parallel to the forming plane are also provided in the forming chamber 2. A scraper 9 driven by the second guide rail 8 and moving along the length direction of the second guide rail 8 is provided on the second guide rail 8, and the bottom of the scraper 9 can pass through the surface of the powder cylinder 5 and the forming cylinder 3, as shown in FIG. Figure 2As shown, the scraper 9 has an initial position 91 and a working position 92 on the second guide rail 8. When the scraper 9 is at the initial position 91, the bottom of the scraper 9 is arranged between the powder cylinder 5 and the frame of the forming chamber 2. When the scraper 9 is at the working position 92, the bottom of the scraper 9 is arranged between the powder recovery cylinder 6 and the frame of the forming chamber 2. The first guide rail 7 is provided with a flexible brush 10 and a third guide rail 11 driven by the first guide rail 7 and moving along the length direction of the first guide rail 7, and the bottom of the flexible brush 10 can pass through the surface of the protective mirror 4. The third guide rail 11 is provided with a milling head 12 driven by the third guide rail 11 and moving along the length direction of the third guide rail 11 (the milling head 12 refers to a tool for fixing the milling cutter. The milling head 12 has multiple embodiments in the prior art, and the specific structure of the milling head 12 is not repeated here). A milling cutter disc 13 for placing multiple groups of milling cutters of different models is provided in the forming chamber 2, so that the milling cutter head 12 can clamp different milling cutters in the milling cutter disc 13.

[0033] The forming chamber 2 is provided with a vacuum pump 14 for extracting the gas in the forming chamber 2. The vacuum environment can avoid oxidation and component contamination during the processing of active metals (pure metals, titanium alloys, aluminum alloys and magnesium alloys, etc.), and reduce the spattering phenomenon of laser processing. The low-pressure environment of the forming chamber 2 helps to stabilize the molten pool and avoid the entrainment and expansion effects of gas (the vacuum pump 14 has a variety of embodiments in the prior art, and the specific structure of the vacuum pump is not repeated here).

[0034] In order to monitor whether the air content in the forming chamber 2 reaches the vacuum environment required for material forming and maintain the stability of the pressure in the forming chamber 2, in a preferred embodiment of the present invention, a pressure gauge 15 for monitoring the pressure information in the forming chamber 2 is provided on the forming chamber 2. By monitoring the changes in the pressure information in the forming chamber 2, it is determined whether the vacuum pump 14 has evacuated the air in the forming chamber 2 to achieve the vacuum environment required for material forming (the pressure gauge 15 has a variety of embodiments in the prior art, and the specific structure of the pressure gauge 15 will not be repeated here).

[0035] In order to connect the forming chamber 2 with the external air (i.e., to release the vacuum environment in the forming chamber 2), as a preferred embodiment of the present invention, a vent valve 16 is provided on the forming chamber 2 (the vent valve 16 has various embodiments in the prior art, and the specific structure of the vent valve 16 will not be described in detail here).

[0036] In order to prevent the powder volume in the powder recovery cylinder 6 from being too large and causing the powder recovery cylinder 6 to be blocked, as a preferred embodiment of the present invention, a screen 17 is provided on the powder recovery cylinder 6 (in a specific embodiment, the mesh size of the screen 17 is between 50-200 meshes).

[0037] In order to maintain the temperature stability in the forming cylinder 3, as a preferred embodiment of the present invention, a cooling water circuit 18 is provided in the forming cylinder 3 (the cooling water circuit 18 can be close to the surface of the printed part to make the temperature distribution of the printed part more uniform, eliminate hot spots and cold spots, thereby achieving a more uniform cooling effect, shortening the forming cycle, and improving the quality of the printed part. The cooling water circuit 18 has multiple embodiments in the prior art, and the cooling water circuit 18 is not described in detail here); in order to be able to monitor the temperature change information in the cooling water circuit, as a preferred embodiment of the present invention, a temperature monitoring device is provided in the cooling water circuit 18. The vacuum laser additive and subtractive material device also includes an industrial computer, which is electrically connected to the temperature monitoring device and the cooling water circuit respectively. The temperature monitoring device transmits the temperature information in the cooling water circuit to the industrial computer, so that the industrial computer adjusts the cooling water circuit according to the transmitted temperature information, so that a suitable temperature is maintained in the forming cylinder, thereby ensuring that the printing material has good fluidity and adhesion during the printing process, thereby improving the printing quality and efficiency (in a specific embodiment, a cooling water circuit 18 for cooling the milling cutter head is also provided in the milling cutter head 12).

[0038] A method for manufacturing additive and subtractive materials using a vacuum laser additive and subtractive material device capable of dynamic beam shaping, comprising the following steps:

[0039] S1: After adding a sufficient amount of metal powder into the powder cylinder 5, turn on the vacuum pump 14 to remove the gas in the forming chamber 2;

[0040] S2: Start the laser 101;

[0041] S3: After the powder cylinder 5 rises one layer, the scraper 9 moves from the initial position 91 to the working position 92, brings enough powder to the forming plane and ensures the flatness of the forming plane, and then returns to the initial position 91;

[0042] S4: After the laser solidifies the design area in the forming plane according to the set cross section, the forming cylinder 3 descends one layer;

[0043] S5: Repeat steps S3 and S4. After the multi-layer solid forming of the part is completed, the flexible brush 10 is first started. The flexible brush 10 moves left and right on the first guide rail 7 to complete the cleaning of the protective mirror 4; then the milling cutter head 12 is started. The milling cutter head 12 first moves to the top of the milling cutter disc 13, and after clamping a suitable milling cutter in the milling cutter disc 13, it moves to the top of the formed part for subtractive processing, and then the milling cutter head 12 returns to its original position;

[0044] S6: starting the scraper 9, the scraper 9 moves from the initial position 91 to the working position 92 and then returns to the initial position 91, and this process brings the chips on the forming plane to the powder recovery cylinder 6;

[0045] S7: Repeat steps S3 to S6 until the entire part is manufactured.

[0046] The vacuum laser additive and subtractive material device capable of dynamic beam shaping and the additive and subtractive material manufacturing method provided by the present invention, through the provision of a milling cutter head 12 and a milling cutter disc 13, enables the device to process the printed part after the printed material is formed, thereby improving the surface quality and mechanical properties of the printed part.

[0047] The above-described embodiments only express the implementation methods of the present invention, but they cannot be understood as limiting the scope of the patent of the present invention. 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, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A vacuum laser additive and subtractive device capable of dynamic beam shaping, comprising a forming chamber (2) and an optical group (1), wherein the optical group (1) is arranged above the forming chamber (2), a forming cylinder (3) is arranged in the forming chamber (2), the forming cylinder (3) is used to carry printing materials and printed parts, and the optical group (1) emits laser to solidify the printing materials and forms them on a forming plane at the top of the forming cylinder (3); A protective mirror (4) is provided through the forming chamber (2) to prevent dust and slag from entering the optical group (1) through the forming chamber (2). A powder cylinder (5) and a powder recovery cylinder (6) are provided in the forming chamber (2) and are distributed on both sides of the forming cylinder (3). A first guide rail (7) and a second guide rail (8) parallel to the forming plane are also provided in the forming chamber (2). A scraper (9) is provided on the second guide rail (8) and is driven by the second guide rail (8) and moves along the length direction of the second guide rail (8). The bottom of the scraper (9) can pass through the surface of the powder cylinder (5) and the forming cylinder (3). The scraper (9) has an initial position (91) and a working position (92) on the second guide rail (8). When the scraper (9) is in the initial position (91), the bottom of the scraper (9) is arranged at the powder cylinder (5). Between the material cylinder (5) and the frame of the forming chamber (2), when the scraper (9) is located at the working position (92), the bottom of the scraper (9) is arranged between the powder recovery cylinder (6) and the frame of the forming chamber (2), the first guide rail (7) is provided with a flexible brush (10) and a third guide rail (11) driven by the first guide rail (7) and moving along the length direction of the first guide rail (7), and the bottom of the flexible brush (10) can pass through the surface of the protective mirror (4), the third guide rail (11) is provided with a milling cutter head (12) driven by the third guide rail (11) and moving along the length direction of the third guide rail (11), and the forming chamber (2) is provided with a milling cutter disc (13) for placing multiple groups of milling cutters of different models, so that the milling cutter head (12) can clamp different milling cutters in the milling cutter disc (13); The forming chamber (2) is provided with a vacuum pump (14) for extracting gas from the forming chamber (2).

2. The vacuum laser additive and subtractive material device capable of dynamic beam shaping and the additive and subtractive material manufacturing method thereof according to claim 1, characterized in that: The optical group (1) comprises a laser (101), a collimator (102), a galvanometer (103) and a focusing mirror (104); the laser (101) emits Gaussian light which passes through the collimator (102), the galvanometer (103) and the focusing mirror (104) in sequence and is projected onto a forming plane of a forming cylinder (3); the optical group (1) further comprises a diffractive optical element (105); the diffractive optical element (105) is arranged between the collimator (102) and the galvanometer (103) and is used to convert the Gaussian light emitted by the laser (101) into flat top light or annular light; The optical group (1) also includes a controller (106), which is electrically connected to the diffractive optical element (105) and is used to control the diffractive optical element (105) so that the laser light emitted by the optical group (1) can be switched to annular light, flat top light or Gaussian light.

3. The vacuum laser additive and subtractive material device capable of dynamic beam shaping and the additive and subtractive material manufacturing method thereof according to claim 1, characterized in that: The forming chamber (2) is provided with a pressure gauge (15) for monitoring the pressure information in the forming chamber (2).

4. The vacuum laser additive and subtractive material device capable of dynamic beam shaping and the additive and subtractive material manufacturing method thereof according to claim 1, characterized in that: A ventilation valve (16) is provided on the forming chamber (2).

5. The vacuum laser additive and subtractive material device capable of dynamic beam shaping and the additive and subtractive material manufacturing method thereof according to claim 1, characterized in that: A screen (17) is provided on the powder recovery cylinder (6).

6. The vacuum laser additive and subtractive material device capable of dynamic beam shaping and the additive and subtractive material manufacturing method thereof according to claim 1, characterized in that: A cooling water channel (18) is provided in the forming cylinder (3).

7. The vacuum laser additive and subtractive material device capable of dynamic beam shaping and the additive and subtractive material manufacturing method thereof according to claim 6, characterized in that: A temperature monitoring device is arranged in the cooling water circuit (18). The vacuum laser material adding and subtracting device also includes an industrial computer. The industrial computer is electrically connected to the temperature monitoring device and the cooling water circuit respectively. The temperature monitoring device transmits temperature information in the cooling water circuit to the industrial computer.

8. A method for additive and subtractive material manufacturing using a vacuum laser additive and subtractive material device capable of dynamic beam shaping, using the vacuum laser additive and subtractive material device capable of dynamic beam shaping according to any one of claims 1 to 7, characterized in that: The operation steps are as follows: S1: After adding a sufficient amount of metal powder into the powder tank (5), the vacuum pump (14) is turned on to remove the gas in the forming chamber (2); S2: Start the laser (101); S3: After the powder cylinder (5) rises one layer, the scraper (9) moves from the initial position (91) to the working position (92), brings a sufficient amount of powder to the forming plane and ensures that the forming plane is flat, and then returns to the initial position (91); S4: After the laser solidifies the design area in the forming plane according to the set cross section, the forming cylinder (3) descends one layer; S5: Repeat steps S3 and S4. After completing the multi-layer solid forming of the part, first start the flexible brush (10), and the flexible brush (10) moves left and right on the first guide rail (7) to complete the cleaning of the protective mirror (4); then start the milling cutter head (12), and the milling cutter head (12) first moves to the top of the milling cutter disc (13), and after clamping a suitable milling cutter in the milling cutter disc (13), it moves to the top of the formed part to perform subtractive processing, and then the milling cutter head (12) returns to its original position; S6: starting the scraper (9), the scraper (9) moves from the initial position (91) to the working position (92) and then returns to the initial position (91), and this process brings the chips on the forming plane to the powder recovery cylinder (6); S7: Repeat steps S3 to S6 until the entire part is manufactured.

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