Additive manufacturing method and device for rapid prototyping of large components

Abstract

This invention discloses an additive manufacturing method and apparatus for rapid prototyping of large components. The additive manufacturing method first performs targeted partitioning and path planning on the component slices, then calculates and compares to obtain the shortest printing path and printing scheme. Finally, it controls two print heads on the printing device to simultaneously print according to the shortest partition path and printing scheme. This ensures that the shortest printing path and printing scheme are always selected during the additive manufacturing process, significantly improving the low printing efficiency caused by unreasonable printing path planning. This significantly increases the efficiency of the dual-printer additive manufacturing method, significantly shortens the printing cycle of large components, and facilitates the large-scale application of additive manufacturing technology in the forming process of large components.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, and in particular to an additive manufacturing method and apparatus for rapidly prototyping large components. Background Technology

[0002] Titanium alloy components are widely used in the aerospace field due to their superior performance and light weight. Furthermore, the advantages of 3D printing over traditional machining, such as higher precision, lower cost, and the ability to easily form complex structures, have led to an increasing preference for 3D printing for titanium alloy components. The basic principle of 3D printing for titanium alloy components is as follows: a powder feeding system delivers spherical or granular titanium alloy powder to the print head, where it converges on the printing surface. A laser then irradiates the converged powder, melting it to form a molten pool. The print head moves along a pre-set printing path, and the molten pool cools and solidifies, completing the stacking of titanium alloy material to form the titanium alloy component. During the 3D printing process, the powder feed rate of the print head, the melting efficiency of the laser, and the printing process path determine the printing efficiency. In existing 3D printing technologies, the powder feeding rate for printing titanium alloy components is generally 10-40 g / min. However, the weight of large titanium alloy components used in the aerospace field generally ranges from several hundred kilograms to one ton. The printing time for a single component usually exceeds 30 days. This printing time not only requires extremely high continuous stability of the printing equipment, but also seriously affects the forming efficiency and assembly period of the component, which is obviously not conducive to the application of 3D printing technology in the forming of large titanium alloy components.

[0003] To shorten the time required to form large titanium alloy components using 3D printing technology and increase the powder feed rate of the print head, 3D printers with two or more print heads have been designed. Using multiple print heads increases the powder feed rate during the printing process, thereby improving the efficiency of forming large titanium alloy components and shortening the forming time, which is beneficial for the application of 3D printing technology in the forming of large titanium alloy components. However, in practical applications, it has been found that while existing 3D printers with two or more print heads increase the powder feed rate during the printing process, unreasonable print path planning prevents the print heads from working at their maximum efficiency during forming. This results in the forming efficiency not reaching the theoretical value, and the improvement in printing efficiency is limited. In fact, the increase in print heads may lead to decreased printing accuracy, increased printing energy consumption, and increased printing equipment costs, thus limiting the application of 3D printers with two or more print heads in the forming of large titanium alloy components. Summary of the Invention

[0004] The purpose of this invention is to overcome the low forming efficiency of existing dual-printhead 3D printers when printing large components. It proposes an additive manufacturing method and apparatus for rapid prototyping of large components. This additive manufacturing method significantly improves the low printing efficiency caused by unreasonable printing path planning by performing targeted partitioning and path planning on component slices and calculating the printing scheme and path with the shortest time. This significantly increases the efficiency of the dual-printhead additive manufacturing method and facilitates the large-scale application of additive manufacturing technology in the forming process of large components.

[0005] To achieve the above-mentioned objective, the present invention provides an additive manufacturing method for rapid prototyping of large components, comprising the following steps:

[0006] Step S1: Obtain the model and data of the component to be formed, and use slicing software to slice the model of the component to be formed according to the printing forming plane to obtain the slice outline data of the component.

[0007] Step S2: Obtain the printing path of the corresponding slice based on the slice outline data; select printing parameters and safety distance; calculate the time required to print the slice using synchronous even printing and synchronous symmetrical printing based on the printing path, obtain the time for the two printing methods, compare the time of the two printing methods, and obtain the printing method with the shorter time.

[0008] Step S3: Control the printing equipment to use a printing method that takes less time to complete the printing of the slice;

[0009] Step S4: Repeat steps S2 and S3 until all slices of the component to be printed are printed.

[0010] This invention discloses an additive manufacturing method for rapid prototyping of large components. The method first performs targeted partitioning and path planning on the component slices, then calculates and compares the shortest printing path and scheme to obtain the fastest printing time. Finally, it controls two print heads on the printing device to simultaneously print according to the shortest partition path and printing scheme. This ensures that the shortest printing path and scheme are always selected during the additive manufacturing process, significantly improving the low printing efficiency caused by unreasonable printing path planning. This significantly increases the efficiency of the dual-printer additive manufacturing method, significantly shortens the printing cycle of large components, and facilitates the large-scale application of additive manufacturing technology in the forming process of large components.

[0011] Preferably, in step S1, the component is a component whose maximum length of the component slice (the distance between the two farthest points on the slice outline; for example, the maximum length of a rectangular slice is the distance between two diagonal points) is not less than 1.0m; the preferred component size has a larger mass, and conventional 3D printing takes longer to form. After printing using the method of the present invention, the improvement in printing efficiency is more obvious.

[0012] Preferably, in step S1, the component is a titanium alloy component; the forming cost of forming titanium alloy components by machining is higher and more difficult, and it is more suitable to form them by additive manufacturing methods.

[0013] In step S1, the slicing software refers to graphics processing software that can slice the three-dimensional model of a component according to a specified plane and form a two-dimensional contour graphic; preferably, the slicing software is one or more of cura, s3d or RepetierHost; the preferred slicing software has fast slicing speed, high accuracy, good compatibility and simpler operation.

[0014] In step S2, the safety distance (L) is not less than the sum of the radii of the two printheads' maximum physical hardware dimensions (with the center of the molten pool of the two printheads as the center); the safety distance is set to avoid collisions between the two printheads when they are working at the same time, which would affect the printing effect.

[0015] In step S2, the printing path refers to the line connecting the center points of the print head when the slice is printed using only one print head, which is the movement path when the slice is printed using a single print head.

[0016] In step S2, the printing parameters are necessary process parameters for additive manufacturing of components, including printing speed, powder feeding amount, laser power, etc.

[0017] In step S2, when calculating the time required for synchronous even printing and synchronous symmetrical printing, it is necessary to ensure that the distance between the two print heads is not less than the safe distance; by controlling the distance between the print heads, collisions between the print heads can be effectively prevented and the printing quality can be improved.

[0018] In step S2, the synchronous evenly divided printing includes: first, dividing the printing path of the slice into two equal parts according to the total path length; then controlling two print heads to simultaneously and independently complete the printing of the slice according to the evenly divided printing path parts; wherein, during the synchronous evenly divided printing process, when the distance between the two print heads tends to shrink to less than the safe distance, the print head whose movement trend is to shrink the distance between the two print heads will pause printing, while the other print head will continue printing; when it is determined that when the two print heads are printing simultaneously, the distance between the print heads will no longer tend to shrink to less than the safe distance, the paused print head will restart printing.

[0019] The time calculation formula for synchronous evenly distributed printing is: t = t1 + 2t2 + t3; where t is the total time for synchronous evenly distributed printing; t1 is the time for the two print heads to print simultaneously before the distance between the two print heads tends to shrink to less than the safe distance; t2 is the time for the print head to pause printing; and t3 is the time required for the paused print head to restart printing and complete the slice printing task during the printing process.

[0020] In step S2, the synchronous symmetrical printing includes: first dividing the printing path of the slice into three regions with the overlapping region as the middle region; then controlling two print heads to simultaneously and independently complete the printing of the two regions other than the overlapping region; and finally controlling any one of the print heads to complete the printing of the overlapping region.

[0021] The overlapping area is a region on the printing path of the slice where the distance between two printheads tends to decrease to less than the safe distance (it must be in the middle of the printing path of the slice).

[0022] The time calculation formula for synchronous symmetrical printing is: T = T1 + T2; where T is the total time for synchronous symmetrical printing; T1 is the time for two print heads to print two regions simultaneously and independently, excluding the overlapping region; and T2 is the time for any print head to print the overlapping region alone.

[0023] Preferably, in step S3, the printing device is a 3D printing device with at least two independently operable print heads that can print simultaneously on the same printing plane.

[0024] To achieve the above-mentioned objectives, the present invention further provides an additive manufacturing apparatus for rapid prototyping of large components, including a control module and a printing module, wherein the control module and the printing module are electrically connected, and the printing module is controlled by the control module; the control module and the printing module jointly execute the above-mentioned additive manufacturing method; the printing module is a 3D printing device having at least two independently operable print heads that can print simultaneously on the same printing plane.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] 1. The additive manufacturing method of the present invention performs targeted partitioning and path planning on component slices, thereby ensuring that the shortest printing path and printing scheme are always selected for component printing during the additive manufacturing process, which significantly increases the efficiency of the dual-printhead additive manufacturing method.

[0027] 2. The additive manufacturing method of the present invention is simple, reliable and highly practical, and is suitable for large-scale application in the additive manufacturing of components. Attached image description:

[0028] Figure 1 This is a schematic diagram of the slicing and printing path in the additive manufacturing method of the present invention;

[0029] Figure 2 This is a schematic diagram of the synchronous and evenly distributed printing path in the additive manufacturing method of the present invention;

[0030] Figure 3 This is a schematic diagram of the synchronous symmetrical printing path in the additive manufacturing method of the present invention;

[0031] Figure 4 This is a schematic diagram of the safety distance in the additive manufacturing method of the present invention;

[0032] Reference numerals: 1-Component slice; 2-Printing path; 3-First print head; 301-First print head molten pool; 302-Maximum physical size of the first print head; 4-Second print head; 401-Second print head molten pool; 502-Maximum physical size of the second print head; 5-Printing path of the first print head; 6-Printing path of the second print head; 7-Overlapping area; 8-Midpoint of the printing path. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to experimental examples and specific embodiments. However, this should not be construed as limiting the scope of the above-mentioned subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0034] The equipment used is a dual-printhead coaxial powder feeding laser cladding equipment, which consists of a control module and a printing module. The control module and the printing module are electrically connected, and the printing module is controlled by the control module. The printing module consists of two printheads that can operate independently and can print simultaneously on the same printing plane.

[0035] Example 1:

[0036] Titanium alloy components: a regular quadrilateral titanium alloy frame (frame thickness is 60mm), dimensions: 900mm*600mm*300mm;

[0037] The additive manufacturing method of this invention is used for molding, and the specific steps are as follows:

[0038] Step S1: Obtain the model and data of the component to be formed, and use slicing software to slice the model of the component to be formed according to the printing forming plane to obtain the slice outline data of the component.

[0039] Step S2: Obtain the printing path of the corresponding slice based on the slice outline data; select printing parameters and safety distance; calculate the time required to print the slice using synchronous even printing and synchronous symmetrical printing based on the printing path, obtain the time for the two printing methods, compare the time of the two printing methods, and obtain the printing method with the shorter time.

[0040] Step S3: Control the printing equipment to use a faster printing method (synchronous and evenly distributed printing) to complete the printing of the slice;

[0041] Step S4: Repeat steps S2 and S3 until all slices of the component to be printed are printed.

[0042] Example 2:

[0043] Titanium alloy component: A cylindrical titanium alloy beam with different sizes at both ends and a uniform transition, 1500mm in length, 500mm in diameter at the larger end and 400mm in diameter at the smaller end;

[0044] The additive manufacturing method of this invention is used for molding, and the specific steps are as follows:

[0045] Step S1: Obtain the model and data of the component to be formed, and use slicing software to slice the model of the component to be formed according to the printing forming plane to obtain the slice outline data of the component.

[0046] Step S2: Obtain the printing path of the corresponding slice based on the slice outline data; select printing parameters and safety distance; calculate the time required to print the slice using synchronous even printing and synchronous symmetrical printing based on the printing path, obtain the time for the two printing methods, compare the time of the two printing methods, and obtain the printing method with the shorter time.

[0047] Step S3: Control the printing equipment to use a faster printing method (synchronous symmetrical printing) to complete the printing of the slice;

[0048] Step S4: Repeat steps S2 and S3 until all slices of the component to be printed are printed.

[0049] Comparative Example 1: The component in Example 1 was formed using a dual-head printer (but only one printhead was in operation);

[0050] The specific molding method is as follows:

[0051] Step S1: Obtain the model and data of the component to be formed, and use slicing software to slice the model of the component to be formed according to the printing forming plane to obtain the slice outline data of the component.

[0052] Step S2: Plan the printing path of the corresponding slice based on the slice outline data;

[0053] Step S3: Control the printing equipment to complete the printing of the slice according to the printing path;

[0054] Step S4: Repeat steps S2 and S3 until all slices of the component to be printed are printed.

[0055] Comparative Example 2: The component in Example 1 is formed using a dual-head printer, but its printing path is a conventional printing path (the component is directly divided into two equal parts, and one print head is responsible for printing one part).

[0056] The specific molding method is as follows:

[0057] Step S1: Obtain the model and data of the component to be formed, and use slicing software to slice the model of the component to be formed according to the printing forming plane to obtain the slice outline data of the component.

[0058] Step S2: Divide the component slice into two parts from the middle position, and independently plan the printing path of the corresponding slices for the two parts based on the slice outline data;

[0059] Step S3: Control the print head on the printing equipment to independently complete the printing of the corresponding slices according to the planned path;

[0060] Step S4: Repeat steps S2 and S3 until all slices of the component to be printed are printed.

[0061] Comparative Example 3: The component in Example 2 was formed using a dual-head printer (but only one printhead was in operation); the specific forming method was the same as that in Comparative Example 1.

[0062] Comparative Example 4: The component in Example 2 was formed using a dual-head printer, with the specific forming method being the same as Comparative Example 2. The processing time and cost for Examples 1-2 and Comparative Examples 1-4 were statistically analyzed, and the results are as follows:

[0063] Serial Number Molding time (approximately) Molding cost (approximately) Example 1 160 hours 180,000 yuan Example 2 300 hours 430,000 yuan Comparative Example 1 240 hours 200,000 yuan Comparative Example 2 215 hours 190,000 yuan Comparative Example 3 550 hours 500,000 yuan Comparative Example 4 400 hours 450,000 yuan

[0064] Analysis of the molding time and cost in Examples 1-2 and Comparative Examples 1-4 shows that the molding method of the present invention can significantly shorten the molding time and reduce the molding cost, making it suitable for large-scale application in rapid prototyping processes for large components.

Claims

1. An additive manufacturing method for rapid prototyping of large components, characterized in that, Includes the following steps: Step S1: Obtain the model and data of the component to be formed, and use slicing software to slice the model of the component to be formed according to the printing forming plane to obtain the slice outline data of the component. Step S2: Obtain the printing path of the corresponding slice based on the slice outline data; Select printing parameters and safety distance; based on the printing path, calculate the time required to print the slice using synchronous even printing and synchronous symmetrical printing respectively, obtain the time for the two printing methods, compare the time of the two printing methods, and obtain the printing method with the shorter time; Step S3: Control the printing equipment to use a printing method that takes less time to complete the printing of the slice; Step S4: Repeat steps S2 and S3 until all slices of the component to be printed are printed. In step S1, the component is a component whose maximum length of the component slice is not less than 1.0m; In step S2, the safety distance is not less than the sum of the radii of the two printheads' maximum physical hardware dimensions; In step S2, the synchronous evenly divided printing includes: first, dividing the printing path of the slice into two equal parts according to the total path length, and then controlling two print heads to simultaneously and independently complete the printing of the slice according to the evenly divided printing path parts; wherein, during the synchronous evenly divided printing process, when the distance between the two print heads tends to shrink to less than the safe distance, the print head whose movement trend is to shrink the distance between the two print heads will pause printing, while the other print head will continue printing; when it is determined that when the two print heads are printing simultaneously, the distance between the print heads will no longer tend to shrink to less than the safe distance, the paused print head will be restarted to continue printing; In step S2, the synchronous symmetrical printing includes: first dividing the printing path of the slice into three regions with the overlapping region as the middle region; then controlling two print heads to simultaneously and independently complete the printing of the two regions other than the overlapping region; and finally controlling any one of the print heads to complete the printing of the overlapping region. In step S2, when calculating the time required for synchronous even printing and synchronous symmetrical printing, it is necessary to ensure that the distance between the two print heads is not less than the safe distance.

2. The additive manufacturing method according to claim 1, characterized in that, The calculation formula for the time taken for synchronous and evenly distributed printing is: t = t1 + 2t2 + t3; where t is the total time taken for synchronous and evenly distributed printing; t1 is the time taken for the two print heads to print simultaneously before the distance between the two print heads tends to shrink to less than the safe distance; t2 is the time for the print head to pause printing; and t3 is the time required for the paused print head to restart printing and complete the slice printing task during the printing process.

3. The additive manufacturing method according to claim 1, characterized in that, The time calculation formula for synchronous symmetrical printing is: T = T1 + T2; where T is the total time for synchronous symmetrical printing; T1 is the time for two print heads to print two regions simultaneously and independently, excluding the overlapping region; and T2 is the time for any print head to print the overlapping region alone.

4. The additive manufacturing method according to any one of claims 1-3, characterized in that, In step S3, the printing device is a 3D printing device with two print heads that can operate independently and print simultaneously on the same printing plane.

5. An additive manufacturing apparatus for rapid prototyping of large components, characterized in that, The device includes a control module and a printing module, which are electrically connected. The printing module is controlled by the control module. The control module and the printing module jointly execute the additive manufacturing method according to any one of claims 1-4. The printing module is a 3D printing device having at least two print heads that can operate independently and print simultaneously on the same printing plane.

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