3D printing path planning method, laser 3D printing method and storage medium

Abstract

The present application relates to the field of 3D printing, aims to solve the problems in the prior art, and provides a 3D printing path planning method, a laser 3D printing method, and a storage medium. The 3D printing path planning method includes: planning a first scanning path for a first type of closed loop on a slice of a workpiece, wherein the first type of closed loop is a closed loop whose area is less than or equal to a set area threshold or whose width is less than or equal to a set width threshold; the first scanning path includes an internal scanning path, an inner contour scanning path, and an outer contour scanning path performed in sequence, wherein the inner contour is a contour obtained by offsetting the outer contour to the inside of the first type of closed loop by a set distance. The beneficial effect of the present application is that it can achieve high-quality molding of microstructures in the workpiece.

Description

Technical Field

[0001] The present application relates to the field of 3D printing, and more specifically, to a 3D printing path planning method, a laser 3D printing method, and a storage medium. Background Art

[0002] Some 3D-printed parts have tiny structures. For example, porous implants used in medical applications have a large number of pores, which form small internal structures called microrods.

[0003] The inventors found in production practice that the quality of printed parts with micro-rod structures formed by conventional 3D printing processes is poor and is not easy to meet actual needs. Summary of the Invention

[0004] The present application aims to provide a 3D printing path planning method, a laser 3D printing method and a storage medium to solve the problem of poor quality of printed parts with micro-rod structures formed by conventional 3D printing processes.

[0005] The embodiment of the present application is implemented as follows:

[0006] This application provides a 3D printing path planning method for planning the path of a workpiece to be printed, comprising:

[0007] Planning a first scanning path for a first type of closed loop on the slice of the workpiece, wherein the first type of closed loop is a closed loop whose area S is less than or equal to a set area threshold S0 or whose width D is less than or equal to a set width threshold D0;

[0008] The first scanning path includes an internal scanning path, an inner contour scanning path and an outer contour scanning path which are performed in sequence; the internal scanning path is used to fill the entity within the first type of closed loop, the inner contour scanning path is a path for scanning along the inner contour of the first type of closed loop, and the outer contour scanning path is a path for scanning along the outer contour of the first type of closed loop; the internal scanning path passes through the inner contour and is connected to the outer contour; wherein, the inner contour is a contour obtained by offsetting the outer contour by a set distance L toward the inside of the first type of closed loop.

[0009] The 3D printing path planning method in this application divides the types of closed loops by area and width standards, and scans closed loops whose area or width is less than a set threshold by performing internal scanning, inner contour scanning, and outer contour scanning in sequence. This can achieve high-quality molding of tiny structures in the workpiece, which is conducive to meeting actual needs.

[0010] In one possible implementation:

[0011] Planning a second scanning path for a second type of closed loop on the slice of the workpiece, wherein the second type of closed loop is a closed loop having an area S greater than a set area threshold S0 and a width D greater than a set width threshold D0;

[0012] The second scanning path includes a solid filling scanning path and an outer contour scanning path.

[0013] In one possible implementation:

[0014] The set area threshold S0 is set to 1-100mm 2 , the set width threshold D0 is 0.1-0.8mm.

[0015] In one possible implementation:

[0016] The first type of closed loop is scanned first, and then the second type of closed loop is scanned.

[0017] In one possible implementation:

[0018] A scanning pitch of an inner scanning path of the first scanning path is smaller than a scanning pitch of a physical filling scanning path of the second scanning path.

[0019] In one possible implementation:

[0020] A scanning speed of the outer contour scanning path of the first scanning path is higher than a scanning speed of the outer contour scanning path of the second scanning path.

[0021] The present application provides a laser 3D printing method for printing a medical porous part, wherein the medical porous part includes a microrod structure connected in a network, and pores exist between the microrod structures in the network. The laser 3D printing method includes the following steps:

[0022] Slicing the medical porous part to be printed; wherein the slice of the microrod structure has at least a first type closed loop with an area S less than or equal to a set area threshold S0 or a width D less than or equal to a set width threshold D0;

[0023] A first scanning path is planned for the first type of closed loop on the slice of the medical porous part; wherein the first scanning path includes an internal scanning path, an inner contour scanning path, and an outer contour scanning path performed in sequence; the internal scanning path is used to fill the entity within the first type of closed loop, the inner contour scanning path is a path scanned along the inner contour of the first type of closed loop, and the outer contour scanning path is a path scanned along the outer contour of the first type of closed loop; the internal scanning path passes through the inner contour and is connected to the outer contour; wherein the inner contour is a contour obtained by offsetting the outer contour by a set distance L toward the inside of the first type of closed loop; laser scanning is performed according to the first scanning path to form the first type of closed loop.

[0024] In one possible implementation:

[0025] The medical porous member further includes a solid portion, wherein the solid portion and the microrod structure are connected as a whole; a slice of the solid portion includes at least a portion of a second type closed loop having an area S greater than a set area threshold S0 and a width D greater than a set width threshold D0;

[0026] Planning a second scanning path for the second type of closed loop on the slice of the medical porous member, the second scanning path including a solid filling scanning path and an outer contour scanning path;

[0027] Performing laser scanning along the second scanning path to form the second type of closed loop;

[0028] For each slice, the first type of closed loop is scanned first, and then the second type of closed loop is scanned.

[0029] In one possible implementation:

[0030] The laser power of the laser scanning performed along the outer contour scanning path of the first scanning path is less than the laser power of the laser scanning performed along the outer contour scanning path of the second scanning path;

[0031] The scanning speed of the laser scanning performed along the outer contour scanning path of the first scanning path is greater than the scanning speed of the laser scanning performed along the outer contour scanning path of the second scanning path;

[0032] A scanning speed of the inner contour scanning path of the first scanning path is the same as a scanning speed of the inner scanning path of the first scanning path.

[0033] The present application also provides a storage medium, which includes computer instructions. The storage medium stores computer-readable instructions, and when the computer-readable instructions are executed by a processor, the 3D printing path planning method or the laser 3D printing method as described above is implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 A schematic diagram of a slice of a printed piece in one embodiment of the present application;

[0036] Figure 2 for Figure 1 An enlarged view of the second scanning path of the slice at A;

[0037] Figure 3 for Figure 2 A schematic diagram of a physical filling scan path of a second scan path;

[0038] Figure 4 for Figure 1 An enlarged view of the first scanning path of the slice at B;

[0039] Figure 5 for Figure 4 A schematic diagram of an internal scanning path of a first scanning path;

[0040] Figure 6 for Figure 4 Schematic diagram of the internal scanning path and the inner contour scanning path of the second scanning path.

[0041] Description of the main component symbols: 10-slice; 11-solid part; 12-microrod structure; 13-pore; M1-first scanning path; M11-inner scanning path; M12-inner contour scanning path; M13-outer contour scanning path; M2-second scanning path; M21-solid filling scanning path; M22-outer contour scanning path. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0043] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may also be a central component. When a component is considered to be "set on" another component, it may be directly set on the other component or there may also be a central component. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "or / and" as used herein includes any and all combinations of one or more of the relevant listed items.

[0045] Some embodiments of the present application are described in detail. In the absence of conflict, the following embodiments and features of the embodiments can be combined with each other.

[0046] 3D printing has numerous applications, particularly for the manufacture of custom parts, non-standard parts, or parts with complex shapes. For example, medical implants sometimes require single-piece manufacturing to better fit different individuals or body parts. In these cases, 3D printing offers significant efficiency and cost advantages over traditional subtractive manufacturing methods.

[0047] However, the applicant has discovered in practice that when conventional 3D printing processes are directly applied to workpieces with microrod structures, the microrod structure suffers from poor molding quality, primarily manifested in noticeable powder adhesion to the microrod surface. Due to the reduced size or gaps in the microrod structure itself, these defects are difficult to resolve through subsequent processing steps, limiting the application of 3D printing technology.

[0048] For example, Figure 1 A slice 10 of a medical implant is shown. The slice 10 includes a relatively large solid portion 11 and a plurality of microrod structures 12 connected in a network. Pores 13 exist between the microrod structures and between the microrod structures and the solid portion, making the medical implant as a whole a porous medical device. Figure 1 This is for illustration only. The actual structure of medical porous parts is more complex. It may be a porous structure composed entirely of micro-rod structures (see structural forms such as foam aluminum), or it may be a structure combining a micro-rod structure and a solid part. This is not limited here.

[0049] The inventors found in production practice that the quality of printed parts with micro-rod structures formed by conventional laser 3D printing processes is poor and is not easy to meet actual needs. After analysis, one possible reason is that the micro-rod structure is small in size, and some closed rings with very small area or width may appear after slicing. When the laser printing equipment scans these closed rings with small area or width, the surface molding quality is poor.

[0050] In view of this, the embodiment of the present application provides a laser 3D printing method, which can form the medical porous parts described above with high quality through special processes such as special path planning. Figure 1 The medical porous member shown is used as an example for explanation.

[0051] The laser 3D printing method in this embodiment includes the following steps:

[0052] S1: Slice

[0053] The medical porous part to be printed is sliced; the thickness of the slices can be set as needed and will not be described in detail here.

[0054] S2: Path Planning and Scanning

[0055] The new 3D printing path planning method proposed in this embodiment is used to perform path planning on each slice.

[0056] In this 3D printing path planning method, a first scanning path is planned for a first type of closed loop on a slice of a workpiece, wherein the first type of closed loop is a closed loop whose area S is less than or equal to a set area threshold S0 or whose width D is less than or equal to a set width threshold D0; and a second scanning path is planned for a second type of closed loop on a slice of the workpiece, wherein the second type of closed loop is a closed loop whose area S is greater than the set area threshold S0 and whose width D is greater than the set width threshold D0.

[0057] In this embodiment, the area threshold S0 can be set in the range of 1-100 mm. 2 , the value range of the width threshold D0 can be set to 0.1-0.8mm. Non-limitingly, the width of the closed loop can be determined as the length of the longest scan line of the closed loop, that is, the maximum value of the distance between the two sides of the boundary along the scan line direction. For example, in a specific printing example, take S0=50mm 2 , D0=0.4mm, that is, the area within the slice is less than or equal to 50mm 2 Or the closed loop with a width of less than 0.4mm in the slice is identified as the first type of closed loop; the area in the slice is greater than 50mm 2 And the closed loop with a width greater than 0.4mm in the slice is identified as the second type of closed loop.

[0058] Identification of closed loops within the cross-section, acquisition of the area / width of each closed loop, etc. can be achieved through conventional graphics processing or other feasible methods, which will not be described in detail here.

[0059] In this embodiment, see Figure 2 and Figure 3 , the second scanning path M2 includes a solid filling scanning path M21 and an outer contour scanning path M22 performed in sequence to form a second type of closed loop inner structure, such as Figure 1 The area of ​​the solid portion 11, Figure 2 and Figure 3 Only shown Figure 1 The second scanning path can adopt a common scanning process, including internal scanning strategy, scanning speed, laser power, scanning spacing, melting channel overlap offset, contour scanning speed, scanning power, etc., which will not be described in detail here.

[0060] For the first type of closed loops, such as the areas corresponding to the microrod structures in some slices, the molded model will have obvious powder sticking phenomenon when the aforementioned scanning process is used, and the unmelted powder will stick to the surface of the structure.

[0061] This embodiment adopts a different process from the above for the first type of closed loop, which can better solve the above problems. Figure 1 and Figure 4 , Figure 1 The area of ​​the microrod structure in the slice shown is smaller than the set area threshold S0, and belongs to the first type of closed loop, so the first scanning path M1 is adopted. Figure 4 The first scanning path M1 includes an inner scanning path M11, an inner contour scanning path M12, and an outer contour scanning path M13, which are performed sequentially. The inner scanning path is used to fill the entity within the first type of closed loop. The inner contour scanning path is a path that scans along the inner contour of the first type of closed loop, and the outer contour scanning path is a path that scans along the outer contour of the first type of closed loop. The inner scanning path passes through the inner contour and connects to the outer contour. The inner contour is a contour obtained by offsetting the outer contour inward of the first type of closed loop by a set distance L. The offset set distance L can be close to the scanning pitch of the inner scanning path, for example, 0.01-0.5 times the scanning pitch of the inner scanning path.

[0062] When scanning specifically, first, see Figure 5 The laser scans along the internal scanning path, mainly completing the entity filling of the micro-rod structure. The specific path can include a set of parallel lines connected end to end. The maximum value of the extension direction of the parallel lines can be considered as the width of the closed loop in the slice. Figure 6 , the laser scans along the inner contour of the closed loop; again, see Figure 4The laser scans along the outer contour of the closed loop to obtain a scan of the microrod structure portion of the slice. The scanning speed of the inner contour scanning path of the first scanning path is the same as the scanning speed of the inner scanning path of the first scanning path. This can be used to supplement the scanning of the solid portion at the edge, reducing the problem of powder adhesion to the structure surface due to incomplete melting at the edge, which affects the surface quality of the structure.

[0063] At the same time, the scanning process of the first scanning path is different from the scanning process of the second scanning path in the following ways:

[0064] The scanning pitch of the internal scanning path of the first scanning path is smaller than the scanning pitch of the entity filling scanning path of the second scanning path, the scanning speed of the outer contour scanning path of the first scanning path is higher than the scanning speed of the outer contour scanning path of the second scanning path, the laser power of the laser scanning performed according to the outer contour scanning path of the first scanning path is smaller than the laser power of the laser scanning performed according to the outer contour scanning path of the second scanning path, and the scanning speed of the laser scanning performed according to the outer contour scanning path of the first scanning path is greater than the scanning speed of the laser scanning performed according to the outer contour scanning path of the second scanning path.

[0065] In this embodiment, in each slice, the first type of closed loop is scanned first, and then the second type of closed loop is scanned.

[0066] In summary, the 3D printing path planning method and the laser 3D printing method in the embodiments of the present application divide the types of closed loops by area and width standards, and scan closed loops whose area or width is less than a set threshold value by sequentially performing internal scanning, inner contour scanning, and outer contour scanning. The scanning line of the internal scanning path passes through the inner contour and connects to the outer contour. At the edge of the first type of closed loop, it can receive superimposed scanning from different directions from the two ends of the internal scanning path, the inner contour scanning path, and the outer contour scanning path. The smaller scanning spacing greatly reduces the phenomenon of unmelted powder on the surface of the tiny structure adhering to the structure, ensuring that the structure can achieve high-quality molding. The embodiments of the present application also provide a storage medium, the storage medium includes computer instructions, and the storage medium stores computer-readable instructions. When the computer-readable instructions are executed by the processor, the aforementioned 3D printing path planning method or the aforementioned laser 3D printing method is implemented.

[0067] The above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent replacements of the technical solutions of the present application should not depart from the spirit and scope of the technical solutions of the present application.

Claims

1. A 3D printing path planning method for planning the path of a workpiece to be printed, characterized by: Planning a first scanning path for a first type of closed loop on the slice of the workpiece, wherein the first type of closed loop is a closed loop whose area S is less than or equal to a set area threshold S0 or whose width D is less than or equal to a set width threshold D0; The first scanning path includes an inner scanning path, an inner contour scanning path, and an outer contour scanning path, which are performed sequentially; the inner scanning path is used to fill the entity within the first type of closed loop, the inner contour scanning path is a path scanned along the inner contour of the first type of closed loop, and the outer contour scanning path is a path scanned along the outer contour of the first type of closed loop; the inner scanning path passes through the inner contour and connects to the outer contour; wherein the inner contour is a contour obtained by offsetting the outer contour toward the inside of the first type of closed loop by a set distance L; Planning a second scanning path for a second type of closed loop on the slice of the workpiece, wherein the second type of closed loop is a closed loop having an area S greater than a set area threshold S0 and a width D greater than a set width threshold D0; The second scanning path includes a solid filling scanning path and an outer contour scanning path; A scanning pitch of an internal scanning path of the first scanning path is smaller than a scanning pitch of a physical filling scanning path of the second scanning path; A scanning speed of the outer contour scanning path of the first scanning path is higher than a scanning speed of the outer contour scanning path of the second scanning path.

2. The 3D printing path planning method according to claim 1, wherein: The set area threshold S0 is set to 1-100mm 2 , the set width threshold D0 is 0.1-0.8mm.

3. The 3D printing path planning method according to claim 1 or 2, characterized in that: The first type of closed loop is scanned first, and then the second type of closed loop is scanned.

4. A laser 3D printing method for printing a medical porous part, wherein the medical porous part comprises a microrod structure connected in a network, wherein pores exist between the microrod structures in the network, characterized in that: The laser 3D printing method comprises the following steps: Slicing the medical porous part to be printed; wherein the slice of the microrod structure has at least a first type closed loop with an area S less than or equal to a set area threshold S0 or a width D less than or equal to a set width threshold D0; A first scanning path is planned for a first type of closed loop on a slice of the medical porous component; wherein the first scanning path includes an inner scanning path, an inner contour scanning path, and an outer contour scanning path performed sequentially; the inner scanning path is used to fill a solid within the first type of closed loop, the inner contour scanning path is a path scanned along the inner contour of the first type of closed loop, and the outer contour scanning path is a path scanned along the outer contour of the first type of closed loop; the inner scanning path passes through the inner contour and connects to the outer contour; wherein the inner contour is a contour obtained by offsetting the outer contour by a set distance L toward the inside of the first type of closed loop; laser scanning is performed according to the first scanning path to form the first type of closed loop; The medical porous member further includes a solid portion, wherein the solid portion and the microrod structure are connected as a whole; a slice of the solid portion includes at least a portion of a second type closed loop having an area S greater than a set area threshold S0 and a width D greater than a set width threshold D0; Planning a second scanning path for the second type of closed loop on the slice of the medical porous member, the second scanning path including a solid filling scanning path and an outer contour scanning path; Performing laser scanning along the second scanning path to form the second type of closed loop; For each slice, the first type of closed loop is scanned first, and then the second type of closed loop is scanned; The laser power of the laser scanning performed along the outer contour scanning path of the first scanning path is less than the laser power of the laser scanning performed along the outer contour scanning path of the second scanning path; The scanning speed of the laser scanning performed along the outer contour scanning path of the first scanning path is greater than the scanning speed of the laser scanning performed along the outer contour scanning path of the second scanning path; A scanning speed of the inner contour scanning path of the first scanning path is the same as a scanning speed of the inner scanning path of the first scanning path.

5. A storage medium, characterized in that The storage medium includes computer instructions, and computer-readable instructions are stored on the storage medium. When the computer-readable instructions are executed by the processor, the 3D printing path planning method according to any one of claims 1 to 3 or the laser 3D printing method according to claim 4 is implemented.

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