Supporting structure suitable for selective laser melting forming process and design method

Abstract

The invention provides a supporting structure suitable for a selective laser melting forming process and a design method. The supporting structure comprises a plurality of vertical plate supports, a plurality of transverse rod supports, a hollowed-out contour support and a strip-shaped contour support. The multiple vertical plate supports are arranged at intervals in the vertical direction. The multiple transverse rod supports and the multiple vertical plate supports are connected in a penetrating and inserting mode and are perpendicular to each other, the multiple transverse rod supports are arranged into multiple layers at intervals in the height direction, and the transverse rod supports in each layer are arranged at intervals in the horizontal direction; the hollowed-out outline supports are arranged on the periphery of the vertical plate supports in an enveloping mode. The strip-shaped contour support wraps the periphery of the vertical plate supports, and the strip-shaped contour support and the hollowed-out contour support are arranged in an overlapping mode; the whole formed by the vertical plate support, the transverse rod support, the hollowed-out contour support and the strip-shaped contour support is formed through selective laser melting. The technical problems that in the prior art, a supporting structure is high in strength, the powder cleaning difficulty is large, and powder is difficult to remove can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of selective laser melting forming, and particularly relates to a support structure and a design method suitable for selective laser melting forming process. Background Art

[0002] One of the characteristics of additive manufacturing is that it provides great design freedom to create complex and impressive parts. Among them, selective laser melting (SLM) technology is one of the effective means currently applicable to the manufacture of complex and practical products in the high-end manufacturing field. However, based on the characteristics of layer-by-layer high-precision laser sintering of selective laser melting forming technology, to realize the process of product manufacturing, many complex but necessary intermediate steps are required for the complex structure of the product, such as support addition, powder cleaning, support removal, etc.

[0003] In the selective laser melting (SLM) technology, due to the repeated rapid cooling and heating processes during the forming process, thermal stress accumulates inside the part, and warping is likely to occur when forming a large-area overhanging entity. At this time, appropriate addition of a support structure can effectively inhibit this phenomenon. At the same time, the support can timely conduct the generated heat to the substrate, reducing the thermal stress of the part. Common support forms include block support, cone support, rib support, wire support, contour support, etc. And the common added support body is mostly block support, but the strength of block support is low, it is easy to be scraped and broken by the scraper, and the powder cleaning difficulty of block support is very large. The powder is caked inside the support, resulting in a significant increase in the difficulty of support removal. Summary of the Invention

[0004] The present invention provides a support structure and a design method suitable for selective laser melting forming process, which can solve the technical problems of low strength of the support structure, large powder cleaning difficulty and difficult removal in the prior art.

[0005] According to one aspect of the present invention, a support structure suitable for selective laser melting forming process is provided. The structure includes a plurality of vertical plate supports, a plurality of horizontal bar supports, a hollowed-out contour support and a strip-shaped contour support; the plurality of vertical plate supports are arranged at intervals in the vertical direction; the plurality of horizontal bar supports are inserted and connected with the plurality of vertical plate supports and are perpendicular to each other, and the plurality of horizontal bar supports are arranged in multiple layers at intervals in the height direction, and each layer of the horizontal bar supports is arranged at intervals in the horizontal direction; the hollowed-out contour support envelopes the periphery of the plurality of vertical plate supports; the strip-shaped contour support envelopes the periphery of the plurality of vertical plate supports and is arranged overlapping with the hollowed-out contour support; the overall formed by the vertical plate supports, the horizontal bar supports, the hollowed-out contour support and the strip-shaped contour support is formed by selective laser melting.

[0006] Preferably, the thickness range of each of the vertical plate supports is 0.2 mm - 0.6 mm, and the spacing range between two adjacent vertical plate supports is 0.2 mm - 0.6 mm.

[0007] Preferably, the diameter range of each of the cross-bar supports is 0.2 mm - 0.8 mm, and the spacing range between two adjacent cross-bar supports is 0.2 mm - 0.6 mm.

[0008] Preferably, the thickness range of the hollowed-out profile support is 0.2 - 0.5 mm.

[0009] Preferably, the strip width range of the strip profile support is 0.2 - 0.4 mm, and the gap range between two adjacent strips is 0.2 - 0.4 mm.

[0010] Preferably, during the selective laser melting forming process of the support structure, printing is performed using the parameters of the solid support. The laser power used is 40 - 80 W lower than the laser power for printing the block support, and the scanning speed used is 150 - 400 mm / s lower than the scanning speed of the block support.

[0011] According to another aspect of the present invention, there is provided a design method for a support structure applicable to the selective laser melting forming process. The method designs any one of the above-mentioned support structures, and the method includes:

[0012] Determine the forming placement position of the part;

[0013] Based on determining the forming placement position of the part, use the modeling module to add vertical plate supports, hollowed-out profile supports, and strip profile supports to the positions of the part where supports are required;

[0014] Use the modeling module to add cross-bar supports to the positions of the part where supports are required, wherein the cross-bar supports are perpendicular to the vertical plate supports;

[0015] Use the modeling module to repair the vertical plate supports, hollowed-out profile supports, strip profile supports, and cross-bar supports of the part, and delete the fragmented supports, thereby completing the design of the support structure.

[0016] Preferably, using the modeling module to add cross-bar supports to the positions of the part where supports are required includes:

[0017] Use the modeling module to add volume supports to the positions of the part where supports are required. The top and bottom of the volume supports are both offset by 0.5 mm - 3 mm;

[0018] Use the modeling module to convert the added volume supports into editable entities, and then convert these entities into cross-bar supports.

[0019] Applying the technical solution of the present invention, the support structure that combines and nests the vertical plate support, the cross-bar support, the hollow profile support, and the strip profile support not only improves the strength of the support structure, ensures the stability during the part printing process, but also reduces the difficulty of powder cleaning inside the support, thereby reducing the difficulty of removing the support and improving the production efficiency of the part. In addition, during the selective laser melting forming process, by using appropriate process parameters, while the added nested support has high strength, the connection strength between the support and the part is weakened, making it easy to remove. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings included are used to provide a further understanding of the embodiments of the present invention, which form a part of the specification, are used to illustrate the embodiments of the present invention, and together with the written description are used to explain the principles of the present invention. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts.

[0021] Figure 1 FIG. shows a schematic structural diagram of a vertical plate support provided according to an embodiment of the present invention;

[0022] Figure 2 FIG. shows a schematic structural diagram of a cross-bar support provided according to an embodiment of the present invention;

[0023] Figure 3 FIG. shows a schematic structural diagram of a hollow profile support provided according to an embodiment of the present invention;

[0024] Figure 4 FIG. shows a schematic structural diagram of a strip profile support provided according to an embodiment of the present invention;

[0025] Figure 5 FIG. shows a schematic structural diagram of the combination of a vertical plate support and a cross-bar support provided according to an embodiment of the present invention;

[0026] Figure 6 FIG. shows a front view of the nested combination of a vertical plate support, a cross-bar support, a hollow profile support, and a strip profile support provided according to an embodiment of the present invention;

[0027] Figure 7 FIG. shows a top view of the nested combination of a vertical plate support, a cross-bar support, a hollow profile support, and a strip profile support provided according to an embodiment of the present invention.

[0028] Among them, the above-mentioned accompanying drawings include the following reference numerals:

[0029] 1, vertical plate support; 2, cross-bar support; 3, hollow profile support; 4, strip profile support. Detailed Implementation Modes

[0030] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present invention.

[0031] It should be noted that the terms used herein are only for describing specific implementation modes and are not intended to limit the exemplary implementation modes according to the present application. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0032] Unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for the sake of convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and devices should be regarded as part of the authorized specification. In all the examples shown and discussed herein, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0033] Such as Figures 1-7As shown in the figure, the present invention provides a support structure applicable to the selective laser melting forming process. The structure includes a plurality of vertical plate supports 1, a plurality of horizontal bar supports 2, a hollowed-out contour support 3, and a strip-shaped contour support 4; the plurality of vertical plate supports 1 are arranged at intervals in the vertical direction; the plurality of horizontal bar supports 2 are inserted and connected with the plurality of vertical plate supports 1 and are perpendicular to each other, and the plurality of horizontal bar supports 2 are arranged in multiple layers at intervals in the height direction, and each layer of the horizontal bar supports 2 is arranged at intervals in the horizontal direction; the hollowed-out contour support 3 envelopes the periphery of the plurality of vertical plate supports 1; the strip-shaped contour support 4 envelopes the periphery of the plurality of vertical plate supports 1 and is overlapped with the hollowed-out contour support 3; the overall formed by the vertical plate supports 1, the horizontal bar supports 2, the hollowed-out contour support 3, and the strip-shaped contour support 4 is formed by selective laser melting.

[0034] The present invention adopts a support structure in which the vertical plate supports 1, the horizontal bar supports 2, the hollowed-out contour supports 3, and the strip-shaped contour supports 4 are combined and nested with each other, which not only improves the strength of the support structure, ensures the stability during the part printing process, but also reduces the difficulty of powder cleaning inside the support, thereby reducing the difficulty of removing the support and improving the production efficiency of the part. In addition, during the selective laser melting forming process, by adopting appropriate process parameters, while the added nested support has a high strength, the connection strength between the support and the part is weakened, making it easy to remove.

[0035] In the present invention, the horizontal bar supports 2 are perpendicular to the vertical plate supports 1, are inserted and connected in the vertical plate supports 1, a hollowed-out contour support 3 is added to envelope the whole around the vertical plate supports 1, and a strip-shaped contour support 4 is added in an overlapping manner at the position of the hollowed-out contour support 3, so that the hollowed-out contour support 3 and the strip-shaped contour support 4 are in contact with each other, increasing the overall strength.

[0036] According to an embodiment of the present invention, the thickness range of each vertical plate support 1 is 0.2 mm - 0.6 mm, and the spacing range between two adjacent vertical plate supports 1 is 0.2 mm - 0.6 mm.

[0037] According to an embodiment of the present invention, the diameter range of each horizontal bar support 2 is 0.2 mm - 0.8 mm, and the spacing range between two adjacent horizontal bar supports 2 is 0.2 mm - 0.6 mm.

[0038] According to an embodiment of the present invention, the thickness range of the hollowed-out contour support 3 is 0.2 - 0.5 mm. The strip width range of the strip-shaped contour support 4 is 0.2 - 0.4 mm, and the gap range between two adjacent strips is 0.2 - 0.4 mm.

[0039] Specifically, without affecting the support for powder cleaning, the hollow contour support 3 envelopes the vertical plate support 1 to prevent scraping between the scraper and the edge of the vertical plate support 1 during printing, which may affect the printing quality. Then, strip contours are added at the position of the hollow contour support 3. The strip contours have high strength, which can strengthen the strength of the outer contour and improve the stability during printing.

[0040] Furthermore, the appropriate support thickness of the vertical plate support 1 and the contour support added to the part should be selected with reference to the part to facilitate subsequent support removal.

[0041] According to an embodiment of the present invention, during the selective laser melting forming process of the support structure, printing is carried out using the parameters of the solid support. The laser power used is 40 - 80W lower than that of the printing block support, and the scanning speed used is 150 - 400mm / s lower than that of the block support.

[0042] Among them, each layer is scanned once to enhance the strength of the support and ensure the stability of product printing.

[0043] The present invention also provides a design method for a support structure suitable for the selective laser melting forming process. The method designs any of the above - mentioned support structures, and the method includes:

[0044] Determine the forming placement position of the part and repair the part;

[0045] Based on determining the forming placement position of the part, use the modeling module to add the vertical plate support 1, the hollow contour support 3, and the strip contour support 4 to the positions where the part needs to add supports;

[0046] Use the modeling module to add the cross - bar support 2 to the positions where the part needs to add supports. Among them, the cross - bar support 2 is perpendicular to the vertical plate support 1;

[0047] Use the modeling module to repair the vertical plate support 1, the hollow contour support 3, the strip contour support 4, and the cross - bar support 2 of the part, and delete the fragmented supports to ensure the forming quality of the support, thereby completing the design of the support structure.

[0048] According to an embodiment of the present invention, the MAGICS software is used for the forming placement and model repair of the part.

[0049] According to an embodiment of the present invention, the modeling module can adopt the MAGICS software.

[0050] According to an embodiment of the present invention, using the modeling module to add the cross - bar support 2 to the positions where the part needs to add supports includes:

[0051] Use the modeling module to add volume supports at the positions where supports are required for the part, with a 0.5 mm - 3 mm offset at both the top and bottom of the volume supports;

[0052] Use the modeling module to convert the added volume supports into editable solids, and then convert the solids into cross-bar supports 2.

[0053] Specifically, after the volume supports are converted into cross-bar supports 2, some relatively fine and fragmented supports will be generated, which will affect the printing of the product. The fine and fragmented supports of the cross-bar supports 2 need to be deleted to ensure the forming quality of the supports.

[0054] During the subsequent printing process, export the added supports as a whole, then import and repair them. Then use the selective laser melting forming process for printing. After that, clean the powder from the printed part and its supports, and then remove the supports.

[0055] To further understand the present invention, the support structure of the present invention will be described in detail below.

[0056] In this embodiment, the support structure of the present invention is used to support the part and obtain the part, which specifically includes the following steps: Use MAGICS software to repair errors such as broken edges, holes, and gaps of the part that requires support addition. Then add vertical plate supports 1, cross-bar supports 2, hollow profile supports 3, and strip profile supports 4 with appropriate support parameters. After exporting the added supports as a whole, import them again to form a nested whole, and repair errors such as broken edges, holes, and gaps of the added supports. Use a selective laser melting forming device to prepare the part with the added supports, and perform selective laser melting forming on the part with supports. The laser power of the added combined supports is 60 W lower than that of the block supports, and its scanning speed is 300 mm / s slower than that of the block supports. Print layer by layer, and the selective laser melting forming is carried out in an Ar gas protection atmosphere. After printing is completed, clean the powder from the part and the added supports. After ensuring that the powder inside the supports is cleaned, cut it from the substrate and remove the supports to obtain the required part.

[0057] In summary, the present invention provides a support structure and design method applicable to the selective laser melting forming process. By adding vertical plate supports 1, connecting them with cross-bar supports 2, and enclosing them with a thin layer of hollow profile supports 3 to form a whole, the strength of the support is greatly improved, the stability of the product during printing is ensured, the error tolerance is increased, and sufficient gaps are left in the support parts, making it easier to clean the powder and reducing the difficulty of removing the supports.

[0058] For ease of description, spatial relative terms such as "above", "over", "on the upper surface", "upper" etc. may be used herein to describe the spatial positional relationship of one device or feature to other devices or features as shown in the figures. It should be understood that the spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, a device described as "above" or "over" other devices or structures will then be positioned "below" or "under" the other devices or structures. Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the corresponding explanations for the spatial relative descriptions used herein will be made accordingly.

[0059] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of differentiating the corresponding components. Without additional statements, the above terms have no special meanings, and thus should not be construed as limiting the protection scope of the present invention.

[0060] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A support structure applicable to the selective laser melting forming process, characterized in that, the structure includes a plurality of vertical plate supports, a plurality of horizontal rod supports, a hollowed-out contour support and a strip-shaped contour support; the plurality of vertical plate supports are arranged at intervals in the vertical direction; the plurality of horizontal rod supports are inserted and connected with the plurality of vertical plate supports and are perpendicular to each other, and the plurality of horizontal rod supports are arranged in multiple layers at intervals in the height direction, and each layer of the horizontal rod supports is arranged at intervals in the horizontal direction; the hollowed-out contour support envelopes the periphery of the plurality of vertical plate supports; the strip-shaped contour support envelopes the periphery of the plurality of vertical plate supports and is arranged overlapping with the hollowed-out contour support; the overall formed by the vertical plate supports, the horizontal rod supports, the hollowed-out contour support and the strip-shaped contour support is formed by selective laser melting.

2. The structure according to claim 1, characterized in that, the thickness range of each vertical plate support is 0.2 mm - 0.6 mm, and the spacing range between adjacent two vertical plate supports is 0.2 mm - 0.6 mm.

3. The structure according to claim 1, characterized in that, the diameter range of each horizontal rod support is 0.2 mm - 0.8 mm, and the spacing range between adjacent two horizontal rod supports is 0.2 mm - 0.6 mm.

4. The structure according to claim 1, characterized in that, the thickness range of the hollowed-out contour support is 0.2 - 0.5 mm.

5. The structure according to claim 1, characterized in that, the strip width range of the strip-shaped contour support is 0.2 - 0.4 mm, and the gap range between adjacent two strips is 0.2 - 0.4 mm.

6. The structure according to claim 1, characterized in that, during the selective laser melting forming process of the support structure, printing is carried out with the parameters of solid support, the laser power used is 40 - 80 W lower than the laser power for printing block support, and the scanning speed used is 150 - 400 mm / s lower than the scanning speed of block support.

7. A design method of a support structure applicable to the selective laser melting forming process, characterized in that, the method designs any one of the support structures according to claims 1 - 6, and the method includes: determining the forming placement position of the part; on the basis of determining the forming placement position of the part, using a modeling module to add vertical plate supports, hollowed-out contour supports and strip-shaped contour supports to the positions where the part needs to add supports; using the modeling module to add horizontal rod supports to the positions where the part needs to add supports, wherein the horizontal rod supports are perpendicular to the vertical plate supports; using the modeling module to repair the vertical plate supports, hollowed-out contour supports, strip-shaped contour supports and horizontal rod supports of the part, and deleting the fragmented supports, thereby completing the design of the support structure.

8. The method according to claim 7, characterized in that, using the modeling module to add horizontal rod supports to the positions where the part needs to add supports includes: using the modeling module to add volume supports to the positions where the part needs to add supports, and offsetting 0.5 mm - 3 mm at both the top and bottom of the volume supports. Use the modeling module to convert the added volume support into an editable entity, and then convert this entity into a cross-bar support.

Images