Selective laser melting forming deformation control method for thin-wall cavity plate type structural component
By combining partitioned printing and ribbed auxiliary structures, the deformation and cracking problems of thin-walled cavity plate structures in laser selective melting forming were solved, achieving efficient and stable forming results.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-25
- Publication Date
- 2026-03-27
AI Technical Summary
When manufacturing large-sized thin-walled cavity plate structures, laser selective melting forming technology can cause internal stress concentration, leading to deformation and cracking, which affects the forming quality.
The method of partitioned printing is adopted, combined with a ribbed auxiliary structure, process parameters are adjusted, and long and short auxiliary structures are added to improve rigidity and avoid warping and twisting. The integrity is ensured by overlapping the connecting parts.
It effectively reduces stress concentration during the printing process, improves forming quality, avoids cracking, enhances overall rigidity, and increases printing success rate.
Smart Images
Figure CN121732837A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of 3D printing technology, and in particular to a method for controlling deformation during laser selective melting forming of thin-walled cavity plate structural parts. Background Technology
[0002] Selective laser melting (SLM) uses specialized software to slice and layer a 3D digital model of a part, obtaining contour data for each cross-section. A high-energy laser beam then selectively melts metal powder layer by layer according to this contour data. This process of layer-by-layer powder deposition, melting, and solidification creates a 3D solid part. In recent years, with the continuous maturation of SLM technology and the increase in the types of metal materials that can be applied, this technology has been widely used in the manufacture of various complex thin-walled structural parts. However, there are still significant challenges in forming large-size thin-walled cavity plate structures using this technology. This is mainly because the metal powder undergoes two stages during SLM, rapid melting and rapid solidification, which easily leads to large temperature gradients and internal stresses within the part. Due to their structural characteristics, thin-walled cavity plate structures have more concentrated stress distributions within the components. Furthermore, the overall stiffness of thin-walled parts is relatively low, and excessive internal stress can easily cause deformation during the forming process. Once the stress exceeds the material's yield strength, the entire structure will crack.
[0003] Therefore, there is an urgent need for a new printing method or equipment to solve the problem of printing failure or forming quality defects caused by internal stress concentration during the printing of large thin-walled components. Summary of the Invention
[0004] In view of this, the purpose of this invention is to provide a method for controlling deformation during laser selective melting forming of thin-walled cavity plate structural components. This solves the problem of warping or fracture caused by internal stress concentration during the printing of large thin-walled components, leading to printing failures or defects in forming quality.
[0005] The present invention provides a laser selective melting forming deformation control method for a thin-walled cavity plate structure, comprising the following steps:
[0006] S1. Model the thin-walled cavity plate structure, import it into the special software of the laser selective melting forming equipment for repair, and set the dividing line along the length direction of the thin-walled cavity plate structure to decompose the components into several components;
[0007] S2. Based on the segmented components, add a ribbed auxiliary structure;
[0008] S3. Import the printing task and set the process parameters;
[0009] S4. Determine the placement of structural components, fill with a suitable type of protective gas, and print at intervals along the length of the structural components;
[0010] S5. Printing complete.
[0011] Furthermore, in step S1, the component has a connecting part at its end, which can be connected to the next component.
[0012] Furthermore, the dividing line in step S1 does not pass through the circular hole, corner, or the location of key features.
[0013] Furthermore, in step S2, the ribbed auxiliary structure includes a long-side auxiliary structure and a short-side auxiliary structure. The long-side auxiliary structure is located on the outer side of the long side of the thin-walled cavity plate structure to improve the lateral stiffness of the long side; the short-side auxiliary structure is located on the outer side of the short side of the thin-walled cavity plate structure to improve the lateral stiffness of the short side.
[0014] Furthermore, the long-side auxiliary structure includes a side plate and several connecting plates; the several connecting plates are disposed at stress concentration points on the outside of the component to release stress and connect the workpiece; the side plate connects to the several connecting plates to improve the overall rigidity of the long-side auxiliary structure and form an auxiliary cavity.
[0015] Furthermore, the short-side auxiliary structure includes two side plates and diagonal bracing bars disposed between the two side plates, wherein the diagonal bracing bars are continuously arranged scissor bracing mechanisms.
[0016] Furthermore, in step S3, the process parameters for each component are the same.
[0017] Furthermore, the thickness of the ribbed auxiliary structure can be adjusted according to the thin-walled cavity plate structure, and the auxiliary cavity can be increased or decreased according to the amount of stress generated by the component.
[0018] The beneficial effects of the present invention are as follows: The present invention provides a laser selective melting forming deformation control method for thin-walled cavity plate structural parts; the method of printing in a partitioned manner reduces the stress generated during printing, and with the auxiliary structure added to the outside of the workpiece, the rigidity of the auxiliary structure itself effectively suppresses the warping, torsion deformation or interlayer cracking of the thin-walled structure. After the workpiece is printed in partitions, there are overlapping areas between the components formed. The setting of the overlapping areas can ensure the integrity and strength of the workpiece after the partitioned printing, and avoid the occurrence of structural weak points. Attached Figure Description
[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments:
[0020] Figure 1 This is a schematic diagram of the printed structure of the thin-walled cavity plate structure of the present invention;
[0021] Figure 2 This is a schematic diagram of the segmented structure of the thin-walled cavity plate structure of the present invention;
[0022] Figure 3 This is an enlarged view of point A in the present invention. Detailed Implementation
[0023] like Figures 1 to 3 As shown: A method for controlling deformation during laser selective melting forming of thin-walled cavity plate structural components, comprising the following steps:
[0024] S1. Modeling of thin-walled cavity plate structure 1: Dividing lines 101 are set along the length of thin-walled cavity plate structure 1 to decompose the component into several components 102; After the thin-walled cavity plate structure 1 is modeled, it is imported into the special software of laser selective melting forming equipment for testing and repair. For possible defects, such as missing corners, through holes, etc., modifications are made; and dividing lines 101 are set in the software to initially divide the printing area, that is, the components 102 in each area; a connecting part 103 is also provided at the dividing line 101.
[0025] S2. Based on the segmented component 101, add corresponding stiffener-type auxiliary structures; the stiffener-type auxiliary structure refers to the fact that the stress and deformation of various large-size thin-walled cavity plate structural components are different. When designing the stiffener-type auxiliary structure, parameters such as the thickness of the stiffener, the height of the stiffener, and the spacing of the stiffener can be adjusted to change the overall rigidity and prevent deformation.
[0026] S3. Set the printing task and import the process parameters; the process parameters include laser power, scanning speed and layer thickness, and print layer by layer from bottom to top; ensure the coordination of each component during the printing process and the overall effect after printing. The internal stress of the structural components can also be controlled by adjusting the specific process parameters, which is existing technology and will not be described in detail here.
[0027] S4. Determine the placement of structural components, fill with inert protective gas, and print at intervals along the length of the structural components; depending on the size of the structural components, select lateral or forward placement on the substrate and add cutting allowance. The interval printing refers to non-continuous printing, that is, after printing the current component layer, the adjacent component layer is not printed, but the adjacent component layer is skipped and the next component layer is printed directly, and so on, until the last component layer is completed. After that, the adjacent component layers are printed one by one, and the entire structural component is printed in one layer in this way; by adjusting the printing form and sequence of the structural components, the high temperature gradient and large internal stress generated in the one-piece forming process are effectively avoided, which greatly improves the success rate of printing in one go.
[0028] S5. After printing is complete, use wire cutting to remove excess stiffener-type auxiliary structures, and smooth the contact points before heat treatment, or cool them down before proceeding to the next process.
[0029] In this embodiment, component 102 in step S1 has a connecting portion 103 at its end, which can overlap with the next component 102. In this embodiment, the thin-walled cavity plate structure 1 has dimensions of length > 750mm, width < 50mm, height > 750mm, wall thickness < 5mm, and internal cavity or dot matrix filling. Each segment of component 101 is 150-250mm long. Too short a segment length will increase scanning time and the number of components 102 to be joined, which affects the forming efficiency and quality of the thin-walled cavity plate structure 1. If component 102 exceeds 250mm, the reduction of overall stress will be significantly weakened. The width of the connecting portion 103 is generally between 0-0.2mm, which can effectively reduce the impact of intermittent printing on the overall integrity. Furthermore, the connecting portion 103 can remelt and fuse with adjacent connecting portions during layer-by-layer printing, ensuring final integral molding and reducing subsequent processing.
[0030] In this embodiment, the dividing line 101 in step S1 does not pass through the circular hole, corner, or the location of key features; this can effectively ensure the integrity of key features and avoid the forming effects caused by printing errors after division and repeated melting and casting of the connecting parts.
[0031] In this embodiment, the ribbed auxiliary structure in step S2 includes a long-side auxiliary structure 2 and a short-side auxiliary structure 3. The long-side auxiliary structure 2 is located on the outer side of the long side of the thin-walled cavity plate structure to improve lateral stiffness; the short-side auxiliary structure 3 is located on the outer side of the short side of the thin-walled cavity plate structure to improve lateral stiffness. Because of its small size, large heat dissipation area, and significant temperature gradient, the thin-walled cavity plate structure generates substantial residual stress. When this residual stress exceeds the material's yield strength, the thin-walled structure, due to its low rigidity, cannot resist stress release, leading to warping or twisting. Simultaneously, metal undergoes volume shrinkage when cooling from a molten state to a solid state. The thin-walled cavity plate structure, with its small cross-section, experiences concentrated shrinkage, making it prone to uneven deformation due to anisotropic shrinkage. The shrinkage after each layer of printing melts exerts tensile force on the already solidified lower layer, also causing the thin-walled cavity plate structure to bend due to insufficient strength. The ribbed auxiliary structure effectively assists the thin-walled cavity plate structure in improving lateral stiffness and reducing warping and twisting.
[0032] In this embodiment, the long-side auxiliary structure includes a side plate 201 and several connecting plates 202. The connecting plates 202 are disposed at stress concentration points on the outside of the component to release stress and connect the component 102. The side plate 201 connects to the connecting plates 202 to improve the overall rigidity of the long-side auxiliary structure and form an auxiliary cavity. The size of the auxiliary cavity has a significant impact on the circumferential deformation resistance of the thin-walled cavity plate structure. As the spacing distance decreases, the circumferential deformation resistance is significantly improved. Generally, the auxiliary cavity is a rectangle with a long side of 100-350mm.
[0033] In this embodiment, the short-side auxiliary structure includes two side plates 302 and a diagonal brace 301 disposed between the two side plates. The diagonal brace 301 is a continuously arranged scissor brace structure. The scissor brace structure can effectively cover the short-side side to improve rigidity and prevent warping and twisting caused by stress release.
[0034] In this embodiment, the process parameters in step S3 are the same for all components. Printing with the same process parameters can combine adjacent components well, thus reducing the impact of intermittent printing and maintaining the overall performance of the thin-walled cavity plate structure 1.
[0035] In this embodiment, the thickness of the ribbed auxiliary structure can be adjusted according to the component, and the auxiliary cavity can be increased or decreased according to the stress generated by the component. Although the ribbed auxiliary structure improves the overall anti-deformation ability by adjusting the rib thickness, rib height, or reducing the rib spacing, the marginal reduction effect occurs after each variable reaches a certain value. Furthermore, adjusting the variables of the ribbed auxiliary structure will increase printing time, increase material waste, and increase the difficulty of removing the ribs in post-processing. Therefore, adaptively adding ribbed auxiliary structures to stress-generating areas is the key to improving printing efficiency and yield, which will not be elaborated further here.
[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.
Claims
1. A method for controlling deformation during laser selective melting forming of thin-walled cavity plate structural components, characterized in that: Includes the following steps: S1. Model the thin-walled cavity plate structure, import it into the special software of the laser selective melting forming equipment for repair, and set the dividing line along the length direction of the thin-walled cavity plate structure to decompose the components into several components; S2. Based on the segmented components, add a ribbed auxiliary structure; S3. Import the printing task and set the process parameters; S4. Determine the placement of structural components, fill with a suitable type of protective gas, and print at intervals along the length of the structural components; S5. Printing complete.
2. The laser selective melting deformation control method for thin-walled cavity plate structural components according to claim 1, characterized in that: The component in step S1 has a connecting part at its end, which can be connected to the next component.
3. The laser selective melting deformation control method for thin-walled cavity plate structural components according to claim 1, characterized in that: The dividing line in step S1 does not pass through the circular hole, corner, or the location of key features.
4. The laser selective melting deformation control method for thin-walled cavity plate structural components according to claim 1, characterized in that: The ribbed auxiliary structure in step S2 includes a long-side auxiliary structure and a short-side auxiliary structure. The long-side auxiliary structure is located on the outer side of the long side of the thin-walled cavity plate structure to improve the lateral stiffness of the long side; the short-side auxiliary structure is located on the outer side of the short side of the thin-walled cavity plate structure to improve the lateral stiffness of the short side.
5. The laser selective melting forming deformation control method for a thin-walled cavity plate structure according to claim 4, characterized in that: The long-side auxiliary structure includes a side plate and several connecting plates; the several connecting plates are disposed at stress concentration points on the outside of the component and connect to the workpiece; the side plate connects to the several connecting plates to improve the overall rigidity of the long-side auxiliary structure and form an auxiliary cavity.
6. The laser selective melting forming deformation control method for a thin-walled cavity plate structure according to claim 4, characterized in that: The short-side auxiliary structure includes two side plates and diagonal bracing between the two side plates. The diagonal bracing is a continuously arranged scissor bracing mechanism.
7. The laser selective melting forming deformation control method for a thin-walled cavity plate structure according to claim 1, characterized in that: In step S3, the process parameters are the same for all components.
8. The laser selective melting deformation control method for thin-walled cavity plate structural components according to claim 4, characterized in that: The thickness of the ribbed auxiliary structure can be adjusted according to the thin-walled cavity plate structure, and the auxiliary cavity can be increased or decreased according to the amount of stress generated by the component.