Selective laser melting forming deformation control method for thin-wall lip part

Abstract

The invention relates to the technical field of part machining, in particular to a selective laser melting forming deformation control method for thin-wall lip parts, and aims at typical lip parts. The method comprises the following steps: firstly, preliminarily analyzing the shrinkage deformation condition of a modeled thin-wall lip part in three-dimensional modeling software during forming, then adding a process allowance in sequence, analyzing a structure, determining the position of a suspension surface, presetting a part placement inclination angle, adjusting a model placement angle according to the position, and constructing a bottom support body structure; and performing simulation and trial printing on the model with the process allowance and the bottom support, and constructing an auxiliary support structure according to a result. And then the model is imported into magics software, after parameters of a 3D printer are set, a part with a related structure is printed, and finally structures such as process allowance and the like are removed. According to the technical scheme, the problems that a cutter is easy to block during part forming and the precision is difficult to control can be solved, and the thin-wall lip part with the size precision and the performance test reaching the standard can be prepared.

Description

Technical Field

[0001] The present invention relates to the technical field of part processing, and particularly to a method for controlling the deformation of laser selective melting forming of thin-walled lip parts. Background Art

[0002] Laser selective melting forming is a kind of 3D printing technology, which is an advanced manufacturing technology integrating computer graphics processing, digital information and control, laser technology and material technology, etc. After designing the three-dimensional model of the part, adding supports, and then slicing it into two-dimensional graphics layer by layer, the powder is melted layer by layer by a laser beam and stacked layer by layer to complete the manufacturing of the three-dimensional solid model.

[0003] Many thin-walled components have complex structures, and it is impossible to process parts using conventional sheet metal, machining, welding and other processes. Laser selective melting forming must be used. However, 3D printing is a process of continuous heat circulation. In the process of laser additive manufacturing of thin-walled parts, problems such as large thermal stress, easy deformation, and easy cracking will occur, resulting in unstable shape and quality of the formed parts. Lip parts have a thin wall thickness, complex shapes, and are mostly hollow structural parts, and the selected materials are metal materials such as titanium alloy, aluminum alloy, and stainless steel. Due to the large stress during 3D printing and the thin wall thickness of the parts, it is difficult to control deformation, and problems such as tool jamming and deformation are likely to occur during the additive manufacturing process. Summary of the Invention

[0004] Aiming at the problem of easy deformation of laser selective melting forming of typical thin-walled lip parts (thin-walled, hollow, overhanging surface structure parts), the present invention proposes a method for controlling the deformation of laser selective melting forming of thin-walled lip parts, conducts deformation control for typical lip parts, solves problems such as easy tool jamming and difficult control of part accuracy during the part forming process, and prepares parts with dimensional accuracy and performance test meeting the requirements.

[0005] The present application specifically realizes the above object through the following technical solutions: A method for controlling the deformation of laser selective melting forming of thin-walled lip parts, comprising the following steps: S1, in three-dimensional modeling software, for the thin-walled lip part model that has completed modeling, preliminarily analyze the shrinkage deformation situation existing in the forming process of the thin-walled lip part; S2, according to the shrinkage deformation situation preliminarily analyzed, add process allowances to the thin-walled lip part model; S3, analyze the structural characteristics of the part to determine the position of the overhanging surface structure inside the part, and preset the placement inclination angle of the part based on the overhanging surface structure; S4, according to the preset placement inclination angle of the part, adjust the placement angle of the thin-walled lip part model on the forming substrate surface, and construct a bottom support structure between the bottom of the thin-walled lip part model and the forming substrate surface; S5, performing part simulation and trial printing on the thin-walled lip part model in which the process allowance and the bottom support structure are constructed, and constructing an auxiliary support structure in the thin-walled lip part model according to the deformation of the part simulation and the trial printing; S6, import the thin-walled lip part model into the magics software, set the 3D printer parameters, and print out the thin-walled lip part with process allowance, auxiliary support structure and bottom support structure; S7, removing the process allowance, auxiliary support structure and bottom support structure on the thin-walled lip part, and completing the printing.

[0006] Preferably, in step S1, the preliminary analysis of shrinkage deformation includes analyzing the deformation trend of the thin-walled lip part shrinking from the periphery to the middle and the non-uniformity of the shrinkage amount.

[0007] Preferably, in step S2, adding process allowance includes adding flat-axis ribs between the inner layer and the outer layer of the thin-walled lip part model, and the flat-axis ribs and the inner layer and the outer layer of the thin-walled lip part model form an "I"-shaped structure; adjusting the spacing between the flat-axis ribs according to the shrinkage deformation conditions analyzed in the preliminary analysis, and encrypting the flat-axis ribs in the local deformation-prone area.

[0008] Preferably, in step 3, the preset part placement inclination angle is based on the overhang surface structure, and the thin-walled lip part is placed to a position where the angle α between the overhang surface structure and the forming substrate surface is 40-50°, and the angle α is the preset part placement inclination angle.

[0009] Preferably, in step S4, constructing the bottom support structure includes: constructing a plurality of layers of coaxial columnar support structures at the bottom of the thin-walled lip part model, and arranging a plurality of flat-axis reinforcing ribs on the columnar support structures at intervals along the circumferential direction.

[0010] Preferably, step S5 further includes pre-deforming the size of the thin-walled lip part model by using an inverse deformation method according to the deformation of the part simulation and trial printing, that is, enlarging the inner layer size of the thin-walled lip part model to different sizes along different directions, and keeping the spacing between the inner and outer layers of the thin-walled lip part model unchanged or enlarging proportionally with the change of the inner layer size.

[0011] Preferably, in step S5, constructing the auxiliary support structure includes: adding two layers of baffles, namely an upper flat diameter baffle and a lower flat diameter baffle, in the middle position of the thin-walled lip part model; adding a number of criss-crossing flat axis partitions between the upper flat diameter baffle and the lower flat diameter baffle, and each flat axis partition forms an "I"-shaped structure with the upper flat diameter baffle and the lower flat diameter baffle.

[0012] Preferably, in the step S5, constructing the auxiliary support structure further includes: determining the relatively more deformable local positions on the thin-walled lip part according to the part simulation and the deformation situation during trial printing, and constructing flat-diameter partitions at the inner and outer layers of the thin-walled lip part model corresponding to the foregoing local positions.

[0013] Preferably, in the step S5, constructing the auxiliary support structure further includes adding a lattice structure or a honeycomb structure as an interlayer between the upper flat-diameter baffle and the lower flat-diameter baffle.

[0014] Preferably, in the step S5, constructing the auxiliary support structure further includes adding a number of crosswise and longitudinally intersecting baffle reinforcing ribs on the upper flat-diameter baffle and the lower flat-diameter baffle respectively.

[0015] Preferably, the process margin, the auxiliary support structure, and the bottom support structure are all connected to the thin-walled lip part by a sawtooth structure.

[0016] Preferably, the process margin, the auxiliary support structure, and / or the bottom support structure are uniformly provided with material-saving holes.

[0017] Preferably, in the step S6, setting the 3D printer parameters includes: setting the printing layer thickness of the process margin, the auxiliary support structure, and the bottom support structure to be 2-4 times that of the thin-walled lip part; setting the scanning speed of the process margin, the auxiliary support structure, and the bottom support structure to be 1.5-3 times that of the thin-walled lip part.

[0018] The beneficial technical effects brought by the present invention: 1) Accurately analyze the root cause of deformation and lay a foundation for effective control. Aiming at the deformation problem of thin-walled lip parts in laser selective melting forming, this invention starts from a deep analysis of the shrinkage deformation situation, carefully studies the shrinkage trend and the non-uniformity of shrinkage amount from the periphery to the middle, and accurately locates the root cause of deformation. This in-depth analysis goes beyond the broad understanding of the deformation problem of thin-walled parts in the background technology, provides a solid direction for a series of subsequent deformation control strategies, enables the deformation control measures to be carried out in a targeted manner, and greatly improves the pertinence and effectiveness of dealing with the deformation problem.

[0019] 2) Multi - element collaborative deformation control to construct an all - round protection net. In terms of deformation control means, the invention content demonstrates diverse and collaborative characteristics. From the process margin addition link, an "I" - shaped structure is constructed with flat - axis rib plates and the spacing is flexibly adjusted to strengthen the strength of the part itself; to accurately presetting the placement inclination angle of the part according to the overhanging surface structure to resolve the contradiction between internal support and gravity deformation; and then to the elaborate construction of the bottom support structure and various forms of auxiliary support structures, comprehensively restricting and correcting the deformation of the thin - walled lip - shaped part from the whole to the part, from the horizontal to the vertical direction. These measures cooperate with each other to weave a tight deformation control protection net, effectively overcoming the deformation dilemma caused by complex structure and thin wall thickness in the background technology.

[0020] 3) Innovative dimension accuracy guarantee to ensure that parts meet the standards precisely. To solve the key problem of difficult control of part accuracy, the invention adopts the innovative measure of the anti - deformation method. According to the results of part simulation and trial printing, the inner - layer dimensions of the thin - walled lip - shaped part model are ingeniously pre - deformed with multi - directional and differential magnification to ensure that after experiencing the shrinkage deformation during the printing process, the final dimensions of the part can precisely meet the requirements. This method fills the gap in dimension accuracy control in the background technology, provides a reliable technical guarantee for the production of high - precision thin - walled lip - shaped parts, and effectively improves the quality and performance stability of the product.

[0021] 4) Considering cost - efficiency optimization to achieve comprehensive benefit improvement. While pursuing deformation control and accuracy guarantee, the invention content fully considers cost and efficiency factors. By adopting the serrated - structure connection process for the process margin, auxiliary support structure, and bottom support structure, it not only meets the deformation control requirements but also facilitates subsequent removal; and material - saving holes are arranged on these structures to reduce the powder usage for printing, effectively reducing the material cost. In addition, the parameters of the 3D printer are optimized, and the printing layer thickness and scanning speed are reasonably adjusted, significantly improving the construction speed of the auxiliary part and the overall printing efficiency. This design concept that takes multiple aspects into account makes up for the deficiencies in cost and efficiency considerations in the background technology and achieves a significant improvement in comprehensive benefits.

[0022] 5) Integrating the complete forming process to provide a practical solution. The invention integrates and forms a complete set of deformation control processes for the selective laser melting forming of thin - walled lip - shaped parts. From the initial deformation analysis, to the gradual construction of various support structures, precise control of part dimension accuracy, and then to the final printing and post - processing links, each step is closely connected and interlocked. This complete and systematic method effectively solves many thorny problems such as easy deformation, easy tool jamming, and difficult accuracy control of thin - walled lip - shaped parts during the selective laser melting forming process in the background technology, and provides a practical and efficient solution for preparing parts that meet the requirements of dimension accuracy and performance testing in actual production, with extremely high practical value and promotion potential. Brief Description of the Drawings

[0023] Figure 1 This is the basic implementation flowchart of the technical solution; Figure 2 This is a top-view structural schematic diagram of a thin-walled lip part; Figure 3 This is a side-view structural schematic diagram of a thin-walled lip part; Figure 4 is Figure 2 the A-A cross-sectional structural schematic diagram of; Figure 5 This is a structural schematic diagram of adding process allowance to the part and constructing an auxiliary support structure; Figure 6 This is a structural schematic diagram of an auxiliary support structure; Figure 7 This is a structural schematic diagram of constructing a bottom support structure at the bottom of the part.

[0024] In the figure: 1. Material-saving hole; 2. Serrated structure; 3. Baffle stiffener; 4. Flat-diameter partition; 5. Upper flat-diameter baffle; 6. Lower flat-diameter baffle; 7. Flat-axis partition; 8. Columnar support structure; 9. Flat-axis stiffener; 10. Flat-axis rib plate; 11. Thin-walled lip part; 11.1 Inner layer; 11.2 Outer layer; 11.3 Overhanging surface structure; 11.4 Hollow structure; 12. Forming substrate surface. Specific implementation manners

[0025] To make the purpose, technical solution and advantages of the invention clearer, the technical solution in the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments.

[0026] Therefore, the detailed description of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] Embodiment 1 This embodiment discloses a deformation control method for selective laser melting forming of thin-walled lip parts. As Figures 2 to 4Shown is the structure of a typical thin-walled lip part 11. The thin-walled lip part 11 has the characteristic of a relatively thin wall thickness, and its interior is a hollow structure 11.4 with a overhanging surface structure 11.3. If the overhanging surface is placed horizontally during the forming of the thin-walled lip part 11, internal supports must be added to the hollow structure 11.4 below the overhanging surface structure 11.3, but the internal supports added to the hollow structure 11.4 cannot be removed, resulting in the existence of redundant materials. Thus, as a preferred embodiment of the present invention, the following steps are included: S1. In a 3D modeling software, for the model of the thin-walled lip part 11 that has been modeled, preliminarily analyze the shrinkage deformation situation existing during the forming process of the thin-walled lip part 11. This step is the basis for the entire deformation control. The thin-walled lip part 11 is extremely prone to deformation during the forming process, especially the shrinkage deformation from the periphery to the middle (i.e., the inner layer 11.1 and the outer layer 11.2 shrink face to face), and the shrinkage amount from the periphery to the middle of the part is uneven, resulting in a smaller size in the middle of the lip. Thus, through the analysis of the shrinkage deformation trend and the unevenness of the shrinkage amount from the periphery to the middle of the thin-walled lip part 11 during the forming process, the direction of subsequent deformation control can be preliminarily located.

[0028] S2. According to the preliminarily analyzed shrinkage deformation situation, add process allowances to the model of the thin-walled lip part 11 to reduce the shrinkage of the inner layer 11.1 and the outer layer 11.2 of the thin-walled lip part 11 face to face. Adding process allowances according to the shrinkage deformation situation is an effective pre-compensation means. By appropriately increasing the material amount in the part model, a part of the dimensional deviation caused by shrinkage can be offset during the subsequent forming process, thereby reducing the influence of the shrinkage of the inner layer 11.1 and the outer layer 11.2 face to face on the final dimensional accuracy of the part.

[0029] S3. Analyze the structural characteristics of the part to determine the position of the overhanging surface structure 11.3 inside the part, and preset the placement inclination angle of the part based on the overhanging surface structure 11.3. This step is based on an in-depth study of the angle between the overhanging surface structure 11.3 and the forming substrate surface 12. By adjusting the placement angle of the part with a specific overhanging surface structure 11.3 as the reference, it fully considers the influence of the part's structural characteristics on the forming process and is a key link to improve the forming quality. Through experiments, it is determined that when the angle α between the overhanging surface structure 11.3 and the forming substrate surface 12 (XOY horizontal plane) is less than 40°, the overhanging surface cannot be directly formed without adding internal supports; when the angle α between the overhanging surface structure 11.3 and the forming substrate surface 12 (XOY horizontal plane) is greater than 50°, local deformation of the thin-walled lip part 11 will be caused by gravity. Therefore, the preset placement inclination angle of the part is based on the overhanging surface structure 11.3, and the thin-walled lip part 11 is placed to make the angle α between the overhanging surface structure 11.3 and the forming substrate surface 12 be in the range of 40° to 50°. This angle α is the preset placement inclination angle of the part. In this way, it can not only ensure the smooth forming of the overhanging surface without adding internal supports, but also effectively avoid local deformation caused by gravity.

[0030] S4. According to the preset placement inclination angle of the part, adjust the placement angle of the thin-walled lip part 11 model on the forming substrate surface 12, and construct a bottom support structure between the bottom of the thin-walled lip part 11 model and the forming substrate surface 12. Constructing the bottom support structure is crucial for preventing the thin-walled lip part 11 from collapsing, warping, and deforming during the printing process. The bottom support can provide a stable foundation for the part and evenly disperse the stress during the printing process. Especially for the thin-walled lip part 11 with a hollow structure 11.4 and a thin wall thickness, the bottom support can effectively make up for the problem of insufficient structural strength of its own and ensure the smooth progress of the printing process.

[0031] S5. Conduct part simulation and trial printing on the thin-walled lip part 11 model with the process margin and bottom support structure constructed. According to the deformation situation of the part simulation and trial printing, construct an auxiliary support structure in the thin-walled lip part 11 model to overcome the overall and / or local shrinkage deformation of the thin-walled lip part 11. The auxiliary support structure also belongs to a kind of process margin. Part simulation can simulate the printing process in a virtual environment and predict possible deformation situations. Combining the actual results of the trial printing, the construction position and form of the auxiliary support structure can be determined more accurately. The auxiliary support structure can provide additional support force for the overall and / or local shrinkage deformation of the part, and further optimize the forming accuracy of the part. For example, add targeted auxiliary supports in local areas prone to large shrinkage deformation.

[0032] S6. Import the thin-walled lip part 11 model into Magics software. After setting the 3D printer parameters, print out the thin-walled lip part 11 with machining allowances, auxiliary support structures, and bottom support body structures. S7. Remove the machining allowances, auxiliary support structures, and bottom support body structures from the thin-walled lip part 11 to obtain the final thin-walled lip part 11 that meets the requirements.

[0033] Therefore, the present technical solution has the following technical advantages: Improve dimensional accuracy: Through the analysis of shrinkage deformation and the addition of machining allowances, the dimensional deviation caused by shrinkage is effectively compensated, making the final dimensions of the thin-walled lip part 11 closer to the design requirements. In particular, a better solution is provided for the problem that the middle dimension of the lip is prone to being smaller, improving the overall dimensional accuracy.

[0034] Optimize the overhang surface forming: The determined part placement inclination angle of 40° - 50° skillfully solves the contradiction between the addition of internal supports and gravity deformation during overhang surface forming. It not only avoids the problem of residues that cannot be removed in the hollow structure 11.4 due to the addition of internal supports but also prevents local deformation caused by gravity, improving the forming quality of the overhang surface and the integrity of the overall part structure.

[0035] Enhance structural stability: The construction of the bottom support body structure and the auxiliary support structure improves the structural stability of the thin-walled lip part 11 during the printing process from different levels. The bottom support prevents the part from collapsing and warping, and the auxiliary support provides additional protection against shrinkage deformation, reducing the rejection rate caused by deformation and improving production efficiency and product quality.

[0036] Embodiment 2 This embodiment discloses a deformation control method for selective laser melting forming of thin-walled lip parts. As a preferred implementation of the present invention, based on Embodiment 1, in step S2, to ensure the distance between the inner layer 11.1 and the outer layer 11.2 of the thin-walled lip part 11, the machining allowances added include adding flat-axis rib plates 10 (i.e., rib plates parallel to the central axis of the thin-walled lip part 11 model) between the inner layer 11.1 and the outer layer 11.2 of the thin-walled lip part 11 model. The flat-axis rib plates 10 and the inner layer 11.1 and the outer layer 11.2 of the thin-walled lip part 11 model form an "I"-shaped structure to connect the inner layer 11.1 and the outer layer 11.2 of the thin-walled lip part 11 into a whole, rather than two separate thin-walled structures, greatly increasing the strength and stiffness of the thin-walled lip part 11 model and effectively reducing the deformation between the inner layer 11.1 and the outer layer 11.2. Further, adjust the spacing of the flat-axis rib plates 10 according to the initially analyzed shrinkage deformation situation, and densify the flat-axis rib plates 10 in the locally easily deformed areas.

[0037] In the above technical solution, the method of adding a flat shaft rib plate 10 between the inner layer 11.1 and the outer layer 11.2 of the thin-walled lip part 11 model to form an "I"-shaped structure effectively improves the strength and stiffness of the part based on the principle of structural mechanics. The "I"-shaped structure is widely used in the engineering field to bear large loads and reduce deformation. By connecting the inner layer 11.1 and the outer layer 11.2 into a whole, it changes the state of the thin-walled structure under independent stress. For example, when the thin-walled lip part 11 is subjected to external pressure or internal stress, the flat shaft rib plate 10 can, like the crossbeam of a bridge, evenly disperse the force to the inner layer 11.1 and the outer layer 11.2, enabling the entire structure to bear the force synergistically, thus greatly improving the ability to resist deformation. This structure has a significant effect on reducing the deformation between the inner layer 11.1 and the outer layer 11.2. Since the thin-walled lip part 11 is prone to face-to-face shrinkage of the inner layer 11.1 and the outer layer 11.2 during the forming process, the "I"-shaped structure restricts this relative displacement. The presence of the flat shaft rib plate 10 causes the inner layer 11.1 and the outer layer 11.2 to restrict each other during the shrinkage process, avoiding the problem of excessive change in the distance due to independent shrinkage of each layer, thus ensuring the distance stability between the inner layer 11.1 and the outer layer 11.2 of the part and contributing to maintaining the overall shape and dimensional accuracy of the part.

[0038] Adjusting the spacing of the flat shaft rib plates 10 according to the initially analyzed shrinkage deformation conditions and densifying the locally prone-to-deform areas is a refined deformation control measure. For example, in areas with a large shrinkage deformation amount, the densified flat shaft rib plates 10 can provide stronger support and restraint. If a certain area shows an obvious shrinkage deformation trend due to structural characteristics or forming process factors, by increasing the number of flat shaft rib plates 10 in this area, the occurrence of deformation can be more effectively restricted. This is like adding more support columns at the weak parts of a building to enhance its seismic resistance. This adjustment strategy takes into account both the locally prone-to-deform areas and the structural characteristics of the entire part. Instead of uniformly densifying the rib plates in all areas, it is carried out targeted according to the shrinkage deformation analysis results. This not only avoids problems such as increased part weight, material waste, and extended forming time caused by excessive addition of rib plates, but also effectively controls deformation at key parts, achieving a good balance between the overall structural stability and local deformation control, and improving the economy and practicality of the deformation control method.

[0039] Example 3 This embodiment discloses a method for controlling deformation in the selective laser melting forming of thin-walled lip parts. As a preferred implementation of the present invention, based on Embodiment 1 or 2, in step S4, the construction of the bottom support structure includes: constructing several layers of coaxial columnar support structures 8 at the bottom of the thin-walled lip part 11 model, and arranging several flat-axis reinforcing ribs 9 (i.e., reinforcing ribs parallel to the central axis of the columnar support structure 8) at intervals along the circumferential direction on the columnar support structure 8.

[0040] In this technical solution, several layers of coaxial columnar support structures 8 are constructed at the bottom of the thin-walled lip part 11 model and made perpendicular to the forming substrate. This design is mainly based on the principle of mechanical support. The columnar support structure 8 can provide a vertically upward supporting force, effectively bearing the weight of the thin-walled lip part 11 and preventing the part from sinking or deforming due to its own gravity during the forming process.

[0041] Flat-axis reinforcing ribs 9 are arranged at intervals along the circumferential direction on the columnar support structure 8. This design of the reinforcing ribs parallel to the central axis of the columnar support structure 8 is to further enhance the strength of the columnar support structure 8. From a mechanical perspective, the flat-axis reinforcing ribs 9 can share a part of the force when the columnar support structure 8 bears pressure or tension, making the overall force on the columnar support structure 8 more uniform, thereby improving its ability to resist deformation.

[0042] By setting the flat-axis reinforcing ribs 9, the advantage of reducing the thickness of the columnar support structure can be achieved. On the premise of ensuring sufficient strength of the support structure, reducing the thickness helps to save materials and reduce production costs. At the same time, the thinner support structure may also be relatively easier to remove in the subsequent process, reducing the impact on the surface quality of the part.

[0043] The advantages of this technical solution are as follows: Reducing the risk of tool jamming. The bottom support structure fixes the part on the forming substrate surface 12, which can effectively reduce the risk of tool jamming. During the selective laser melting forming process, the tool (such as a laser beam, etc.) needs to process the part according to a predetermined path. If the part is unstable on the substrate surface, such as shaking or tilting, it is very easy to cause the tool to collide with the part or the support structure, resulting in tool jamming. And the stable bottom support structure can ensure that the part is fixed in position during the processing, avoiding this unnecessary collision and ensuring the smooth progress of the forming process.

[0044] Reducing the amount of deformation: In addition to reducing the risk of tool jamming, the bottom support structure also plays an important role in reducing the deformation of the thin-walled lip part 11. It provides a stable support environment for the part, enabling the stresses on the part during the forming process to be effectively dispersed and balanced. Whether it is the shrinkage stress of the part itself or the stress generated by external factors (such as temperature changes, etc.), it can be transmitted to the forming substrate through the bottom support structure, thereby reducing the deformation of the part caused by stress concentration and improving the forming quality and dimensional accuracy of the part.

[0045] In summary, this design method of constructing the bottom support structure ensures the stability and quality of the thin-walled lip part 11 during the selective laser melting forming process from multiple aspects, and is of great significance for improving production efficiency, reducing costs, and ensuring that the product meets the requirements.

[0046] Example 4 This example discloses a method for controlling the deformation of the selective laser melting forming of thin-walled lip parts. As a preferred implementation of the present invention, based on Example 1, 2, or 3, it is considered that during the printing process of the thin-walled lip part 11, the large thermal stress is a key influencing factor. The generation of thermal stress mainly stems from the cycle of rapid heating and melting and cooling and solidification of the material during the selective laser melting forming process, which will cause an uneven temperature distribution inside the part, thereby forming thermal stress. At the same time, the added process margin may also shrink during this process. The combined action of thermal stress and process margin shrinkage makes the inner layer 11.1 and the outer layer 11.2 of the thin-walled lip part 11 prone to face-to-face shrinkage. If this shrinkage is not effectively controlled, it will seriously affect the final dimensional accuracy and assembly relationship of the part, because the accuracy of the dimensions of each part of the part is crucial for its smooth assembly with other components.

[0047] Based on this, in step S5, the anti-deformation method is introduced to pre-deform the model size of the thin-walled lip part 11. Its core principle is to make targeted adjustments (pre-deformation) to the part model size in advance according to the part simulation results and the deformation situation after trial printing, so as to offset the shrinkage deformation that may occur during the subsequent printing process, thereby accurately controlling the lip size and the overall part size of the thin-walled lip part 11 after 3D printing.

[0048] The specific implementation method is to enlarge the size of the inner layer 11.1 of the thin-walled lip part 11 by different sizes along different directions.

[0049] In this process, it should be noted that when the part structure is relatively simple, by means of reasonable dimension enlargement operations, the distance between the inner layer 11.1 and the outer layer 11.2 of the thin-walled lip part 11 can be ensured to remain unchanged. This is because the dimension enlargement is mainly for pre-compensating the possible shrinkage of the inner layer 11.1. Under ideal circumstances, after subsequent printing shrinkage, the dimensions of all parts of the part still meet the accuracy requirements, and the relative positional relationship between the inner layer 11.1 and the outer layer 11.2 remains unchanged.

[0050] However, when the part shape is complex, the situation will be slightly different. Due to the structural characteristics of complex parts, the distance between their inner layer 11.1 and outer layer 11.2 may be enlarged proportionally with the change of the inner layer 11.1 dimension. This is because the interconnections between various parts of complex parts are more closely related, and a change in one dimension may trigger a chain reaction in other parts. Even so, through precise simulation analysis and trial printing verification, it is still possible to determine the appropriate dimension enlargement ratio and direction, so that the dimensions of the thin-walled lip part 11 meet the accuracy requirements after printing shrinkage, ensuring that the part can be perfectly matched with other components during assembly.

[0051] Thus, by adopting the anti-deformation method, this technical solution can effectively solve the problem of part dimension accuracy caused by thermal stress and process allowance shrinkage. By pre-deforming the part model in advance, the printed part can still meet the accuracy standards required by the design after experiencing shrinkage deformation, greatly improving the manufacturing quality of the part and reducing the scrap rate caused by unqualified dimensions.

[0052] Embodiment 5 This embodiment discloses a deformation control method for selective laser melting forming of thin-walled lip parts. As a preferred implementation of the present invention, that is, based on Embodiment 1, 2, 3 or 4, considering that the inner layer 11.1 and the outer layer 11.2 of the thin-walled lip part 11 form an integral body and tend to shrink towards the center direction after adding process allowances, therefore, in step S5, the construction of the auxiliary support structure includes: adding two upper and lower baffle plates at the middle position of the thin-walled lip part 11 model, namely the upper flat diameter baffle plate 5 and the lower flat diameter baffle plate 6 (i.e., baffle plates parallel to the radial direction of the thin-walled lip part 11). Its principle of action is similar to setting a barrier in the middle of a structure that is prone to caving inwards. By restricting the inward displacement of the thin-walled lip part 11 in the central axial direction, the deformation amount of the overall shrinkage towards the middle is effectively reduced. For example, imagine a circular thin-walled structure, and the two upper and lower baffle plates are like restraint belts in its diameter direction, preventing it from caving inwards and deforming, thus playing a preliminary role in controlling the deformation of the lip part.

[0053] Further, a number of horizontally and vertically staggered flat shaft partitions 7 (i.e., partitions parallel to the axis of the thin-walled lip part 11) are added between the upper flat diameter baffle 5 and the lower flat diameter baffle 6. Each flat shaft partition 7 forms an "I"-shaped structure with the upper flat diameter baffle 5 and the lower flat diameter baffle 6. For the problem that the thin-walled lip part 11 shrinks unevenly towards the center around its circumference and has a large deformation amount around its circumference, adding the horizontally and vertically staggered flat shaft partitions 7 between the upper flat diameter baffle 5 and the lower flat diameter baffle 6 is a very ingenious design. Since the flat shaft partition 7 forms an "I"-shaped structure with the upper and lower baffles, from the perspective of mechanical structure, this structure greatly increases the strength and stiffness between the upper flat diameter baffle 5 and the lower flat diameter baffle 6. Just as in a building frame structure, adding diagonal braces between the main beams and longitudinal beams to enhance the stability of the overall frame, the flat shaft partition 7 enables the upper and lower baffles to be more capable of resisting the stress generated by the uneven shrinkage around the circumference, better maintaining their own shape and position, and thus more precisely controlling the local deformation of the thin-walled lip part 11, ensuring the dimensional accuracy and shape stability of the entire thin-walled lip part 11.

[0054] Embodiment 6 This embodiment discloses a method for controlling the deformation of a thin-walled lip part during selective laser melting forming. As a preferred implementation of the present invention, that is, based on Embodiment 5, in step S5 of constructing the auxiliary support structure, it further includes: according to the part simulation and the deformation situation of the trial printing, determining the relatively more deformable local positions on the thin-walled lip part 11, and constructing flat diameter partitions 4 (i.e., partitions parallel to the radius of the thin-walled lip part 11) corresponding to the aforementioned local positions in the inner layer 11.1 and the outer layer 11.2 of the thin-walled lip part 11 model.

[0055] Basis for determining the deformable positions: Determining the relatively more deformable local positions on the thin-walled lip part 11 through part simulation and the deformation situation of the trial printing is a precise positioning method based on the combination of practice and theory. Part simulation can simulate the printing process in a virtual environment and predict the deformation trends caused by factors such as stress concentration and temperature change that may occur in different parts. The trial printing is the actual verification of the simulation results, which can reflect the influence of some factors that are difficult to accurately simulate in the simulation on the part deformation in the real environment, such as the actual characteristic fluctuations of the material and the small errors of the equipment. The combination of the two can accurately find out those local areas that are most likely to deform during the actual printing process, providing a reliable basis for constructing the flat diameter partitions 4 subsequently.

[0056] Principle of action of the flat-diameter partition 4: The flat-diameter partition 4 is constructed at the corresponding locally deformable positions of the inner layer 11.1 and the outer layer 11.2 of the thin-walled lip part 11 model, mainly to control deformation from the perspective of local strengthening. The flat-diameter partition 4 forms an additional support structure in these locally deformable areas, similar to adding a reinforcing beam in a weak wall. When the thin-walled lip part 11 is subjected to various stresses during the forming process, the flat-diameter partition 4 can bear a part of the stress, restrict the relative displacement of the inner layer 11.1 and the outer layer 11.2 in the local area, and thus effectively reduce the deformation amount at this local position. For example, at a certain corner or thickness mutation of the thin-walled lip part 11, where stress is prone to concentration and deformation is relatively large, the flat-diameter partition 4 can provide strong support at these key positions, preventing the entire thin-walled lip part 11 from being scrapped due to excessive local deformation.

[0057] Balancing local and overall deformation: Although the flat-diameter partition 4 is constructed for locally deformable positions, it has a positive balancing effect on the deformation control of the entire thin-walled lip part 11. During the forming process of the thin-walled lip part 11, if local deformation cannot be effectively controlled, it may trigger a chain reaction, seriously affecting the shape and dimensional accuracy of the entire thin-walled lip part 11. By setting the flat-diameter partition 4 at key local positions, the local deformation is controlled within a smaller range, making the deformation distribution of the entire thin-walled lip part 11 more uniform, which is beneficial to maintaining the stability of the overall structure and the accuracy of dimensions. This is like in a large mechanical structure, timely repairing small faults of individual components can prevent the spread of faults and ensure the normal operation of the entire mechanical system.

[0058] Optimizing the overall deformation control strategy: The construction of the flat-diameter partition 4 further enriches the deformation control strategy of the thin-walled lip part 11. Cooperating with the previously mentioned bottom support structure, upper and lower flat-diameter baffles 6, and flat-axis partition 7, etc., it forms a multi-level and all-round deformation control system. The bottom support focuses on basic stable support, the middle baffles and partitions mainly control the overall and local horizontal shrinkage deformation, while the flat-diameter partition 4 strengthens specific local weak links. This comprehensive deformation control strategy can better adapt to the complex structural characteristics and forming process requirements of the thin-walled lip part 11, improve the effect and reliability of deformation control, and provide a strong guarantee for producing high-quality thin-walled lip parts 11.

[0059] Example 7 This embodiment discloses a method for controlling deformation in the selective laser melting forming of thin-walled lip parts. As a preferred implementation of the present invention, based on Embodiment 5 or 6, in order to further enhance the strength and stiffness between the upper flat diameter baffle 5 and the lower flat diameter baffle 6, in step S5, constructing the auxiliary support structure further includes adding a lattice structure or a honeycomb structure as a sandwich layer between the upper flat diameter baffle 5 and the lower flat diameter baffle 6.

[0060] A lattice structure is a spatial structure composed of discrete points connected in a specific way. It has high specific strength, high specific stiffness, and good energy absorption characteristics. The lattice units inside it can be arranged and combined according to different design requirements, so as to achieve precise control of the mechanical properties of the structure. For example, when under pressure, the lattice structure can evenly disperse the pressure to each part through the cooperative action between points, effectively resisting deformation.

[0061] A honeycomb structure is a honeycomb-like structure composed of a series of cells in the shape of hexagons, etc. It also has relatively high strength and stiffness, and has the characteristics of light weight and high material utilization rate. When the honeycomb structure is under external force, its hexagonal cells can form a stable support system, enabling the external force to be transmitted and dispersed along the cell walls, thus maintaining the stability of the structure and reducing the occurrence of deformation.

[0062] The principle of enhancing the strength and stiffness between the baffles: Placing the lattice structure or the honeycomb structure as a sandwich layer between the upper flat diameter baffle 5 and the lower flat diameter baffle 6 mainly utilizes their above-mentioned mechanical properties to further enhance the strength and stiffness between the baffles. When the thin-walled lip part 11 is subjected to various stresses such as thermal stress and shrinkage stress during the forming process, the upper flat diameter baffle 5 and the lower flat diameter baffle 6, as the main blocking and constraining components, will bear a large amount of pressure. The lattice structure or the honeycomb structure in the sandwich layer can work together with the baffles to share part of the pressure, making the baffles more "confident" when resisting deformation. It is like adding a reinforcement layer with a special structure between two pillars, making the two pillars more stable when facing external force impacts and not prone to bending or deformation.

[0063] The sandwich layer can be in direct contact with the diameter of the thin-walled lip part 11 or not in direct contact with the thin-walled lip part 11, and each of these two contact methods has its own design intention.

[0064] When the sandwich contacts the thin-walled lip part 11 at its diameter, it can participate to a greater extent in the overall force-bearing process of the thin-walled lip part 11. It can directly share a part of the stress from the thin-walled lip part 11, and at the same time, it can better transfer the stress it bears to other parts of the thin-walled lip part 11, forming a more closely force-bearing collaborative system. This contact method is more applicable to situations that require stronger overall deformation control effects. For example, in some key parts of the thin-walled lip part 11, extremely strict requirements are imposed on deformation control. Through direct contact, it can ensure that the sandwich can fully play its role in enhancing strength and stiffness.

[0065] When the sandwich does not directly contact the thin-walled lip part 11, it is mainly for the convenience of subsequent support removal. After the thin-walled lip part 11 is formed, the auxiliary support structure needs to be removed. If the sandwich directly contacts the thin-walled lip part 11, it may cause damage to the surface of the thin-walled lip part 11 during the removal process, or increase the difficulty of removal. By maintaining a certain interval, it is more convenient and fast to remove the support structure, and at the same time, it can also ensure the surface finish of the thin-walled lip part 11 to a certain extent, reducing the impact on the final quality of the thin-walled lip part 11.

[0066] Example 8 This embodiment discloses a method for controlling the deformation of a thin-walled lip part during selective laser melting forming. As a preferred implementation of the present invention, based on Example 5, 6 or 7, in step S5 of constructing the auxiliary support structure, several crosswise and longitudinally intersecting baffle stiffeners 3 are respectively added to the upper flat diameter baffle 5 and the lower flat diameter baffle 6. The main purpose of setting the baffle stiffeners 3 is to enhance the strength and stiffness between the upper flat diameter baffle 5 and the lower flat diameter baffle 6. From the perspective of mechanical structure, when the upper flat diameter baffle 5 and the lower flat diameter baffle 6 are subjected to various stress actions generated during the forming process of the thin-walled lip part 11, such as thermal stress, shrinkage stress, etc., the crosswise and longitudinally intersecting baffle stiffeners 3 can effectively share these stresses. It is like building a fine support network inside the baffle, making the baffle more stable when bearing external forces, not prone to deformation or damage, and thus better playing its role in controlling the inward shrinkage deformation of the thin-walled lip part 11.

[0067] Therefore, the following advantages exist in this technical solution: Saving powder usage: After adding the baffle rib 3, the thickness of the upper flat-diameter baffle 5 and the lower flat-diameter baffle 6 can be appropriately reduced. This measure brings significant advantages in saving powder usage. In the selective laser melting forming process, the consumption of powder materials is closely related to the volume of the built parts and support structures. By reducing the thickness of the baffle, it means that on the premise of ensuring that the support structure has sufficient strength and stiffness to control part deformation, the powder material used for building the baffle is reduced, thereby reducing production costs and improving material utilization rate. This is of great economic significance for large-scale production of thin-walled lip parts 11.

[0068] Shortening the printing time: In addition to saving powder usage, reducing the baffle thickness can also shorten the printing time. During the selective laser melting forming process, the printing time is proportional to the amount of material that needs to be melted and solidified. Since the baffle thickness is reduced, the volume of material that needs to be laser-treated is correspondingly reduced, shortening the time for laser scanning and melting these materials. This not only improves production efficiency but also reduces problems such as heat accumulation that may be caused by long-term printing to a certain extent, further optimizing the stability and reliability of the forming process.

[0069] Example 9 This example discloses a method for controlling deformation in the selective laser melting forming of thin-walled lip parts. As a preferred implementation of the present invention, based on any one of Examples 1 to 8, its process margin, auxiliary support structure, and bottom support body structure all use the serrated structure 2 to connect with the thin-walled lip part 11.

[0070] The serrated structure 2 realizes the connection with its special serrated shape. Each serration has a certain connection length with the thin-walled lip part 11, about 0.5 mm to 3 mm. This connection method can, on the one hand, effectively transfer stress and ensure that the control effect of the support structure on the deformation of the thin-walled lip part 11 is fully exerted; on the other hand, its relatively discrete connection characteristics make it convenient to remove these support structures and process margins subsequently, without being difficult to separate due to overly tight connection.

[0071] Example 10 This embodiment discloses a method for controlling deformation in the selective laser melting forming of thin-walled lip parts. As a preferred implementation of the present invention, that is, based on any one of Embodiments 1 to 9, the process margin, the auxiliary support structure, and / or the bottom support structure are uniformly provided with material-saving holes 1. The core purpose is to reduce the amount of printing powder used. In the manufacturing process of selective laser melting forming, material cost is often one of the key factors to be considered. Although the process margin, the auxiliary support structure, and the bottom support structure play an important role in controlling the deformation of the thin-walled lip part 11, they are parts that need to be removed after the final forming of the part and are not effective components of the final product. Therefore, by arranging the material-saving holes 1 on the auxiliary support structure, the amount of printing powder used in the manufacturing process can be effectively reduced without affecting its function of controlling part deformation, thus achieving the effect of reducing material cost.

[0072] Taking the auxiliary support structure as an example, it is an important component for further controlling the deformation of the thin-walled lip part 11, such as the upper and lower layers of baffles arranged at the middle position of the part model, the horizontal and vertical shaft partitions 7 that crisscross, etc. Arranging the material-saving holes 1 on these auxiliary support structures can also reduce the amount of printing powder used. For a support structure like the upper and lower layers of baffles, the material-saving holes 1 can penetrate the baffle. During the laser scanning process, the laser beam will skip the area of the material-saving holes 1, thus saving the powder used to form these areas. Moreover, by reasonably designing the layout of the material-saving holes 1 on the auxiliary support structure, such as determining the density of the holes according to the stress conditions of different parts of the support structure, more material-saving holes 1 can be appropriately arranged in the parts with less stress, which can not only ensure the overall strength of the support structure to control deformation but also minimize the powder usage to the greatest extent.

[0073] Improvement of cost-effectiveness: The most direct impact of the setting of the material-saving holes 1 is to reduce the amount of printing powder used, and thus reduce the material cost. For the large-scale production of thin-walled lip parts 11, this reduction in cost can significantly improve the economic benefits of production. In the manufacturing environment where market competition is increasingly fierce, controlling costs through such refined design means helps enterprises improve their competitiveness while ensuring product quality.

[0074] Embodiment 11 This embodiment discloses a method for controlling deformation in the selective laser melting forming of thin-walled lip parts. As a preferred implementation of the present invention, that is, based on any one of Embodiments 1 to 10, in step S6, the parameters of the 3D printer are set as follows: the printing layer thickness of the process margin, the auxiliary support structure, and the bottom support structure is set to be 2 - 4 times the printing layer thickness of the thin-walled lip part 11; the scanning speed for the process margin, the auxiliary support structure, and the bottom support structure is set to be 1.5 - 3 times the scanning speed for the thin-walled lip part 11.

[0075] The printing layer thickness of the process margin, auxiliary support structure, and bottom support structure is set to 2 - 4 times that of the thin-walled lip part 11, mainly considering the functions of these parts and subsequent processing requirements. The process margin is mainly used to compensate for the deformation of the part during the forming process, the auxiliary support structure is used to enhance the stability of the part and control deformation, and the bottom support structure is used to prevent the part from collapsing and warping. These parts do not have extremely high requirements for dimensional accuracy and surface quality like the thin-walled lip part 11. Appropriately increasing the printing layer thickness can improve their building speed while ensuring sufficient strength to achieve the corresponding functions. From the perspective of printing efficiency, a thicker printing layer thickness means that at the same printing height, fewer layers are required to print the process margin, auxiliary support structure, and bottom support structure, which can greatly shorten the printing time of these parts and improve the overall printing efficiency. In terms of structural strength, a thicker printing layer thickness will make these structures thicker, thereby enhancing their ability to resist deformation. Taking the bottom support structure as an example, a thicker printing layer thickness can better bear the weight of the thin-walled lip part 11 and reduce part deformation caused by insufficient support force.

[0076] The scanning speed of the process margin, auxiliary support structure, and bottom support structure is set to 1.5 - 3 times that of the thin-walled lip part 11 because these parts need to be removed in the final product and have relatively low requirements for their surface quality and details. By increasing the scanning speed, the printing efficiency can be further improved on the premise of ensuring their basic functions. Increasing the scanning speed will increase the area scanned by the laser per unit time. Since the functions of the process margin, auxiliary support structure, and bottom support structure are mainly to assist in the forming of the thin-walled lip part 11 and have low requirements for their microstructures and surface qualities, appropriately accelerating the scanning speed will not cause substantial damage to their functions. From the perspective of the overall printing time, accelerating the scanning speed can significantly shorten the printing time of the process margin, auxiliary support structure, and bottom support structure. This helps to improve the efficiency of the entire 3D printing process, reduce energy consumption, and the occupancy time of the equipment.

[0077] This parameter setting of the printing layer thickness and scanning speed complements each other and jointly optimizes the entire printing process. The combination of a thicker printing layer thickness and a faster scanning speed enables the process margin, auxiliary support structure, and bottom support structure to be built with sufficient strength in a shorter time. This provides strong guarantee for the high-quality printing of the thin-walled lip part 11. Because after these auxiliary parts are quickly built, the printing equipment can focus more on the fine printing of the thin-walled lip part 11 itself, and at the same time reduces various problems that may be caused by the too long printing time of the auxiliary parts, such as the influence of heat accumulation on the thin-walled lip part 11, thereby improving the success rate and quality of the entire 3D printing of the thin-walled lip part 11.

[0078] Example 12 In this example, a method for controlling the deformation of a thin-walled lip-shaped part during selective laser melting forming is applied in practice as follows: The material of the thin-walled lip-shaped part 11 is TC4 titanium alloy. The overall size of the thin-walled lip-shaped part 11 is approximately 320*200*120 mm. The size of the inner layer 11.1 of the thin-walled lip-shaped part 11 is 248*128 mm. The distance between the inner layer 11.1 and the outer layer 11.2 is 36 mm. The wall thickness of the thin-walled lip-shaped part 11 is 1 mm.

[0079] The cross-sectional view of the thin-walled lip-shaped part 11 is as shown in Figure 4 Figure [not provided]. The inside of the thin-walled lip-shaped part 11 is a hollow structure 11.4 and has an overhanging surface structure 11.3. To ensure that no internal support is required for the overhanging surface structure 11.3 inside the thin-walled lip-shaped part 11, the placement method of the thin-walled lip-shaped part 11 is as shown in Figure 7 Figure [not provided]. The overall inclination angle between the thin-walled lip-shaped part 11 and the substrate plane is 48°, and the inclination angle α≥40°, meeting the angle requirement for not adding internal support.

[0080] The titanium alloy thin-walled lip-shaped part 11 is extremely prone to deformation during the forming process, especially shrinkage deformation from the periphery to the middle, and the shrinkage amount from the periphery to the middle is uneven. The inward shrinkage dimension of the thin-walled lip-shaped part 11 ranges from 1 to 5 mm, resulting in a smaller size in the middle of the lip. To control the deformation of the thin-walled lip-shaped part 11, process allowances are added between the middle, the inner inner layer 11.1 and the outer layer 11.2 of the thin-walled lip-shaped part 11 to reduce the shrinkage of the thin-walled lip-shaped part 11 from the periphery to the middle.

[0081] To ensure the distance between the inner layer 11.1 and the outer layer 11.2 of the thin-walled lip-shaped part 11, flat-axis rib plates 10 are added between the inner layer 11.1 and the outer layer 11.2 of the thin-walled lip-shaped part 11, as shown in Figure 5 Figure [not provided]. The distance between the flat-axis rib plates 10 is approximately 40 mm; for local positions prone to deformation, the flat-axis rib plates 10 are appropriately densified, and the distance between the flat-axis rib plates 10 is adjusted to 20 mm. The flat-diameter rib plates form an I-shaped structure with the inner layer 11.1 and the outer layer 11.2 of the thin-walled lip-shaped part 11, connecting the inner layer 11.1 and the outer layer 11.2 into a whole, greatly increasing the strength and stiffness of the thin-walled part and effectively reducing the deformation between the inner layer 11.1 and the outer layer 11.2.

[0082] According to the part simulation results and the deformation situation after trial printing, an auxiliary support structure is constructed in the thin-walled lip-shaped part 11. It includes: For the local positions with relatively large deformation between the inner layer 11.1 and the outer layer 11.2 of the thin-walled lip-shaped part 11, a flat-diameter partition 4 is added at a local position between the inner layer 11.1 and the outer layer 11.2, as shown in Figure 5 It should be noted that the figures mentioned in the original text are not provided in the translation, so the corresponding figure references are marked as [not provided]. If the figures are available, the correct figure numbers or descriptions should be filled in for a more accurate translation.As shown, prevent the outer layer 11.2 of the lip from shrinking towards the middle.

[0083] After the inner layer 11.1 and the outer layer 11.2 form an I-shaped whole, the thin-walled lip part 11 is prone to shrink towards the middle position as a whole. Add an upper flat diameter baffle 5 and a lower flat diameter baffle 6 with a thickness of 1 mm at the middle position to reduce the deformation amount of the thin-walled lip part 11 shrinking from the periphery to the middle, and control the deformation of the lip thin-walled lip part 11, as Figure 5 shown.

[0084] To strengthen the deformation control effect of the upper flat diameter baffle 5 and the lower flat diameter baffle 6 on the inward shrinkage of the thin-walled lip part 11 and solve the problems of uneven shrinkage from the periphery to the middle and large deformation amount around the thin-walled lip part 11, add criss-crossed flat shaft partitions 7 between the upper flat diameter baffle 5 and the lower flat diameter baffle 6. The thickness of the flat shaft partition 7 is 0.6 mm, so that an I-shaped structure is formed between the upper flat diameter baffle 5 and the lower flat diameter baffle 6 and the flat shaft partition 7, increasing the strength and stiffness of the upper flat diameter baffle 5 and the lower flat diameter baffle 6. Add criss-crossed baffle reinforcing ribs 3 on the upper flat diameter baffle 5 and the lower flat diameter baffle 6. The thickness of the baffle reinforcing rib 3 is 1 mm and the height is 1 mm, increasing the stiffness of the upper flat diameter baffle 5 and the lower flat diameter baffle 6.

[0085] Due to the large thermal stress of the thin-walled lip part 11 during the printing process, the thin-walled lip part 11 shrinks from the periphery to the middle. The anti-deformation method is used to accurately control the lip size after 3D printing, and pre-deform the size of the thin-walled lip part 11. According to the part simulation results and the deformation situation after trial printing, the longitudinal dimension of 248 mm of the inner layer 11.1 of the thin-walled lip part 11 shrinks inward by 0.6 mm, and the transverse dimension of 128 mm shrinks inward by 0.3 mm. Therefore, expand the size of the lip inner layer 11.1 to 248.6 mm along the longitudinal direction and to 128.3 mm along the transverse direction, and keep the dimension between the inner layer 11.1 and the outer layer 11.2 of the thin-walled lip part 11 unchanged.

[0086] Determine the placement method of the thin-walled lip part 11. After adding the process margin and the auxiliary support structure, import the model of the thin-walled lip part 11 and the process margin model (including the process margin and the auxiliary support structure) into the magics software. The placement method of the thin-walled lip part 11 is as Figure 7 shown. Support with a layer of columnar support structure 8 under the thin-walled lip part 11, and at the same time add several flat shaft reinforcing ribs 9 at intervals along the circumferential direction on the columnar support structure 8 to increase the strength and reduce the thickness of the columnar support structure 8.

[0087] Further, in view of the problem that it is difficult to remove the above-mentioned process allowance, solid support structure and columnar support structure 8, a micropore with a gap connection or a sawtooth structure 2 in the shape of "concave-convex" is designed on structures such as the flat diameter partition 4, upper flat diameter baffle 5, lower flat diameter baffle 6, flat shaft partition 7, columnar support structure 8 and flat shaft rib plate 10. The connection length of a single sawtooth and the thin-wall lip part 11 is 2 mm.

[0088] Further, to shorten the printing time and facilitate the removal of the process allowance, auxiliary support structure and bottom support structure, the printing parameters at the corresponding positions can be different from those of the thin-wall lip part 11. The printing parameters of the thin-wall lip part 11 are: powder spreading layer thickness 60 μm, laser power 280 - 380 W, scanning rate 800 - 1600 mm / s, and scanning pitch 0.1 - 0.18 μm. The printing parameters of the process allowance, auxiliary support structure and bottom support structure are: powder spreading layer thickness 120 - 240 μm, laser power 320 - 420 W, scanning rate 1200 - 3000 mm / s, and scanning pitch 0.1 - 0.18 μm.

[0089] Further, to reduce the amount of printing powder used and shorten the printing time, a material-saving hole 1 with a diameter of 1 mm can be added at positions such as the process allowance, auxiliary support structure and bottom support structure.

Claims

1. A deformation control method for selective laser melting forming of thin-walled lip-like parts, characterized in that, It includes the following steps: S1. In 3D modeling software, for the model of the thin-walled lip part (11) that has been modeled, preliminarily analyze the shrinkage deformation situation during the forming process of the thin-walled lip part (11). S2. According to the preliminarily analyzed shrinkage deformation situation, add process allowances to the model of the thin-walled lip part (11). S3. Analyze the structural characteristics of the part to determine the position of the internal overhanging surface structure (11.3) of the part, and preset the part placement inclination angle based on the overhanging surface structure (11.3). S4. According to the preset part placement inclination angle, adjust the placement angle of the thin-walled lip part (11) model on the forming substrate surface (12), and construct a bottom support structure between the bottom of the thin-walled lip part (11) model and the forming substrate surface (12). S5. Perform part simulation and trial printing on the thin-walled lip part (11) model with process allowances and bottom support structure constructed. According to the part simulation and trial printing deformation situation, construct an auxiliary support structure in the thin-walled lip part (11) model. S6. Import the thin-walled lip part (11) model into magics software. After setting the 3D printer parameters, print out the thin-walled lip part (11) with process allowances, auxiliary support structure and bottom support structure. S7. Remove the process allowances, auxiliary support structure and bottom support structure on the thin-walled lip part (11), and the printing forming is completed.

2. The deformation control method for selective laser melting forming of thin-walled lip parts as described in claim 1, wherein In the step S1, the preliminary analysis of the shrinkage deformation situation includes analyzing the deformation trend of the thin-walled lip part (11) shrinking from the periphery to the middle and the non-uniformity of the shrinkage amount.

3. The deformation control method for selective laser melting forming of thin-walled lip parts according to claim 1, characterized in that, In the step S2, adding process allowances includes adding flat-axis rib plates (10) between the inner layer (11.1) and the outer layer (11.2) of the thin-walled lip part (11) model. The flat-axis rib plates (10) and the inner layer (11.1) and the outer layer (11.2) of the thin-walled lip part (11) model form an "I"-shaped structure; adjust the spacing of the flat-axis rib plates (10) according to the preliminarily analyzed shrinkage deformation situation, and encrypt the flat-axis rib plates (10) in the locally easily deformed areas.

4. The deformation control method for selective laser melting forming of thin-walled lip parts according to claim 1, wherein In the step 3, the preset part placement inclination angle is based on the overhanging surface structure (11.3), and the thin-walled lip part (11) is placed to a position where the angle α between the overhanging surface structure (11.3) and the forming substrate surface (12) is 40 - 50°. This angle α is the preset part placement inclination angle.

5. The deformation control method for selective laser melting forming of thin-walled lip parts as claimed in claim 1, wherein In the step S4, constructing the bottom support structure includes: constructing several layers of coaxial columnar support structures (8) at the bottom of the thin-walled lip part (11) model, and arranging several flat-axis stiffening ribs (9) at intervals along the circumferential direction on the columnar support structures (8).

6. The deformation control method for selective laser melting forming of thin-walled lip parts as described in claim 1, characterized in that, In the step S5, it also includes pre-deforming the dimensions of the thin-walled lip part (11) model by using the inverse deformation method according to the part simulation and trial printing deformation situation, that is: enlarging the dimensions of the inner layer (11.1) of the thin-walled lip part (11) model by different dimensions in different directions, and keeping the distance between the inner layer (11.1) and the outer layer (11.2) of the thin-walled lip part (11) model unchanged or enlarging it proportionally as the dimensions of the inner layer (11.1) change.

7. The deformation control method for selective laser melting forming of thin-walled lip parts according to claim 1, characterized in that In the step S5, the construction of the auxiliary support structure includes: adding two upper and lower layers of baffles at the middle position of the thin-walled lip part (11) model, namely the upper flat diameter baffle (5) and the lower flat diameter baffle (6); adding a number of horizontally and vertically criss-crossed flat shaft partitions (7) between the upper flat diameter baffle (5) and the lower flat diameter baffle (6), and each flat shaft partition (7) forms an "I"-shaped structure with the upper flat diameter baffle (5) and the lower flat diameter baffle (6).

8. The deformation control method for selective laser melting forming of thin-walled lip parts according to claim 7, wherein, In the step S5, the construction of the auxiliary support structure further includes: determining the relatively more deformable local positions on the thin-walled lip part (11) according to the part simulation and the deformation situation during trial printing, and constructing flat diameter partitions (4) on the inner layer (11.1) and the outer layer (11.2) of the thin-walled lip part (11) model corresponding to the aforementioned local positions.

9. The deformation control method for selective laser melting forming of thin-walled lip parts according to claim 7, characterized in that In the step S5, the construction of the auxiliary support structure further includes adding a lattice structure or a honeycomb structure as an interlayer between the upper flat diameter baffle (5) and the lower flat diameter baffle (6).

10. The deformation control method for selective laser melting forming of thin-walled lip parts as described in claim 7, characterized in that, In the step S5, the construction of the auxiliary support structure further includes adding a number of horizontally and vertically crossed baffle reinforcing ribs (3) on the upper flat diameter baffle (5) and the lower flat diameter baffle (6) respectively.

11. The deformation control method for selective laser melting forming of thin-walled lip parts as described in claim 1, characterized in that, The process margin, the auxiliary support structure and the bottom support body structure are all connected to the thin-walled lip part (11) by a sawtooth structure (2).

12. The deformation control method for selective laser melting forming of thin-walled lip parts according to claim 1, characterized in that, The process margin, the auxiliary support structure and / or the bottom support structure are evenly provided with material-saving holes (1).

13. The deformation control method for selective laser melting forming of thin-walled lip parts according to claim 1, characterized in that, In the step S6, setting the 3D printer parameters includes: setting the printing layer thickness of the process margin, the auxiliary support structure and the bottom support body structure to be 2-4 times that of the thin-walled lip part (11); setting the scanning speed of the process margin, the auxiliary support structure and the bottom support body structure to be 1.5-3 times that of the thin-walled lip part (11).

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