Thin-wall part with supporting structure used in laser powder bed melting additive manufacturing thin-wall cavity

Abstract

The invention discloses a thin-wall part with a supporting structure used in a laser powder bed melting additive manufacturing thin-wall cavity, and belongs to the technical field of powder bed melting additive manufacturing. The thin-wall part comprises a thin part main body internally provided with a cavity, the cavity is flat, and a supporting main body is arranged in the cavity; the supporting body is of a rib structure which is reserved in a boundary track after Boolean operation is conducted between a honeycomb structure formed by ribs and the boundary track formed at the maximum cross section of the cavity, the rib structure comprises a main rib part and a boundary rib part, and the main rib part is of a plurality of hexagonal structures defined by the ribs. The boundary rib parts are a plurality of opening rib structures which are located in the boundary track and close to the boundary track; the method is favorable for controlling the deformation of the thin-wall surface and the high-precision and effective forming of the thin-wall cavity part; after the powder bed is melted, residual powder in the cavity can be cleaned, the influence of residual powder agglomeration or caking caused by subsequent heat treatment can be avoided, the part forming quality is guaranteed, and the part performance is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of powder bed fusion additive manufacturing, and in particular to a thin-walled component with a support structure used in laser powder bed fusion additive manufacturing of a thin-walled cavity. Background Art

[0002] Powder bed fusion is a widely used manufacturing technology in additive manufacturing. It uses laser or electron beam as heat source and processes discrete materials in a layer-by-layer manner through the three-dimensional sheet model in computer software. This technology can directly form metal parts close to full density. Compared with traditional processing technology, the overall utilization rate of materials is high and the cycle is short. It can form freely designed and manufactured complex structural parts. Therefore, this technology has good market prospects and broad application prospects in the fields of aerospace, medical and so on.

[0003] Powder bed fusion technology is an important technology in additive manufacturing. It uses the laser emitted by the laser to melt the metal powder in a programmed order. After each layer of powder is laid, the molten layer solidifies and is continuously superimposed to finally produce a molded part. The formation of cavity structures is of great significance to the lightweight of parts and products, and additive manufacturing technology is particularly suitable for the formation of cavity structures. The following problems exist at present: 1) In the current design process of thin-walled cavity structures based on additive manufacturing technology, it is necessary to add a self-supporting structure inside the thin-walled cavity structure for forming, and the internal cavity is too large, which can easily cause the surface of the formed cavity to produce surface unevenness due to stress, thereby affecting the surface forming accuracy; 2) After the parts are formed, small parts without cavities can be cleaned in the cabin, but in the face of complex cavity structures, it is difficult to completely clean the powder inside the cavity, and incomplete cleaning of the powder may affect the subsequent heat treatment. In addition to the fact that excess powder may affect the vacuum pump of vacuum heat treatment, the residual powder inside the part may also agglomerate during subsequent heat treatment, thereby affecting the performance and quality of the part. Therefore, it is very necessary to design a thin-walled part with a support structure for laser powder bed melting additive manufacturing of thin-walled cavities. Summary of the invention

[0004] The object of the present invention is to provide a thin-walled component with a support structure for laser powder bed fusion additive manufacturing in a thin-walled cavity, so as to solve the problems raised in the above-mentioned background technology.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a thin-walled part with a support structure for laser powder bed fusion additive manufacturing in a thin-walled cavity, comprising a thin part body with a cavity inside, the cavity is flat, a support body is arranged in the cavity, the support body is a rib structure retained within the boundary track after Boolean operation between a honeycomb structure formed by ribs and a boundary track formed at the maximum cross-section of the cavity, the rib structure comprises a main rib part and a boundary rib part, the main rib part is a plurality of hexagonal structures surrounded by ribs, and the boundary rib part is a plurality of open rib structures located within and adjacent to the boundary track;

[0006] The hexagonal structure and the inner wall of the cavity form a closed first chamber, and the open rib structure and the inner wall of the cavity form a closed second chamber;

[0007] The plurality of hexagonal structures and the plurality of open rib structures each have at least one connecting hole, and the connecting hole is used to connect two adjacent first chambers or two adjacent second chambers or an adjacent first chamber and a second chamber;

[0008] A plurality of powder discharge holes arranged at intervals are also provided on the thin part body at positions along the boundary track, and the plurality of powder discharge holes arranged at intervals are all communicated with the second chamber adjacent to the corresponding powder discharge holes.

[0009] In a further embodiment, a reinforcing oblique rib is further provided in the cavity between two points of the longest straight-line distance of the boundary track.

[0010] In a further embodiment, the reinforcing oblique rib passes through the first cavity or the second cavity.

[0011] In a further embodiment, the width of the reinforcing oblique ribs is 5-10 mm.

[0012] In a further embodiment, the rib width is 2-5 mm.

[0013] In a further embodiment, the communicating hole has a diameter of 3-6 mm.

[0014] In a further embodiment, the powder discharge hole has a diameter of 3-6 mm.

[0015] In a further embodiment, the boundary track is a polygonal structure, and the adjacent powder discharge holes are arranged at positions corresponding to each side of the polygonal structure on the thin part body with a spacing of 30-50 mm;

[0016] The maximum distance of the cavity perpendicular to the maximum cross section is 50 mm, and the minimum distance of the cavity perpendicular to the maximum cross section is 3 mm;

[0017] When the distance of the cavity perpendicular to the maximum cross-section is less than 3 mm, no powder discharge hole is provided on the thin part body at a position corresponding to one of the sides of the polygonal structure; when the distance of the cavity perpendicular to the maximum cross-section is greater than 3 mm, and when the length of one of the sides of the polygonal structure is greater than 50 mm, at least one powder discharge hole is provided on the thin part body at a position corresponding to one of the sides of the above-mentioned polygonal structure.

[0018] In a further embodiment, the thin part body is a structure with the maximum cross section as a symmetry plane.

[0019] In a further embodiment, a skin is provided on the inner side of the cavity.

[0020] Compared with the prior art, the beneficial effects achieved by the present invention are: by structurally optimizing the internal model of the thin part body, it is beneficial to control the deformation of the thin-walled surface, which is beneficial to the high-precision and effective forming of thin-walled cavity parts, and prevents the surface of the cavity from being uneven due to stress, thereby affecting the forming accuracy of the surface; through the setting of connecting holes and powder discharge holes, the powder remaining in the cavity can be cleaned after the powder bed is melted, which can avoid the influence of residual powder agglomeration or agglomeration caused by subsequent heat treatment, thereby ensuring the forming quality of the parts and improving the performance of the parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0022] The reference numerals in the drawings are: thin part body 1, supporting body 2, reinforcing oblique ribs 3, connecting holes 4, powder discharge holes 5, ribs 6, and skin 7. DETAILED DESCRIPTION

[0023] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known in the art are not described.

[0024] See also Figure 1The present invention provides a technical solution: a thin-walled part with a support structure for laser powder bed fusion additive manufacturing in a thin-walled cavity, comprising a thin part body 1 with a cavity inside, the cavity is flat, and a support body 2 is arranged in the cavity, the support body 2 is a rib structure retained in the boundary track after Boolean operation between a honeycomb structure formed by ribs 6 and a boundary track formed at the maximum cross-section of the cavity, the rib structure includes a main rib part and a boundary rib part, the main rib part is a plurality of hexagonal structures surrounded by ribs 6, and the boundary rib part is a plurality of open rib structures located in and adjacent to the boundary track;

[0025] The hexagonal structure and the inner wall of the cavity form a closed first chamber, and the open rib structure and the inner wall of the cavity form a closed second chamber;

[0026] The plurality of hexagonal structures and the plurality of open rib structures each have at least one connecting hole 4, and the connecting hole 4 is used to connect two adjacent first chambers or two adjacent second chambers or an adjacent first chamber and a second chamber;

[0027] A plurality of powder discharge holes 5 arranged at intervals are also provided on the thin part body 1 along the boundary track, and the plurality of powder discharge holes 5 arranged at intervals are all connected to the second chamber adjacent to the corresponding powder discharge holes 5 .

[0028] Through the above technical scheme, the thin part body 1 is supported by the support body 2, which is beneficial to controlling the deformation of the thin-walled surface of the thin part body 1, and is beneficial to the high-precision and effective forming of the thin part body 1, and preventing the surface of the cavity from being uneven due to stress, thereby affecting the forming accuracy of the surface; through the setting of the connecting hole 4 and the powder discharge hole 5, it is ensured that all the first chambers and the second chambers are connected, which facilitates the cleaning of the powder inside the cavity of the thin part body 1, avoids the influence of residual powder agglomeration or agglomeration caused by subsequent heat treatment, and ensures the part forming quality and improves the part performance.

[0029] In a further embodiment, a reinforcing oblique rib 3 is further provided between two points of the longest straight-line distance of the boundary track in the cavity.

[0030] Through the above technical solution, the thin part body 1 is supported by reinforcing the oblique ribs 3 .

[0031] In a further embodiment, the reinforcing oblique rib 3 passes through the first cavity or the second cavity.

[0032] The above technical solution ensures that the thin component body 1 is stable.

[0033] In a further embodiment, the width of the reinforcing diagonal rib 3 is 5-10 mm.

[0034] The above technical solution ensures the structural strength of the diagonal reinforcement 3.

[0035] In a further embodiment, the rib 6 has a width of 2-5 mm.

[0036] Through the above technical solution, the structural strength of the support body 2 is guaranteed, so that the internal support of the cavity structure of the thin part body 1 is stable.

[0037] In a further embodiment, the communicating hole 4 has a diameter of 3-6 mm.

[0038] The above technical solution, in combination with the powder discharge hole 5, is conducive to the rapid cleaning of the internal powder after the powder bed of the cavity structure of the thin part body 1 is melt-formed.

[0039] In a further embodiment, the powder discharge hole 5 has a diameter of 3-6 mm.

[0040] The above technical solution, in combination with the connecting hole 4, is conducive to the rapid cleaning of the internal powder after the powder bed of the cavity structure of the thin part body 1 is melt-formed.

[0041] In a further embodiment, the boundary track is a polygonal structure, and adjacent powder discharge holes 5 are arranged at a distance of 30-50 mm on the thin part body 1 at positions corresponding to each side of the polygonal structure;

[0042] The maximum distance of the cavity at the vertical maximum cross section is 50 mm, and the minimum distance of the cavity at the vertical maximum cross section is 3 mm;

[0043] When the distance of the cavity at the vertical maximum cross-section is less than 3 mm, no powder discharge hole 5 is provided on the thin part body 1 at a position corresponding to one of the sides of the polygonal structure; when the distance of the cavity at the vertical maximum cross-section is greater than 3 mm, and when the length of one of the sides of the polygonal structure is greater than 50 mm, at least one powder discharge hole 5 is provided on the thin part body 1 at a position corresponding to one of the sides of the above-mentioned polygonal structure.

[0044] Through the above technical solution, by taking advantage of the different thicknesses and lengths of different sides of the thin part body 1, powder discharge holes 5 are provided at intervals, thereby ensuring the strength of the thin part body 1 while improving the rapid cleaning of powder.

[0045] In a further embodiment, the thin component body 1 is a structure with the largest cross section as the symmetry plane.

[0046] The above technical solution facilitates the additive manufacturing of the thin part body 1 and the subsequent cleaning of the powder.

[0047] In a further embodiment, a skin 7 is provided inside the cavity.

[0048] When the above-mentioned thin part body 1 is subjected to powder cleaning, the thin part body 1 with the powder discharge hole 5 is installed on the base plate of the rotating table, the base plate is in a horizontal position, and a powder suction pipe and a plurality of powder blowing pipes are installed according to the position of the powder discharge hole 5, so that the gas pressure storage tank is connected with the thin part body 1 through the powder blowing pipe, and the vacuum cleaner is connected with the thin part body 1 through the powder suction pipe, the total number of the powder suction pipe and the powder blowing pipe is equal to the number of the powder discharge holes 5, and the powder suction pipe and the powder blowing pipe are both provided with threaded joints that match the threaded structure of the powder discharge hole 5, the thin part body 1 is a part with the largest cross section as the symmetry plane, and the rotating axis of the rotating table and the largest cross section of the thin part body 1 are in the same plane;

[0049] Then, the rotating table is driven to rotate around the rotating axis by a preset angle, the gas pressure storage tank and the vacuum cleaner are turned on to clean the powder, and the gas pressure storage tank and the vacuum cleaner are turned off after the preset time is reached. The rotating table is driven to rotate around the rotating axis in the opposite direction by twice the preset angle, and the gas pressure storage tank and the vacuum cleaner are turned on again to clean the powder, and the gas pressure storage tank and the vacuum cleaner are turned off after the preset time is reached, and the substrate is reset to a horizontal state;

[0050] Then disconnect the powder suction pipe from the corresponding exhaust hole 5, disconnect one of the powder blowing pipes from the corresponding exhaust hole 5, connect the above powder suction pipe to the exhaust hole 5 corresponding to the above powder blowing pipe, connect the above powder blowing pipe to the powder exhaust hole 5 corresponding to the above powder suction pipe, and repeat the above steps until the last powder blowing pipe and the powder suction pipe have completed the position exchange;

[0051] Finally, the powder suction pipe that has completed the position exchange is disconnected from the corresponding exhaust hole 5, and the powder exhaust hole 5 connected to the powder suction pipe is checked for residual powder. If there is residual powder, the powder cleaning operation is repeated until the powder cleaning is completed.

[0052] By cooperating with the supporting body 2 and the reinforcing oblique ribs 3, the internal model of the thin-walled cavity structure is structurally optimized, and the thin part body 1 is supported, which is beneficial to controlling the deformation of the thin-walled surface of the thin part body 1, and is beneficial to the high-precision and effective forming of the thin part body 1, and preventing the surface of the cavity from being uneven due to stress, thereby affecting the forming accuracy of the surface; through the setting of the connecting hole 4 and the powder discharge hole 5, the first chamber and the second chamber are connected, which is convenient for cleaning the powder inside the cavity of the thin part body 1, avoiding the influence of residual powder agglomeration or agglomeration caused by subsequent heat treatment, and ensuring the forming quality of the part and improving the performance of the part.

[0053] The preferred specific embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above specific embodiments. Within the technical concept of the present invention, various equivalent transformations can be made to the technical scheme of the present invention, and these equivalent transformations all belong to the protection scope of the present invention.

Claims

1. A thin-walled part with a support structure for laser powder bed fusion additive manufacturing in a thin-walled cavity, characterized in that: The invention comprises a thin part body (1) having a cavity inside, wherein the cavity is flat, and a support body (2) is arranged inside the cavity, wherein the support body (2) is a rib structure retained within the boundary track after a Boolean operation between a honeycomb structure formed by ribs (6) and a boundary track formed at the maximum cross section of the cavity, wherein the rib structure comprises a main rib part and a boundary rib part, wherein the main rib part is a plurality of hexagonal structures surrounded by ribs (6), and the boundary rib part is a plurality of open rib structures located within and adjacent to the boundary track; The hexagonal structure and the inner wall of the cavity form a closed first chamber, and the open rib structure and the inner wall of the cavity form a closed second chamber; The plurality of hexagonal structures and the plurality of open rib structures each have at least one connecting hole (4), and the connecting hole (4) is used to connect two adjacent first chambers or two adjacent second chambers or an adjacent first chamber and a second chamber; A plurality of powder discharge holes (5) arranged at intervals are also provided on the thin part body (1) at positions along the boundary track, and the plurality of powder discharge holes (5) arranged at intervals are all connected to the second chamber adjacent to the corresponding powder discharge holes (5).

2. A thin-walled component with a support structure for laser powder bed fusion additive manufacturing in a thin-walled cavity according to claim 1, characterized in that: A reinforcing oblique rib (3) is also provided in the cavity between two points located at the longest straight-line distance of the boundary track.

3. A thin-walled component with a support structure for laser powder bed fusion additive manufacturing in a thin-walled cavity according to claim 2, characterized in that: The reinforcing oblique rib (3) passes through the first cavity or the second cavity.

4. A thin-walled component with a support structure for laser powder bed fusion additive manufacturing in a thin-walled cavity according to claim 2, characterized in that: The width of the reinforcing diagonal rib (3) is 5-10 mm.

5. The thin-walled component with a support structure for laser powder bed fusion additive manufacturing in a thin-walled cavity according to claim 1, characterized in that: The rib (6) has a width of 2-5 mm.

6. The thin-walled component with a support structure for laser powder bed fusion additive manufacturing in a thin-walled cavity according to claim 1, characterized in that: The connecting hole (4) has a diameter of 3-6 mm.

7. The thin-walled component with a support structure for laser powder bed fusion additive manufacturing in a thin-walled cavity according to claim 1, characterized in that: The diameter of the powder discharge hole (5) is 3-6 mm.

8. The thin-walled component with a support structure for laser powder bed fusion additive manufacturing in a thin-walled cavity according to claim 1, characterized in that: The boundary track is a polygonal structure, and the adjacent powder discharge holes (5) are arranged at positions corresponding to each side of the polygonal structure on the thin part body (1) with a spacing of 30-50 mm; The maximum distance of the cavity perpendicular to the maximum cross section is 50 mm, and the minimum distance of the cavity perpendicular to the maximum cross section is 3 mm; When the distance of the cavity perpendicular to the maximum cross section is less than 3 mm, no powder discharge hole (5) is provided on the thin part body (1) at a position corresponding to one of the sides of the polygonal structure; when the distance of the cavity perpendicular to the maximum cross section is greater than 3 mm, and when the length of one of the sides of the polygonal structure is greater than 50 mm, at least one powder discharge hole (5) is provided on the thin part body (1) at a position corresponding to one of the sides of the polygonal structure.

9. The thin-walled component with a support structure for laser powder bed fusion additive manufacturing in a thin-walled cavity according to claim 1, characterized in that: The thin part body (1) is a structure with the maximum cross section as a symmetry plane.

10. The thin-walled component with a support structure for laser powder bed fusion additive manufacturing in a thin-walled cavity according to claim 1, characterized in that: A skin (7) is provided on the inner side of the cavity.

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