Conformal supporting device and method for selective laser melting

Abstract

The present invention relates to the technical field of metal additive manufacturing. Disclosed are a conformal supporting device and method for selective laser melting. The conformal supporting device comprises a lifting platform. The lifting platform is provided with an inner cavity. A plurality of first through holes in communication with the inner cavity of the lifting platform are formed in the top wall of the lifting platform. The plurality of first through holes are formed at equal intervals. A plurality of driving assemblies are arranged in the lifting platform. The plurality of driving assemblies are in one-to-one correspondence with the plurality of first through holes. An output end of each of the driving assemblies extends out of the lifting platform through the corresponding first through hole and is provided with a supporting rod. An extending end of the supporting rod is detachably connected with a sacrificial assembly. The sacrificial assembly is configured to metallurgically connect to a formed workpiece. A plurality of second through holes are formed in a porous substrate. The plurality of second through holes are in communication with the plurality of first through holes on a one-to-one basis. The supporting rods respectively run through the corresponding second through holes. According to the present invention, after additive preparation of the formed workpiece is completed, the sacrificial assembly can be easily removed. In addition, the sacrificial assembly is easy to trim, and the workload of subsequent supporting structures of the formed workpiece is reduced.

Description

A selective laser melting conformal support device and method Technical Field

[0001] The present invention belongs to the technical field of metal additive manufacturing, and in particular relates to a device and method for selective laser melting conformal support. Background Art

[0002] Selective Laser Melting (SLM) is an additive manufacturing method based on powder fusion technology. It uses a laser beam to scan and melt metal powder layer by layer, consolidating it into shape. Unlike traditional processing technologies, powder-based laser additive manufacturing enables lightweight, personalized, and integrated manufacturing of complex parts, providing components with superior mechanical properties, surface quality, and higher dimensional accuracy.

[0003] In principle, SLM technology can form metal parts of any complex shape. However, since the loose powder cannot effectively bear the weight during the processing, geometric features such as thin plates, sharp corners, and overhanging surface structures cannot be perfectly formed. At the same time, deformation and thermal stress accumulation during the processing can easily lead to distortion or cracking. Therefore, the use of support structures is unavoidable.

[0004] Currently, a common approach is to simultaneously additively print support structures onto the substrate while printing the component. This support provides strength and facilitates heat transfer to the substrate. However, the metallurgical bonding of the substrate, support, and component increases the complexity of subsequent machining steps and the difficulty of finishing the surfaces contacted by the support.

[0005] Summary of the Invention

[0006] In order to solve the above technical problems, the present invention proposes a selective laser melting conformal support device and method, which aims to solve or improve at least one of the above technical problems.

[0007] To achieve the above-mentioned object, the present invention provides a selective laser melting conformal support device, comprising:

[0008] A lifting base, the lifting base having an inner cavity, and a plurality of first through holes in communication with the inner cavity of the lifting base are opened on the top wall of the lifting base, the plurality of first through holes are arranged at equal intervals, a plurality of drive components are arranged in the lifting base, the plurality of drive components are arranged in a one-to-one correspondence with the plurality of first through holes, and the output end of the drive component extends out of the lifting base through the first through hole and is provided with a support rod, the protruding end of the support rod is detachably connected to a sacrificial component, the sacrificial component is used for metallurgical connection with the formed workpiece;

[0009] A porous substrate is mounted on the top surface of the lifting platform by bolts. A plurality of second through holes are opened on the porous substrate. The plurality of second through holes correspond to and are connected with the plurality of first through holes one by one. The support rod passes through the second through holes.

[0010] Optionally, the support rod is a hollow tubular structure.

[0011] Optionally, the driving assembly includes a driver, which is fixedly installed in the inner cavity of the lifting base, and the output end of the driver is fixedly connected to a driving shaft, the driving shaft passes through the first through hole, the driving shaft is connected to the support rod, and the driver is electrically connected to an electronic control element.

[0012] Optionally, the sacrificial assembly includes a sacrificial block, one end of the sacrificial block is connected to the support rod, and the other end is used to contact the formed workpiece, and a side wall of the sacrificial block is provided with a groove.

[0013] Optionally, one end of the sacrificial block close to the support rod and one end of the support rod close to the drive shaft are respectively fixed with coaxial cylindrical pins, and the cylindrical pins are plugged into the inner cavity of the support rod.

[0014] Optionally, the fitting tolerance between the cylindrical pin and the inner cavity of the support rod is: H7 / k6.

[0015] Optionally, the first through hole and the second through hole have the same aperture, which is 0.5-4 mm.

[0016] Optionally, the spacing between the first through holes is 1-10 mm.

[0017] Optionally, the fitting tolerance between the first through hole and the drive shaft is H8 / f7.

[0018] A method for selective laser melting conformal support, comprising the following steps:

[0019] Establish CAD 3D model data of formed workpiece;

[0020] Additive preparation of formed workpieces;

[0021] Removal of formed workpieces;

[0022] Bending is performed along the groove, and the surface of the workpiece is sandblasted and polished to shape it.

[0023] Compared with the prior art, the present invention has the following advantages and technical effects:

[0024] The present invention provides a plurality of support rods and an array of multi-point conformal supports, which can adapt to the support of complex overhanging surfaces, avoid the preparation of support structures during the selective laser melting process, and is conducive to improving processing efficiency and enhancing the surface quality of the formed workpiece.

[0025] The present invention forms a metallurgical connection with the formed workpiece through a sacrificial component that is detachably connected to the top of the support rod. After the additive preparation of the formed workpiece is completed, the sacrificial component is separated from the support rod along with the formed workpiece and is easy to disassemble. At the same time, the sacrificial component is easy to trim, which reduces the workload of the subsequent support structure of the formed workpiece. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings:

[0027] FIG1 is a schematic diagram of the overall structure of the present invention;

[0028] Figure 2 is a cross-sectional view of the present invention;

[0029] FIG3 is a schematic diagram showing the connection between the sacrificial block and the support rod according to the present invention.

[0030] In the figure: 1. lifting base; 2. porous substrate; 21. second through hole; 3. support rod; 4. driving assembly; 41. electronic control element; 42. driver; 43. driving shaft; 5. sacrificial block; 51. groove; 52. cylindrical pin; 6. formed workpiece; 7. bolt. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] 1-3 , this embodiment provides a selective laser melting conformal support device, comprising:

[0034] A lifting base 1, the lifting base 1 has an inner cavity, and a plurality of first through holes communicating with the inner cavity of the lifting base 1 are opened on the top wall of the lifting base 1, the plurality of first through holes are arranged at equal intervals, a plurality of drive components 4 are arranged in the lifting base 1, the plurality of drive components 4 are arranged in a one-to-one correspondence with the plurality of first through holes, and the output end of the drive component 4 extends out of the lifting base 1 through the first through hole and is provided with a support rod 3, the protruding end of the support rod 3 is detachably connected to a sacrificial component, the sacrificial component is used for metallurgical connection with the formed workpiece 6;

[0035] The porous substrate 2 is mounted on the top surface of the lifting platform 1 by bolts 7 . A plurality of second through holes 21 are formed on the porous substrate 2 . The plurality of second through holes 21 correspond to and are connected to the plurality of first through holes one by one. The support rods 3 pass through the second through holes 21 .

[0036] By setting up a number of support rods 3, the array multi-point conformal support can adapt to the support of complex overhanging surfaces, avoiding the preparation of support structures during the selective laser melting process, which is beneficial to improving processing efficiency and enhancing the surface quality of the formed workpiece 6.

[0037] A metallurgical connection is formed between the sacrificial component detachably connected to the top of the support rod 3 and the formed workpiece. After the additive preparation of the formed workpiece 6 is completed, the sacrificial component is separated from the support rod 3 along with the formed workpiece 6, and is easy to disassemble. At the same time, the sacrificial component is easy to trim, which reduces the workload of the subsequent support structure of the formed workpiece.

[0038] According to a further optimization scheme, the support rod 3 is a hollow tubular structure, and the support rod 3 is preferably made of tungsten steel, titanium alloy or the like.

[0039] To further optimize the solution, the drive assembly 4 includes a driver 42, which is fixedly installed in the inner cavity of the lifting base 1. The output end of the driver 42 is fixedly connected to a drive shaft 43, which passes through the first through hole. The drive shaft is connected to the support rod 3, and the driver 42 is electrically connected to the electronic control element 41.

[0040] The driver 42 is controlled by the electric control element 41 to lift the driving shaft 43 , thereby driving the support rod 3 to rise and fall synchronously through the driving shaft 43 .

[0041] According to a further optimized solution, the sacrificial assembly includes a sacrificial block 5 , one end of which is connected to the support rod 3 , and the other end is used to contact the formed workpiece 6 , and a groove 51 is provided on the side wall of the sacrificial block 5 .

[0042] The sacrificial block 5 is made of the same material as the formed workpiece 6, and the groove 51 is convenient for bending and trimming.

[0043] As a further optimization solution, one end of the sacrificial block 5 close to the support rod 3 and one end of the support rod 3 close to the drive shaft 43 are respectively fixed with coaxial cylindrical pins 52 , and the cylindrical pins 52 are plugged into the inner cavity of the support rod 3 .

[0044] The cylindrical latch 52 is provided to facilitate the detachable connection between the support rod 3 and the sacrificial block 5 , as well as the detachable connection between the drive shaft 43 and the support rod 3 .

[0045] According to a further optimization scheme, the matching tolerance between the cylindrical pin 52 and the inner cavity of the support rod 3 is: H7 / k6.

[0046] According to a further optimized solution, the first through hole and the second through hole 21 have the same aperture, which is 0.5-4 mm.

[0047] According to a further optimized solution, the spacing between the first through holes is 1-10 mm.

[0048] According to a further optimization solution, the matching tolerance between the first through hole and the drive shaft 43 is H8 / f7.

[0049] A method for selective laser melting conformal support, comprising the following steps:

[0050] Establish CAD three-dimensional model data of the formed workpiece 6, obtain the data of the lower surface to be supported, place it in the Cartesian coordinate system, obtain the height of the end of the array-distributed drive shaft 43 from the lower surface of the formed workpiece 6, which is called the preset height h(i, j), where i∈(1,2,...,N), N is the number of holes opened in the X direction of the second through hole 21 of the porous substrate 2; j∈(1,2,...,K), K is the number of holes opened in the Y direction of the second through hole 21 of the porous substrate 2, slice the CAD three-dimensional model data of the formed workpiece 6, obtain the data of each slice layer, and start the selected area additive system.

[0051] For additive manufacturing of a molded workpiece, the lifting platform 1 lowers the powder layer as a whole. When the extended length of the drive shaft 43 does not reach the preset height h(i, j), the electronic control element 41 activates the driver 42, causing the support rod 3 to rise to the height of the powder layer, and the selective laser melting system begins to lay the powder. At this point, the height of the top of the powder layer is consistent with the height of the end of the sacrificial block 5 that has not reached the preset height h(i, j). The laser is activated, acting on the surface of the powder layer to perform selective laser melting or sintering. These steps are repeated until the molded workpiece 6 is completed.

[0052] The formed workpiece 6 is removed and the formed workpiece 6 is lifted vertically, and the sacrificial block 5 which is metallurgically connected with the formed workpiece 6 is separated from the supporting unit;

[0053] The workpiece surface is bent along the groove, and is sandblasted and polished to shape the workpiece surface. The workpiece surface is bent along the groove 51 of the sacrificial block 5, and is sandblasted and polished to shape the workpiece surface.

[0054] This embodiment uses a hemispherical workpiece with a hemispherical surface of 80mm in diameter and 4mm in thickness. The component is prepared using Ti6Al4V powder with a particle size of 15-53μm. The top of the lifting base is arrayed with 20×20 circular through holes with a spacing t of 5mm and an aperture d of 0.5mm. The sacrificial unit is made of Ti6Al4V material, and the CAD three-dimensional model data of the hemispherical workpiece is established. The data of the lower surface to be supported is obtained and placed in a Cartesian coordinate system. The height of the end of the drive shaft of the array-distributed drive unit from the lower surface of the workpiece is obtained, which is called the preset height h(i, j), where i∈(1,2,…,20); j∈(1,2,…,20). The above method is used subsequently.

[0055] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" and the like to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0056] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A selective laser melting conformal support device, characterized in that: include: A lifting base (1), the lifting base (1) having an inner cavity, and a plurality of first through holes communicating with the inner cavity of the lifting base (1) are opened on the top wall of the lifting base (1), the plurality of first through holes being arranged at equal intervals, a plurality of driving components (4) being arranged in a one-to-one correspondence with the plurality of first through holes, and an output end of the driving component (4) extending out of the lifting base (1) through the first through hole and being provided with a support rod (3), the protruding end of the support rod (3) being detachably connected with a sacrificial component, the sacrificial component being used for metallurgical combination with a formed workpiece (6); A porous substrate (2), the porous substrate (2) being mounted on the top surface of the lifting platform (1) by means of bolts (7), the porous substrate (2) being provided with a plurality of second through holes (21), the plurality of second through holes (21) corresponding one-to-one to and connected with the plurality of first through holes, the support rod (3) passing through the second through holes (21).

2. The selective laser melting conformal support device according to claim 1, characterized in that: The support rod (3) is a hollow tubular structure.

3. The selective laser melting conformal support device according to claim 2, characterized in that: The driving assembly (4) comprises a driver (42), wherein the driver (42) is fixedly mounted in the inner cavity of the lifting base (1), and an output end of the driver (42) is fixedly connected with a driving shaft (43), wherein the driving shaft (43) passes through the first through hole, and the driving shaft is connected to the support rod (3), and the driver (42) is electrically connected with an electric control element (41).

4. The selective laser melting conformal support device according to claim 3, characterized in that: The sacrificial assembly comprises a sacrificial block (5), one end of the sacrificial block (5) is connected to the support rod (3), and the other end is used to contact the formed workpiece (6), and a groove (51) is provided on the side wall of the sacrificial block (5).

5. The selective laser melting conformal support device according to claim 4, characterized in that: One end of the sacrificial block (5) close to the support rod (3) and one end of the support rod (3) close to the drive shaft (43) are respectively fixed with coaxial cylindrical pins (52), and the cylindrical pins (52) are plugged into the inner cavity of the support rod (3).

6. The selective laser melting conformal support device according to claim 5, characterized in that: The matching tolerance between the cylindrical plug (52) and the inner cavity of the support rod (3) is: H7 / k6.

7. The selective laser melting conformal support device according to claim 1, characterized in that: The first through hole and the second through hole (21) have the same diameter, which is 0.5-4 mm.

8. The selective laser melting conformal support device according to claim 1, characterized in that: The spacing between the first through holes is 1-10 mm.

9. The selective laser melting conformal support device according to claim 3, characterized in that: The matching tolerance between the first through hole and the driving shaft (43) is H8 / f7.

10. A method for selective laser melting conformal support, based on a selective laser melting conformal support device according to any one of claims 1 to 9, comprising the following steps: Establish CAD 3D model data of formed workpiece; Additive preparation of molded workpieces; Removing formed workpieces; Bend along the groove and sandblast and polish the surface of the workpiece.

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