Method for removing supports of thin-walled ring-shaped structural parts manufactured by laser additive manufacturing, its applications and support removal aid

Abstract

The present application relates to the field of laser additive manufacturing, in particular to a support removal method for laser additive manufacturing of thin-walled ring structure parts and application and a support removal auxiliary device. The support removal method for laser additive manufacturing of thin-walled ring structure parts provided by the present application can monitor the deformation amount of the part in real time during the support removal process, can find deformation in time and inhibit large size deformation of the part through air cooling, and greatly improve the forming quality. In addition, the deformation amount of the part is collected in real time through a piezoresistive sensor, and the cooling process is synchronized, which is simple to operate, simple in structure, low in equipment cost, good in applicability, effectively solves the deformation and cracking problem of laser additive manufacturing of thin-walled ring structure parts, and greatly improves the manufacturing efficiency and forming quality. At the same time, the piezoresistive sensor, the position, size and shape of the air outlet hole of the temperature control system are designed, so that the processing amount is minimized and the use of materials is minimized while the function is fully exerted.

Description

Technical Field

[0001] This invention relates to the field of laser additive manufacturing, specifically to a method for removing supports in laser additive manufacturing of thin-walled annular structural parts, its application, and an auxiliary device for support removal. Background Technology

[0002] Laser additive manufacturing is a near-net-shape forming process that manufactures parts without the need for molds, through layer-by-layer deposition. Because there are no tooling fixtures during the forming process, supports must be added to the suspended parts of the part to prevent collapse under gravity. Simultaneously, the support structure also improves the overall rigidity of the part, preventing deformation and cracking, improving dimensional accuracy, and ensuring part quality. After laser additive manufacturing is completed, the supports become useless and need to be completely removed.

[0003] During the support removal process in laser additive manufacturing, the mechanical interaction between the tool and the part causes a localized temperature increase, resulting in thermal stress. For thin-walled annular components manufactured using laser additive manufacturing, their inherent structural rigidity is relatively poor. The increased localized stress during support removal can easily lead to deformation or even cracking, causing the part to fail to meet usage requirements. Therefore, there is an urgent need to develop a process method to avoid deformation and cracking in thin-walled annular parts manufactured using laser additive manufacturing, improve the dimensional accuracy control of the parts, and enhance the forming quality of the parts. Summary of the Invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide a method for removing the support of a thin-walled annular structure part manufactured by laser additive manufacturing, its application, and an auxiliary device for support removal. The removal method provided by the present invention can suppress or avoid the problem of easy deformation and cracking of the part caused by the removal of the support of the thin-walled annular part during laser additive manufacturing, and the part after removing the support has high dimensional accuracy.

[0005] This invention provides a method for removing supports in laser additive manufacturing of thin-walled annular structural parts, comprising the following steps:

[0006] S1) Provides a support removal auxiliary device, which includes a main structure (4) and at least one monitoring structure (5);

[0007] The main structure (4) includes a first surface and a second surface opposite to each other; the interior of the main structure (4) is also provided with a cooling gas channel for cooling gas circulation that runs through the first surface and the second surface;

[0008] The monitoring structure (5) includes a piezoresistive sensor (9), a trigger mechanism plate (10), a fixing frame (11), and a deformation transmission mechanism column (12);

[0009] The deformation conduction mechanism column (12) is axially slidably arranged in the main body structure (4), and one end is arranged to protrude from the first surface and the other end is arranged to protrude from the second surface;

[0010] The piezoresistive sensor (9) is fixed to the second surface; one end of the trigger mechanism piece (10) is in contact with the end of the deformation conduction mechanism column (12) protruding from the second surface, and the other end is in contact with the piezoresistive sensor (9);

[0011] One end of the fixed frame (11) is fixed to the second surface, and the other end is hingedly connected to the non-end of the trigger mechanism piece (10), so that when the end of the trigger mechanism piece (10) in contact with the end of the deformation conduction mechanism column (12) protruding from the second surface is stressed, the trigger mechanism piece (10) can rotate and the other end can press the piezoresistive sensor (9);

[0012] S2) The end of the deformation conduction mechanism column (12) of the support removal auxiliary device protruding from the first surface is in contact with the opposite wall of the wall on which the support of the laser additive manufacturing thin-walled ring structure part is arranged, and then the support is mechanically removed; when the piezoresistive sensor (9) gives a deformation prompt, the mechanical removal is paused, the laser additive manufacturing thin-walled ring structure part is cooled until the deformation prompt stops, and the mechanical removal is continued.

[0013] The removal method provided by the application first provides a support removal auxiliary device, which includes a main body structure (4) and at least one monitoring structure (5). The main body structure (4) of the application is a functional entity of the temperature control system of the support removal auxiliary device, and the height of the main body structure (4) is the same as the height of the laser additive manufacturing thin-walled ring structure part. The three-dimensional shape of the main body structure (4) of the application is a square ring body arc segment with a cavity inside, and the wall thickness is 3 mm to 10 mm. If the wall thickness is too small, the overall rigidity of the main body structure (4) is poor, and the main body structure (4) is easily damaged during use, and the processing difficulty is large. If the wall thickness is too large, the inner flow channel is too small, the volume of the cooling gas that can be accommodated inside is reduced, and the best cooling effect cannot be achieved. The thickness of the main body structure (4) is 15 mm to 30 mm. The thickness of the main body structure (4) refers to the thickness between any normal section between the first surface and the second surface. If the thickness is too small, the overall rigidity of the main body structure (4) is poor, and the main body structure (4) is easily damaged during use, and the processing difficulty is large. If the thickness is too large, the overall volume of the main body structure (4) is too large, which not only cannot significantly improve the processing effect, but also wastes materials and causes inconvenience during use.

[0014] The main body structure (4) comprises opposite first and second surfaces. Specifically, the main body structure (4) is a square ring body arc segment with a cavity inside, the first surface is the outer diameter end surface of the square ring body arc segment, and the second surface is the inner diameter end surface of the square ring body arc segment; the outer diameter of the main body structure (4) is 5-10 mm smaller than the inner diameter of the laser additive manufacturing thin-walled ring-shaped structure part; if the outer diameter of the main body structure (4) is too small, the distance between the gas outlet hole and the surface of the part is too large, and the cooling effect is poor; if the outer diameter of the main body structure (4) is too large, the distance between the part and the main body structure (4) is too close during operation, and the operation space is too small, so the part is not easy to fit with the main body structure (4).

[0015] The central angle corresponding to the outer diameter of the main body structure (4) is 5-20°. If the central angle is too small, the number of gas outlet holes (6) that can be arranged on the first surface of the main body structure (4) is limited, the cooling effect is poor, and the processing efficiency is affected; if the central angle is too large, the overall volume of the main body structure (4) is too large, which not only cannot significantly improve the processing effect, but also causes inconvenience during use.

[0016] The main body structure (4) further comprises a cooling gas passage for cooling gas circulation through the first and second surfaces. Specifically, the main body structure (4) is provided with a gas outlet hole (6) penetrating the first surface, and the main body structure (4) is provided with an air inlet passage (8) penetrating the second surface, the gas outlet hole (6) and the air inlet passage (8) are respectively communicated with the cavity of the main body structure (4) to form a cooling gas passage for cooling gas circulation through the first and second surfaces, so that the gas can enter from the air inlet passage (8) and be discharged from the gas outlet hole (6).

[0017] According to the central angle corresponding to the outer diameter of the main body structure (4), every 1-4° is provided with a group of gas outlet holes, and each group of gas outlet holes is provided with a plurality of gas outlet holes (6) along the height direction of the main body structure (4), and the interval of each gas outlet hole (6) is 5-10 mm. If the interval angle of the gas outlet hole group is too small, the number of gas holes will increase, which not only increases the processing difficulty, but also causes the overall strength of the main body structure (4) to decrease; if the interval angle is too large, the cooling gas cannot fully cover the surface of the part after being blown out, and the cooling effect is affected. If the interval distance of each gas outlet hole (6) of the gas outlet hole group is too small, the number of gas holes will also increase, which not only increases the processing difficulty, but also causes the overall strength of the main body structure (4) to decrease; if the interval distance is too large, the cooling gas cannot fully cover the surface of the part after being blown out, and the cooling effect is affected.

[0018] The diameter of the air inlet channel (8) is 5-10 mm; if the diameter is too small, the flow of cooling gas is insufficient, and the cooling effect is poor; if the diameter is too large, the use of cooling gas is too high, and the cooling effect cannot be significantly improved, but the gas consumption is increased, resulting in increased cost.

[0019] The air outlet hole (6) is coaxially connected by a first flat-top conical hole section, a second flat-top conical hole section and a third flat-top conical hole section; the bottom surface of the first flat-top conical hole section faces the first surface of the main body structure (4), the top surface of the first flat-top conical hole section is connected with the top surface of the second flat-top conical hole section, the bottom surface of the second flat-top conical hole section is connected with the top surface of the third flat-top conical hole section, and the bottom surface of the third flat-top conical hole section faces the inside of the main body structure (4); the top surface diameter of the first flat-top conical hole is the same as the top surface diameter of the second flat-top conical hole, and the bottom surface diameter of the second flat-top conical hole is the same as the top surface diameter of the third flat-top conical hole; the bottom surface diameter of the first flat-top conical hole is 2.5-7 mm, the top surface diameter is 1.5-5 mm, and the height is 2-8 mm; the bottom surface diameter of the second flat-top conical hole is 2-6 mm, the top surface diameter is 1.5-5 mm, and the height is 1-4 mm; the bottom surface diameter of the third flat-top conical hole is 3-8 mm, the top surface diameter is 2-6 mm, and the height is 2-8 mm. The shape of the air outlet hole is designed in this way, so that the cooling gas flow has a large flow rate and coverage area when it is blown to the surface of the part through the air outlet hole, and the cooling effect is better.

[0020] The monitoring structure (5) is a functional entity of a deformation monitoring system, which includes a piezoresistive sensor (9), a trigger mechanism piece (10), a fixing frame (11) and a deformation transmission mechanism column (12); wherein the deformation transmission mechanism column (12) is axially slidably arranged in the main body structure (4), and one end is arranged to pass through the first surface and the other end is arranged to pass through the second surface. Specifically, the main body structure (4) is provided with a through fixing hole (7) which penetrates the first surface and the second surface, and the number of the through fixing hole (7) is at least the same as the number of the monitoring structure (5); the deformation transmission mechanism column (12) is axially slidably arranged in the through fixing hole (7) of the main body structure (4). The diameter of the deformation transmission mechanism column (12) is 1-2 mm, and the length is 25-50 mm. The purpose of this design is that it is difficult to process if the size is too small, and it is unnecessary if the size is too large. Under the premise of ensuring the function, the size of the deformation transmission mechanism column (12) is small and easy to process.

[0021] The piezoresistive sensor (9) is fixed on the second surface; one end of the triggering mechanism piece (10) is in contact with one end of the deformation transmission mechanism column (12) which is out of the second surface, and the other end is in contact with the piezoresistive sensor (9). Specifically, the triggering mechanism piece (10) is in an "L" shape structure, one end of the short side of the triggering mechanism piece (10) is in contact with the piezoresistive sensor (9), and one end of the long side of the triggering mechanism piece (10) is in contact with one end of the deformation transmission mechanism column (12) which is out of the second surface of the main body structure (4). Preferably, the triggering mechanism piece (10) is in an "L" shape structure, the width is 2 mm~6 mm, and the thickness is 1 mm~5 mm. The purpose of this design is that it is difficult to process if the size is too small, and it is unnecessary if the size is too large. Under the premise of ensuring the function, the size of the deformation transmission mechanism is smaller and easier to process.

[0022] One end of the fixed frame (11) is fixed on the second surface, and the other end is hinged to the non-end of the triggering mechanism piece (10), so that when the end of the triggering mechanism piece (10) in contact with one end of the deformation transmission mechanism column (12) which is out of the second surface is stressed, the other end can be pressed to the piezoresistive sensor (9). Specifically, the triggering mechanism piece (10) is in an "L" shape structure, and the long side of the "L" shape structure has a through hole. One end of the fixed frame (11) away from the second surface is hinged to the non-end of the long side of the "L" shape structure of the triggering mechanism piece (10) through a plug-in cylinder (13) with the same diameter as the through hole. The diameter of the through hole is 0.5 mm~1.5 mm. If the diameter is too small, it is not easy to process, and if the diameter is too large, the diameter of the corresponding plug-in cylinder (13) also needs to be increased, which cannot significantly improve the processing effect, but wastes materials.

[0023] The support removal auxiliary device comprises at least one monitoring structure (5); preferably, according to the central angle corresponding to the outer diameter of the main body structure (4), one set of monitoring structure groups are arranged every 2°~5°, and a plurality of monitoring structures (5) are arranged along the height direction of the main body structure (4) in each monitoring structure group. The interval of each monitoring structure (5) is 1 / 3~1 / 5 of the height of the main body structure (4). This arrangement can uniformly distribute the monitoring structures in the height direction of the main body structure, more fully monitor the deformation of the parts, and use the least number of piezoresistive sensors to fully monitor the deformation of the parts during the support removal process.

[0024] The thrust generated by the deformation of the laser additive manufacturing thin-walled ring structure part can push the deformation transmission mechanism column (12) to slide axially, the thrust generated by the axial sliding can push the triggering mechanism piece (10) to rotate around the hinge point and press the piezoresistive sensor (9) to issue a deformation prompt.

[0025] The removal method provides that after the support removal auxiliary device, the end of the deformation conduction mechanism column (12) of the support removal auxiliary device is in contact with the opposite wall of the wall on which the support of the laser additive manufacturing thin-walled ring structure part is located through the first surface, and then the support is mechanically removed; when the piezoresistive sensor (9) gives a deformation prompt, the mechanical removal is paused, the laser additive manufacturing thin-walled ring structure part is cooled until the deformation prompt stops, and the mechanical removal is continued.

[0026] Specifically, the laser additive manufacturing thin-walled ring structure part is fixed on a workbench, and the support removal auxiliary device is pushed towards the part along the radial direction of the laser additive manufacturing thin-walled ring structure part, so that the end of the deformation conduction mechanism column (12) of the support removal auxiliary device is in contact with the opposite wall of the wall on which the support of the laser additive manufacturing thin-walled ring structure part is located through the first surface, and then the support is mechanically removed. The present application pushes the support removal auxiliary device towards the part along the radial direction of the laser additive manufacturing thin-walled ring structure part, which can ensure that the support removal auxiliary device is in full contact with the inner wall of the part, achieving the best monitoring effect of deformation. The support of the laser additive manufacturing thin-walled ring structure part targeted by the removal method is all arranged on the outer ring wall of the laser additive manufacturing thin-walled ring structure part.

[0027] After the support is mechanically removed until the support is completely removed, the support removal auxiliary device is withdrawn along the radial direction of the laser additive manufacturing thin-walled ring structure part. The advantage of this operation is that the deformation conduction mechanism column (12) can be prevented from being scratched with the surface of the part during the withdrawal of the support removal auxiliary device, thereby preventing the device from being damaged.

[0028] During the support removal process of the removal method, once the part deforms due to temperature rise, the cylinder in contact with the surface of the part will be displaced. After the cylinder moves, it will lift the L-shaped sheet, so that the piezoresistive sensor receives a pressure signal, prompting the operator that the part deforms. When the deformation of the part is monitored, the support removal is paused, and the part is cooled by blowing through the support removal auxiliary device. After the deformation is eliminated, the support removal is continued. Based on this, the deformation amount of the part is monitored in real time, so that the deformation can be found in time and inhibited by air cooling, and the forming quality is greatly improved.

[0029] The present application also provides a laser additive manufacturing method for a thin-walled ring structure part, comprising the following steps:

[0030] a) establishing a CAD digital model of a thin-walled ring structure part;

[0031] b) using the CAD digital model obtained in step a), laser additive manufacturing is used to manufacture the part, and a laser additive manufacturing thin-walled ring structure part is obtained;

[0032] c) using any of the above-described removal methods, the laser additive manufacturing thin-walled ring structure part obtained in step b) is supported and removed, and a thin-walled ring structure part is obtained.

[0033] The present application first establishes a CAD digital model of a thin-walled ring structure part. Specifically, in this process, a suitable part placement angle is selected, so that the support is all set on the outer wall of the laser additive manufacturing thin-walled ring structure part; based on the support removal auxiliary device described in the present application, the support added to the inner wall of the part will hinder the support removal auxiliary device from playing a role, so the support is all set on the outer wall of the laser additive manufacturing thin-walled ring structure part.

[0034] After the present application establishes a CAD digital model of a thin-walled ring structure part, the CAD digital model obtained in step a) is used to manufacture the part by laser additive manufacturing, and a laser additive manufacturing thin-walled ring structure part is obtained. Specifically, the metal powder is placed in the powder bin of the laser additive manufacturing equipment, and according to the established CAD digital model, the part manufacturing with support is completed through laser additive manufacturing technology, and a laser additive manufacturing thin-walled ring structure part is obtained.

[0035] After the present application obtains a laser additive manufacturing thin-walled ring structure part, the laser additive manufacturing thin-walled ring structure part obtained in step b) is supported and removed using any of the above-described removal methods, and a thin-walled ring structure part is obtained. After the present application supports and removes the laser additive manufacturing thin-walled ring structure part obtained in step b), the part after support removal is also subjected to sandblasting treatment, and a thin-walled ring structure part is obtained.

[0036] The present application also provides a support removal auxiliary device for laser additive manufacturing thin-walled ring structure parts, which is the same as the above-described support removal auxiliary device and will not be repeated.

[0037] The application provides a support removal method for laser additive manufacturing of thin-walled annular structure parts and application and a support removal auxiliary device.The support removal method for laser additive manufacturing of thin-walled annular structure parts provided by the application can monitor the deformation amount of the part in real time during the support removal process, can find deformation in time and inhibit large size deformation of the part through the air cooling cooling method, and greatly improves the forming quality. In addition, the deformation amount of the part is collected in real time through the piezoresistive sensor, and the cooling process is synchronized, which is simple to operate, simple in structure, low in equipment cost, good in applicability, effectively solves the deformation and cracking problem of the laser additive manufacturing of thin-walled annular structure parts, greatly improves the manufacturing efficiency and forming quality. At the same time, the piezoresistive sensor, the position, size and shape of the air outlet hole of the temperature control system are designed, so that the processing amount is minimized and the used material is minimized while the function is fully exerted. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 It is a part support removal process schematic diagram in the embodiment 1 of the application;

[0039] Figure 2 It is a front view of the support removal auxiliary device in the embodiment 1 of the application;

[0040] Figure 3 It is a side view of the support removal auxiliary device in the embodiment 1 of the application;

[0041] Figure 4 It is a top view of the support removal auxiliary device in the embodiment 1 of the application;

[0042] Figure 5 It is a sectional view of A-A plane in the embodiment 1 of the application; Figure 2

[0043] It is a sectional view of B-B plane in the embodiment 1 of the application; Figure 6 Figure 2 It is a local enlarged view of the area C in the embodiment 1 of the application;

[0044] Figure 7 Figure 5 It is a local enlarged view of the area C in the embodiment 1 of the application;

[0045] Figure 8 It is an assembly schematic diagram of the monitoring system in the embodiment 1 of the application;

[0046] Wherein: 1 is a part, 2 is a support to be removed, 3 is a workbench, 4 is a main body structure, 5 is a monitoring structure, 6 is an air outlet hole, 7 is a through fixing hole, 8 is an air inlet channel, 9 is a piezoresistive sensor, 10 is a trigger mechanism piece, 11 is a fixing frame, 12 is a deformation transmission mechanism column, and 13 is a bolt cylinder. DETAILED DESCRIPTION

[0047] ​The application discloses a support removal method for laser additive manufacturing of a thin-walled annular structure part and application and a support removal auxiliary device thereof. Those skilled in the art can refer to the content herein and properly improve process parameters to realize. It is particularly pointed out that all similar replacements and changes are obvious to those skilled in the art and are regarded as being included in the application. The method and application of the application have been described through preferred embodiments, and relevant personnel can obviously change or properly change and combine the method and application herein without departing from the content, spirit and scope of the application, to realize and apply the technology of the application.

[0048] The application provides a laser additive manufacturing and support removal method for an aero-engine TC4 titanium alloy bearing seat. Figures 1-8 As shown in the figure, Figure 1 It is a part support removal process schematic diagram in the embodiment 1 of the application, Figure 2 It is a front view of the support removal auxiliary device in the embodiment 1 of the application; Figure 3 It is a side view of the support removal auxiliary device in the embodiment 1 of the application; Figure 4 It is a top view of the support removal auxiliary device in the embodiment 1 of the application; Figure 5 It is Figure 2 A sectional view of A-A plane in the figure; Figure 6 It is Figure 2 A sectional view of B-B plane in the figure; Figure 7 It is Figure 5 A local enlarged view of region C in the figure; Figure 8 It is an assembly schematic diagram of the monitoring system in the embodiment 1 of the application.

[0049] The application is further described below in combination with embodiments:

[0050] Embodiment 1

[0051] The embodiment provides a laser additive manufacturing and support removal method for an aero-engine TC4 titanium alloy bearing seat, wherein the aero-engine TC4 titanium alloy bearing seat is a part to be removed support, the inner diameter of which is 230 mm, the wall thickness is 2.5 mm, and it is a typical thin-walled annular structure part.

[0052] The specific steps of the laser additive manufacturing and support removal of the aero-engine TC4 titanium alloy bearing seat are as follows:

[0053] Step 1: Establish a CAD digital model of the TC4 titanium alloy bearing seat.

[0054] Step two: Put the TC4 titanium alloy powder with particle size of 15-53 μm into the powder bin of the laser selective melting additive manufacturing equipment, and complete the manufacturing of the bearing seat with support through the laser selective melting additive manufacturing technology according to the CAD digital model established in step one. The process parameters used are: laser power 280 W, laser scanning speed 1250 mm / s, layer thickness 60 μm.

[0055] Step three: Fix the bearing seat on the workbench, place the support removal auxiliary device on the inner wall of the bearing seat, push it to the bearing seat along the radial direction of the bearing seat, and make it contact with the bearing seat. The support removal auxiliary device is composed of a main body structure 4 and a monitoring structure 5. The outer shape of the main body structure 4 is a hollow square ring body arc segment with a wall thickness of 3 mm, the outer diameter of the square ring body arc segment is 225 mm, the central angle corresponding to the outer diameter is 5°, and the thickness is 15 mm. The diameter of the air inlet channel 8 of the main body structure 4 is 5 mm. The main body structure 4 is arranged with one group of air outlet holes 6 every 1°, and the air outlet holes 6 in each group are spaced 5 mm apart in the radial direction. The shape of the air outlet hole 6 is an irregular shape composed of three flat-topped cones. The bottom diameter of one flat-topped cone is 0.75 mm, the top diameter is 0.45 mm, and the height is 1.2 mm; the bottom diameter of the second flat-topped cone is 0.6 mm, the top diameter is 0.45 mm, and the height is 0.6 mm; the bottom diameter of the third flat-topped cone is 0.9 mm, the top diameter is 0.6 mm, and the height is 1.2 mm. The monitoring structure 5 is composed of a piezoresistive sensor 9, a trigger mechanism piece 10, a fixing frame 11 and a deformation transmission mechanism column 12. The deformation transmission mechanism column 12 is a cylinder with a diameter of 1 mm and a length of 25 mm. The trigger mechanism piece 10 is an L-shaped sheet with a width of 2 mm and a thickness of 1 mm. The L-shaped sheet has a through hole with a diameter of 0.5 mm on the long side, which is connected to one end of the fixing frame 11 through a plug-in cylinder 13 with the same diameter, and the other end of the fixing frame 11 is fixed on the main body structure 4. The long side of the L-shaped sheet is in contact with the deformation transmission mechanism column 12, the short side is in contact with the piezoresistive sensor 9, and the deformation transmission mechanism column 12 is in contact with the surface of the part. The monitoring structure 5 is arranged with one group every 2°.

[0056] Step four: Mechanically remove the support to be removed, and monitor the deformation of the bearing seat in real time through the support removal auxiliary device.

[0057] Step five: When the deformation of the bearing seat is monitored, stop the support removal, and blow the bearing seat through the support removal auxiliary device to cool it down, and then continue the support removal after the deformation is eliminated.

[0058] Step six: After the support removal is completed, remove the support removal auxiliary device along the radial direction of the bearing seat.

[0059] Step seven: sandblasting treatment is conducted on the bearing seat after support removal, and the manufacturing of the bearing seat is completed.

[0060] Example 2

[0061] This embodiment provides a laser additive manufacturing and support removal method for an aero-engine GH3536 high-temperature alloy flame tube. The flame tube has an inner diameter of 760 mm and a wall thickness of 3 mm, and is a typical thin-walled annular structure part. The specific steps are as follows:

[0062] Step one: a CAD digital model of the GH3536 high-temperature alloy flame tube is established.

[0063] Step two: GH3536 high-temperature alloy powder with a particle size of 15 μm~53 μm is placed in the powder bin of the laser selective melting additive manufacturing equipment. According to the CAD digital model established in step one, the flame tube with support is manufactured by laser selective melting additive manufacturing technology. The process parameters used are: laser power 285 W, laser scanning speed 960 mm / s, and layer thickness 60 μm.

[0064] Step three: the flame tube is fixed on the workbench, and the support removal auxiliary device is placed on the inner wall of the flame tube, pushed towards the flame tube along the radial direction of the flame tube, and contacted with the flame tube. The support removal auxiliary device is composed of a main body structure 4 and a monitoring structure 5. The outer shape of the main body structure 4 is a hollow square ring body arc segment with a wall thickness of 8 mm, the outer diameter of the square ring body arc segment is 752 mm, the central angle corresponding to the outer diameter is 10°, and the thickness is 23 mm. The diameter of the air inlet channel 8 of the main body structure 4 is 7 mm. The main body structure 4 is arranged with one group of air outlet holes 6 every 2°, and the air outlet holes 6 in each group are spaced 6 mm apart in the radial direction. The shape of the air outlet hole 6 is an irregular shape composed of three flat-top cones. The base diameter of the first flat-top cone is 3 mm, the top diameter is 2 mm, and the height is 3 mm; the base diameter of the second flat-top cone is 2.5 mm, the top diameter is 2 mm, and the height is 2 mm; the base diameter of the third flat-top cone is 3.5 mm, the top diameter is 2.5 mm, and the height is 3 mm. The monitoring structure 5 is composed of a piezoresistive sensor 9, a trigger mechanism piece 10, a fixing frame 11, and a deformation transmission mechanism column 12. The deformation transmission mechanism column 12 is a cylinder with a diameter of 1.5 mm and a length of 40 mm. The trigger mechanism piece 10 is an L-shaped sheet with a width of 4 mm and a thickness of 4.5 mm. The L-shaped sheet has a through hole with a diameter of 1.3 mm on the long side, which is connected to one end of the fixing frame 11 through a plug-in cylinder 13 with the same diameter, and the other end of the fixing frame 11 is fixed on the main body structure 4. The long side of the L-shaped sheet is in contact with the deformation transmission mechanism column 12, the short side is in contact with the piezoresistive sensor 9, and the deformation transmission mechanism column 12 is in contact with the surface of the part. The monitoring structure 5 is arranged with one group every 3°.

[0065] Step four: mechanical removal of the support to be removed, and real-time monitoring of the deformation of the flame tube by the support removal auxiliary device.

[0066] Step five: when the deformation of the flame tube is monitored, the support removal is suspended, and the support removal auxiliary device is used to blow air to cool the flame tube, and the support removal is continued after the deformation is eliminated.

[0067] Step six: after the support removal is completed, the support removal auxiliary device is removed along the radial direction of the flame tube.

[0068] Step seven: sandblasting treatment is performed on the flame tube after the support removal, and the manufacturing of the flame tube is completed.

[0069] Example 3

[0070] This embodiment provides a laser additive manufacturing and support removal method for an aero-engine GH3625 high-temperature alloy case. The inner diameter of the flame tube is 1060 mm, the wall thickness is 1.5 mm, and it is a typical thin-walled annular structure part. The specific steps are as follows:

[0071] Step one: establish a CAD digital model of the GH3625 high-temperature alloy case.

[0072] Step two: put the GH3625 high-temperature alloy powder with a particle size of 15 μm~53 μm into the powder bin of the laser selective melting additive manufacturing equipment, and complete the manufacture of the case with support according to the CAD digital model established in step one by using the laser selective melting additive manufacturing technology. The process parameters used are: laser power 290 W, laser scanning speed 980 mm / s, layer thickness 60 μm.

[0073] Step three: fix the machine case on the workbench, place the support removal auxiliary device on the inner wall of the machine case, push it to the machine case along the radial direction of the machine case, and contact with the machine case. The support removal auxiliary device is composed of a main body structure 4 and a monitoring structure 5. The outer shape of the main body structure 4 is a hollow square ring body arc segment with a wall thickness of 10 mm, the outer diameter of the square ring body arc segment is 1050 mm, the central angle corresponding to the outer diameter is 20°, and the thickness is 30 mm. The diameter of the air inlet channel 8 of the main body structure 4 is 10 mm. The main body structure 4 is arranged with one group of air outlet holes every 4°, and the air outlet holes 6 in each group are spaced apart by 10 mm along the radial direction. The shape of the air outlet hole 6 is an irregular shape composed of three flat top cones. The bottom diameter of one flat top cone is 3.5 mm, the top diameter is 2.5 mm, and the height is 4 mm; the bottom diameter of the second flat top cone is 3 mm, the top diameter is 2.5 mm, and the height is 2 mm; the bottom diameter of the third flat top cone is 4 mm, the top diameter is 3 mm, and the height is 4 mm. The monitoring structure 5 is composed of a piezoresistive sensor 9, a trigger mechanism piece 10, a fixing frame 11 and a deformation transmission mechanism column 12. The deformation transmission mechanism column 12 is a cylinder with a diameter of 2 mm and a length of 50 mm. The trigger mechanism piece 10 is an L-shaped sheet with a width of 6 mm and a thickness of 5 mm. The L-shaped sheet has a through hole with a diameter of 1.5 mm on the long side, which is connected to one end of the fixing frame 11 through a plug-in cylinder 13 with the same diameter, and the other end of the fixing frame 11 is fixed on the main body structure 4. The long side of the L-shaped sheet is in contact with the deformation transmission mechanism column 12, the short side is in contact with the piezoresistive sensor 9, and the deformation transmission mechanism column 12 is in contact with the surface of the part. The monitoring structure 5 is arranged with one group every 5°.

[0074] Step four: mechanically remove the support structure, and monitor the deformation of the machine case in real time through the support removal auxiliary device.

[0075] Step five: when the deformation of the machine case is monitored, stop the support removal, and blow the machine case through the support removal auxiliary device to cool it down, and then continue the support removal after the deformation is eliminated.

[0076] Step six: after the support removal is completed, take out the support removal auxiliary device along the radial direction of the machine case.

[0077] Step seven: sandblast the machine case after the support removal, and complete the manufacture of the machine case.

[0078] The above is only the preferred specific implementation of the present application, but the protection scope of the present application is not limited to this. Any skilled person in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A method of support removal for laser additive manufacturing of thin-walled annular structural parts, characterized in that, The method comprises the following steps: S1) providing a support removal auxiliary device comprising a main body structure (4) and at least one monitoring structure (5); The main body structure (4) comprises opposite first and second surfaces; the interior of the main body structure (4) is further provided with a cooling gas passage for cooling gas flow through the first and second surfaces; The monitoring structure (5) comprises a piezoresistive sensor (9), a trigger mechanism piece (10), a fixed frame (11) and a deformation conduction mechanism column (12); The deformation conduction mechanism column (12) is axially slidably arranged in the main body structure (4), with one end passing through the first surface and the other end passing through the second surface; The piezoresistive sensor (9) is fixed to the second surface; The trigger mechanism piece (10) has an "L" shape structure, with one end of the short side of the trigger mechanism piece (10) in contact with the piezoresistive sensor (9) and one end of the long side of the trigger mechanism piece (10) in contact with the end of the deformation conduction mechanism column (12) passing through the second surface of the main body structure (4); One end of the fixed frame (11) is fixed to the second surface, and the other end is hingedly connected to the non-end of the trigger mechanism piece (10), so that when the end of the trigger mechanism piece (10) in contact with the end of the deformation conduction mechanism column (12) passing through the second surface is stressed, the trigger mechanism piece (10) can rotate and the other end can press the piezoresistive sensor (9); The three-dimensional shape of the main body structure (4) is a square ring body arc segment with a cavity in the interior with a wall thickness of 3 mm to 10 mm, the first surface is the outer diameter end surface of the square ring body arc segment, and the second surface is the inner diameter end surface of the square ring body arc segment; the central angle corresponding to the outer diameter of the main body structure (4) is 5° to 20°; the outer diameter of the main body structure (4) is smaller than the inner diameter of the laser additive manufacturing thin-walled ring-shaped structure part by 5 mm to 10 mm; the thickness of the main body structure (4) is 15 mm to 30 mm; The main body structure (4) is provided with through fixing holes (7) passing through the first surface and the second surface, the number of the through fixing holes (7) is at least the same as the number of the monitoring structures (5); the deformation conduction mechanism column (12) is axially slidably arranged in the through fixing holes (7) of the main body structure (4); According to the central angle corresponding to the outer diameter of the main body structure (4), one set of monitoring structure groups is arranged every 2° to 5°, each monitoring structure group is arranged in the height direction of the main body structure (4) and comprises a plurality of monitoring structures (5), and the interval between each monitoring structure (5) is 1 / 3 to 1 / 5 of the height of the main body structure (4); S2) the end of the deformation transmission mechanism column (12) of the support removal auxiliary device in step S1) is in contact with the opposite wall of the wall where the support of the laser additive manufacturing thin-walled ring structure part is located, and then the support is mechanically removed; when the piezoresistive sensor (9) gives a deformation prompt, the mechanical removal is paused, the laser additive manufacturing thin-walled ring structure part is cooled until the deformation prompt stops, and the mechanical removal is continued.

2. The removal method according to claim 1, characterized by, In step S1), the main body structure (4) is provided with an air outlet hole (6) penetrating the first surface, and the main body structure (4) is provided with an air inlet channel (8) penetrating the second surface, and the air outlet hole (6) and the air inlet channel (8) are respectively communicated with the cavity of the main body structure (4) to form a cooling gas channel for cooling gas flow through the first surface and the second surface; According to the central angle corresponding to the outer diameter of the main body structure (4), every 1°-4° is provided with a group of air outlet holes, and each group of air outlet holes is provided with a plurality of air outlet holes (6) in the height direction of the main body structure (4), and the interval of each air outlet hole (6) is 5-10 mm; The diameter of the air inlet channel (8) is 5-10 mm.

3. The removal method according to claim 2, characterized in that, In step S1), the air outlet hole (6) is formed by coaxially connecting a first flat-topped conical hole section, a second flat-topped conical hole section and a third flat-topped conical hole section; The bottom surface of the first flat-topped conical hole section faces the first surface of the main body structure (4), the top surface of the first flat-topped conical hole section is connected with the top surface of the second flat-topped conical hole section, the bottom surface of the second flat-topped conical hole section is connected with the top surface of the third flat-topped conical hole section, and the bottom surface of the third flat-topped conical hole section faces the inside of the main body structure (4); The top surface diameter of the first flat-topped conical hole section is the same as the top surface diameter of the second flat-topped conical hole section, and the bottom surface diameter of the second flat-topped conical hole section is the same as the top surface diameter of the third flat-topped conical hole section; The bottom surface diameter of the first flat-topped conical hole section is 2.5-7 mm, the top surface diameter is 1.5-5 mm, and the height is 2-8 mm; The bottom surface diameter of the second flat-topped conical hole section is 2-6 mm, the top surface diameter is 1.5-5 mm, and the height is 1-4 mm; The bottom surface diameter of the third flat-topped conical hole section is 3-8 mm, the top surface diameter is 2-6 mm, and the height is 2-8 mm.

4. The removal method according to claim 1, characterized by, In step S2), the supports of the laser additive manufacturing thin-walled ring structure part are all arranged on the outer diameter end surface wall of the laser additive manufacturing thin-walled ring structure part.

5. Method for laser additive manufacturing of thin-walled ring-shaped structural parts, characterized in that, The steps include: a) establishing a CAD digital model of a thin-walled ring structure part; b) according to the CAD digital model obtained in step a), using laser additive manufacturing to manufacture the part to obtain a laser additive manufacturing thin-walled ring structure part; c) removing the supports from the laser additive manufacturing thin-walled ring structure part obtained in step b) by using the removing method of any one of claims 1-4 to obtain a thin-walled ring structure part.

6. A support removal aid for laser additive manufacturing of thin-walled annular structural parts, characterized in that It comprises a main body structure (4) and at least one monitoring structure (5); The main body structure (4) comprises opposite first and second surfaces; the inside of the main body structure (4) is further provided with a cooling gas passage for cooling gas flow through the first and second surfaces; The monitoring structure (5) comprises a piezoresistive sensor (9), a trigger mechanism piece (10), a fixed frame (11) and a deformation conduction mechanism column (12); The deformation conduction mechanism column (12) is axially slidably arranged in the main body structure (4), one end of which passes out of the first surface and the other end of which passes out of the second surface; The piezoresistive sensor (9) is fixed on the second surface; The trigger mechanism piece (10) is in an "L" shape structure, one end of the short side of the trigger mechanism piece (10) being in contact with the piezoresistive sensor (9) and one end of the long side of the trigger mechanism piece (10) being in contact with the end of the deformation conduction mechanism column (12) passing out of the second surface of the main body structure (4); One end of the fixed frame (11) is fixed on the second surface, and the other end is hingedly connected to the non-end of the trigger mechanism piece (10), so that when the end of the trigger mechanism piece (10) in contact with the end of the deformation conduction mechanism column (12) passing out of the second surface is stressed, the trigger mechanism piece (10) can rotate and the other end can press the piezoresistive sensor (9); The three-dimensional shape of the main body structure (4) is a square ring body arc segment with a cavity inside and a wall thickness of 3 mm to 10 mm, the first surface is the outer diameter end face of the square ring body arc segment, and the second surface is the inner diameter end face of the square ring body arc segment; the central angle corresponding to the outer diameter of the main body structure (4) is 5° to 20°; the outer diameter of the main body structure (4) is 5 mm to 10 mm smaller than the inner diameter of the laser additive manufacturing thin-walled ring structure part; the thickness of the main body structure (4) is 15 mm to 30 mm; The main body structure (4) is provided with through fixing holes (7) passing through the first surface and the second surface, the number of the through fixing holes (7) being at least the same as the number of the monitoring structures (5); the deformation conduction mechanism column (12) is axially slidably arranged in the through fixing holes (7) of the main body structure (4); According to the central angle corresponding to the outer diameter of the main body structure (4), one set of monitoring structure groups is arranged every 2° to 5°, each monitoring structure group is arranged in multiple monitoring structures (5) along the height direction of the main body structure (4), and the interval of each monitoring structure (5) is 1 / 3 to 1 / 5 of the height of the main body structure (4).

7. The support removal aid of claim 6, wherein, The main body structure (4) is provided with air outlet holes (6) penetrating the first surface, and the main body structure (4) is provided with air inlet channels (8) penetrating the second surface, the air outlet holes (6) and the air inlet channels (8) are respectively communicated with the cavities of the main body structure (4) to form cooling air channels for cooling gas flow through the first surface and the second surface; According to the central angle corresponding to the outer diameter of the main body structure (4), every 1°-4° is provided with a group of air outlet holes, and each group of air outlet holes is provided with a plurality of air outlet holes (6) in the height direction of the main body structure (4), and the interval of each air outlet hole (6) is 5-10 mm; The diameter of the air inlet channel (8) is 5-10 mm.

8. The support removal aid of claim 7, wherein, The air outlet hole (6) is formed by coaxially connecting a first flat-topped conical hole section, a second flat-topped conical hole section and a third flat-topped conical hole section; The bottom surface of the first flat-topped conical hole section faces the first surface of the main body structure (4), the top surface of the first flat-topped conical hole section is connected with the top surface of the second flat-topped conical hole section, the bottom surface of the second flat-topped conical hole section is connected with the top surface of the third flat-topped conical hole section, and the bottom surface of the third flat-topped conical hole section faces the inside of the main body structure (4); The top surface diameter of the first flat-topped conical hole section is the same as the top surface diameter of the second flat-topped conical hole section, and the bottom surface diameter of the second flat-topped conical hole section is the same as the top surface diameter of the third flat-topped conical hole section; The bottom surface diameter of the first flat-topped conical hole section is 2.5-7 mm, the top surface diameter is 1.5-5 mm, and the height is 2-8 mm; The bottom surface diameter of the second flat-topped conical hole section is 2-6 mm, the top surface diameter is 1.5-5 mm, and the height is 1-4 mm; The bottom surface diameter of the third flat-topped conical hole section is 3-8 mm, the top surface diameter is 2-6 mm, and the height is 2-8 mm.

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