Method for controlling deformation and precision of parts in parallel during additive manufacturing process
20200130267 ยท 2020-04-30
Assignee
Inventors
Cpc classification
B33Y10/00
PERFORMING OPERATIONS; TRANSPORTING
B22F3/164
PERFORMING OPERATIONS; TRANSPORTING
G05B2219/49023
PHYSICS
B23K9/044
PERFORMING OPERATIONS; TRANSPORTING
B23K2103/26
PERFORMING OPERATIONS; TRANSPORTING
B23K15/0093
PERFORMING OPERATIONS; TRANSPORTING
B23K10/027
PERFORMING OPERATIONS; TRANSPORTING
B22F2999/00
PERFORMING OPERATIONS; TRANSPORTING
B33Y40/20
PERFORMING OPERATIONS; TRANSPORTING
B23K9/23
PERFORMING OPERATIONS; TRANSPORTING
B23K26/0006
PERFORMING OPERATIONS; TRANSPORTING
B29C64/393
PERFORMING OPERATIONS; TRANSPORTING
B23K31/003
PERFORMING OPERATIONS; TRANSPORTING
G05B2219/49013
PHYSICS
B33Y50/02
PERFORMING OPERATIONS; TRANSPORTING
B22F3/24
PERFORMING OPERATIONS; TRANSPORTING
B23K26/0093
PERFORMING OPERATIONS; TRANSPORTING
B23P9/02
PERFORMING OPERATIONS; TRANSPORTING
B22F2003/247
PERFORMING OPERATIONS; TRANSPORTING
B22F10/38
PERFORMING OPERATIONS; TRANSPORTING
B33Y30/00
PERFORMING OPERATIONS; TRANSPORTING
B23K15/0086
PERFORMING OPERATIONS; TRANSPORTING
B22F10/18
PERFORMING OPERATIONS; TRANSPORTING
B22F10/85
PERFORMING OPERATIONS; TRANSPORTING
B23P23/04
PERFORMING OPERATIONS; TRANSPORTING
B29C64/188
PERFORMING OPERATIONS; TRANSPORTING
G05B19/4099
PHYSICS
B22F3/162
PERFORMING OPERATIONS; TRANSPORTING
B29C64/118
PERFORMING OPERATIONS; TRANSPORTING
Y02P90/02
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
B22F2999/00
PERFORMING OPERATIONS; TRANSPORTING
B22F12/90
PERFORMING OPERATIONS; TRANSPORTING
Y02P10/25
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
B22F12/84
PERFORMING OPERATIONS; TRANSPORTING
International classification
B29C64/188
PERFORMING OPERATIONS; TRANSPORTING
B29C64/393
PERFORMING OPERATIONS; TRANSPORTING
B29C64/118
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A method for controlling deformation and precision of a part in parallel during an additive manufacturing process includes steps of: performing additive forming and isomaterial shaping or plastic forming, and simultaneously, performing one or more members selected from a group consisting of isomaterial orthopedic process, subtractive process and finishing process in parallel at a same station, so as to achieve a one-step ultra-short process, high-precision and high-performance additive manufacturing, wherein: performing in parallel at the same station refers to simultaneously implement different processes in a same pass or different passes of different processing layers or a same processing layer when a clamping position of the part to be processed is unchanged. The method can realize the one-step high-precision and high-performance additive manufacturing which has the ultra-short process, has high processing precision, and the parts can be directly applied, so that the method has strong practical application value.
Claims
1. A method for controlling deformation and precision of a part in parallel during an additive manufacturing process, which comprises steps of: performing additive forming and isomaterial shaping or plastic forming, and simultaneously, performing one or more members selected from a group consisting of isomaterial orthopedic process, subtractive process and finishing process in parallel at a same station, so as to achieve a one-step ultra-short process, high-precision and high-performance additive manufacturing, wherein: performing in parallel at the same station refers to simultaneously implement different processes in a same pass or different passes of different processing layers or a same processing layer when a clamping position of the part to be processed is unchanged.
2. The method for controlling deformation and precision of the part in parallel during the additive manufacturing process, as recited in claim I, further comprising a step of performing followed-up controlled rolling and controlled cold heat treatment for controlling deformation and improving performance, so that through controlling process parameters such as temperature, degree of deformation, rate of deformation, and cooling conditions during the plastic forming, or supplemented by electromagnetism or ultrasonic vibration, crystalline morphologies and mechanical properties of a formed body are improved, residual stress and deformation are reduced, and a forming precision is improved.
3. The method for controlling deformation and precision of the part in parallel during the additive manufacturing process, as recited in claim 2, wherein: the subtractive process or the finishing process is specifically simultaneous and follow-up milling by laser, electromachining or ultrasound; if the precision does not meet requirements of the part, mechanical milling or grinding finishing is performed till the precision meets the requirements of the part.
4. The method for controlling deformation and precision of the part in parallel during the additive manufacturing process, as recited in claim 3, wherein: in different passes, or in an interval between the additive forming process of different passes of different processing layers or a same processing layer, oxides, impurities and defects on a surface of a fused deposition modeling zone are cleaned up in a follow-up cleaning manner during the additive forming process, so as to obtain a substrate surface or a part surface with good quality which is conducive to high-quality fused deposition modeling of a next pass.
5. The method for controlling deformation and precision of the part in parallel during the additive manufacturing process, as recited in claim 4, further comprising after performing additive forming, plastic forming or isomaterial orthopedic process, in a forming processing unit, performing heat treatment on the formed body or the part, so as to remove residual stress thereof, reduce deformation and cracking, and improve mechanical properties.
6. The method for controlling deformation and precision of the part in parallel during the additive manufacturing process, as recited in claim 5, further comprising detecting the defects which comprises through using a numerical control system of a manufacturing equipment, and an inverse device and a defect detection device connected with the manufacturing equipment, inversely calculating a shape and a size of the formed body in parallel, and performing internal and external defect detection on blind areas which are complex in shape and are difficult to perform defect detection after a complete of forming; when there are defects, removing the defects with a reduction system and then continuously forming, wherein after completing the forming, a defect detection on the part at the same station in the manufacturing equipment is performed.
7. The method for controlling deformation and precision of the part in parallel during the additive manufacturing process, as recited in claim 1, wherein different processes are implemented at different positions in the same pass or different passes of different processing layers or the same processing layer.
8. The method for controlling deformation and precision of the part in parallel during the additive manufacturing process, as recited in claim 2, wherein: the process parameters comprising temperature, degree of deformation, rate of deformation, and cooling conditions during the plastic forming process are controlled, which is assisted by electromagnetic or ultrasonic vibration; a plasma fused deposition gun using gas tungsten arc welding is adopted as a heat source for additive forming, a micro roll moves synchronously with the plasma fused deposition gun, the micro roll for plastic forming is applied to a surface of a fresh post-solidification zone of a molten pool in situ; a fused deposition current of the plasma fused deposition gun is 180 A; according to performance requirements of a forging mold cavity to be fused and deposited, a mold steel welding wire is used, micro-casting fused deposition additive forming and micro-forging plastic forming are performed simultaneously layer by layer in accordance with a digital forming processing path obtained from a three-dimensional CAD (computer-aided design) model of the mold on a substrate; through the follow-up controlled rolling and controlled cold heat treatment, in the process of additive forming and plastic forming, air cooling is changed to gas cooling or liquid nitrogen cooling; or in the forming process, electromagnetism is applied to the molten pool for auxiliary forming; if the shape of the mold cavity is complex, it is necessary to perform contactless laser milling on the surface of the formed body to be processed during the above-mentioned synchronous forming process; if during the synchronous forming process, the size and surface precision of the formed body are still unable to meet the requirements due to a short time, mechanical finishing is able to be performed in a manner of layer by layer or segmented composition of several layers; the finishing process is synchronized with the synchronous forming process till a complete of mold cavity forming.
9. The method for controlling deformation and precision of the part in parallel during the additive manufacturing process, as recited in claim 3, wherein: if the precision does not meet the requirements, mechanical milling or grinding finishing is able to be continuously adopted till the precision of parts meet the requirement.
10. The method for controlling deformation and precision of the part in parallel during the additive manufacturing process, as recited in claim 4, wherein: a gas-protected laser fused deposition gun is adopted as a heat source for additive fused deposition forming, a micro roll moves synchronously with the gas-protected laser fused deposition gun, impact forming laser for plastic forming is applied to a surface of a post-solidification zone of a molten pool; a power of the gas-protected laser fused deposition gun is 2000 W; according to performance requirements of an aircraft engine case to be additively manufactured, a superalloy wire is used, fused deposition modeling and micro-plastic forming are performed simultaneously layer by layer in accordance with a digital forming processing path obtained from a three-dimensional CAD model of parts on a substrate; due to a large size of the case, the deformation of fused deposition modeling is large, so that the isomaterial orthopedic process needs to be performed after the synchronous forming process; the isomaterial orthopedic process is performed followed by the laser impact forming till the complete of part forming so as to correct the deformation to the minimum; or ultrasonic vibrations are applied to a formed area for auxiliarily forming during the forming process so as to improve microstructure and properties and reduce residual stress; if the shape of the component is complex, it is necessary to perform contactless laser milling during the synchronous forming process, or perform intermittent contact ultrasonic machining, or perform the above process or mechanical finishing in a manner of segmented composition of several layers on the parts that are difficult to be processed after the whole forming; the finishing process is synchronized with the synchronous forming process till the complete of part forming.
11. The method for controlling deformation and precision of the part in parallel during the additive manufacturing process, as recited in claim 5, wherein: a composite of electric arc or plasma arc of a gas tungsten arc welding gun and laser is adopted as a heat source for additive forming, a micro roll moves synchronously with a composite heat source generator, the micro roll for isomaterial shaping is applied to a surface of a post-solidification zone of a molten pool; a fused deposition current of the gas-protected electric arc or plasma arc fused deposition gun is 200 A and a laser power thereof is 2000 W; according to the performance requirements of an aircraft frame beam to be additively manufactured, a titanium alloy welding wire is used, fused deposition modeling and micro-plastic forming are performed simultaneously layer by layer in accordance with a digital forming processing path obtained from a three-dimensional CAD model of parts on a substrate; due to a large size of the aircraft frame beam, the deformation of fused deposition modeling is large, so that the isomaterial orthopedic process needs to be performed after the synchronous forming process, the isomaterial orthopedic process is performed followed by the micro-plastic forming till the complete of part forming so as to correct the deformation to the minimum; however, due to high performance requirements of aeronautical parts, oxides and impurities on a surface of each layer are not allowed to be brought into a lower forming body, so that oxides, impurities and defects on the surface of the fused deposition modeling zone during additive forming are required to be cleaned up in a high-efficiency follow-up cleaning manner, so as to obtain a substrate surface or a part surface with good quality which is conducive to high-quality fused deposition modeling of a next pass; the surface cleaning is synthesized with the forming process till the complete of part forming; a solid-state laser with a power of 2000 W is adopted, a superalloy wire is used as a forming material, a micro roll fixed on a laser head moves synchronously with the laser head, a side vertical roll follows a side of a melt softening zone, a perforated horizontal roll flexibly tracks a semi-solidified softened area near a back of a molten pool; according to a digital forming processing path obtained from a three-dimensional CAD model of oil pipe fittings on a substrate, laser fused deposition modeling and micro-forced forming are performed simultaneously on superalloy parts layer by layer; a heat treatment device located in a forming processing unit is used to perform heat treatment on the formed parts or components after the complete of all forming processes, so as to remove residual stresses, reduce deformation and cracking, and improve mechanical properties of the formed body or part.
12. The method for controlling deformation and precision of the part in parallel during the additive manufacturing process, as recited in claim 6, wherein: during the additive manufacturing process, through a numerical control system or a robot system of the manufacturing equipment, and an inverse device and a defect detection device connected with the manufacturing equipment, inversely calculating the shape and size of the formed body in parallel, and performing internal and external defect detection on blind areas which are complex in shape and are difficult to perform defect detection after the complete of forming.
13. The method for controlling deformation and precision of the part in parallel during the additive manufacturing process, as recited in claim 6, wherein: a powder feeder made from functionally functional materials and a plasma fused deposition gun with a transfer arc current of 170 A are adopted, a micro roll is fixed on a wrist of an industrial robot, the wrist of the industrial robot keeps synchronized with the numerical control plasma fused deposition gun which is used in fused deposition modeling, a side vertical roll follows a side of a melt softening zone, a perforated horizontal roll flexibly tracks a semi-solidified softened area near a back of a molten pool; according to a digital fused deposition modeling path obtained from a three-dimensional CAD model with gradient functional material composition distribution information, nickel-aluminum intermetallic compound powders and nickel-based superalloy powders are used, plasma fused deposition modeling and micro-excrusion forming are performed simultaneously layer by layer on the part made from the functionally gradient materials; because the gradient functional material is prone to crack, the shape and size of the formed body are reversed calculated in parallel during the additive manufacturing process by using an inverse device and a defect detection device, and then detected; if there are defects, a material reduction system is used to remove the defects and then forming is continued; or blind areas with complex shapes, that are difficult to be performed defect inspection after completing the forming, are performed defect inspection; if there are defects, the material reduction system is used to remove the defects and then forming is continued; or after completing the forming, the same reverse inspection method is adopted at the same station in the manufacturing equipment to complete the defect detection of parts.
Description
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0033] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail with reference to the embodiments as follows. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.
[0034] The present invention provides a method for controlling deformation and precision of a part in parallel during an additive manufacturing process, which comprises steps of: performing additive forming and isomaterial shaping or plastic forming, and simultaneously, performing one or more members selected from a group consisting of isomaterial orthopedic process, subtractive process and finishing process in parallel at the same station, so as to achieve the one-step ultra-short process, high-precision and high-performance additive manufacturing. Performing in parallel at the same station refers to simultaneously implement different processes in the same pass or different passes of different processing layers or the same processing layer when the clamping position of the part to be processed is unchanged.
[0035] In the additive manufacturing process, since the additive forming process and the isomaterial shaping process occur in parallel in the same pass, in the fresh solidification zone of the molten pool, dynamic recrystallization can be generated with only a small pressure, thereby forming equiaxed fine grains in the hot forged state; the isomaterial orthopedic process is generally performed in parallel in the same pass or in the same layer or in different layers during the forming process.
[0036] The method further comprises a step of performing followed-up controlled rolling and controlled cold heat treatment for controlling deformation and improving performance, so that through controlling process parameters such as temperature, degree of deformation, rate of deformation, and cooling conditions during the plastic forming, mechanical properties of a formed body are improved, the residual stress and deformation are reduced, and the forming precision is improved.
[0037] Because the processes are performed in parallel at the same station, the shaping process of the same part immediately follows the additive forming process and occurs in the same pass of the same layer; the temperature is high and there are metal splashes. It is generally considered that the shaping mechanism needs heat resistance, cooling performance, anti-metal sputtering pollution, etc., which causes that it is difficult for device manufacturing and plastic deformation controlling. At the same part of the component, the isomaterial shaping is performed after the complete of additive forming. However, in fact, at the same time in time, all of the additive forming process, the isomaterial shaping process or the plastic forming process, and the isomaterial orthopedic process performed when necessary are simultaneously carried out, but only at different positions of the part.
[0038] Further, the subtractive process or the finishing process is specifically simultaneous and follow-up milling by laser, electromachining or ultrasound.
[0039] It is generally considered that mechanical milling is an effective finishing method, but because it is a contact type and requires force, machine-type software and hardware systems are required. The numerical control system is unable to perform milling machining in parallel when the additive manufacturing equipment performs additive forming, isomaterial shaping and isomaterial orthopedic, and only the milling can be performed after these processes are completed; or a numerical control system is added, which will reduce the forming efficiency; and adding the numerical control system and transmission system will increase the cost and equipment complexity. In addition, the milling process is thermal and dry milling, which is very difficult and consumes tools. The contactless method such as laser has simple galvanometer mechanism and control, which can be performed in parallel with the above forming process in the same pass or the same layer or different layers.
[0040] Further, in the interval between the additive forming process of different processing layers, surface defects in the fused deposition modeling zone are cleaned up in a follow-up cleaning manner, so as to obtain a substrate surface or a part surface with good quality which is conducive to high-quality fused deposition modeling of a next pass.
[0041] It is generally considered that while resurfacing welding in the atmosphere, oxides on the surface of the welding layer will float to the surface during the next welding and are generally not cleaned. However, additive forming is multi-layer forming, and the surface layer is repeatedly oxidized and contaminated, which may affect the performance of the formed body. For part manufacturing that requires high toughness and fatigue performance such as aerospace, follow-up cleaning methods that can be performed in parallel with the above-mentioned forming processes without reducing efficiency are required.
[0042] Further, the method further comprises after performing additive forming, plastic forming or isomaterial orthopedic process, in the forming processing unit, performing heat treatment on the formed body or the part, so as to remove residual stress thereof, reduce deformation and cracking, and improve mechanical properties. This heat treatment does not cause the part to melt, and has low temperature, which is mainly used to remove residual stress, and reduce deformation and cracking.
[0043] it is generally considered that for the additive formed part, which is formed by resurfacing welding, the formed part should be removed from the manufacturing unit after the complete of forming and is subjected to heat treatment such as stress relief annealing to eliminate residual stress and deformation, and prevent the parts which are difficult to be formed from cracking. However, these processes will affect the forming processing precision and manufacturing efficiency. Therefore, in view of the low temperature of the stress relief annealing heat treatment, the heat treatment device is installed in the manufacturing unit, so that the manufacturing efficiency is not reduced, and the final finishing process can be performed after the heat treatment, thereby obtaining ultra-short process high-precision high-performance additive manufacturing.
[0044] Further, the method further comprises through using a numerical control system of the manufacturing equipment, and an inverse device and a defect detection device connected with the manufacturing equipment, inversely calculating the shape and size of the formed body in parallel, and performing internal and external defect detection on blind areas which are complex in shape and are difficult to perform defect detection after the complete of forming; when there are defects, removing the defects with a reduction system and then continuously forming.
[0045] It is generally considered that traditional manufacturing is to detect the defects of the formed parts. However, if the defects of the parts exceed the standard after the defect detection, the parts can only be scrapped. In addition, during the detection process, some parts have complex shapes, and some parts may not be detected, so that a detection dead zone is formed. Therefore, the detection during the forming process will not be limited by the detection dead zone.
[0046] In order to explain the method in detail, the present invention is described with reference to specific embodiments as follows.
First Embodiment
[0047] A plasma fused deposition gun using gas tungsten arc welding (laser, gas metal arc welding, gas tungsten arc welding and electron beam) is adopted as a heat source for additive forming, a micro roll moves synchronously with the plasma fused deposition gun, the micro roll for isomaterial shaping is applied to a surface of a fresh post-solidification zone of a molten pool. A fused deposition current of the plasma fused deposition gun is 180 A. According to performance requirements of a forging mold cavity to be fused and deposited, a mold steel welding wire is used, fused deposition modeling and plastic forming are performed simultaneously layer by layer in accordance with a digital forming processing path obtained from a three-dimensional CAD (computer-aided design) model of the mold on a substrate. If the shape of the mold cavity is complex, it is necessary to perform contactless laser milling on the surface of the formed body to be processed during the above-mentioned synchronous forming process. If during the above-mentioned synchronous forming process, the size and surface precision of the formed body still cannot meet the requirements due to the short time, mechanical finishing is able to be performed by segmented composition of several layers. The finishing process is synchronized with the synchronous forming process (that is, implementation in parallel at the same station) till the complete of mold cavity forming.
Second Embodiment
[0048] A plasma fused deposition gun using gas tungsten arc welding is adopted as a heat source for additive forming, a micro roll moves synchronously with the plasma fused deposition gun, the micro roll for isomaterial shaping is applied to a surface of a fresh post-solidification zone of a molten pool. A fused deposition current of the plasma fused deposition gun is 180 A. According to the performance requirements of a mold cavity for a sheet metal forming to be fused and deposited, a mold steel wire is used, laser fused deposition modeling and plastic forming are performed simultaneously layer by layer in accordance with a digital forming processing path obtained from a three-dimensional CAD model of the mold on a substrate. In order to control deformation and improve performance, a follow-up controlled rolling and controlled cold heat treatment process is used; during the process of additive forming and thermoforming (plastic forming), air cooling is changed to liquid nitrogen cooling to increase a cooling rate, thereby improving the strength and hardness of the mold. Or during the forming process, electromagnetism is applied to a molten pool for auxiliary forming, so as to improve microstructure and properties and reduce residual stress. The above process is synchronized with the forming process, that is, parallel implementation at the same station, till the complete of mold cavity forming.
Third Embodiment
[0049] A gas-protected laser fused deposition modeling gun is adopted as a heat source for additive forming, a micro roll moves synchronously with the gas-protected laser fused deposition modeling gun, impact forming laser for plastic forming is applied to a surface of a post-solidification zone of a molten pool. A power of the gas-protected laser fused deposition modeling gun is 2000 W. According to the performance requirements of an aircraft engine case to be additively manufactured, a superalloy wire is used, fused deposition modeling and micro-plastic forming are performed simultaneously layer by layer in accordance with a digital forming processing path obtained from a three-dimensional CAD model of the part on a substrate. Due to the large size of the frog, the deformation of fused deposition modeling is large. Therefore, the isomaterial orthopedic forming needs to be performed after the synchronous forming described above. This isomaterial orthopedic forming is performed followed by the laser impact forming till the complete of part forming, so as to correct the deformation to the minimum. Or ultrasonic vibrations are applied to a formed area for auxiliary forming during the forming process, so as to improve microstructure and properties, and reduce residual stress. If the shape of the part is complex, it is necessary to perform contactless laser milling during the above-mentioned synchronous forming process or perform mechanical finishing by segmented composite of several layers on the part that are difficult to be processed after forming. The finishing process is synchronized with the synchronous forming process, that is, both of them are implemented in parallel at the same station, till the complete of part forming.
Fourth Embodiment
[0050] A gas-protected laser fused deposition modeling gun is adopted as a heat source for additive forming, a micro roll moves synchronously with the gas-protected laser fused deposition modeling gun, the micro roll for isomaterial shaping is applied to a surface of a fresh post-solidification zone of a molten pool. A fused deposition current of the gas-protected laser fused deposition modeling gun is 200 A and a laser power thereof is 2000 W. According to the performance requirements of an aircraft frame beam to be additively manufactured, a titanium alloy welding wire is used, fused deposition modeling and micro-plastic forming are performed simultaneously layer by layer in accordance with a digital forming processing path obtained from a three-dimensional CAD model of the part on a substrate. Due to the large size of the aircraft frame beam, the deformation of fused deposition modeling is large. Therefore, the isomaterial orthopedic forming needs to be performed after the synchronous forming described above. This isomaterial orthopedic forming is performed followed by the micro-plastic forming till the complete of part forming, so as to correct the deformation to the minimum. However, due to the high performance requirements of aeronautical parts, oxides and impurities on the surface of each layer are not allowed to be brought into a lower forming body. Therefore, oxides, impurities and defects on the surface of the fused deposition modeling zone during additive forming are required to be cleaned up in a high-efficiency follow-up cleaning manner, so as to obtain a substrate surface or a part surface with good quality which is conducive to high-quality fused deposition modeling of a next pass. The surface cleaning is synthesized with the forming process (that is, implementation in parallel at the same station) till the complete of part forming.
Fifth Embodiment
[0051] A solid-state laser with a power of 2000 W is adopted, a superalloy wire is used as a forming material, a micro roll fixed on a laser head moves synchronously with the laser head, a side vertical roll follows a side of a melt softening zone, a perforated horizontal roll flexibly tracks a semi-solidified softened area near a back of a molten pool; according to a digital forming processing path obtained from a three-dimensional CAD model of oil pipe fittings on a substrate, laser fused deposition modeling and micro-forced forming are performed simultaneously on superalloy parts layer by layer, that is, parallel implementation at the same station. A heat treatment device located in a forming processing unit is used to perform heat treatment on the formed parts or components after the completion of all forming processes to remove residual stresses of the formed parts or components, reduce deformation and cracking, and improve mechanical properties of the formed parts or the components.
Sixth Embodiment
[0052] A powder feeder made from functionally gradient materials and a plasma fused deposition gun with a transfer arc current of 170 A are adopted, a micro roll is fixed on a wrist of an industrial robot, the wrist of the industrial robot keeps synchronized with the numerical control plasma fused deposition gun which is used in fused deposition modeling, a side vertical roll follows a side of a melt softening zone, a perforated horizontal roll flexibly tracks a semi-solidified softened area near a back of a molten pool. According to a digital fused deposition modeling path obtained from a three-dimensional CAD model with gradient functional material composition distribution information, nickel-aluminum intermetallic compound powders and nickel-based superalloy powders are used, plasma fused deposition modeling and micro-excrusion forming are performed simultaneously layer by layer on the part made from gradient functional materials. Because the gradient functional material is prone to crack, the shape and size of the formed body must be reversed in parallel during the additive manufacturing process by using a reverse device and a defect detection device, and then detected. If there are defects, a material reduction system is used to remove the defects and then forming is continued. Or blind areas with complex shapes, that are difficult to be performed defect inspection after completing the forming, are performed defect inspection. If there are defects, the material reduction system is used to remove the defects and then forming is continued, that is, parallel implementation at the same station. Or after completing the forming, the same reverse inspection method is adopted at the same station in this manufacturing equipment to complete the defect detection of parts.
[0053] In order to explain the technical effects of the present invention in detail, the present invention is further described with specific experiments as follows.
[0054] First Experiment: Medium carbon steel engine transition section during micro-casting, forging and milling (additive, isomaterial, subtractive) composite manufacturing process
[0055] The weldability of medium carbon steel is extremely poor, and there is no international precedent for 3D printing; the tensile stress in width and depth directions of the deformed microdomain is changed to the compressive stress. Defects such as cracks are reduced, residual stress is reduced by 70% and deformation is reduced. Columnar crystals become ultrafine equiaxed crystals. The performance significantly exceeds traditional forgings. The medium carbon steel engine transition section passes aero engine standard X-ray internal defect detection. Medium carbon steel as-cast column/dendritic obtained by single arc forming, grade 7-8 equiaxed coarse crystals obtained by traditional forging, and 12-level ultrafine equiaxed crystals obtained by micro-casting and forging composite are contrasted. The X-ray detection is performed on the medium carbon steel engine transition section, and there is no defect.
TABLE-US-00001 TABLE 1 Test results of mechanical properties of medium carbon steel engine transition section (30% reduction) Impact Tensile Elong- Shrink- Tough- Hard- strength ation age ness/ ness/ Performance Method b/MPa /(%) /(%) (J .Math. mm.sup.2) (HBS) Casting Aviation 540 12 20 29.4 152- standards 170 Forging National 835 10 40 36.9 229- Standard GB 285 5024-77 Present Longitudinal 963 18 60 47.5 301- Invention Direction 308 Tangential 982 12 43 43.5 307- Direction 324
[0056] Second Experiment: Through the experiment, micro-casting and forging (additive, isomaterial) composite forming TC4 titanium alloy microstructure and properties as-cast pillars/dendritic crystals are changed into forged equiaxed crystals, the performance exceeds forgings.
[0057] Third Experiment: Through the experiment, superalloy In718 grain structure is obtained through micro-casting and forging forming (30% deformation).
[0058] Fourth Experiment: Through the experiment, the energy consumption and material consumption of aircraft landing gears manufactured by traditional process and micro casting forging composite process are compared, as shown in Table 2.
TABLE-US-00002 TABLE 2 Comparison of Energy Consumption and Material Consumption of Aircraft Landing Gears Manufactured by Traditional Process and Micro Casting Forging Composite Process Material Manufacturing Comparison Items Blank Quality Utilization Cycle Traditional 800 kg 10% 3-6 months Process Micro Casting 120 kg 68% 3-6 weeks Forging Composite Process
TABLE-US-00003 TABLE 3 Comparison of Energy Consumption between Micro Casting Forging Milling Process and Traditional Process Traditional Casting Forcing Milling Total Process (kj) (kj) (kj) (kj) 9.37 10.sup.6 8.64 10.sup.7 3.2 10.sup.5 9.6 10.sup.7 Micro Casting Micro Micro Micro Milling Tota1 Forging Casting Forging (kj) Milling 1.06 10.sup.6 4.5 10.sup.5 2.3 10.sup.4 1.5 10.sup.6 Process
[0059] Referring to Table 3, in the micro forging process, 4.510.sup.5 kj of energy is consumed and less than 1 ton of micro forging pressure is used instead of the traditional 10,000-ton forging pressure, and the energy consumption is less than 10% of the traditional forging.
[0060] Through the above experiments, it can be seen that in the method provided by the present invention, the super high strength steel material utilization is 6.8 times higher than that of traditional manufacturing; the energy consumption is reduced by 90%, which will significantly improve the energy consumption structure. The present invention breaks through the performance bottleneck, has high strength, high toughness, high performance reliability and uniform forged ultrafine equiaxed crystal structure, and fully meets the need for weight loss in high-end fields such as large aircrafts. The present invention has an ultra-short process. Casting-forging-welding-milling multiple processes are integrated into one manufacturing unit, so that a new model of directly manufacturing high-end parts with one device is established, which achieves parallel control of part shape and performance and reduces manufacturing cycles and processes by more than 60%. The present invention has the advantages of high efficiency and low cost, transforming the traditional manufacturing mode of high energy consumption materials and heavy pollution, saving more than 90% of energy consumption and realizing transformative green manufacturing. According to the present invention, design-monitor-control-repair are integrated manufactured. A series of large-scale equipment for large-scale complex melt-forging-milling composite ultra-short process manufacturing is developed.
[0061] Those skilled in the art can easily understand that the above description is only the preferred embodiments of the present invention and is not intended to limit the present invention. Any modification, equivalent replacement and improvement made within the spirit and principle of the present invention should be included in the protective scope of the present invention.