A method and apparatus for additive and subtractive forming of composite parts

Abstract

The application discloses a composite part additive-subtractive forming method and equipment, and relates to the technical field of composite part composite manufacturing. The forming method comprises the following steps: step 1, shape feature decomposition of target forming; step 2, determination of forming strategies of each feature obtained by the decomposition in step 1; step 3, determination of material deformation and material allowance according to part performance and process; step 4, determination of process parameters and forming paths of each scheme; and step 5, execution of numerical control codes by the composite part additive-subtractive forming device to complete part forming. The forming method is matched with the forming equipment of the application, additive manufacturing is mainly used, and traditional manufacturing is used as auxiliary, so that the limit of current single material and single forming process in aspects of forming performance, forming precision and forming efficiency is broken, and the forming method is suitable for in-situ synchronous composite forming of multiple materials and multiple processes.

Description

Technical Field

[0001] The present invention relates to the technical field of composite manufacturing of composite parts, and in particular to a method and equipment for additive and subtractive forming of composite parts. Background Art

[0002] The development of major national projects such as aviation, aerospace, shipbuilding, and nuclear power has placed stringent performance and precision requirements on parts. The performance of a single material has reached its limits, making it difficult to meet the demands of today's high-performance parts. Leveraging the performance differences between different materials, leveraging their strengths and weaknesses, and producing composite materials with high overall performance, low cost, and high reliability is a practical and effective approach with broad potential for development. At the same time, high-performance materials present machining difficulties, further challenging processing techniques and efficiency. Part forming methods generally include subtractive methods such as cutting, milling, and grinding; isotropic methods such as forging, stamping, and rolling; and additive methods such as arc machining, laser cladding, and thermal spraying. Each of these methods has its own advantages and disadvantages. For example, subtractive machining offers high machining precision and low material utilization; isotropic machining offers good structural properties and high equipment energy consumption; and additive manufacturing offers high material utilization and high cost. Taking the four major hot-end components of aircraft engines as an example, the operating temperature limits of traditional metal materials used in guide vanes, turbine blades, turbine disks, and combustion chambers are approaching. Intermetallic compounds, carbon-based composites, and ceramics and ceramic composites are expected to gain application. Composite materials consist of two or more materials, leveraging the complementary properties of each material to enhance overall performance. Composite materials combine the advantages of each component and generally possess properties such as high specific strength, wear resistance, high temperature resistance, and corrosion resistance.

[0003] Therefore, it is of great significance to develop a method that is mainly based on additive manufacturing and supplemented by traditional manufacturing, break through the current limitations of a single material and a single forming process in terms of forming performance, forming accuracy, and forming efficiency, and propose a method and equipment suitable for in-situ synchronous composite forming of multiple materials and multiple processes. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and equipment for additive and subtractive forming of composite parts to solve the problems existing in the above-mentioned prior art and is suitable for in-situ synchronous composite forming of multiple materials and multiple processes.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a method for additive and subtractive forming of composite material parts, comprising the following steps:

[0007] Step 1: Shape feature decomposition of target forming;

[0008] Step 2: Determine the forming strategy for each feature decomposed in step 1. Based on the material type, feature type and size, determine the forming strategy for each feature according to the point, line, surface and body schemes.

[0009] Step 3: Determine the material deformation and material allowance based on part performance and process;

[0010] Step 4: Determine the process parameters and forming path for each solution; Based on the forming strategy and material type in step 2 and the material deformation and material allowance in step 3, determine the process parameters and forming path for each solution; Use slicing software to slice and generate NC code that can be executed by the composite forming machine tool;

[0011] Step 5: The composite part additive and subtractive forming device executes the NC code to complete the part forming.

[0012] Optionally, the material types in step 2 include powders, wires, plates and blocks, etc.; the corresponding melting heat sources are one or more of laser, electron beam, arc, resistance, stir friction or ultrasonic waves.

[0013] Optionally, the forming strategies in step 2 include body forming using a block as a matrix or block combination welding, surface forming using plate stacking welding, line forming using wire fusion deposition, and point forming using powder fusion deposition.

[0014] Optionally, in the surface forming of step 2, a dual-power welding forming strategy is adopted to address the phenomenon of weld core offset in welding plates of unequal thickness and plates of dissimilar materials. The dual-power welding forming strategy includes using two annular electrodes respectively arranged upper and lower, and on the premise of ensuring the electrode current density, the coaxial annular electrode adopts a scheme of connecting two sets of power supplies. The current path is between the center electrode and the outer electrode, and the area with the largest current density is between the center electrode and the outer electrode, ultimately obtaining an annular weld core and a controllable magnetic field.

[0015] The present invention also provides a device for additive and subtractive forming of composite parts, comprising a rotatable forming workbench, on which parts to be formed are placed; a double-moving beam gantry is provided above the forming workbench, on which a melting heat source is movably provided; a feeding mechanism is provided on one side of the forming workbench; and a forming tool library and a raw material library are provided on one side of the feeding mechanism.

[0016] Optionally, a shaft-type matrix, a plate-type matrix and a plate-frame-type matrix can be installed on the workbench to perform shaft-type part forming, double-sided solid forming and single-sided hollow forming respectively.

[0017] Optionally, the forming tool library contains welding guns, milling cutters, rollers, electrodes, fixtures, etc.

[0018] Optionally, the raw material library contains blocks, plates, wires, and powders.

[0019] Compared with the prior art, the present invention has achieved the following technical effects:

[0020] The present invention uses a single piece of equipment for in-situ composite production, achieving ultra-short process manufacturing. It employs multiple materials and multiple heat sources, fully considering the characteristics and material properties of the parts to select the optimal forming process and parameters. It adopts a block welding strategy, utilizing stir friction and ultrasonic welding schemes to improve efficiency while ensuring high performance. For plate welding, a dual-power supply resistance welding forming scheme is proposed, solving the problem of weld nugget offset in plates of unequal thickness and dissimilar thickness. To address the multi-material composite problem, multiple forming mechanisms and different feeding schemes are proposed, which not only improve efficiency but also easily change the composition of different materials during the simultaneous melting of multiple materials, resulting in different composite materials. Furthermore, by controlling the feed rates of multiple materials to continuously change, a stepless change in material composition is achieved to produce a gradient material. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 This is a schematic flow chart of the additive and subtractive forming method for composite parts of the present invention;

[0023] Figure 2 Schematic diagram of electrode arrangement of the present invention;

[0024] Figure 3 It is a partial schematic diagram of the equipment for additive and subtractive forming of composite parts according to the present invention;

[0025] Figure 4 Schematic diagram of powder materials in the raw material library of the present invention;

[0026] Figure 5 This is a schematic diagram of welding wire in the raw material warehouse of the present invention;

[0027] Figure 6 Schematic diagram of the plate material library of the present invention;

[0028] Figure 7 Schematic diagram of a block of the raw material library of the present invention;

[0029] Figure 8 A schematic diagram of a welding gun of a forming tool library of the present invention;

[0030] Figure 9A schematic diagram of a milling cutter of a forming tool library of the present invention;

[0031] Figure 10 A schematic diagram of the rollers of the forming tool library of the present invention;

[0032] Figure 11 Schematic diagram of the electrodes of the forming tool library of the present invention;

[0033] Figure 12 A schematic diagram of a fixture of a forming tool library of the present invention;

[0034] Explanation of the accompanying symbols: 1-upper center electrode; 2-upper ceramic sleeve; 3-upper outer electrode; 4-material one; 5-material two; 6-lower ceramic sleeve; 7-lower center electrode; 8-lower outer electrode; 9-weld core; 10-block; 11-plate; 12-wire; 13-powder material; 14-welding gun; 15-milling cutter; 16-roller; 17-electrode; 18-clamp; 19-forming workbench; 20-double-moving beam gantry; 21-feeding mechanism. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0036] The purpose of the present invention is to provide a method and equipment for additive and subtractive forming of composite parts to solve the problems existing in the above-mentioned prior art and is suitable for in-situ synchronous composite forming of multiple materials and multiple processes.

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] The present invention provides a composite material part additive and subtractive forming method, that is, a part efficient forming method based on additive, equal and subtractive forming, with reference to the attached Figure 1 As shown, the following steps are included:

[0039] Step 1: Decomposition of target shape features, including shaft features, hole features, rib features, boss features, and complex surface features;

[0040] Step 2: Determine the forming strategy for each feature decomposed in step 1, mainly based on the material type, feature type and size, and determine the forming strategy for each feature according to the point, line, surface and body schemes. Generally, body forming (block as the substrate, or block combination welding) is preferred, followed by surface forming (plate stacking welding), then line forming (wire melting deposition), and finally point forming (powder melting deposition). When the material is difficult to form, it is analyzed specifically according to its characteristics, such as high entropy alloys, ceramics or dissimilar materials; the material types include powder, wire, plate and block, etc., and the corresponding melting heat sources are generally laser or electron beam, laser or arc, arc or resistance, stir friction or ultrasonic, etc.; in plate forming, in view of the molten core offset phenomenon of welding plates of unequal thickness and dissimilar materials, a dual-power welding forming strategy is proposed to achieve the regulation of welding temperature field and magnetic field, refer to the attached. Figure 2 The specific plan is as follows:

[0041] By setting two electrodes at the top and bottom, respectively, which include a coaxial upper central electrode 1, an upper outer electrode 3 and a coaxial lower central electrode 7, a lower outer electrode 8, an upper ceramic sleeve 2 is provided between the upper central electrode 1 and the upper outer electrode 3, a lower ceramic sleeve 6 is provided between the lower central electrode 7 and the lower outer electrode 8, and material one 4 and material two 5 are provided between the upper and lower electrodes. Under the premise of ensuring the same current density as the traditional electrode, the coaxial annular electrode adopts a scheme of two sets of power supply connections. The current path is between the central electrode and the outer electrode, and the area with the largest current density is between the central electrode and the outer electrode, so that an annular weld core 9 will be obtained in the end. At the same time, according to the principle of magnetic field superposition, the induced magnetic fields generated by the two current loops can be superimposed, so as to realize the free adjustment of the strength and direction of the magnetic field in the welding area. Therefore, an annular weld core and an adjustable magnetic field can be obtained when welding with two sets of power supplies;

[0042] Step 3: Determine the material deformation variable and material allowance based on the part performance and process; the higher the material performance, the larger the deformation variable is required. The relationship between the material performance and deformation variable can be obtained through experiments. The material allowance generally only considers the mating surface. The mating surface requires high mating accuracy, and a subtractive forming solution is required. Different forming solutions are considered for different materials. Generally, a 3-5mm allowance is reserved for body forming and surface forming. Generally, a 1-2mm allowance is reserved for wire forming, and a 1mm allowance is reserved for powder forming. For other non-mating surfaces, the same material processing solution is used, and generally no allowance or an allowance of about 1mm is reserved;

[0043] Step 4: Determine the process parameters and forming path for each solution; Based on the forming strategy and material type in step 2 and the material deformation and material allowance in step 3, determine the process parameters and forming path for each solution; Use slicing software to slice and generate NC code that can be executed by the composite forming machine tool;

[0044] Step 5: The composite part additive and subtractive forming device executes the NC code to complete the part forming.

[0045] The present invention also provides a composite material parts additive and subtractive forming equipment, refer to the attached Figure 3 As shown, it includes a rotatable forming workbench 19, on which the parts to be formed are placed; a double-moving beam gantry 20 is provided above the forming workbench 19, on which a melting heat source is movably provided; a feeding mechanism 21 is provided on one side of the forming workbench 19; and a forming tool library and a raw material library are provided on one side of the feeding mechanism 21.

[0046] Specifically, the workbench can be installed with shaft-type substrates, plate-type substrates and plate-frame-type substrates, which can be used to form shaft-type parts, double-sided solid forming and single-sided hollow forming respectively. The double-moving beams can be formed separately and collaboratively at the same time, wherein the collaborative forming includes one supporting the other while the other performs additive forming; one supporting the other while the other performs equal material forming; one supporting the other while the other performs subtractive forming; one preheating and slow cooling the other while the other performs additive forming; one preheating and slow cooling the other while the other performs equal material forming; one preheating and slow cooling the other while the other performs hot subtractive forming. Refer to the attached Figure 4 , Attachment Figure 5 , Attachment Figure 6 , Attachment Figure 7 , Attachment Figure 8 , Attachment Figure 9 , Attachment Figure 10 , Attachment Figure 11 and attached Figure 12 As shown, the forming tool library contains welding guns 14, milling cutters 15, rollers 16, electrodes 17, and fixtures 18. The raw material library contains blocks 10, plates 11, wires 12, and powder materials 13. Blocks and plates 11 are typically fed and positioned using electromagnetic or negative pressure suction by a multi-axis robotic arm; wire 12 uses a dedicated wire feeder; and powder material 13 uses a powder feeder. A single unit can be equipped with multiple wire feeders and powder feeders depending on the material composition of the part being formed. The multi-axis robotic arm's integrated measurement unit enables precise measurement and positioning of the materials being fed.

[0047] In the description of the present invention, it should be noted that the terms "center," "top," "bottom," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0048] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A method for additive and subtractive forming of composite parts, characterized by: A composite material part additive and subtractive forming device is used, the composite material part additive and subtractive forming device includes a rotatable forming workbench, the forming workbench is used to place the part to be formed; a double-moving beam gantry is provided above the forming workbench, and a melting heat source is movably provided on the double-moving beam gantry; a feeding mechanism is provided on one side of the forming workbench; a forming tool library and a raw material library are provided on one side of the feeding mechanism; the method includes the following steps: Step 1: Shape feature decomposition of target forming; Step 2: Determine the forming strategy of each feature decomposed in step 1, and determine the forming strategy of each feature according to the point, line, surface and body schemes based on the material type, feature type and size; the forming strategy includes body forming with a block as a matrix or block combination welding, surface forming with plate stacking welding, line forming with wire melt deposition, and point forming with powder melt deposition; two electrodes are set up at the top and bottom, respectively, which include a coaxial upper central electrode, an upper outer electrode and a coaxial lower central electrode, a lower outer electrode, an upper ceramic sleeve is provided between the upper central electrode and the upper outer electrode, a lower ceramic sleeve is provided between the lower central electrode and the lower outer electrode, and material one and material two are provided between the upper and lower electrodes; in order to solve the phenomenon of nugget offset in welding plates of unequal thickness and plates of dissimilar materials, a dual power supply welding forming strategy is adopted, which includes two annular electrodes set up at the top and bottom, and under the premise of ensuring the electrode current density, the coaxial annular electrode adopts a scheme of connecting two sets of power supplies, the current path is between the central electrode and the outer electrode, and the area with the largest current density is between the central electrode and the outer electrode, and finally a ring-shaped nugget and a controllable magnetic field are obtained; Step 3: Determine the material deformation and material allowance based on part performance and process; reserve a 3-5mm allowance for body forming and surface forming, a 1-2mm allowance for wire forming, and a 1mm allowance for powder forming; Step 4: Determine the process parameters and forming path for each solution; Based on the forming strategy and material type in step 2 and the material deformation and material allowance in step 3, determine the process parameters and forming path for each solution; Use slicing software to slice and generate NC code that can be executed by the composite forming machine tool; Step 5: The composite part additive and subtractive forming device executes the NC code to complete the part forming.

2. The method for additive and subtractive forming of composite parts according to claim 1, characterized in that: The material types in step 2 include powder, wire, plate and block; the corresponding melting heat source is one or more of laser, electron beam, arc, resistance, stir friction or ultrasonic.

3. The method for additive and subtractive forming of composite parts according to claim 1, characterized in that: The workbench can be equipped with shaft-type substrates, plate-type substrates and plate-frame-type substrates to perform shaft-type part forming, double-sided solid forming and single-sided hollow forming respectively.

4. The method for additive and subtractive forming of composite parts according to claim 1, characterized in that: The forming tool library includes welding guns, milling cutters, rollers, electrodes, and fixtures.

5. The method for additive and subtractive forming of composite parts according to claim 1, characterized in that: The raw material library includes blocks, plates, wires and powders.

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