Additive with three-dimensional space heterogeneous structure characteristic and preparation method and system thereof

Abstract

The invention discloses a preparation method and system of an additional material with three-dimensional space heterogeneous structure characteristics, the additional material comprises a soft phase region and hard phase regions located on the two sides of the soft phase region, the soft phase region comprises coarse grain layers and fine grain layers which are alternately distributed, and the hard phase regions are the fine grain regions. The preparation method comprises the following steps: manufacturing a prefabricated body with alternate coarse and fine crystals in the Z-axis direction through electric arc additive manufacturing; isomers with opposite large deformation areas and opposite small deformation areas are formed on the two side faces of the prefabricated body through a corrugated roller, wherein the large deformation areas are opposite to the large deformation areas, and the small deformation areas are opposite to the small deformation areas; and the isomer is subjected to heat treatment, and the additive with the three-dimensional space heterogeneous structure characteristic is obtained. The three-dimensional space heterogeneous structure of the additive comprises a composite structure formed by alternately arranging coarse grain layers and fine grain layers and fine grain areas located on the two sides of the composite structure, and the method has the advantages of being high in three-dimensional space heterogeneous structure forming efficiency, good in effect and customizable on the basis of additive heat cycle input and corrugated rolling shaping.

Description

Technical Field

[0001] The present invention belongs to the field of additive manufacturing technology, and specifically relates to additive materials with three-dimensional spatial heterogeneous structural characteristics, and a preparation method and system thereof. Background Art

[0002] There is a mutual constraint between the strength and plasticity of metal materials. This is because high strength often comes from hindering the movement of dislocations, while mobile dislocations are necessary for the material to undergo plastic deformation.

[0003] To overcome this dilemma of achieving both strength and ductility, existing research has proposed numerous strategies, such as adding rare earth elements, introducing nano-ultrafine grains, or nano-twinning. However, these strategies either incur high material costs and environmental burdens, or require extremely strict microstructural control at the nanoscale, hindering low-cost, large-scale industrial production and unsuitable for aluminum alloys. In recent years, "heterogeneous metal materials," inspired by nature, have garnered widespread attention for addressing the strength-ductility trade-off in metallic materials.

[0004] In the process of realizing the present invention, the inventors found that there are at least the following problems in the prior art: 1) poor process stability and difficulty in controlling the microstructure; 2) low forming efficiency and difficulty in low-cost large-scale production of large-sized heterogeneous components. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an additive material with three-dimensional spatial heterogeneous structural characteristics, and a preparation method and system thereof in response to the deficiencies of the above-mentioned prior art.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: an additive material with three-dimensional spatial heterogeneous structural characteristics, including a soft phase region and hard phase regions located on both sides of the soft phase region, and the soft phase region includes coarse-grained layers and fine-grained layers distributed alternately.

[0007] In the present invention, in the additive material, the distance W1 between the two hard phase regions is 4500-5500 μm, and the sum of the widths W2 of adjacent coarse-grained layers and fine-grained layers is 1500-2500 μm.

[0008] Another aspect of the present invention provides a method for manufacturing the additive material having three-dimensional spatial heterogeneous structural characteristics, comprising:

[0009] Arc additive manufacturing of preforms with alternating coarse and fine grains in the Z-axis direction;

[0010] Using a corrugated roller to make isomers with large deformation areas facing each other and small deformation areas facing each other on both sides of the preform;

[0011] The isomer is heat treated to obtain an additive material with three-dimensional spatial heterogeneous structural characteristics.

[0012] In the above method, the additive raw material is aluminum alloy.

[0013] In the above method, in arc additive manufacturing, the layer height is 2.5-4 mm, the processing path is unidirectional movement within the layer, the interlayer dwell time is 30-60 s, the interlayer temperature is 80-130 ° C, the wire feeding speed is 6-7 m / min, and the travel speed is 5-8 mm / s.

[0014] In the above method, the thickness of the coarse crystal layer in the preform is 1000-1500 μm, the thickness of the fine crystal layer is 150-300 μm, the coarse crystal size is 80-120 μm, and the fine crystal size is 20-40 μm.

[0015] In the above method, the corrugation radius R of the corrugated roller is 1 to 3 mm, and r is 0.5 mm.

[0016] In the above method, the rolling force of the corrugated roller is 30 kN, the rolling temperature is 100° C., and the rolling speed is 10 mm / s.

[0017] In the above method, the corrugation pitch angle θ is 8° and the roller radius is 30 mm.

[0018] On the other hand, the present invention also provides the above-mentioned additive manufacturing system with three-dimensional spatial heterogeneous structural characteristics, including a corrugated rolling device, which includes: two corrugated rollers, a servo motor that controls the two corrugated rollers to move synchronously along the X direction, and an electric cylinder that controls the positioning of the two corrugated rollers along the Z direction to apply a predetermined rolling force to the preform.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] 1. The present invention provides a method for preparing an additive material having three-dimensional spatial heterogeneous tissue characteristics, wherein the three-dimensional spatial heterogeneous tissue includes a composite structure composed of alternating coarse-grained layers and fine-grained layers, and fine-grained regions located on both sides of the composite structure. The method is based on additive thermal cycle input and corrugated rolling shaping, and has the characteristics of high efficiency, good effect and customizability in the formation of three-dimensional spatial heterogeneous tissue.

[0021] 2. Preferably, the method of the present invention includes arc additive manufacturing and roller rolling deformation, with a deposition efficiency of 1 to 4 kg / h and a rolling efficiency of 10 to 20 m / min. Compared with traditional powder bed additive manufacturing, powder spraying additive manufacturing, interlayer impact plastic deformation, and interlayer hammering plastic deformation, it has high deposition efficiency and rolling efficiency, low cost, and is conducive to the large-scale production of large-sized heterogeneous components.

[0022] The technical solution of the present invention is further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic flow chart of Example 1;

[0024] Figure 2 This is a schematic diagram of the corrugated roller structure of Example 1;

[0025] Figure 3 This is a scanning electron microscope image of the XOZ plane cross-sectional structure of the component in Example 1;

[0026] Figure 4 This is a schematic structural diagram of the corrugated rolling device of Example 2.

[0027] Description of Reference Numerals

[0028] 1-corrugated roller; 2-servo motor; 3-electric cylinder;

[0029] 4-Turbine screw; 5-Handwheel. DETAILED DESCRIPTION

[0030] The following will be combined with the embodiments of this application and the accompanying drawings to clearly and completely describe the technical solution. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0031] In the following description, the term "and / or" is used to describe the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, B exists alone, and A and B exist at the same time. A and B can be singular or plural.

[0032] In the following description, the terms "include", "comprising", "having" and "containing" are open-ended terms, meaning including but not limited to.

[0033] Those skilled in the art should understand that in the following description of the embodiments of the present application, the order of serial numbers does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0034] It will be understood by those skilled in the art that the numerical ranges in the examples of the present application are to be understood as also specifically disclosing each intermediate value between the upper and lower limits of the ranges. Each smaller range between any intermediate value within a stated value or stated range and any other stated value or intermediate value within the stated range is also included in the present application. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

[0035] Unless otherwise indicated, the technical / scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which this application belongs. Although this application describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of this application. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In the event of any conflict with any incorporated document, the content of this specification shall prevail.

[0036] The technical principle adopted by the present invention is as follows: a coarse-fine grain alternating body is obtained by depositing multiple layers, dislocations are increased based on double-sided rolling, and recrystallization is achieved by heat treatment to obtain an additive with three-dimensional spatial heterogeneous structural characteristics.

[0037] In some embodiments, an additive material having three-dimensional spatial heterogeneous structural characteristics is provided, comprising a soft phase region and hard phase regions located on both sides of the soft phase region, wherein the soft phase region comprises coarse-grained layers and fine-grained layers that are alternately distributed, and the hard phase region is a fine-grained region.

[0038] In some embodiments, in the additive manufacturing process, the distance W1 between two hard phase regions is 4500-5500 μm, and the sum of the widths W2 of adjacent coarse-grained layers and fine-grained layers is 1500-2500 μm.

[0039] In some embodiments, a method for preparing an additive material having three-dimensional spatial heterogeneous structural properties is provided, comprising:

[0040] Arc additive manufacturing of preforms with alternating coarse and fine grains in the Z-axis direction;

[0041] Using a corrugated roller to form isomers with large deformation areas facing each other and small deformation areas facing each other on both sides of the preform;

[0042] The isomer is heat treated to obtain an additive material with three-dimensional spatial heterogeneous structural characteristics.

[0043] By depositing multiple layers, double-sided rolling, and heat treatment to achieve recrystallization, an additive material with three-dimensional spatial heterogeneous structural characteristics is obtained, consisting of a coarse-fine grain interlaced complex and fine-grained regions located on both sides of the complex. In this additive material, the coarse-fine grain interlaced complex has high plasticity, the fine-grained region has high strength, and has the structural characteristics of a "hard phase" encapsulating a "soft phase".

[0044] In some embodiments, arc additive manufacturing (AM) employs a layer height of 2.5 to 4 mm, a unidirectional machining path within the layer, a dwell time of 30 to 60 seconds between layers, an interlayer temperature of 80 to 130°C, a wire feed speed of 6 to 7 m / min, and a travel speed of 5 to 8 mm / s. In some embodiments, the wire feed speed is 7 m / min, the travel speed is 5 mm / s, and the interlayer temperature is 80°C. By controlling the wire feed speed, travel speed, and interlayer temperature, the volume percentage of the fine-grained layer can be controlled in the AM process.

[0045] In some embodiments, the thickness of the coarse-grained layer in the preform is 1000-1500 μm, the thickness of the fine-grained layer is 150-300 μm, the size of the coarse grains is 80-120 μm, and the size of the fine grains is 20-40 μm.

[0046] In some embodiments, the corrugation radius R of the corrugated roller is 1-3 mm, and r is 0.5 mm. By controlling the corrugation radius, the volume percentage of the fine grain region in the additive material can be controlled.

[0047] In some embodiments, the rolling force is 30 kN, the rolling temperature is 100°C, and the rolling speed is 10 mm / s. During the rolling process, the large and small radius areas of the corrugated roller are machined to different heights on the specimen, forming a structure with alternating peaks and valleys. By controlling the rolling parameters of the corrugated roller, the volume percentage of the total fine-grained layer in the additive material and the width of adjacent coarse-grained and fine-grained layers can be controlled.

[0048] In some embodiments, the corrugation pitch angle θ is 8°, and the roller radius is 30 mm. By controlling the roller shape, the distance W1 between the two hard phase regions can be controlled.

[0049] The present invention has been subjected to a series of experiments before the application is filed. A part of the experimental results is now listed to further describe the invention in detail, and the following is a detailed description in conjunction with the embodiments.

[0050] Example 1

[0051] This embodiment provides an additive material with three-dimensional spatial heterogeneous structural characteristics, including a soft phase region and hard phase regions located on both sides of the soft phase region, wherein the soft phase region includes coarse-grained layers and fine-grained layers that are alternately distributed.

[0052] This embodiment also provides a method for preparing the above-mentioned additive material with three-dimensional spatial heterogeneous structural characteristics, wherein the additive material is an aluminum alloy rectangular component with dimensions of 50mm (length) * 50mm (width) * 60mm (height), and the welding wire is GR2319 aluminum alloy with a welding wire diameter of 1.2mm.

[0053] like Figure 1 As shown, the method includes:

[0054] Step 1: Create a 3D model of an aluminum alloy cuboid component, slice it into single layers, set the layer height to 2.5mm, use a unidirectional motion within the layer, a dwell time of 45s between layers, control the interlayer temperature at 80°C, use a reciprocating swing deposition forming direction, a wire feed speed of 7m / min, and a travel speed of 5mm / s; use the CMT-PA mode;

[0055] Step 2: Start the arc additive equipment, the welding gun starts working, emits an arc, the wire melts on the substrate, and the aluminum alloy welding wire is deposited layer by layer along the forming path by synchronous wire feeding to obtain a preform with alternating coarse and fine grains in the Z-axis direction; wherein the average thickness of the coarse grain layer is 1000 μm, the average thickness of the fine grain layer is 150 μm, the coarse grain size is 80-120 μm, and the fine grain size is 20-40 μm;

[0056] Step 3: Select a corrugated roller according to the height of the preform so that the height of the preform is equal to the width of the corrugated roller, place the two selected corrugated rollers in a spaced relationship, place the preform in the space, reduce the distance between the two corrugated rollers, press each corrugated roller against one side of the preform, start the corrugated rollers, and make the two corrugated rollers roll the two sides of the preform synchronously to form an isomer with peak-to-peak and valley-to-valley relative to each other; wherein the corrugation radius R of the corrugated roller is 2 mm, r is 0.5 mm, the corrugation pitch angle θ=8°, the roller radius is 30 mm, the rolling force is 30 kN, the rolling temperature is 100°C, and the rolling speed is 10 mm / s; the corrugated roller structure in this embodiment is shown in FIG. Figure 2 As shown;

[0057] Step 4: heat treating the isomer obtained in step 3, specifically including annealing at 510° C. for 10 minutes and air cooling to obtain an additive material having three-dimensional spatial heterogeneous structural characteristics;

[0058] Step 5: Cut the additive material to obtain a component with a size of 50mm (length) * 50mm (width) * 60mm (height); cut the component along the XOZ plane, and the cross-sectional SEM image is as follows: Figure 3 As shown, according to Figure 3 It can be seen that the component generally presents alternating coarse-grained areas and remelted fine-grained areas on the Z axis, forming a "soft zone". The two sides of the "soft zone" are "hard zones" composed of recrystallized fine-grained areas, which have three-dimensional spatial heterogeneous structural characteristics.

[0059] In the process of preparing the three-dimensional spatial heterogeneous structural characteristics additive manufacturing in this embodiment, the rolling speed is 10 mm / s, which has higher efficiency than the traditional hammer-assisted additive manufacturing.

[0060] Example 2

[0061] This embodiment provides an additive manufacturing system with three-dimensional spatial heterogeneous tissue characteristics, including a corrugated rolling device, the structural schematic diagram of the corrugated rolling device is shown in FIG. Figure 4 As shown, it includes: two corrugated rollers 1, a servo motor 2 for controlling the synchronous movement of the two corrugated rollers 1 along the X direction, and an electric cylinder 3 for controlling the positioning of the two corrugated rollers 1 along the Z direction so as to apply a predetermined rolling force to the preform; the corrugated rolling device also includes a turbine screw 4 connected to the corrugated rollers 1, and a handwheel 5 for controlling the distance between the corrugated rollers.

[0062] The method for preparing an additive material having three-dimensional spatial heterogeneous structural characteristics using the system of this embodiment is the same as that of Example 1, except that step three is:

[0063] The preform is placed between two corrugated rollers 1, and the distance between the two corrugated rollers is adjusted by the hand wheel 5 so that each corrugated roller presses against one side of the preform. The electric cylinder 3 and the servo motor 2 are started to apply a rolling force of 30kN to the preform, and the two sides of the preform are rolled synchronously to form an isomer with peak-to-peak and valley-to-valley relative to each other; wherein the corrugated roller 1 is the same as the corrugated roller in Example 1.

Claims

1. An additive material with three-dimensional heterogeneous structural characteristics, characterized in that: It comprises a soft phase region and hard phase regions located on both sides of the soft phase region, wherein the soft phase region comprises coarse crystal layers and fine crystal layers that are distributed alternately.

2. The additive material having three-dimensional spatial heterogeneous structural characteristics according to claim 1, characterized in that: In the additive manufacturing process, the distance W1 between the two hard phase regions is 4500-5500 μm, and the sum of the widths W2 of adjacent coarse-grained layers and fine-grained layers is 1500-2500 μm.

3. A method for manufacturing an additive material having three-dimensional spatial heterogeneous structural characteristics as claimed in claim 1, characterized in that: include: Arc additive manufacturing of preforms with alternating coarse and fine grains in the Z-axis direction; Using a corrugated roller to make isomers with large deformation areas facing each other and small deformation areas facing each other on both sides of the preform; The isomer is heat treated to obtain an additive material with three-dimensional spatial heterogeneous structural characteristics.

4. The method according to claim 3, characterized in that The raw material for the additive manufacturing process is aluminum alloy.

5. The method according to claim 3, characterized in that In arc additive manufacturing, the layer height is 2.5 to 4 mm, the processing path is unidirectional movement within the layer, the interlayer dwell time is 30 to 60 seconds, the interlayer temperature is 80 to 130°C, the wire feed speed is 6 to 7 m / min, and the travel speed is 5 to 8 mm / s.

6. The method according to claim 3, characterized in that The thickness of the coarse grain layer in the preform is 1000-1500 μm, the thickness of the fine grain layer is 150-300 μm, the size of the coarse grain is 80-120 μm, and the size of the fine grain is 20-40 μm.

7. The method according to claim 3, characterized in that The corrugation radius R of the corrugated roller is 1 to 3 mm, and r is 0.5 mm.

8. The method according to claim 3, characterized in that The rolling force of the corrugated roller is 30 kN, the rolling temperature is 100 °C, and the rolling speed is 10 mm / s.

9. The method according to claim 3, characterized in that The corrugation pitch angle θ is 8° and the roller radius is 30 mm.

10. An additive manufacturing system with three-dimensional spatial heterogeneous structural characteristics as claimed in claim 1, characterized in that: The invention comprises a corrugation rolling device, which comprises: two corrugation rollers (1), a servo motor (2) for controlling the two corrugation rollers (1) to move synchronously along the X direction, and an electric cylinder (3) for controlling the two corrugation rollers (1) to position along the Z direction so as to apply a predetermined rolling force to the preform.

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