Method for realizing lightweight additive manufacturing

Abstract

The embodiment of the invention discloses a method for achieving component lightweight additive manufacturing, relates to the field of metal additive manufacturing, and can improve the interface bonding strength of heterogeneous materials. The method comprises the steps that a model of a component to be processed is established, topological optimization is carried out on the model of the component, and the topological optimization target is to carry out lightweight design on the model of the component. The optimized component model comprises a lightweight structure, and the type of the lightweight structure comprises a topological optimization structure (comprising a suspended structure and a lattice structure (comprising a lattice structure), and the method mainly aims at the suspended structure; the area with the lightweight structure in the model of the component is replaced with a lightweight material filling area, and the lightweight material filling area covers the area with the lightweight structure; a'mortise and tenon interlocking 'joint structure is additionally arranged at the interface of the heterogeneous materials, and a convex part made of one material in the joint structure goes deep into a concave part of the other material.

Description

Technical Field

[0001] The present invention relates to the field of metal additive manufacturing, and in particular to a method for realizing lightweight additive manufacturing of components. Background Art

[0002] Lightweight design is the future of manufacturing - reducing carbon emissions on one hand and enabling better component performance on the other. In simple terms, lightweight design is the act of reducing the amount of material in a component to lower its overall weight without sacrificing reliability or functionality. This is most common in the automotive and aerospace industries, where lightweight design improves fuel efficiency and enhances the performance of aircraft and electric vehicles.

[0003] Lightweight design is divided into material lightweight and structural lightweight. In the existing structural lightweight design, bionic lightweight design starts from the unique macro-microstructure function and structural size of biological organisms. Based on the principle of similarity, bionic design methods and means are used to obtain a structural design method with similar functions and mechanical characteristics to the original organism. This method is expected to obtain a lightweight structure with excellent comprehensive mechanical properties and unique functions, thereby meeting the lightweight demand. Caiazzo et al. used selective laser melting (SLM) manufacturing technology to produce a foam bionic porous structure, which reduced its volume by 68%; with the development of parametric design technology and advanced manufacturing technology, cellular structures with strong designability and versatility have been rapidly developed and applied. Based on the additive manufacturing process, Zhu Xiaodong used a spatial lattice structure to achieve the lightweight design of the shock absorber strut. The maximum stress of the shock absorber strut decreased by 16.67%, and the mass of the shock absorber strut decreased by 18%. Xiao Zefeng used SLM technology to design a lightweight grid structure for intervertebral fusion cage based on stress distribution, which reduced the maximum von Mises stress by 12.5%; Jia et al. used SLM280 selective laser powder melting metal 3D printer to print a grid compressor impeller, which was reduced by 20.19% from the original 195.3g to 149.4g, and the maximum residual stress was reduced by 8.72%. Topological optimization is a mathematical method that optimizes the material distribution in a given area according to given load conditions, constraints and performance indicators. It is one of the current mainstream structural lightweight technologies. Lin Wanchun et al. designed an automobile bearing support with a weight reduction of 53.89% through two lightweight methods for additive manufacturing, topological optimization and lattice filling.

[0004] In terms of lightweight material design, with the high requirements for lightweight, the performance of traditional single-material parts cannot meet the stringent service environment requirements of complex components. The emergence of heterogeneous components provides an opportunity to solve this problem. The large cross-application of titanium alloys, high-temperature nickel-based alloys, aluminum alloys and iron-based alloys, which are commonly used materials in the aerospace field, connect multiple materials with high performance to achieve multifunctional intelligent devices with shape memory properties and excellent mechanical properties. They are ideal materials for future spacecraft. However, the large differences in thermophysical properties between materials and the formation of brittle intermetallic compounds (IMCs) make it difficult for the comprehensive performance of heterogeneous connection materials to meet the actual application requirements. Xie Yong proposed a transition layer design idea to form a solid solution at the steel-aluminum interface, which improved the problem of the presence of a metal compound layer at the heterogeneous interface, thereby reducing the bonding strength; Xia Shaochou successfully prepared a 316-FeCrCuV-TC4 heterogeneous interface component with a connection strength of 253MPa using a FeCrCuV high-entropy alloy transition layer; Wang Jiandong improved the strength and plasticity of TiC / Ti6Al4V gradient composites with increasing TiC particle volume fractions of 0-50% by preparing in-situ TiC reinforced Ti6Al4V composites and heat treatment methods.

[0005] The above-mentioned multi-material systems processed by AM are all layered structures, that is, heterogeneous structures with properties only along one direction. The processing methods and design motivations behind these layered heterogeneous structures may be limited by the layer-by-layer deposition characteristics of the AM process. For this reason, Zhang Tianchi et al. used laser-assisted 3D printing (LAAM) to deposit two metal materials into one part to form a spatial heterogeneous structure material (SHM) with a configurable structure, but the layered structure between different materials is still very obvious; Tan et al. used laser-assisted 3D printing (LAAM) to deposit two metal materials into one part to form a spatial heterogeneous structure material with a configurable structure with a yield strength YS value (1090MPa) much higher than that of the constitutive material. Xingran Li et al. adjusted the volume fractions of the two constitutive materials by adopting different material distribution patterns to achieve a heterogeneous structure material BHM with multi-scale periodic soft-hard-soft stratification; Li et al. proposed a bionic mechanical interlocking structure strategy of stainless steel 316L and Inconel625, which expanded the crack propagation path and avoided the premature damage of the weak interface layer. These methods make the parts have relatively balanced mechanical properties in all directions. However, the interface between different materials still relies on the "viscosity" generated when the two materials are combined to interact with each other, presenting a "clear distinction" state, which places strict requirements on the control of materials and processes in the additive manufacturing process. However, most of the additive manufacturing equipment currently used in production on the market cannot meet these conditions, so the method of achieving lightweight through multiple materials is difficult to apply on a large scale, and it is urgent to solve the new problems it faces through technological innovation.

[0006] Judging from the development trend of heterogeneous material interface bonding methods, in addition to the requirements for the bonding strength of the materials themselves, more and more studies are beginning to seek to improve the strength of heterogeneous materials through structural means. However, in existing research, the form of the bonding surface is mostly "linear". This may be affected by the inertia of a single material in additive manufacturing. In the case where cracks are very likely to appear on the bonding surface of heterogeneous materials, linear transition is actually a disadvantage.

[0007] Therefore, how to improve the interface bonding strength of heterogeneous materials has become a topic that needs further research. Summary of the invention

[0008] An embodiment of the present invention provides a method for realizing lightweight additive manufacturing of components, which can improve the interface bonding strength of heterogeneous materials.

[0009] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0010] S1. Establish a model of the component to be processed, and perform topological optimization on the component model, wherein the topological optimization target is to lightweight the component model, and the optimized component model includes a lightweight structure; wherein, the topological optimization structure in the traditional structural lightweight design is relatively complex and not conducive to printing and forming, so it is replaced with a lightweight material, and other areas with less stress can also be replaced with lightweight materials. At the same time, the structural stress concentration area is replaced with a high-performance material to reduce the amount of ordinary materials, and the lightweight design of the component is achieved while meeting or improving the performance. The lightweight structure in this embodiment is a topological optimization structure, such as a suspended structure.

[0011] S2. replacing the area with the lightweight structure in the component model with a lightweight material filled area, wherein the lightweight material filled area covers the area with the lightweight structure;

[0012] S3. Adding a mortise and tenon interlocking structure at the interface of heterogeneous materials, wherein the protruding portion formed by the lightweight material in the mortise and tenon interlocking structure penetrates into the recessed portion of the main material.

[0013] S4. Perform forming experiments on the model of the component to be processed after being processed in S3, and test its performance.

[0014] S5. If the performance test in S4 is passed, prepare the sample and test the performance again.

[0015] Among them, S3 includes: printing the mortise and tenon interlocking structure by a tower printing method, including: selecting one of the lightweight material and the main material as material No. 1, and printing the first part of the material No. 1 of the mortise and tenon interlocking structure in a manner of reducing the printing area layer by layer from bottom to top, and the edge of the first part of the material No. 1 forms a slope; selecting a material different from the material No. 1 from the lightweight material and the main material as material No. 2, and printing the first part of the material No. 2 of the mortise and tenon interlocking structure, wherein the printed first part of the material No. 2 covers the slope formed by the edge of the first part of the material No. 1; printing the second part of the material No. 2 of the mortise and tenon interlocking structure in a manner of reducing the printing area layer by layer from bottom to top, and the edge of the second part of the material No. 2 forms a slope; printing the second part of the material No. 1 of the mortise and tenon interlocking structure, wherein the printed second part of the material No. 1 covers the slope formed by the edge of the second part of the material No. 2.

[0016] The process of detecting the performance in S4 includes: detecting the bonding strength at the heterogeneous material interface between the lightweight material and the main material by a tensile test; if at least one metal material is used in the lightweight material and the main material, it also includes: analyzing the properties of the metal bonding layer at the heterogeneous material interface by an electron microscope;

[0017] The process of detecting performance in S5 includes: detecting the bonding strength at the heterogeneous material interface between the lightweight material and the main material through a tensile test; and comparing the printed components in the area where the lightweight structure exists with the original components in the area where the lightweight structure does not exist, and recording the comparison results, which include: the quality and strength data of the two.

[0018] Furthermore, a material combination includes a main material and a lightweight material for making a component, and the density of the main material is greater than that of the lightweight material; the material combination includes: an iron-based alloy as the main material and a titanium alloy as the lightweight material; or, the material combination includes: a nickel-based alloy as the main material and an iron-based alloy as the lightweight material; or, the material combination includes: a titanium alloy as the main material and an aluminum alloy or a magnesium alloy as the lightweight material.

[0019] A metal bonding layer is added at the interface of the heterogeneous materials, and the metal bonding layer presents a non-straight line in the cross section of the model of the component to be processed. The mortise and tenon interlocking structure includes: a dovetail joint structure and a pentagonal structure. When the component is made of at least three materials, two of the materials form a material combination, one material in a material combination is used as a lightweight material, and the other material is used as a main material.

[0020] The method for realizing lightweight additive manufacturing of components provided by an embodiment of the present invention addresses the problem of strength difference at the interface of heterogeneous materials in a lightweight material model, and adopts a mortise and tenon interlocking structure so that the bonding surfaces of the two materials can maintain their bonding with the help of the force of the structure when receiving other forces, thereby improving the bonding strength of the interface of the heterogeneous materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. 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 creative work.

[0022] Figure 1 A schematic diagram of a method flow chart provided by an embodiment of the present invention;

[0023] Figure 2 to Figure 7 A schematic diagram of a specific example provided for an embodiment of the present invention;

[0024] Figure 8 It is a schematic diagram of the stress condition in the prior art;

[0025] Figure 9-10 A schematic diagram of another specific example provided for an embodiment of the present invention DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention will be described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention. It can be understood by those skilled in the art that, unless specifically stated, the singular forms "one", "one", "said" and "the" used herein may also include plural forms. It should be further understood that the term "including" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or their groups. It should be understood that when we say that an element is "connected" or "coupled" to another element, it can be directly connected or coupled to other elements, or there may also be intermediate elements. In addition, the "connection" or "coupling" used here may include wireless connection or coupling. The term "and / or" used herein includes any unit and all combinations of one or more associated listed items. It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as generally understood by those of ordinary skill in the art to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0027] The embodiment of the present invention provides a method for realizing lightweight additive manufacturing of components, such as Figure 1 As shown, including:

[0028] S1. Establish a model of the component to be processed and perform topological optimization on the component model.

[0029] Among them, the topology optimization optimization goal is to lightweight the model of the component, and the model of the optimized component includes a lightweight structure. Construct a new lightweight component strategy for multiple materials. Specifically, in the topology optimization component stage, when the optimization process removes materials and causes the model to have an overhang or cantilever structure that is difficult to process in additive manufacturing, the lightweight component can be made easier to manufacture by filling it with lightweight materials. The original component can be topologically optimized using the INSPIRE software. For example, the optimization direction is set in the INSPIRE software to maximize the stiffness constraint, the mass is 30% before optimization, and then the optimized model is slightly adjusted, and the final model is imported into NX. In practical applications, there are mainly suspended structures and lattice structures (including lattice structures) to achieve lightweight components. In this embodiment, the problem of heterogeneous material interface bonding strength of suspended structures in additive manufacturing is improved. A part of the entity of the optimized component is replaced with a lightweight material, and the goal of weight reduction can be achieved without using a complex lattice structure.

[0030] S2. Replace the area with lightweight structure in the component model with the area filled with lightweight material.

[0031] The lightweight material filling area covers the lightweight structure area.

[0032] S3. Add mortise and tenon interlocking structure at the interface of heterogeneous materials.

[0033] Among them, after topological optimization, a mortise and tenon interlocking structure is used at the joint of the two materials, for example Figure 2 As shown, in the mortise and tenon interlocking structure, the protruding part made of lightweight material penetrates into the concave part of the main material, and a part of the entity of the optimized component is replaced with lightweight material, so that the goal of weight reduction can be achieved without using a complex lattice structure. There are more than one mortise and tenon interlocking structure. In this embodiment, at least two mortise and tenon interlocking structures are designed, including: Figure 6 The dovetail joint structure shown and Fig. 9 The pentagonal structure shown.

[0034] S4. Perform forming experiments on the model of the component to be processed after the processing in S3, and test the performance. Among them, the tensile test determines the bonding strength, and the electron microscope further analyzes the properties of the metal bonding layer.

[0035] Specifically, the process of detecting the performance in S4 includes: detecting the bonding strength at the heterogeneous material interface between the lightweight material and the main material by a tensile test; if at least one metal material is used in the lightweight material and the main material, it also includes: analyzing the properties of the metal bonding layer at the heterogeneous material interface by an electron microscope;

[0036] S5. If the performance test in S4 is passed, prepare the sample and test the performance again.

[0037] Specifically, the process of detecting performance in S5 includes: detecting the bonding strength at the heterogeneous material interface between the lightweight material and the main material through a tensile test; and comparing the printed components in the area where the lightweight structure exists with the original components in the area where the lightweight structure does not exist, and recording the comparison results, which include: the quality and strength data of the two.

[0038] In summary, in S3, the mortise and tenon interlocking structure is printed by a tower printing method, including:

[0039] Select one of the lightweight material and the main material as material No. 1, and print the first part of the material No. 1 of the mortise and tenon interlocking structure in a manner of reducing the printing area layer by layer from bottom to top, and the edge of the first part of the material No. 1 forms a slope; select a material different from the material No. 1 from the lightweight material and the main material as material No. 2, and print the first part of the material No. 2 of the mortise and tenon interlocking structure, wherein the printed first part of the material No. 2 covers the slope formed by the edge of the first part of the material No. 1; print the second part of the material No. 2 of the mortise and tenon interlocking structure in a manner of reducing the printing area layer by layer from bottom to top, and the edge of the second part of the material No. 2 forms a slope; print the second part of the material No. 1 of the mortise and tenon interlocking structure, wherein the printed second part of the material No. 1 covers the slope formed by the edge of the second part of the material No. 2. For example Figure 3-5 As shown, a slope is formed in the printing layer by adopting the method of large base and small top and gradually reducing it layer by layer, so the next material can be printed upward along the slope to avoid the obstacle effect. At the same time, the number of times the material needs to be switched is greatly reduced. In addition, this printing method also allows the bonding interface of the structure in the z-axis direction to break away from the linear bonding state, thereby improving the mechanical properties in the z-axis direction.

[0040] Furthermore, a material combination includes a main material and a lightweight material for making a component, and the density of the main material is greater than that of the lightweight material; the material combination includes: an iron-based alloy as the main material and a titanium alloy as the lightweight material; or, the material combination includes: a nickel-based alloy as the main material and an iron-based alloy as the lightweight material; or, the material combination includes: a titanium alloy as the main material and an aluminum alloy or a magnesium alloy as the lightweight material.

[0041] A metal bonding layer is added at the interface of the heterogeneous materials, and the metal bonding layer presents a non-straight line in the cross section of the model of the component to be processed. The mortise and tenon interlocking structure includes: a dovetail joint structure and a pentagonal structure.

[0042] A metal bonding layer is added at the interface of the heterogeneous materials, and the metal bonding layer presents a non-straight line in the cross section of the model of the component to be processed. Figure 6 As shown in the figure, the problem of poor strength at the interface of heterogeneous materials in the multi-material lightweight model is dealt with by adopting a mortise and tenon interlocking structure so that the joint surface of the two materials can maintain its own joint with the help of the force of the structure when receiving other forces. The specific printing process can be as follows Figure 7 As shown. Figure 8 The currently existing straight heterogeneous material interface shown in this embodiment has better mechanical properties in the vertical direction and is more resistant to pulling.

[0043] Further, such as Fig.10 As shown, in some cases, the component can be made of multiple materials, such as at least 3 materials. Two of the materials form a material combination, one material in the material combination is used as a lightweight material, and the other material is used as a main material.

[0044] Modern aerospace components need to meet a series of stringent requirements such as lightweight, high performance, high reliability, and low cost at the same time, and the structure of the components is more complex and the design and manufacturing are more difficult. By studying the lightweight method of nonlinear heterogeneous heterogeneous interface additive manufacturing components, it not only reflects the development direction of lightweight and high performance in material selection, but also highlights the development trend of precision and net forming of additive manufacturing technology itself, which can realize the integrated additive manufacturing of materials, structure, and performance and the major engineering applications of additive manufacturing technology in aerospace. Heterogeneous material design combines components of different materials together to form an overall structure. Through the study of lightweight methods of nonlinear heterogeneous heterogeneous interface additive manufacturing components, the overall performance of the structure can be improved, the range of material selection can be broadened, and the integrated manufacturing process of automotive batteries will be further promoted. In short, improving the interface bonding strength of heterogeneous materials has significant application value for lightweight design, which can promote technological progress in the engineering field, realize sustainable utilization of resources, and provide more competitive product solutions for various industries. In this embodiment, the spatial interface interlocking strategy can be used to combine heterogeneous materials in a nonlinear form to achieve lightweight design, which can reduce the weight of the product, improve energy efficiency, and reduce resource consumption and environmental pollution. In addition, the problem of poor strength at the interface of heterogeneous materials in the material lightweight model is dealt with by adopting a mortise and tenon interlocking structure so that the bonding surfaces of the two materials can maintain their own bonding with the help of the force of the structure when receiving other forces, thereby improving the bonding strength of the heterogeneous material interface.

[0045] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The above is only a specific implementation method of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for realizing lightweight additive manufacturing of components, characterized in that: include: S1. Establish a model of a component to be processed, and perform topological optimization on the component model, wherein the topological optimization aims to lightweight the component model, and the optimized component model includes a lightweight structure, and the type of the lightweight structure includes: a topological optimization structure; S2. replacing the area with the lightweight structure in the component model with a lightweight material filled area, wherein the lightweight material filled area covers the area with the lightweight structure; S3. Adding a mortise and tenon interlocking structure at the interface of heterogeneous materials, wherein the protruding portion formed by the lightweight material in the mortise and tenon interlocking structure penetrates into the recessed portion of the main material, or, the protruding portion formed by the main material in the mortise and tenon interlocking structure penetrates into the recessed portion formed by the lightweight material.

2. The method according to claim 1, characterized in that S3 includes: printing the mortise and tenon interlocking structure by a tower printing method, including: Select one of the lightweight material and the main material as the first material, and print the first part of the first material of the mortise and tenon interlocking structure in a manner of gradually reducing the printing area from bottom to top, wherein the edge of the first part of the first material forms a slope; Select a material different from the first material from the lightweight material and the main body material as the second material, and print the first part of the second material of the mortise and tenon interlocking structure, wherein the printed first part of the second material covers the slope formed by the edge of the first part of the first material; Printing the second part of the second material of the mortise and tenon interlocking structure in a manner of gradually reducing the printing area from bottom to top, wherein the edge of the second part of the second material forms a slope; The second part of the first material of the mortise and tenon interlocking structure is printed, wherein the printed second part of the first material covers the slope formed by the edge of the second part of the second material.

3. The method according to claim 1 or 2, characterized in that: Also includes: S4. Perform forming experiments on the model of the component to be processed after being processed in S3, and test its performance.

4. The method according to claim 3, characterized in that Also includes: S5. If the performance test in S4 is passed, prepare the sample and test the performance again.

5. The method according to claim 3, characterized in that: The process of detecting performance in S4 includes: The bonding strength at the heterogeneous material interface between the lightweight material and the main material is detected by a tensile test; if at least one metal material is used in the lightweight material and the main material, it also includes: analyzing the properties of the metal bonding layer at the heterogeneous material interface by an electron microscope.

6. The method according to claim 4, characterized in that The process of detecting performance in S5 includes: detecting the bonding strength at the heterogeneous material interface between the lightweight material and the main material through a tensile test; and comparing the printed components in the area where the lightweight structure exists with the original components in the area where the lightweight structure does not exist, and recording the comparison results, which include: the quality and strength data of the two.

7. The method according to claim 3, characterized in that A material combination includes a main material and a lightweight material for making a component, and the density of the main material is greater than that of the lightweight material; The material combination includes: an iron-based alloy as a main material and a titanium alloy as a lightweight material; Alternatively, the material combination includes: a nickel-based alloy as a main material and an iron-based alloy as a lightweight material; Alternatively, the material combination includes: a titanium alloy as a main material, and an aluminum alloy or a magnesium alloy as a lightweight material.

8. The method according to claim 7, characterized in that Also includes: A metal bonding layer is added at the interface of the heterogeneous materials, and the metal bonding layer presents a non-straight line in the cross section of the model of the component to be processed.

9. The method according to claim 1, characterized in that: The mortise and tenon interlocking structure includes: a dovetail joint structure and a pentagonal structure.

10. The method according to claim 7, characterized in that When a component is made of at least three materials, two of them form a material combination, one material in a material combination is used as a lightweight material, and the other material is used as a main material.

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