Additive manufacturing method of high specific energy absorption eutectic high-entropy alloy curved lattice structure

Abstract

The application provides a high specific energy absorption eutectic high-entropy alloy curved surface lattice structure additive manufacturing method, which comprises the following steps: preparing eutectic high-entropy alloy powder material to be added into a laser powder bed fusion printer, and filling inert gas as a protective gas in the printer; designing a sheet-shaped TPMS lattice structure, deriving a slice file, and then importing the slice file into the laser powder bed fusion printer; starting printing the TPMS lattice structure; after printing is completed, cutting the TPMS lattice structure from a substrate by using a wire cutting machine to obtain the eutectic high-entropy alloy curved surface lattice structure. The laser powder bed fusion formed eutectic high-entropy alloy sheet-shaped TPMS lattice structure obtained by the application first applies the eutectic high-entropy alloy material to a lattice structure energy absorption scene, and combines the energy absorption advantages of materials, structures and processes, and the specific energy absorption of the eutectic high-entropy alloy lattice structure is about 50% higher than that of a traditional stainless steel lattice structure.

Description

Technical Field

[0001] This invention relates to the field of metal additive manufacturing (3D printing) technology, specifically to a method for obtaining a high specific energy absorption curved lattice structure by combining the advantages of materials, structure and process. Background Technology

[0002] High-entropy alloys are a new type of alloy containing five or more main elements. In 2014, Lu Yiping et al. first proposed the concept of eutectic high-entropy alloys and successfully cast the AlCoCrFeNi2.1 eutectic high-entropy alloy. The eutectic structure of this alloy consists of mutually stacked ordered and high-strength BCC phases and ordered and high-toughness FCC phases. It exhibits an unprecedented combination of high tensile plasticity and high fracture strength at room temperature, and also shows extraordinary strain hardening ability, making it advantageous in energy absorption applications.

[0003] The sheet-like three-period minimal surface (TPMS) lattice structure is a type of porous structure. TPMS is a periodic implicit surface with zero mean curvature. Compared with other structures, the surface of the TPMS structure is very smooth, without sharp edges or connection points like other lattice structures. Therefore, the TPMS lattice structure does not have stress concentration areas, and its energy absorption performance is also superior to other lattice structures.

[0004] Additive manufacturing (ADM) technology can be defined as the process of connecting materials layer by layer using a three-dimensional model to form complex structures. This technology allows us to create countless possibilities in a free-designed manner. Scientists have used various matrix materials such as polymers, metals, ceramics, and composite materials to prepare a large number of novel energy-absorbing materials and structures with complex topologies using ADM technology. Among them, laser powder bed melting (LPBF) technology has the advantages of high resolution and minimal layer thickness, making it an ideal technology for manufacturing metal lattices. In addition, compared with other ADM technologies, LPBF technology has the highest temperature gradient and cooling rate during the manufacturing process, which results in parts with refined microstructure and fine interlayer spacing, greatly improving mechanical properties. Currently, in the field of additive manufacturing, stainless steel is the main material used for energy absorption in lattice structures. However, due to the limited yield strength and plasticity of stainless steel, it is difficult to achieve high energy absorption during its deformation process, making it difficult to meet the increasingly demanding application environments of ADM parts. Summary of the Invention

[0005] To address the above problems, this invention provides an additive manufacturing method for curved lattice structures of high specific energy absorption eutectic high entropy alloys. This method can improve the energy absorption capacity per unit mass (specific energy absorption) of the lattice structure, which is beneficial for the energy-absorbing structure to have excellent energy absorption performance while being lightweight.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] An additive manufacturing method for a high-specific-energy-absorbing eutectic high-entropy alloy curved lattice structure includes the following steps:

[0008] Prepare eutectic high-entropy alloy powder material and add it to the laser powder bed fusion printer. Fill the printer with inert gas as a protective gas. Design a sheet-like TPMS lattice structure, export it as a slice file, and then import it into the laser powder bed fusion printer. Start printing the TPMS lattice structure. After printing, use wire cutting to cut the TPMS lattice structure from the substrate to obtain the eutectic high-entropy alloy curved lattice structure.

[0009] Furthermore, the eutectic high-entropy alloy powder is AlCoCrFeNi2.1 high-entropy alloy powder.

[0010] Furthermore, the high-entropy alloy is prepared using powder metallurgy.

[0011] Furthermore, the powder particle size of the high-entropy alloy is 15-53 μm.

[0012] Furthermore, the mass composition of the high-entropy alloy is as follows: Al 8%-9%, Co 17%-19%, Cr 15%-17%, Fe 16%-18%, Ni 39%-41%.

[0013] Furthermore, the sheet-like TPMS lattice structure is a Gyriod lattice structure, designed using the C-level set method. The mathematical surface description formula for the Gyriod lattice structure is as follows:

[0014] ΦG=sinXcosY+sinYcosZ+sinZcosX=±C

[0015] Where X = 2πx, Y = 2πy, Z = 2πz, x, y, z are spatial coordinates, C is a constant, and the relationship between C and the relative density ρ of the lattice structure is ρ = 0.65C.

[0016] Furthermore, the sheet-like TPMS lattice structure has a size of 30mm×30mm×30mm, a unit cell size of 6mm×6mm×6mm, and a relative density of 30% or 35% or 40% or 45%.

[0017] Furthermore, in the laser powder bed melting process, a laser power of 200W, a scanning speed of 600mm / s, a scanning spacing of 100μm, and a powder layer thickness of 40μm were used.

[0018] A eutectic high-entropy alloy curved lattice structure is prepared by the above method.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] The layered TPMS lattice structure prepared by the present invention from eutectic high-entropy alloy powder using laser powder bed melting technology has the following advantages:

[0021] (1) The eutectic high-entropy alloy curved lattice structure of the present invention has a unique FCC / BCC dual-phase nanosheet structure, dislocation strengthening mechanism and solid solution strengthening mechanism, which gives the substrate a balance of high yield strength and high ductility. Its energy absorption performance per unit mass is about 50% higher than that of the stainless steel lattice structure in the literature.

[0022] (2) The sheet-like TPMS lattice structure formed by laser powder bed melting of eutectic high-entropy alloy obtained by the present invention can be applied to passive energy absorption devices in various fields to protect human safety and machine parts. In the aerospace field, such as space landers; in the automotive field, such as energy absorption boxes; in the military field, such as ejection seats, etc. Attached Figure Description

[0023] Figure 1 This is a flowchart illustrating the implementation of the present invention.

[0024] Figure 2 a) is the surface plot generated by the mathematical description formula of the Gyroid three-period minimal surface; b) is the lattice structure unit cell plot obtained by thickening the surface.

[0025] Figure 3 a) shows the 3D model of the TPMS lattice structure with relative densities of 30%, 35%, 40%, and 45%, respectively, and is numbered G30, G35, G40, and G45; b) shows the corresponding TPMS lattice structure solid model printed by laser powder bed melting process.

[0026] Figure 4 Force-displacement curves are obtained after quasi-static compression of TPMS lattice structures with relative densities of 30%, 35%, 40%, and 45%.

[0027] Figure 5 This is a comparison of the specific energy absorption (SEA) per unit mass of the G30, G35, G40, and G45 eutectic high-entropy alloy sheet-like TPMS lattice structures with the performance of lattice structures in the literature. Detailed Implementation

[0028] The present invention will be further described in detail below through embodiments, but it should not be construed as limiting the scope of the present invention to the following embodiments. All technologies implemented based on the above content of the present invention fall within the scope of the present invention.

[0029] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, and the reagents, methods and equipment used are conventional reagents, methods and equipment in this technical field.

[0030] Combination Figure 1 This invention provides an additive manufacturing method for a high-specific-energy-absorbing eutectic high-entropy alloy curved lattice structure, comprising the following steps:

[0031] A lattice structure with a unit cell type of Gyroid, a unit cell size of 6mm×6mm×6mm, and a cell number of 5×5×5 was designed using MSLattice software, and the relative densities of the lattice structure were designed to be 30%, 35%, 40%, or 45%. The model file was arranged and sliced, and then the sliced ​​file was imported into a laser powder bed fusion printer. Argon gas was filled into the printer as a protective gas. Eutectic high-entropy alloy powder was added to the printer. The high-entropy alloy is AlCoCrFeNi2.1; its mass composition is: Al 8%-9%, Co 17%-19%, Cr 15%-17%, Fe 16%-18%, and Ni 39%-41%. A eutectic high-entropy alloy TPMS lattice structure is printed using a printer with the following parameters: laser power 200W, scanning speed 600mm / s, scanning spacing 100μm, and powder layer thickness 40μm. The lattice structure is a Gyriod lattice structure, designed using the C-level set method. The mathematical surface description formula for the Gyriod lattice structure is:

[0032] ΦG=sinXcosY+sinYcosZ+sinZcosX=±C

[0033] Where X = 2πx, Y = 2πy, Z = 2πz, x, y, z are spatial coordinates, C is a constant, and the relationship between C and the relative density ρ of the lattice structure is ρ = 0.65C.

[0034] The present invention will be further described in detail below with reference to specific embodiments:

[0035] Example 1

[0036] This invention provides an additive manufacturing method for a high-specific-energy-absorbing eutectic high-entropy alloy curved lattice structure, resulting in a high-specific-energy-absorbing eutectic high-entropy alloy TPMS lattice structure. The steps are as follows:

[0037] Step 1: Design a TPMS lattice structure with a relative density of 30% and name it G30. Import the slice file into the laser powder bed fusion printer, specifically including the following steps:

[0038] S1, the TPMS lattice structure design software is MSLattice, the overall size of the lattice structure is 30mm×30mm×30mm, the unit cell size is 6mm×6mm×6mm, and the lattice type is Gyroid.

[0039] S2. The software for arranging and slicing parts is Materialise Magics.

[0040] Step 2 involves laser powder bed melting to form a eutectic high-entropy alloy TPMS lattice structure. The material is AlCoCrFeNi2.1 eutectic high-entropy alloy powder, and the specific steps include:

[0041] S1. The equipment used for laser powder bed fusion printing is the Concept Laser M2 device, with the laser power set to 200W, scanning speed to 600mm / s, scanning spacing to 100μm, powder layer thickness to 40μm, and scanning strategy to rotate 90° between layers.

[0042] S2. Add eutectic high-entropy alloy powder to a laser powder bed fusion printer, fill with inert argon gas as a protective gas, and then print a dot matrix structure.

[0043] S3. After printing, the powder is cleaned, the component is removed from the substrate by wire cutting, and ultrasonic vibration is performed under alcohol conditions to clean the surface of the part, resulting in a eutectic high-entropy alloy TPMS lattice structure. Preliminary observation shows that the printed entity does not exhibit macroscopic cracking, and the forming effect is good.

[0044] Quasi-static compression tests were performed on the lattice structure using a compression testing machine. Force-displacement curves were obtained, and the specific energy absorption was calculated. The specific steps included:

[0045] S1. The compression testing machine used is a Sansi integrated compression and flexural testing machine, model UTM7305, with a maximum test force of 300kN. The quasi-static compression rate is 0.1mm / s.

[0046] S2, the formula for calculating specific energy absorption is: (F is force, δ is displacement, and m is mass).

[0047] This invention also protects the eutectic high-entropy alloy TPMS lattice structure manufactured by the above-described manufacturing process.

[0048] Gyroid's three-period minimal surface, such as Figure 2As shown in a), the Gyroid surface is thickened to obtain the Gyroid lattice unit cell, as shown in a). Figure 2 (b) TPMS lattice structure 3D model and printed solid part, such as Figure 3 As shown in a) and b) of the figure. The force-displacement curves obtained from quasi-static compression are as follows. Figure 4 As shown, the G30 lattice structure has a long and gentle energy absorption plateau, which is attributed to the strong and tough balance characteristics brought by the unique FCC / BCC eutectic structure of the eutectic high-entropy alloy and the structural characteristics of TPMS plane with 0 average curvature. It is also attributed to the grain refinement and reduction of interlamellar spacing brought about by the rapid cooling-solidification process of laser powder bed melting, thereby improving the mechanical properties of the lattice structure.

[0049] This invention achieves a high-specific-energy-absorbing, high-entropy alloy curved lattice structure by combining the advantages of materials, structure, and process, such as... Figure 5 The figure shows a comparison of the specific energy absorption of the stainless steel lattice in this invention with that in the literature. A quasi-static compression test was conducted on this embodiment according to the national standard GB / T 31930-2015 "Metallic Materials - Ductility Tests - Compression Tests of Porous and Honeycomb Metals", and the data was processed to obtain a specific energy absorption of 25 J / g for the G30 embodiment. Under similar relative density conditions, the specific energy absorption is comparable to the research results of ALMAHRI S et al. (Additive Manufacturing, 2021, 46:102220) (i.e....). Figure 5 Compared to SS316L[1], it improved by about 47%. This is in line with the research results of NOVAK N et al. (Composite Structures, 2021, 266:113801). Figure 5 Compared to 316L[2], it increased by about 127%.

[0050] Example 2

[0051] This invention provides an additive manufacturing method for a high-specific-energy-absorbing eutectic high-entropy alloy curved lattice structure, resulting in a high-specific-energy-absorbing eutectic high-entropy alloy TPMS lattice structure. The steps are as follows:

[0052] Step 1: Design a TPMS lattice structure with a relative density of 35% and name it G35. Import the slice file into the laser powder bed fusion printer, specifically including the following steps:

[0053] S1, the TPMS lattice structure design software is MSLattice, the overall size of the lattice structure is 30mm×30mm×30mm, the unit cell size is 6mm×6mm×6mm, and the lattice type is Gyroid.

[0054] S2. The software for arranging and slicing parts is Materialise Magics.

[0055] Step 2 involves laser powder bed melting to form a eutectic high-entropy alloy TPMS lattice structure. The material is AlCoCrFeNi2.1 eutectic high-entropy alloy powder, and the specific steps include:

[0056] S1. The equipment used for laser powder bed fusion printing is the Concept Laser M2 device, with the laser power set to 200W, scanning speed to 600mm / s, scanning spacing to 100μm, powder layer thickness to 40μm, and scanning strategy to rotate 90° between layers.

[0057] S2. Add eutectic high-entropy alloy powder to a laser powder bed fusion printer, fill with inert argon gas as a protective gas, and then print a dot matrix structure.

[0058] S3. After printing, the powder is cleaned, the component is removed from the substrate by wire cutting, and ultrasonic vibration is performed under alcohol conditions to clean the surface of the part, resulting in a eutectic high-entropy alloy TPMS lattice structure. Observation shows that the printed entity does not exhibit macroscopic cracking, and the forming effect is good.

[0059] Quasi-static compression tests were conducted on the lattice structure using a compression testing machine. Force-displacement curves were obtained, and the specific energy absorption index was calculated.

[0060] S1. The compression testing machine used is a Sansi integrated compression and flexural testing machine, model UTM7305, with a maximum test force of 300kN. The quasi-static compression rate is 0.1mm / s.

[0061] S2, the formula for calculating specific energy absorption is: (F is force, δ is displacement, and m is mass).

[0062] This invention also protects the eutectic high-entropy alloy TPMS lattice structure manufactured by the above-described manufacturing process.

[0063] A quasi-static compression experiment was conducted on this embodiment, and the data processing yielded a specific energy absorption of 27.5 J / g for the G35 embodiment. Under conditions of similar relative density, this specific energy absorption is consistent with the research results of ALMAHRI S et al. (Additive Manufacturing, 2021, 46:102220). Figure 5 Compared to SS316L[1], it is improved by about 45%. This is in line with the research results of LI X et al. (Additive Manufacturing, 2021, 46:102054) (i.e. Figure 5 Compared to 316L[3]), it increased by about 10%.

[0064] Example 3

[0065] This invention provides an additive manufacturing method for a high-specific-energy-absorbing eutectic high-entropy alloy curved lattice structure, resulting in a high-specific-energy-absorbing eutectic high-entropy alloy TPMS lattice structure. The steps are as follows:

[0066] Step 1: Design a TPMS lattice structure with a relative density of 40% and name it G40. Import the slice file into the laser powder bed fusion printer, specifically including the following steps:

[0067] S1, the TPMS lattice structure design software is MSLattice, the overall size of the lattice structure is 30mm×30mm×30mm, the unit cell size is 6mm×6mm×6mm, and the lattice type is Gyroid.

[0068] S2. The software for arranging and slicing parts is Materialise Magics.

[0069] Step 2 involves laser powder bed melting to form a eutectic high-entropy alloy TPMS lattice structure. The material is AlCoCrFeNi2.1 eutectic high-entropy alloy powder, and the specific steps include:

[0070] S1. The equipment used for laser powder bed fusion printing is the Concept Laser M2 device, with the laser power set to 200W, scanning speed to 600mm / s, scanning spacing to 100μm, powder layer thickness to 40μm, and scanning strategy to rotate 90° between layers.

[0071] S2. Add eutectic high-entropy alloy powder to a laser powder bed fusion printer, fill with inert argon gas as a protective gas, and then print a dot matrix structure.

[0072] S3. After printing, the powder is cleaned, the component is removed from the substrate by wire cutting, and ultrasonic vibration is performed under alcohol conditions to clean the surface of the part, resulting in a eutectic high-entropy alloy TPMS lattice structure. Observation shows that the printed entity does not exhibit macroscopic cracking, and the forming effect is good.

[0073] Quasi-static compression tests were conducted on the lattice structure using a compression testing machine. Force-displacement curves were obtained, and the specific energy absorption index was calculated.

[0074] S1. The compression testing machine used is a Sansi integrated compression and flexural testing machine, model UTM7305, with a maximum test force of 300kN. The quasi-static compression rate is 0.1mm / s.

[0075] S2, the formula for calculating specific energy absorption is: (F is force, δ is displacement, and m is mass).

[0076] This invention also protects the eutectic high-entropy alloy TPMS lattice structure manufactured by the above-described manufacturing process.

[0077] A quasi-static compression experiment was conducted on this embodiment, and the data processing yielded a unit mass energy absorption of 32.5 J / g for the G40 embodiment. Under conditions of similar relative density, the specific energy absorption is consistent with the research results of ALMAHRI S et al. (Additive Manufacturing, 2021, 46:102220). Figure 5 Compared to SS316L[1], it is about 55% higher.

[0078] Example 4

[0079] This invention provides an additive manufacturing method for a high-specific-energy-absorbing eutectic high-entropy alloy curved lattice structure, obtaining a high-specific-energy-absorbing eutectic high-entropy alloy TPMS lattice structure. The steps are as follows:

[0080] Step 1: Design a TPMS lattice structure with a relative density of 45% and name it G45. Import the slice file into the laser powder bed fusion printer, specifically including the following steps:

[0081] S1, the TPMS lattice structure design software is MSLattice, the overall size of the lattice structure is 30mm×30mm×30mm, the unit cell size is 6mm×6mm×6mm, and the lattice type is Gyroid.

[0082] S2. The software used to arrange and slice the parts is Materialise Magics.

[0083] Step 2 involves laser powder bed melting to form a eutectic high-entropy alloy TPMS lattice structure. The material is AlCoCrFeNi2.1 eutectic high-entropy alloy powder, and the specific steps include:

[0084] S1. The equipment used for laser powder bed fusion printing is the Concept Laser M2 device, with the laser power set to 200W, scanning speed to 600mm / s, scanning spacing to 100μm, powder layer thickness to 40μm, and scanning strategy to rotate 90° between layers.

[0085] S2. Add eutectic high-entropy alloy powder to a laser powder bed fusion printer, fill with inert argon gas as a protective gas, and then print a dot matrix structure.

[0086] S3. After printing, the powder is cleaned, the component is removed from the substrate by wire cutting, and ultrasonic vibration is performed under alcohol conditions to clean the surface of the part, resulting in a eutectic high-entropy alloy TPMS lattice structure. Observation shows that the printed entity does not exhibit macroscopic cracking, and the forming effect is good.

[0087] Quasi-static compression tests were conducted on the lattice structure using a compression testing machine. Force-displacement curves were obtained, and the specific energy absorption index was calculated.

[0088] S1. The compression testing machine used is a Sansi integrated compression and flexural testing machine, model UTM7305, with a maximum test force of 300kN. The quasi-static compression rate is 0.1mm / s.

[0089] S2, the formula for calculating specific energy absorption is: (F is force, δ is displacement, and m is mass).

[0090] This invention also protects the eutectic high-entropy alloy TPMS lattice structure manufactured by the above-described manufacturing process.

[0091] A quasi-static compression experiment was conducted on this embodiment, and the data processing yielded a specific energy absorption of 33.5 J / g for the G45 embodiment. Under conditions of similar relative density, this specific energy absorption is consistent with the research results of ALMAHRI S et al. (Additive Manufacturing, 2021, 46:102220). Figure 5 Compared to SS316L[1], it is about 44% higher.

[0092] This invention uses eutectic high-entropy alloy (EHEA) powder, which has energy absorption advantages, as raw material. It employs a powder-based laser powder bed melting (LPBF) process to form a three-dimensional sheet-like three-period minimal surface (TPMS) lattice structure, achieving excellent energy absorption per unit mass (specific energy absorption, SEA) for the eutectic high-entropy alloy sheet-like TPMS lattice structure. The eutectic high-entropy alloy sheet-like TPMS lattice structure obtained by this invention is the first to apply eutectic high-entropy alloy materials to the energy absorption scenario of lattice structures. It combines the energy absorption advantages of materials, structure, and process, improving the specific energy absorption by approximately 50% compared to traditional stainless steel lattice structures.

[0093] The AlCoCrFeNi2.1 eutectic high-entropy alloy used in this invention has a unique FCC / BCC dual-phase nanosheet structure. In addition, the solid solution strengthening and dislocation strengthening mechanisms enable the LPBF-formed eutectic high-entropy alloy curved lattice structure to have a balance between high yield strength and high ductility, and the energy absorption characteristics are greatly improved.

[0094] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for additive manufacturing of a high-specific-energy-absorbing eutectic high-entropy alloy curved lattice structure, characterized in that, Includes the following steps: Prepare eutectic high-entropy alloy powder material, add the eutectic high-entropy alloy powder material to the laser powder bed fusion printer, and fill the printer with inert gas as a protective gas; Design the TPMS dot matrix structure, export it as a slice file, and then import it into a laser powder bed fusion printer; Start printing the TPMS dot matrix structure; After printing, the TPMS lattice structure is cut off from the substrate using wire cutting to obtain the eutectic high-entropy alloy curved lattice structure. The eutectic high-entropy alloy powder is AlCoCrFeNi2.1 high-entropy alloy powder; The TPMS lattice structure is a Gyroid lattice structure, designed using the C-level set method. The mathematical surface description formula for the Gyroid lattice structure is as follows: Where X = 2πx, Y = 2πy, Z = 2πz, x, y, z are spatial coordinates, C is a constant, and the relationship between C and the relative density ρ of the lattice structure is ρ = 0.65C; The TPMS lattice structure has a size of 30mm×30mm×30mm, a unit cell size of 6mm×6mm×6mm, and a relative density of 30% or 35% or 40% or 45%.

2. The additive manufacturing method for a high-specific-energy-absorbing eutectic high-entropy alloy curved lattice structure according to claim 1, characterized in that, The particle size of the eutectic high-entropy alloy powder is 15-53 μm.

3. The additive manufacturing method for a high-specific-energy-absorbing eutectic high-entropy alloy curved lattice structure according to claim 1, characterized in that, The mass composition of AlCoCrFeNi2.1 high-entropy alloy is as follows: Al 8%-9%, Co 17%-19%, Cr 15%-17%, Fe 16-18%, Ni 39%-41%.

4. The additive manufacturing method for a high-specific-energy-absorbing eutectic high-entropy alloy curved lattice structure according to claim 1, characterized in that, In the laser powder bed melting process, the laser power is 200W, the scanning speed is 600mm / s, the scanning spacing is 100μm, and the powder layer thickness is 40μm.

5. A eutectic high-entropy alloy curved lattice structure, characterized in that, The eutectic high-entropy alloy curved lattice structure is prepared by the method described in any one of claims 1-4.

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