Nickel-titanium alloy buffer energy-absorbing lattice structure and preparation method thereof

Abstract

The application relates to a nickel-titanium alloy buffer energy lattice structure and a preparation method thereof. The nickel-titanium alloy buffer energy lattice structure comprises a plurality of unit cells arranged in three directions perpendicular to each other in a three-dimensional space, and the number of unit cells in the three directions is the same. The unit cell is a body-centered cubic, and the unit cell comprises eight spiral-shaped pillars. Each unit cell is composed of a nickel-titanium shape memory alloy, the atomic percentage of Ni in the nickel-titanium shape memory alloy is 50.0%-50.6%, and the balance is Ti atoms. The scheme provided by the application can effectively relieve the concentration of stress and strain through the torsion of the spiral-shaped pillars and the mutual supporting effect, inhibit the formation and expansion of a shear band, and improve the repeated energy absorption capacity and damage tolerance of the nickel-titanium alloy lattice structure.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of shape memory alloys, in particular to a nickel-titanium alloy buffer energy lattice structure and a preparation method thereof. BACKGROUND

[0002] The buffer energy lattice structure can recover its original shape after deforming to absorb energy, achieving the purpose of repeated energy absorption. The nickel-titanium shape memory alloy can realize a maximum recoverable strain of about 6% due to its unique shape memory effect, making it an ideal material for developing reusable buffer energy lattice structures.

[0003] However, the current nickel-titanium alloy lattice structure is prone to shear bands during deformation. In the shear bands, the local strain of the buffer energy lattice structure exceeds the maximum recoverable strain (6%) of the nickel-titanium alloy, leading to irreversible deformation and damage. This greatly reduces the repeated energy absorption capacity of the buffer energy lattice structure. SUMMARY

[0004] To solve or partially solve the problems in the related art, the present application provides a nickel-titanium alloy buffer energy lattice structure and a preparation method thereof, which can effectively alleviate the concentration of stress and strain, inhibit the formation and expansion of shear bands, and improve the repeated energy absorption capacity and damage tolerance of the nickel-titanium alloy lattice structure through the torsion of the spiral pillars and their mutual support.

[0005] The first aspect of the present application provides a nickel-titanium alloy buffer energy lattice structure, comprising a plurality of unit cells arranged in three directions perpendicular to each other in three-dimensional space, the number of unit cells in the three directions being the same; the unit cell is a body-centered cubic, and the unit cell comprises 8 spiral pillars; each unit cell is composed of a nickel-titanium shape memory alloy, the atomic percentage of Ni element in the nickel-titanium shape memory alloy is 50.0%-50.6%, and the balance is Ti atom.

[0006] In combination with the first aspect, in a possible implementation manner of the first aspect, the porosity of the nickel-titanium alloy buffer energy lattice structure is 93.5%-96.5%.

[0007] In combination with the first aspect, in a possible implementation manner of the first aspect, the size of the unit cell is 8-12 mm.

[0008] In combination with the first aspect, in a possible implementation manner of the first aspect, the spiral line diameter of the spiral pillar is 1.4-1.8 mm.

[0009] In combination with the first aspect, in a possible implementation manner of the first aspect, the spiral pillar has 1 spiral turn.

[0010] With reference to the first aspect, in a possible implementation manner of the first aspect, the number of unit cells in the three directions is 4

[0011] The second aspect of the application provides a preparation method of a nickel-titanium alloy buffer energy lattice structure, comprising: mixing nickel-titanium alloy powder according to a preset ratio, wherein the atomic percentage of Ni element in the nickel-titanium alloy powder is 50.0%-50.6%, and the balance is Ti atom; laser powder bed melting is performed on the nickel-titanium alloy powder through printing process parameters to form a plurality of slice layers of the nickel-titanium alloy buffer energy lattice structure, and the printing process parameters include at least one of the following: laser power 120 watts, scanning speed 800 millimeters per second, scanning interval 100 microns, slice layer thickness 30 microns, and spot compensation 0.08 millimeters.

[0012] With reference to the second aspect, in a possible implementation manner of the second aspect, the particle size of the nickel-titanium alloy powder is 15 microns-53 microns.

[0013] With reference to the second aspect, in a possible implementation manner of the second aspect, after printing the nickel-titanium shape memory alloy lattice structure, the nickel-titanium shape memory alloy lattice structure is placed in a forming cylinder for cooling treatment.

[0014] With reference to the second aspect, in a possible implementation manner of the second aspect, the nickel-titanium shape memory alloy lattice structure is removed from the base plate through the electric spark wire.

[0015] With reference to the second aspect, in a possible implementation manner of the second aspect, the nickel-titanium shape memory alloy lattice structure is removed from the base plate through the electric spark wire.

[0016] With reference to the second aspect, in a possible implementation manner of the second aspect, the nickel-titanium shape memory alloy lattice structure is placed in a beaker containing anhydrous ethanol;

[0017] The beaker containing the nickel-titanium shape memory alloy lattice structure is placed in an ultrasonic cleaning device for cleaning for 10 minutes;

[0018] The nickel-titanium shape memory alloy lattice structure after cleaning is subjected to drying treatment.

[0019] With reference to the second aspect, in a possible implementation manner of the second aspect, the laser powder bed fusion of the nickel-titanium alloy powder by the printing process parameter to form the plurality of slice layers of the nickel-titanium alloy buffer energy absorption lattice structure comprises: laser powder bed fusion of the nickel-titanium alloy powder by the printing process parameter and a three-dimensional model of the nickel-titanium alloy buffer energy absorption lattice structure to form the plurality of slice layers of the nickel-titanium alloy buffer energy absorption lattice structure, the three-dimensional model having a length, a width and a height of 32 mm, a porosity of 94.3%, and a cell having a length, a width and a height of 8 mm, and the cell of the nickel-titanium alloy buffer energy absorption lattice structure having a helix line diameter of 1.8 mm.

[0020] With reference to the second aspect, in a possible implementation manner of the second aspect, the laser powder bed fusion of the nickel-titanium alloy powder by the printing process parameter to form the plurality of slice layers of the nickel-titanium alloy buffer energy absorption lattice structure comprises: constructing the three-dimensional model; performing slice processing on the three-dimensional model from one direction to obtain one or more slice layer models, each of the slice layer models corresponding to one slice layer of the nickel-titanium alloy buffer energy absorption lattice structure; writing the printing process parameter and the one or more slice layer models into a printing control file; and importing the printing control file into printing control software of a three-dimensional printer and starting the three-dimensional printer.

[0021] With reference to the second aspect, in a possible implementation manner of the second aspect, the method further comprises: performing a compression test process multiple times, each of the compression test processes comprising: performing uniaxial compression deformation on the nickel-titanium alloy buffer energy absorption lattice structure, placing the nickel-titanium alloy buffer energy absorption lattice structure after the uniaxial compression deformation in water at a temperature of 97.5-98.5 degrees Celsius for shape recovery, and recording a photo of the nickel-titanium alloy buffer energy absorption lattice structure after the shape recovery; the compression direction being a Z-axis direction, the deformation rate being 10 -3 The compression strain rates used in the compression test processes performed multiple times are not completely the same; and the nickel-titanium alloy buffer energy absorption lattice structure is analyzed according to the multiple photos of the nickel-titanium alloy buffer energy absorption lattice structure after the shape recovery.

[0022] With reference to the second aspect, in a possible implementation manner of the second aspect, the compression test processes performed multiple times include compression test processes with compression strain rates of 20%, 40%, 60% and 70%.

[0023] The technical scheme provided in the present application can have the following beneficial effects:

[0024] The nickel-titanium alloy buffer energy absorbing lattice structure of the present application comprises a plurality of unit cells arranged in three directions perpendicular to each other in three-dimensional space, and the number of unit cells in the three directions is the same; the unit cell is a body-centered cubic, and the unit cell comprises eight spiral-shaped pillars; each unit cell is composed of a nickel-titanium shape memory alloy, the atomic percentage of Ni element in the nickel-titanium shape memory alloy is 50.0%-50.6%, and the balance is Ti atom; through the torsion of the spiral-shaped pillars and the mutual supporting effect thereof, the concentration of stress and strain is effectively relieved, the formation and expansion of shear bands are inhibited, and the repeated energy absorbing capacity and damage tolerance of the nickel-titanium alloy lattice structure are improved.

[0025] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0026] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout the several views, and in which the exemplary embodiments of the present application are shown.

[0027] Figure 1 is a three-dimensional model structure schematic diagram of the nickel-titanium alloy buffer energy absorbing lattice structure shown in the embodiment of the present application;

[0028] Figure 2 is a three-dimensional model structure schematic diagram of the unit cell of the nickel-titanium alloy buffer energy absorbing lattice structure shown in the embodiment of the present application;

[0029] Figure 3 is a cyclic compression stress-strain curve schematic diagram of the nickel-titanium alloy buffer energy absorbing lattice structure in embodiment 1 shown in the embodiment of the present application;

[0030] Figure 4 is a cyclic compression deformation photograph schematic diagram of the nickel-titanium alloy buffer energy absorbing lattice structure in embodiment 1 shown in the embodiment of the present application;

[0031] Figure 5 is a cyclic compression stress-strain curve schematic diagram of the nickel-titanium alloy buffer energy absorbing lattice structure in embodiment 2 shown in the embodiment of the present application;

[0032] Figure 6 is a cyclic compression deformation and heating recovery photograph schematic diagram of the nickel-titanium alloy buffer energy absorbing lattice structure in embodiment 2 shown in the embodiment of the present application;

[0033] Figure 7 is a compression stress-strain curve schematic diagram of the nickel-titanium alloy buffer energy absorbing lattice structure in embodiment 3 shown in the embodiment of the present application;

[0034] Figure 8is a photo schematic diagram of the compression deformation and the heating recovery of the nickel-titanium alloy buffer energy lattice structure in Example 1 shown by the embodiment of the present application;

[0035] Figure 9 is a cyclic compression stress-strain curve schematic diagram of the nickel-titanium alloy buffer energy lattice structure in Example 4 shown by the embodiment of the present application;

[0036] Figure 10 is a photo schematic diagram of the compression deformation and the heating recovery of the nickel-titanium alloy buffer energy lattice structure in Example 4 shown by the embodiment of the present application;

[0037] Figure 11 is a cyclic compression stress-strain curve schematic diagram of the nickel-titanium alloy buffer energy lattice structure in Example 5 shown by the embodiment of the present application;

[0038] Figure 12 is a photo schematic diagram of the compression deformation and the heating recovery of the nickel-titanium alloy buffer energy lattice structure in Example 5 shown by the embodiment of the present application;

[0039] Figure 13 is a cyclic compression stress-strain curve schematic diagram of the nickel-titanium alloy buffer energy lattice structure in Comparative Example 1 shown by the embodiment of the present application;

[0040] Figure 14 is a photo schematic diagram of the cyclic compression deformation of the nickel-titanium alloy buffer energy lattice structure in Comparative Example 1 shown by the embodiment of the present application;

[0041] Figure 15 is a cyclic compression stress-strain curve schematic diagram of the nickel-titanium alloy buffer energy lattice structure in Comparative Example 2 shown by the embodiment of the present application;

[0042] Figure 16 is a photo schematic diagram of the compression deformation and the heating recovery of the nickel-titanium alloy buffer energy lattice structure in Comparative Example 2 shown by the embodiment of the present application;

[0043] Figure 17 is a cyclic compression stress-strain curve schematic diagram of the nickel-titanium alloy buffer energy lattice structure in Comparative Example 3 shown by the embodiment of the present application;

[0044] Figure 18 is a photo schematic diagram of the compression deformation and the heating recovery of the nickel-titanium alloy buffer energy lattice structure in Comparative Example 3 shown by the embodiment of the present application. DETAILED DESCRIPTION

[0045] Embodiments of the present application will be described in more detail by referring to the drawings. Although embodiments of the present application are shown in the drawings, it is understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this application will be thorough and complete, and will fully convey the scope of the application to those skilled in the art.

[0046] The terminology used in the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used in the description of the application and the appended claims, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0047] It should be understood that although the terms "first", "second", "third", etc. can be employed in this application to describe various information, such information should not be limited by these terms. These terms are only used to distinguish one piece of information from another piece of information. For example, a first information can also be referred to as a second information, and similarly, a second information can also be referred to as a first information, without departing from the scope of the present application. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0048] First, some of the terms and related technologies involved in the present application are explained and described to facilitate understanding by those skilled in the art.

[0049] Unit cell is a concept used in solid state physics and crystallography, which refers to the smallest geometric unit that can fill the entire three-dimensional space by repeating arrangement. In crystal structure, the unit cell is the basic repeating unit of the crystal, and the entire crystal structure can be generated by translation operation along three mutually perpendicular axes, called crystal axes.

[0050] Laser powder bed fusion (LPBF) is an additive manufacturing technology, also known as selective laser melting (SLM). This technology builds three-dimensional solid parts by using laser as heat source, layer by layer melting metal powder, and then stacking layer by layer. Laser powder bed fusion includes at least laser power, scanning speed, scanning spacing, slice layer thickness, spot compensation and other parameters.

[0051] Wire Electrical Discharge Machining (WEDM or Wire Cut EDM) is a precision machining technique that uses a thin metal wire as a tool electrode to remove material from a workpiece through the generation of electrical sparks caused by pulsed electric current. This technique is widely used in manufacturing fields that require high precision and complex shapes, especially in materials that are difficult to machine using traditional cutting tools. WEDM can be used to accurately cut the connection between a nickel-titanium shape memory alloy dot matrix structure and a substrate, achieving separation.

[0052] Nickel-titanium alloy is a binary alloy composed of nickel and titanium, which is widely used in medical, industrial and other fields due to its unique shape memory effect and superelasticity. The phase transition characteristics of nickel-titanium alloy make it have different crystal structures at different temperatures and pressures, such as austenite phase, martensite phase and R phase. The stretchability of this material exceeds 20%, the fatigue life is as high as 1 x 10 7 times, the damping characteristics are 10 times that of ordinary springs, and the corrosion resistance is better than medical stainless steel.

[0053] In related art, reusable buffer energy-absorbing dot matrix structures are in urgent demand in the fields of aerospace and others. The reusable buffer energy-absorbing dot matrix structure needs to recover its original shape after deforming to absorb energy to achieve the purpose of repeated energy absorption. Traditional buffer energy-absorbing structures represented by aluminum dot matrix and aluminum honeycomb have been unable to meet the use requirements due to irreversible deformation and damage during the deformation and energy absorption process. Nickel-titanium shape memory alloy, with its unique shape memory effect, can achieve a maximum recoverable strain of about 6%, making it an ideal material for developing reusable buffer energy-absorbing dot matrix structures. However, the current nickel-titanium alloy dot matrix structure always appears shear bands during deformation. The local strain of these structures exceeds the maximum recoverable strain (6%) of nickel-titanium alloy on the shear band, leading to irreversible deformation and damage, reducing the repeated energy absorption capacity of the buffer energy-absorbing dot matrix structure.

[0054] Spiral structures can greatly reduce the concentration of local stress and strain caused by shape mutations due to their continuity of geometry. Moreover, spiral structures can transmit stress along the spiral direction by twisting deformation, making all positions of the structure deform and achieving uniform distribution of stress and strain, inhibiting the appearance of shear bands. However, compared with dot matrix structures, the specific strength of spiral structures is low, resulting in poor energy absorption capacity. However, the combination of spiral structures and dot matrix structures is complex in shape and difficult to prepare.

[0055] To solve the above problems, the embodiment of the present application provides a nickel-titanium alloy buffer energy absorbing lattice structure and a preparation method thereof, which can effectively relieve the stress and strain concentration, inhibit the formation and expansion of shear bands, and improve the repeated energy absorbing capacity and damage tolerance of the nickel-titanium alloy lattice structure through the torsion of the spiral-shaped pillars and the mutual support effect thereof.

[0056] The technical solutions of the embodiments of the present application are described in detail below with reference to the drawings.

[0057] Figure 1 FIG. 1 is a structural schematic diagram of a nickel-titanium alloy buffer energy absorbing lattice structure according to an embodiment of the present application.

[0058] Referring to Figures 1-2 A nickel-titanium alloy buffer energy absorbing lattice structure includes a plurality of unit cells arranged in three directions perpendicular to each other in a three-dimensional space, and the number of unit cells in the three directions is the same; the unit cell is a body-centered cubic, and the unit cell includes eight spiral-shaped pillars; each unit cell is composed of a nickel-titanium shape memory alloy, and the atomic percentage of Ni element in the nickel-titanium shape memory alloy is 50.0%-50.6%, and the balance is Ti atoms.

[0059] Specifically, the lattice structure is arranged by the unit cells along three directions perpendicular to each other in a three-dimensional space, and the number of unit cells in the three directions is the same; the unit cell is composed of spiral-shaped pillars, and the structure effectively relieves the stress and strain concentration, inhibits the formation and expansion of shear bands through the torsion of the spiral-shaped pillars and the mutual support effect thereof during the deformation process; each unit cell is composed of a nickel-titanium shape memory alloy, and the atomic percentage of Ni element in the nickel-titanium shape memory alloy is 50.0%-50.6%, and the balance is Ti atoms, for example, the atomic percentage of Ni element can be 50.0%, 50.2%, 50.6%, which is not limited here.

[0060] In a possible implementation, the porosity of the nickel-titanium alloy buffer energy absorbing lattice structure is 93.5%-96.5%.

[0061] Specifically, the porosity of the nickel-titanium alloy buffer energy absorbing lattice structure is 93.5%-96.5%, which can make the nickel-titanium alloy buffer energy absorbing lattice structure have better repeated energy absorbing capacity, for example, the porosity can be 93.5%, 94.1%, 95.1%, 96.5%, etc., which is not limited here.

[0062] In a possible implementation, the size of the unit cell is 8-12 mm, and the size of the unit cell needs to have a suitable size, which is conducive to forming a more stable nickel-titanium alloy buffer energy absorbing lattice structure, for example, the size of the unit cell can be 8 mm, 10 mm, 12 mm, etc., which is not limited here.

[0063] In a possible implementation, the helical line of the helical strut has a diameter of 1.4-1.8 mm.

[0064] Specifically, the diameter of the helical line of the helical strut is 1.4-1.8 mm, which can better enable the nickel-titanium alloy buffer energy-absorbing lattice structure to twist and support each other during deformation, effectively relieving stress and strain concentration, and inhibiting the formation and expansion of shear bands. For example, the diameter of the helical line can be 1.4 mm, 1.5 mm, 1.6 mm, 1.8 mm, etc., which is not limited here.

[0065] In a possible implementation, the helical strut has one helical turn. Generally, the helical strut has one helical turn. Too many or too few turns will not only make it difficult for the nickel-titanium alloy buffer energy-absorbing lattice structure to twist and support each other during deformation, but also make it difficult to form the nickel-titanium alloy buffer energy-absorbing lattice structure or reduce the forming quality, affecting its energy-absorbing and recovery properties.

[0066] In a possible implementation, the number of unit cells in the three directions is 4.

[0067] The nickel-titanium alloy buffer energy-absorbing lattice structure includes a plurality of unit cells arranged in three directions perpendicular to each other in a three-dimensional space, and the number of unit cells in the three directions is the same; the unit cell is a body-centered cubic, and the unit cell includes eight helical struts; each unit cell is composed of a nickel-titanium shape memory alloy, the atomic percentage of Ni in the nickel-titanium shape memory alloy is 50.0%-50.6%, and the balance is Ti atom, which can effectively relieve stress and strain concentration, inhibit the formation and expansion of shear bands, and improve the repeated energy-absorbing capacity and damage tolerance of the nickel-titanium alloy lattice structure through the twisting and mutual support of the helical struts.

[0068] The application also provides a preparation method of the nickel-titanium alloy buffer energy-absorbing lattice structure, including:

[0069] The nickel-titanium alloy powder is mixed according to a preset ratio, and the atomic percentage of Ni in the nickel-titanium alloy powder is 50.0%-50.6%, and the balance is Ti atom;

[0070] The nickel-titanium alloy powder is subjected to laser powder bed melting through printing process parameters to form a plurality of slice layers of the nickel-titanium alloy buffer energy-absorbing lattice structure, and the printing process parameters include at least one of the following: laser power 120 W, scanning speed 800 mm / s, scanning interval 100 microns, slice layer thickness 30 microns, and spot compensation 0.08 mm.

[0071] Specifically, the nickel-titanium alloy powder can be formed according to a preset proportion, and the atomic percentage of the Ni element is 50.0%-50.6%, for example, can be 50.0%, 50.2%, 50.6%, and the balance is Ti atoms. The nickel-titanium alloy powder with an atomic percentage of Ni element of 50.0%-50.6% and an atomic percentage of Ni and Ti atoms of 100% is used as a raw material to prepare the nickel-titanium shape memory alloy lattice structure. The nickel-titanium alloy powder formed according to the preset proportion can make the nickel-titanium shape memory alloy lattice structure prepared according to the preset proportion have better repeated energy absorption capacity.

[0072] Specifically, the execution subject of the preparation method can use the currently conventional SLM metal printer in the art. The SLM metal printer melts and solidifies the nickel-titanium alloy powder by control, and finally obtains the nickel-titanium shape memory alloy lattice structure.

[0073] In a possible implementation, the laser power in the printing process parameters can be 100W-120W, the scanning speed can be 800mm / s-1000mm / s, the scanning interval can be 90um-100um, the layer thickness can be 30um, and the spot compensation can be 0.04mm-0.08mm.

[0074] In a possible implementation, the particle size of the nickel-titanium alloy powder is 15-53 microns.

[0075] In a possible implementation, after the nickel-titanium shape memory alloy lattice structure is printed, the nickel-titanium shape memory alloy lattice structure is placed in a forming cylinder for cooling treatment. After the cooling treatment is completed, the nickel-titanium shape memory alloy lattice structure can be cleaned of excess powder by a powder cleaning device, and then the nickel-titanium shape memory alloy lattice structure is separated from the substrate by wire electrical discharge machining. Finally, the nickel-titanium shape memory alloy lattice structure is placed in a beaker containing anhydrous ethanol, and then the beaker containing the nickel-titanium shape memory alloy lattice structure is placed in an ultrasonic cleaning device for 10 minutes of cleaning. The nickel-titanium shape memory alloy lattice structure after cleaning is dried to obtain the nickel-titanium shape memory alloy lattice structure.

[0076] Specifically, after obtaining the nickel-titanium shape memory alloy lattice structure, the nickel-titanium shape memory alloy lattice structure can be subjected to multiple compression test processes. Each compression test process includes: after the nickel-titanium alloy buffer energy absorption lattice structure is subjected to uniaxial compression deformation, the nickel-titanium alloy buffer energy absorption lattice structure after uniaxial compression deformation is placed in water at 97.5-98.5 degrees Celsius for shape recovery, and a photo of the nickel-titanium alloy buffer energy absorption lattice structure after shape recovery is recorded; the compression direction is the Z-axis direction, the deformation rate is 10 -3The compression strain rates used in the compression test process performed multiple times per second are not exactly the same; nickel-titanium alloy buffer energy absorption lattice structure is analyzed according to the nickel-titanium alloy buffer energy absorption lattice structure photos after shape recovery. Further, the compression test process performed multiple times includes the compression test processes with compression strain rates of 20%, 40%, 60%, and 70%.

[0077] In a possible implementation, the nickel-titanium alloy powder is subjected to laser powder bed melting by printing process parameters and a three-dimensional model of the nickel-titanium alloy buffer energy absorption lattice structure, to form multiple slice layers of the nickel-titanium alloy buffer energy absorption lattice structure, the length, width, and height of the three-dimensional model are all 32 mm, the porosity of the three-dimensional model is 94.3%, the length, width, and height of the unit cell of the three-dimensional model are all 8 mm, and the helix diameter of the unit cell of the nickel-titanium alloy buffer energy absorption lattice structure is 1.8 mm.

[0078] In a possible implementation, the three-dimensional model can be constructed in the process of forming the multiple slice layers of the nickel-titanium alloy buffer energy absorption lattice structure; the three-dimensional model is subjected to slicing processing from one direction to obtain one or more slice layer models, each slice layer model corresponds to one slice layer of the nickel-titanium alloy buffer energy absorption lattice structure; the printing process parameters and the one or more slice layer models are written into a printing control file; the printing control file is imported into printing control software of a three-dimensional printer, and the three-dimensional printer is started.

[0079] To make the application easier to understand, the application will be further described in detail below in conjunction with embodiments, which are only illustrative and do not limit the scope of application. The raw materials or components used in the application can be prepared by commercial means or conventional methods if not specifically stated.

[0080] Example 1

[0081] Referring to Figures 3-4 , (1) a nickel-titanium alloy buffer energy absorption lattice structure unit cell model is established by using three-dimensional modeling software, the unit cell size is 8*8*8mm, the helix diameter is 1.8mm, the unit cells are arrayed along the XYZ three directions, the array number is 4, a three-dimensional model is formed, the three-dimensional model can be a three-dimensional lattice structure model, the size of the model is 32*32*32mm, the porosity is 94.3%, and the unit cells are combined into a complete nickel-titanium alloy buffer energy absorption lattice structure through a combination operation.

[0082] (2) using a three-dimensional slicing software, slicing the three-dimensional model from one direction to obtain one or more slice layer models, each slice layer model corresponding to a slice layer of the nickel-titanium alloy buffer energy absorption lattice structure, and writing the printing process parameters and the one or more slice layer models into a printing control file, the printing process parameters being a laser power of 120 watts, a scanning speed of 800 millimeters per second, a scanning interval of 100 microns, a slice layer thickness of 30 microns, and a light spot compensation of 0.08 millimeters.

[0083] (3) importing the printing control file into the printing control software of the three-dimensional printer, and starting the three-dimensional printer, and using a nickel-titanium alloy powder to manufacture the nickel-titanium shape memory alloy lattice structure layer by layer through a laser powder bed fusion technology, the nickel-titanium alloy powder having an atomic percentage of 50.5% of Ni element and 49.5% of Ti element, and a powder particle size of 15-53 microns, in the forming process, after completing the manufacturing of each slice, the workbench is lowered by a layer thickness of 0.03 mm, and then the printing of the next layer is performed, and the cycle is repeated until the manufacturing of the nickel-titanium shape memory alloy lattice structure is completed.

[0084] (4) after the manufacturing of the nickel-titanium shape memory alloy lattice structure is completed, placing the nickel-titanium shape memory alloy lattice structure into a forming cylinder in the SLM for cooling treatment, removing the excess powder from the nickel-titanium shape memory alloy lattice structure through a powder cleaning device, then placing the nickel-titanium shape memory alloy lattice structure into a beaker containing anhydrous ethanol, placing the beaker carrying the nickel-titanium shape memory alloy lattice structure into an ultrasonic cleaning device for 10 minutes of cleaning, and drying the cleaned nickel-titanium shape memory alloy lattice structure.

[0085] (5) using a universal testing machine to perform 10 times of compression test on the nickel-titanium shape memory alloy lattice structure, the compression test can be a uniaxial compression deformation test, the compression direction is the Z-axis direction, the deformation rate is 1x10 -3 seconds, and the multiple compression strains are all 40%, placing the nickel-titanium alloy buffer energy absorption lattice structure after the uniaxial compression deformation into water at 97.5-98.5 degrees Celsius for shape recovery, recording the photos of the nickel-titanium alloy buffer energy absorption lattice structure after multiple shape recoveries, and obtaining the cyclic compression stress-strain curve of the nickel-titanium alloy buffer energy absorption lattice structure.

[0086] From the multiple photos of the nickel-titanium alloy buffer energy absorption lattice structure, it can be seen that there is no shear band in the nickel-titanium alloy buffer energy absorption lattice structure, and the stress-strain curve has good cyclic stability, that is, the nickel-titanium alloy buffer energy absorption lattice structure has good repeated energy absorption capacity, and greatly improves the damage tolerance.

[0087] Example 2

[0088] Referring to Figures 5-6 , (1) a three-dimensional modeling software is used to establish a model of a nickel-titanium alloy buffer energy absorbing lattice structure, the size of the unit cell is 10x10x10mm, the diameter of the helical line is 1.5mm, the unit cells are arrayed along the XYZ three directions, the array number is 4, a three-dimensional model is formed, the three-dimensional model can be a three-dimensional lattice structure model, the size of the model is 32x32x32mm, the porosity is 95.1%, and the unit cells are combined into a complete nickel-titanium alloy buffer energy absorbing lattice structure through a combination operation.

[0089] (2) a three-dimensional slicing software is used to slice the three-dimensional model from one direction to obtain one or more slice layer models, each slice layer model corresponds to a slice layer of the nickel-titanium alloy buffer energy absorbing lattice structure, and printing process parameters and one or more slice layer models are written into a printing control file, the printing process parameters are laser power 100w, scanning speed 800mm / s, scanning interval 100μm, slice layer thickness 30μm, and spot compensation 0.04mm.

[0090] (3) the printing control file is imported into the printing control software of the three-dimensional printer, and the three-dimensional printer is started, and a nickel-titanium shape memory alloy lattice structure is manufactured layer by layer by using a nickel-titanium alloy powder through a laser powder bed fusion technology, the atomic percentage of Ni element in the nickel-titanium alloy powder is 50.5%, the atomic percentage of Ti element is 49.5%, and the powder particle size is 15-53μm, in the forming process, after the manufacturing of each section is completed, the workbench is lowered by a layer thickness of 0.03mm, and then the printing of the next layer is performed, and the cycle is repeated until the manufacturing of the nickel-titanium shape memory alloy lattice structure is completed.

[0091] (4) after the manufacturing of the nickel-titanium shape memory alloy lattice structure is completed, the nickel-titanium shape memory alloy lattice structure is placed into a forming cylinder in the SLM for cooling treatment, and the nickel-titanium shape memory alloy lattice structure is cleaned of excess powder through a powder cleaning device, then the nickel-titanium shape memory alloy lattice structure is placed into a beaker containing anhydrous ethanol, the beaker carrying the nickel-titanium shape memory alloy lattice structure is placed into an ultrasonic cleaning device for cleaning for 10 minutes, and the cleaned nickel-titanium shape memory alloy lattice structure is dried.

[0092] (5) a universal testing machine is used to perform multiple compression test experiments on the nickel-titanium shape memory alloy lattice structure, the compression test experiment can be a uniaxial compression deformation test, the compression direction is the Z-axis direction, the deformation rate is 1x10 -3The nickel-titanium alloy buffer energy absorption lattice structure after uniaxial compression deformation is placed in water at 97.5-98.5 degrees Celsius for shape recovery, and the photograph of the nickel-titanium alloy buffer energy absorption lattice structure after shape recovery is recorded.

[0093] It can be known from the embodiment that the maximum strength in the compression process does not attenuate, and no shear band is formed by testing the nickel-titanium shape memory alloy lattice structure by different compression strains every two times, and the shape of the nickel-titanium shape memory alloy lattice structure recovers after heating, that is, the nickel-titanium alloy buffer energy absorption lattice structure has good repeated energy absorption capacity.

[0094] Example 3

[0095] Referring to Figures 7-8 , (1) a nickel-titanium alloy buffer energy absorption lattice structure unit cell model is established by using three-dimensional modeling software, the unit cell size is 8*8*8mm, the helical line diameter is 1.4mm, the unit cells are arrayed along the XYZ three directions, the array number is 4, a three-dimensional model is formed, the three-dimensional model can be a three-dimensional lattice structure model, the size of the model is 32*32*32mm, the porosity is 94.1%, and the unit cells are combined into a complete nickel-titanium alloy buffer energy absorption lattice structure through combination operation.

[0096] (2) a three-dimensional slicing software is used to slice the three-dimensional model from one direction to obtain one or more slice layer models, each slice layer model corresponds to a slice layer of the nickel-titanium alloy buffer energy absorption lattice structure, and printing process parameters and one or more slice layer models are written into a printing control file, the printing process parameters are laser power 120w, scanning speed 1000mm / s, scanning interval 100 microns, slice layer thickness 30 microns, and spot compensation 0.06mm.

[0097] (3) the printing control file is imported into the printing control software of the three-dimensional printer, and the three-dimensional printer is started, and the nickel-titanium alloy powder is used for layer-by-layer manufacturing of the nickel-titanium shape memory alloy lattice structure by laser powder bed fusion technology, the atomic percentage of Ni element in the nickel-titanium alloy powder is 50.5%, the atomic percentage of Ti element is 49.5%, and the powder particle size is 15-53 microns, in the forming process, the workbench is lowered by a layer thickness of 0.03mm after completing the manufacturing of each section, and then the next layer is printed, and the cycle is repeated until the manufacturing of the nickel-titanium shape memory alloy lattice structure is completed.

[0098] (4) After the nickel-titanium shape memory alloy lattice structure is manufactured, the nickel-titanium shape memory alloy lattice structure is placed into a forming cylinder in the SLM for cooling treatment, and the nickel-titanium shape memory alloy lattice structure is cleaned of excess powder through a powder cleaning device, then the nickel-titanium shape memory alloy lattice structure is placed into a beaker containing anhydrous ethanol, the beaker carrying the nickel-titanium shape memory alloy lattice structure is placed into an ultrasonic cleaning device for 10 minutes of cleaning, and the nickel-titanium shape memory alloy lattice structure after cleaning is subjected to drying treatment.

[0099] (5) The nickel-titanium shape memory alloy lattice structure is subjected to multiple compression test experiments using a universal testing machine, and the compression test experiment can be a uniaxial compression deformation experiment, the compression direction is the Z-axis direction, the deformation rate is 1x10 -3 per second, the maximum compression strain is 43%, and a stress-strain curve is obtained, the nickel-titanium alloy energy-absorbing lattice structure after uniaxial compression deformation is placed into water at 97.5 to 98.5 degrees Celsius for shape recovery, and the nickel-titanium alloy energy-absorbing lattice structure is photographed at compression strain values of 10%, 20%, 30%, 43%, and after heating recovery.

[0100] It can be known from the embodiment that no shear band appears in the nickel-titanium alloy energy-absorbing lattice structure, and the stress-strain curve is smooth and stable, and there is no strength attenuation, that is, the nickel-titanium alloy energy-absorbing lattice structure has good repeated energy-absorbing capacity, and greatly improves the damage tolerance.

[0101] Example 4

[0102] Referring to Figures 9-10 , (1) A nickel-titanium alloy energy-absorbing lattice structure unit cell model is established by using three-dimensional modeling software, the unit cell size is 8x8x8mm, the helical line diameter is 1.6mm, the unit cells are arrayed along the XYZ three directions, the array number is 4, a three-dimensional model is formed, the three-dimensional model can be a three-dimensional lattice structure model, the size of the model is 32x32x32mm, the porosity is 93.5%, and the unit cells are combined into a complete nickel-titanium alloy energy-absorbing lattice structure through a combination operation.

[0103] (2) A three-dimensional slicing software is used to slice the three-dimensional model from one direction to obtain one or more slice layer models, each slice layer model corresponds to a slice layer of the nickel-titanium alloy energy-absorbing lattice structure, and printing process parameters and the one or more slice layer models are written into a printing control file, the printing process parameters are a laser power of 120 watts, a scanning speed of 800mm per second, a scanning interval of 100 microns, a slice layer thickness of 30 microns, and a light spot compensation of 0.08mm.

[0104] (3) import the print control file into the print control software of the three-dimensional printer, and start the three-dimensional printer, and use the nickel-titanium alloy powder to manufacture the nickel-titanium shape memory alloy dot array structure layer by layer through the laser powder bed fusion technology, the atomic percentage of Ni element in the nickel-titanium alloy powder is 50.5%, the atomic percentage of Ti element is 49.5%, the powder particle size is 15-53 microns, in the forming process, after completing the manufacturing of each section, the workbench is lowered by a layer thickness of 0.03 mm, and then the next layer plane is printed, and the cycle is repeated until the manufacturing of the nickel-titanium shape memory alloy dot array structure is completed.

[0105] (4) after the nickel-titanium shape memory alloy dot array structure is manufactured, the nickel-titanium shape memory alloy dot array structure is placed into the forming cylinder in the SLM for cooling treatment, and the excess powder of the nickel-titanium shape memory alloy dot array structure is removed through the powder cleaning device, then the nickel-titanium shape memory alloy dot array structure is placed into a beaker containing anhydrous ethanol, the beaker carrying the nickel-titanium shape memory alloy dot array structure is placed into an ultrasonic cleaning device for 10 minutes of cleaning, and the nickel-titanium shape memory alloy dot array structure after cleaning is dried.

[0106] (5) use a universal testing machine to perform multiple compression test experiments on the nickel-titanium shape memory alloy dot array structure, the compression test experiment can be a uniaxial compression deformation test, the compression direction is the Z-axis direction, the deformation rate is 1x10 -3 per second, the maximum compression strain is 50%, and a stress-strain curve is obtained, the nickel-titanium alloy energy-absorbing dot array structure after uniaxial compression deformation is placed into water at 97.5-98.5 degrees Celsius for shape recovery, and the photos of the nickel-titanium alloy energy-absorbing dot array structure at compression strain of 10%, 20%, 30%, 40%, 50% and after heating recovery are recorded.

[0107] From the photos of the nickel-titanium alloy energy-absorbing dot array structure, it can be seen that there is no shear band in the nickel-titanium alloy energy-absorbing dot array structure, and the stress-strain curve is smooth and stable, and there is no strength attenuation, that is, the nickel-titanium alloy energy-absorbing dot array structure has good repeated energy-absorbing capacity, and greatly improves the damage tolerance.

[0108] Example 5

[0109] Referring to Figures 11-12, (1) using three-dimensional modeling software to establish a nickel-titanium alloy buffer energy lattice structure unit cell model, the cell size is 8x8x8mm, the helical line diameter is 1.6mm, the unit cell is arrayed along the XYZ three directions, and the array number is 4, forming a three-dimensional model, which can be a three-dimensional lattice structure model, the size of the model is 32x32x32mm, the porosity is 93.5%, and the unit cells are combined into a complete nickel-titanium alloy buffer energy lattice structure through combination operation.

[0110] (2) using three-dimensional slicing software, slicing processing is performed on the three-dimensional model from one direction to obtain one or more slice layer models, each slice layer model corresponds to a slice layer of the nickel-titanium alloy buffer energy lattice structure, and printing process parameters and one or more slice layer models are written into a printing control file, the printing process parameters are laser power 120w, scanning speed 800mm / s, scanning pitch 100 microns, slice layer thickness 30 microns, and spot compensation 0.08mm.

[0111] (3) import the printing control file into the printing control software of the three-dimensional printer, and start the three-dimensional printer, and use the nickel-titanium alloy powder through the laser powder bed fusion technology to manufacture the nickel-titanium shape memory alloy lattice structure layer by layer, the atomic percentage of Ni element in the nickel-titanium alloy powder is 50.2%, the atomic percentage of Ti element is 49.8%, and the powder particle size is 15-53 microns. In the forming process, after completing the manufacturing of each section, the workbench is lowered by a layer thickness of 0.03mm, and then the next layer is printed. Repeat the above steps until the manufacturing of the nickel-titanium shape memory alloy lattice structure is completed.

[0112] (4) after the nickel-titanium shape memory alloy lattice structure is manufactured, the nickel-titanium shape memory alloy lattice structure is placed into the forming cylinder in the SLM for cooling treatment, and the excess powder of the nickel-titanium shape memory alloy lattice structure is removed through the powder cleaning device, then the nickel-titanium shape memory alloy lattice structure is placed into a beaker containing anhydrous ethanol, the beaker carrying the nickel-titanium shape memory alloy lattice structure is placed into an ultrasonic cleaning device for 10 minutes of cleaning, and the cleaned nickel-titanium shape memory alloy lattice structure is dried.

[0113] (5) using a universal testing machine to perform multiple compression test experiments on the nickel-titanium shape memory alloy lattice structure, the compression test experiment can be a uniaxial compression deformation test, the compression direction is the Z-axis direction, the deformation rate is 1x10 -3The maximum compressive strain is 50% per second, and the stress-strain curve is obtained, the nickel-titanium alloy buffer energy absorption lattice structure after uniaxial compression deformation is placed in water at 97.5-98.5 degrees Celsius for shape recovery, and the photos of the nickel-titanium alloy buffer energy absorption lattice structure after compression strain is changed to 10%, 20%, 30%, 40%, 50% and heating recovery are recorded.

[0114] From the photos of the nickel-titanium alloy buffer energy absorption lattice structure, there is no shear band in the nickel-titanium alloy buffer energy absorption lattice structure, and the stress-strain curve is smooth and stable without strength attenuation, that is, the nickel-titanium alloy buffer energy absorption lattice structure has good repeated energy absorption capacity and greatly improves the damage tolerance.

[0115] Comparative Example 1

[0116] Referring to Figures 13-14 , (1) a three-dimensional modeling software is used to establish a nickel-titanium alloy buffer energy absorption lattice structure unit cell model, the unit cell size is 8*8*8mm, the helical line diameter is 0mm, the unit cells are arrayed along the XYZ three directions, the array number is 4, a three-dimensional model is formed, the three-dimensional model can be a three-dimensional lattice structure model, the size of the model is 32*32*32mm, the porosity is 94.3%, and the unit cells are combined into a complete nickel-titanium alloy buffer energy absorption lattice structure through combination operation.

[0117] (2) a three-dimensional slicing software is used to slice the three-dimensional model from one direction to obtain one or more slice layer models, each slice layer model corresponds to a slice layer of the nickel-titanium alloy buffer energy absorption lattice structure, and printing process parameters and one or more slice layer models are written into a printing control file, the printing process parameters are laser power 120w, scanning speed 800mm / s, scanning interval 100microns, slice layer thickness 30microns, and spot compensation 0.08mm.

[0118] (3) the printing control file is imported into the printing control software of the three-dimensional printer, and the three-dimensional printer is started, and the nickel-titanium alloy powder is used for layer-by-layer manufacturing of the nickel-titanium shape memory alloy lattice structure through laser powder bed fusion technology, the atomic percentage of Ni element in the nickel-titanium alloy powder is 50.5%, the atomic percentage of Ti element is 49.5%, and the powder particle size is 15-53microns, in the forming process, the workbench is lowered by a layer thickness of 0.03mm after completing the manufacturing of each section, and then the next layer is printed, and the cycle is repeated until the manufacturing of the nickel-titanium shape memory alloy lattice structure is completed.

[0119] (4) After the nickel-titanium shape memory alloy lattice structure is manufactured, the nickel-titanium shape memory alloy lattice structure is placed into a forming cylinder in the SLM for cooling treatment, and the nickel-titanium shape memory alloy lattice structure is cleaned of excess powder through a powder cleaning device, and then the nickel-titanium shape memory alloy lattice structure is placed into a beaker containing anhydrous ethanol, the beaker carrying the nickel-titanium shape memory alloy lattice structure is placed into an ultrasonic cleaning device for 10 minutes of cleaning, and the nickel-titanium shape memory alloy lattice structure after cleaning is subjected to drying treatment.

[0120] (5) The nickel-titanium shape memory alloy lattice structure is subjected to 10 times of compression test using a universal testing machine, the compression test can be a uniaxial compression deformation test, the compression direction is the Z-axis direction, the deformation rate is 1x10-3s-1, and the multiple compression strains are all 40%, the nickel-titanium alloy energy-absorbing lattice structure after uniaxial compression deformation is placed into water at 97.5-98.5 degrees Celsius for shape recovery, and the nickel-titanium alloy energy-absorbing lattice structure after multiple shape recoveries is recorded, and the cyclic compression stress-strain curve of the nickel-titanium alloy energy-absorbing lattice structure is obtained.

[0121] It can be known from the comparison between the comparative example 1 and the example 1 that the nickel-titanium alloy energy-absorbing lattice structure with a helical line diameter of 0 mm forms a shear band, and the pillars on the shear band are broken, resulting in a large decrease in the strength on the stress-strain curve and poor cyclic stability, so the nickel-titanium alloy energy-absorbing lattice structure with a helical line diameter of 1.4-1.8 mm can avoid the formation of a shear band, and the strength is increased and the cyclic stability is improved.

[0122] Comparative Example 2

[0123] Referring to Figures 15-16 , (1) A nickel-titanium alloy energy-absorbing lattice structure unit cell model is established by using three-dimensional modeling software, the unit cell size is 10x10x10 mm, the helical line diameter is 0 mm, the unit cells are arrayed along the XYZ three directions, the array number is 4, a three-dimensional model is formed, the three-dimensional model can be a three-dimensional lattice structure model, the size of the model is 32x32x32 mm, the porosity is 95.1%, and the unit cells are combined into a complete nickel-titanium alloy energy-absorbing lattice structure through a combination operation.

[0124] (2) using three-dimensional slicing software, slicing the three-dimensional model from one direction to obtain one or more slice layer models, each slice layer model corresponding to a slice layer of the nickel-titanium alloy buffer energy absorption lattice structure, and writing the printing process parameters and one or more slice layer models into the printing control file, the printing process parameters being laser power 100 watts, scanning speed 800 millimeters per second, scanning interval 70 microns, slice layer thickness 30 microns, and spot compensation 0.04 millimeters.

[0125] (3) importing the printing control file into the printing control software of the three-dimensional printer, and starting the three-dimensional printer, and using the nickel-titanium alloy powder to manufacture the nickel-titanium shape memory alloy lattice structure layer by layer through the laser powder bed fusion technology, the atomic percentage of Ni element in the nickel-titanium alloy powder being 50.5%, the atomic percentage of Ti element being 49.5%, and the powder particle size being 15-53 microns, in the forming process, after completing the manufacturing of each section, the workbench is lowered by a layer thickness of 0.03 mm, and then the next layer is printed, and the cycle is repeated until the manufacturing of the nickel-titanium shape memory alloy lattice structure is completed.

[0126] (4) after the nickel-titanium shape memory alloy lattice structure is manufactured, the nickel-titanium shape memory alloy lattice structure is placed into the forming cylinder in the SLM for cooling treatment, and the nickel-titanium shape memory alloy lattice structure is cleaned of excess powder through the powder cleaning device, then the nickel-titanium shape memory alloy lattice structure is placed into a beaker containing anhydrous ethanol, the beaker carrying the nickel-titanium shape memory alloy lattice structure is placed into an ultrasonic cleaning device for 10 minutes of cleaning, and the cleaned nickel-titanium shape memory alloy lattice structure is dried.

[0127] (5) using a universal testing machine to perform multiple compression test experiments on the nickel-titanium shape memory alloy lattice structure, the compression test experiment can be a uniaxial compression deformation test, the compression direction is the Z-axis direction, the deformation rate is 1x10 -3 seconds, the compression strain of each test is 20%, 40%, 60%, and 70%, the nickel-titanium alloy buffer energy absorption lattice structure after uniaxial compression deformation is placed into water at 97.5-98.5 degrees Celsius for shape recovery, and a photo of the nickel-titanium alloy buffer energy absorption lattice structure after shape recovery is recorded.

[0128] It can be seen from the comparison between Comparative Example 2 and Example 2 that the photos of the first compression 20% strain, the first compression 40% strain, the first compression 60% strain, the first compression 70% strain and the shape recovery after heating in Comparative Example 2 all form shear bands, the integrity of the nickel-titanium alloy energy-absorbing lattice structure is damaged after heating, and the maximum strength decreases. Therefore, the nickel-titanium alloy energy-absorbing lattice structure with a helical wire diameter of 1.4-1.8 mm and a laser scanning pitch of 90-100 microns can avoid the formation of shear bands, and increase the strength and improve the cycle stability.

[0129] Comparative Example 3

[0130] Referring to Figures 17-18 , (1) a three-dimensional modeling software is used to establish a nickel-titanium alloy energy-absorbing lattice structure unit cell model, the unit cell size is 10x10x10 mm, the helical wire diameter is 0.8 mm, the unit cells are arrayed along the XYZ three directions, the array number is 4, a three-dimensional model is formed, the three-dimensional model can be a three-dimensional lattice structure model, the size of the model is 32x32x32 mm, the porosity is 95.1%, and the unit cells are combined into a complete nickel-titanium alloy energy-absorbing lattice structure through a combination operation.

[0131] (2) A three-dimensional slicing software is used to slice the three-dimensional model from one direction to obtain one or more slice layer models, each slice layer model corresponds to a slice layer of the nickel-titanium alloy energy-absorbing lattice structure, and printing process parameters and one or more slice layer models are written into a printing control file, the printing process parameters are laser power 100 watts, scanning speed 800 mm / s, scanning pitch 70 microns, slice layer thickness 30 microns, and spot compensation 0.04 mm.

[0132] (3) The printing control file is imported into the printing control software of the three-dimensional printer, and the three-dimensional printer is started, and a nickel-titanium alloy powder is used to manufacture the nickel-titanium shape memory alloy lattice structure layer by layer through a laser powder bed fusion technology, the atomic percentage of Ni element in the nickel-titanium alloy powder is 50.58%, the atomic percentage of Ti element is 49.2%, and the powder particle size is 15-53 microns. In the forming process, after completing the manufacturing of each section, the workbench is lowered by a layer thickness of 0.03 mm, and then the next layer is printed, and the cycle is repeated until the manufacturing of the nickel-titanium shape memory alloy lattice structure is completed.

[0133] (4) After the nickel-titanium shape memory alloy lattice structure is manufactured, the nickel-titanium shape memory alloy lattice structure is placed into a forming cylinder in the SLM for cooling treatment, and the nickel-titanium shape memory alloy lattice structure is cleaned of excess powder by a powder cleaning device, then the nickel-titanium shape memory alloy lattice structure is placed into a beaker containing anhydrous ethanol, the beaker carrying the nickel-titanium shape memory alloy lattice structure is placed into an ultrasonic cleaning device for 10 minutes of cleaning, and the cleaned nickel-titanium shape memory alloy lattice structure is dried.

[0134] (5) The nickel-titanium shape memory alloy lattice structure is subjected to multiple compression test experiments using a universal testing machine, which can be a uniaxial compression deformation test, the compression direction is the Z-axis direction, the deformation rate is 1x10 -3 per second, the maximum compression strain is 43%, and a stress-strain curve is obtained, the nickel-titanium alloy energy-absorbing lattice structure after uniaxial compression deformation is placed in water at 97.5-98.5 degrees Celsius for shape recovery, and the photos of the nickel-titanium alloy energy-absorbing lattice structure at compression strain of 10%, 20%, 30%, 43% and after heating recovery are recorded.

[0135] It can be seen from the comparison of Comparative Example 3 and Example 3 that the photos of the nickel-titanium alloy energy-absorbing lattice structure after 10% compression strain, 20% compression strain, 30% compression strain, 43% compression strain and heating shape recovery in Comparative Example 3 all form shear bands, and the integrity of the nickel-titanium alloy energy-absorbing lattice structure after heating is damaged, and the maximum strength decreases. Therefore, the nickel-titanium alloy energy-absorbing lattice structure with a helical wire diameter of 1.4-1.8 mm and an atomic percentage of Ni element of 50.0%-50.6% can avoid the formation of shear bands, and increase the strength and improve the cyclic stability.

[0136] In summary, it can be seen from the above examples and comparative examples that the nickel-titanium alloy energy-absorbing lattice structure of the present application can effectively relieve the concentration of stress and strain through the torsion of the helical struts and their mutual support, inhibit the formation and expansion of shear bands, and improve the repeated energy-absorbing capacity and damage tolerance of the nickel-titanium alloy lattice structure.

[0137] The above has described the embodiments of the present application, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles, practical applications, or improvements to the technology in the market of the embodiments, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. A method for preparing a nickel-titanium alloy energy-absorbing lattice structure, characterized in that, The application relates to a nickel-titanium alloy buffer energy lattice structure. The nickel-titanium alloy powder is formed by mixing in a preset ratio, wherein the atomic percentage of Ni element in the nickel-titanium alloy powder is 50.0%-50.6%, and the balance is Ti atom; The nickel-titanium alloy powder is subjected to laser powder bed melting through printing process parameters, so as to form a plurality of slice layers of the nickel-titanium alloy buffer energy lattice structure, wherein the printing process parameters include at least one of the following: laser power 120 W, scanning speed 800 mm / s, scanning interval 100 microns, slice layer thickness 30 microns, and spot compensation 0.08 mm, and the particle size of the nickel-titanium alloy powder is 15 microns-53 microns; The nickel-titanium alloy buffer energy lattice structure comprises: A plurality of unit cells arranged in three directions perpendicular to each other in a three-dimensional space, and the number of unit cells in the three directions is the same; The unit cell is a body-centered cubic, and the unit cell comprises eight spiral-shaped pillars; Each unit cell is composed of a nickel-titanium shape memory alloy, and the atomic percentage of Ni element in the nickel-titanium shape memory alloy is 50.0%-50.6%, and the balance is Ti atom.

2. The method of claim 1, wherein the method further comprises the step of: The porosity of the nickel-titanium alloy buffer energy lattice structure is 93.5%-96.5%.

3. The method of claim 1, wherein the method further comprises: The size of the unit cell is 8 mm-12 mm, and the spiral line diameter of the spiral-shaped pillar is 1.4 mm-1.8 mm.

4. The method of claim 1, wherein the method further comprises: The spiral-shaped pillar has one spiral turn, and the number of unit cells in the three directions is four.

5. The method of claim 1, wherein, Further comprising: After printing the nickel-titanium shape memory alloy lattice structure, the nickel-titanium shape memory alloy lattice structure is placed in a forming cylinder for cooling treatment.

6. The method of claim 1, wherein, Further comprising: Excess powder of the nickel-titanium shape memory alloy lattice structure is removed through a powder cleaning device; The nickel-titanium shape memory alloy lattice structure is separated from the substrate through a wire spark; The nickel-titanium shape memory alloy lattice structure is placed in a beaker containing anhydrous ethanol; The beaker containing the nickel-titanium shape memory alloy lattice structure is placed in an ultrasonic cleaning device for cleaning for 10 minutes; The nickel-titanium shape memory alloy lattice structure after cleaning is subjected to drying treatment.

7. The method of claim 1, wherein, Further comprising: The compression test process is performed multiple times, and each time the compression test process includes: after uniaxial compression deformation of the nickel-titanium alloy buffer energy lattice structure, the nickel-titanium alloy buffer energy lattice structure after uniaxial compression deformation is placed in water at 97.5 to 98.5 degrees Celsius for shape recovery, and a photo of the nickel-titanium alloy buffer energy lattice structure after shape recovery is recorded; the compression direction is the Z-axis direction, and the deformation rate is 10 -3 The compression strain rates used in the compression test processes performed multiple times are not exactly the same. The nickel-titanium alloy buffer energy lattice structure is analyzed according to a plurality of photos of the nickel-titanium alloy buffer energy lattice structure after shape recovery, wherein the compression test process includes compression test processes with compression strain rates of 20%, 40%, 60% and 70% in the compression test process executed multiple times.

8. The method of claim 1, wherein, The laser powder bed melting of the nickel-titanium alloy powder through the printing process parameters to form the plurality of slice layers of the nickel-titanium alloy buffer energy lattice structure comprises: The laser powder bed melting of the nickel-titanium alloy powder through the printing process parameters and a three-dimensional model of the nickel-titanium alloy buffer energy lattice structure to form the plurality of slice layers of the nickel-titanium alloy buffer energy lattice structure, wherein the length, width and height of the three-dimensional model are all 32 mm, the porosity of the three-dimensional model is 94.3%, the length, width and height of the unit cell of the three-dimensional model are all 8 mm, and the spiral line diameter of the unit cell of the nickel-titanium alloy buffer energy lattice structure is 1.8 mm.

9. The method of claim 8, wherein, The three-dimensional model of the nickel-titanium alloy buffer energy lattice structure and the printing process parameters are used to perform laser powder bed fusion on the nickel-titanium alloy powder to form a plurality of slice layers of the nickel-titanium alloy buffer energy lattice structure, including: constructing the three-dimensional model; slice processing the three-dimensional model from one direction to obtain one or more slice layer models, each of which corresponds to a slice layer of the nickel-titanium alloy buffer energy lattice structure; writing the printing process parameters and the one or more slice layer models into a printing control file; importing the printing control file into the printing control software of a three-dimensional printer and starting the three-dimensional printer.

Images