Preparation method of multi-component structure gradient material and gradient structure

Abstract

The application provides a preparation method of a multi-component structure gradient material and a gradient structure, relates to the technical field of functional gradient structure design, and comprises the following steps: constructing a component gradient model and a structure gradient model by using simulation software, wherein the component gradient model comprises a plurality of single-component wafers with different densities, and the structure gradient model comprises a plurality of regulating structure units with the same size; the plurality of regulating structure units are arranged on the upper surface of the component gradient model in a preset arrangement mode, so as to form a multi-component gradient structure model, and the cross-sectional area of the structure unit model gradually increases from the direction away from the component gradient model to the direction close to the component gradient model; and a multi-component gradient structure corresponding to the multi-component gradient structure model is prepared based on printing parameters and 3D printing technology, wherein the printing parameters comprise the thickness of the single-component wafer layer, the exposure intensity and the printing speed, and the application is helpful to improve the impedance adjustable range of the structure gradient material.

Description

Technical Field

[0001] The present invention relates to the technical field of functional gradient structure design, and in particular to a preparation method of a multi-component structural gradient material and a gradient structure. Background Art

[0002] Materials in key areas such as national defense security (advanced weapons, artillery) and high-end manufacturing (cutting tools) need to withstand high stress (1 to 100 GPa), wide strain rate (10 4 ~10 6 / s) of extreme service load conditions. Accurately understanding and mastering the evolutionary behavior of materials in extreme service environments is crucial for improving service safety, developing advanced strategic weapons, and establishing a material genetic engineering database. The dynamic high-pressure technologies used to simulate extreme service environments of materials are mainly impact loading technology and Hopkinson bar (SHPB) technology. The former uses homogeneous flying pieces, which leads to high impact pressure and large strain rate (700GPa, 10 8 / s, the latter has a lower loading strain rate (10 -4 ~10 0 Controllable loading technology, on the other hand, involves gradiently varying the wave impedance of a homogeneous flying sheet during impact loading from low to high along its flight direction, generating a loading wave with a slowly increasing pressure upon hitting a target. This technology can economically and effectively simulate the extreme service load environments of key materials in a laboratory environment. It has the advantages of large temporal and spatial scales, relatively controllable wavefronts, high measurement accuracy (absolute measurement), and low technical cost, and has become the mainstream experimental technology internationally for achieving different loading stresses and strain rates.

[0003] Chinese patent publication number CN118269354A discloses a gradient structure and preparation method for achieving controllable stress-strain rate loading. The method comprises the following steps: constructing a dielectric substrate model and multiple identical structural element models using simulation software; placing the multiple structural element models in a predetermined arrangement on the upper surface of the dielectric substrate model to form a gradient structure STL model, wherein the cross-sectional area of ​​the structural element models gradually increases from a direction away from the dielectric substrate model toward a direction close to the dielectric substrate model; preprocessing the gradient structure STL model to obtain a gradient structure slice model, wherein the gradient structure slice model includes multiple two-dimensional slices of equal thickness; and fabricating a surface density gradient structure corresponding to the gradient structure slice model based on printing parameters and surface projection micro-stereolithography technology. However, the above scheme fails to consider the multi-path loading waveform of the component gradient model, the structure-activity relationship between the gradient structure with a wide stress-strain rate control range, the stress-strain rate, and the controllable loading waveform, resulting in a single impedance and a narrow impedance range for the structural gradient material. Therefore, it is highly necessary to provide a preparation method and gradient structure for a multi-component structural gradient material to improve the impedance control range of the structural gradient material. Summary of the Invention

[0004] In light of this, the present invention proposes a method for preparing a multi-component structural gradient material and its gradient structure. By designing single-component discs of varying density within the component gradient model and rationally configuring controllable structural primitives of uniform size within the structural gradient model, dual gradient control of both material composition and structural properties is achieved, thereby improving the impedance controllable range of the structural gradient material.

[0005] The present invention provides a method for preparing a multi-component structural gradient material, the method comprising:

[0006] Constructing a component gradient model and a structural gradient model using simulation software, wherein the component gradient model includes a plurality of single-component discs with different densities, and the structural gradient model includes a plurality of regulatory structural primitives with the same size;

[0007] Arranging a plurality of the regulatory structural primitives in a preset arrangement on the upper surface of the component gradient model to form a multi-component gradient structural model, wherein the cross-sectional area of ​​the structural primitive model gradually increases from a direction away from the component gradient model toward a direction close to the component gradient model;

[0008] Based on printing parameters and 3D printing technology, a multi-component gradient structure corresponding to the multi-component gradient structure model is prepared, wherein the printing parameters include the thickness of the single-component disc layer, exposure intensity and printing speed.

[0009] On the basis of the above technical solution, preferably, based on printing parameters and 3D printing technology, a multi-component gradient structure corresponding to the multi-component gradient structure model is prepared, specifically including:

[0010] Printing a component gradient structure corresponding to the component gradient model using an FDM device, wherein the nozzle temperature of the FDM device is set to 200-230°, the printing speed of the FDM device is set to 25-40 mm, and the layer thickness of the single-component disc is set to 0.05-0.2 mm;

[0011] The SLA device is used to print a structural gradient corresponding to the structural gradient model on the upper surface of the component gradient structure, wherein the light wavelength used by the SLA device is 355nm, the layer thickness of the printing of the SLA device is set to 0.01-0.05mm, and the exposure intensity of the SLA device is set to 20-100mW / cm 2 ;

[0012] The prepared multi-component gradient structure was cleaned and placed under a light intensity of 60-80 mW / cm 2 The secondary curing is completed by irradiating in a curing box for 15 to 30 minutes.

[0013] In the above technical solutions, preferably, the Hill function and the impedance change function of the regulating structural element are respectively:

[0014] f(x)=f(0)+R×(x h ) / (x h +K h )

[0015] Z(x)=k×ρ×C b ×[f(x)] 2

[0016] wherein f(x) represents the Hill function of the regulating structural element, x represents the thickness coordinate of the structural gradient material from the low-density end, f(0) represents the minimum radius of the tip of the actually prepared structural element, R represents the regulating impedance change range, K represents the proportion coefficient of the impedance change span, h represents the Hill coefficient of the regulating impedance change form, Z(x) represents the impedance change function at the x-thickness position from the initial layer, p represents the material density at the x-thickness position from the initial layer, C b represents the normal pressure sound speed at the x-thickness position from the initial layer, and k represents the impedance change proportion coefficient.

[0017] Further preferably, the single-component wafer is prepared from a resin-based composite material filled with metal particles in different contents, and the particle size of the metal particles is 1-10 microns.

[0018] Further preferably, the metal particles are copper particles, and the resin-based composite material is PMMA.

[0019] Further preferably, the mass fraction of the copper particles is any one of 10wt.%, 25wt.%, 40wt.% and 60wt.%, and the mass fraction of the PMMA is any one of 90wt.%, 75wt.%, 60wt.% and 40wt.%.

[0020] Further preferably, the thickness of the single-component wafer is 50-400 microns, and the density of the single-component wafer is 1.3-4.5 g / cm 3 .

[0021] Further preferably, the component gradient model comprises five single-component wafers with different densities, and the single-component wafers are stacked in order of decreasing density to obtain a component gradient model with uniformly increasing component density.

[0022] Further preferably, the regulating structural element comprises any one of polyurethane acrylic resin, polyester acrylic resin and amino acrylic resin, and the bulk density of the regulating structural element is 0-1.3 g / cm3 .

[0023] The application also provides a gradient structure of the multi-component structure gradient material prepared by the preparation method.

[0024] The application provides a preparation method and a gradient structure of a multi-component structure gradient material, which have the following beneficial effects relative to the prior art:

[0025] (1) By designing and reasonably configuring the single-component wafer with different densities in the component gradient model and the size-consistent regulation structure unit in the structure gradient model, dual gradient regulation of material components and structure characteristics is realized, the problem of single structure caused by structure parameter regulation and the limited regulation range are solved, the impedance regulation range of the structure gradient material is improved, the stress concentration phenomenon is effectively improved by the gradual design of the structure unit cross-sectional area, the mechanical properties and stability of the structure are improved, the 3D printing parameters such as layer thickness, exposure intensity and printing speed are accurately controlled to ensure the forming quality and manufacturing efficiency, and the material interface bonding strength is enhanced.

[0026] (2) By organically combining the Hill function and the impedance change function, a quantitative relationship between the structure parameters and the performance is established, the Hill function realizes the continuous controllable change of the structure unit size by adjusting the Hill coefficient h, the proportion coefficient K and the R value, the impedance change function considers the influence of the material density and the sound speed, and the accurate regulation of the impedance is realized, this multi-parameter collaborative control method not only provides theoretical guidance for structure design and mathematical basis for performance prediction, but also has good parameter adjustability and engineering applicability.

[0027] (3) By adopting the multi-level ratio combination of the copper particles with a particle size of 1-10 μm and the PMMA resin-based composite material, the accurate thickness control and density gradient regulation of the single-component wafer are realized, the micron-level copper particles ensure good dispersibility and interface bonding, the PMMA resin matrix provides excellent processing performance and coating performance, and the multi-level ratio optimizes the interface stress distribution, so that not only the continuous controllable change of the material performance is realized, but also practical advantages such as controllable process flow, predictable performance and reasonable cost are achieved. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only some embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0029] Figure 1 The flowchart of the preparation method of the multi-component structure gradient material provided by the application is shown in the figure.

[0030] Figure 2 A schematic structural diagram of the multi-component gradient structure model provided by the present invention;

[0031] Figure 3 A schematic diagram of mathematical function control with different wave impedance distribution indices provided by the present invention;

[0032] Figure 4 A schematic diagram of the structure of a multi-dimensional arrangement for achieving controllable stress and strain rates provided by the present invention;

[0033] Figure 5 A schematic diagram of the control effect of achieving the stress-strain rate range provided by the present invention;

[0034] Figure 6 Impedance distribution diagram for achieving stress-strain rate range provided by the present invention;

[0035] Figure 7 A microstructure diagram of the gradient structure provided by the present invention;

[0036] Figure 8 This is a tensile strength curve diagram for the stress-strain rate range provided by the present invention. DETAILED DESCRIPTION

[0037] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0038] Before introducing the embodiments of the present invention, some terms and their abbreviations involved in the embodiments of the present invention are first defined and explained.

[0039] Gradient materials are materials with gradually changing properties, where their properties or composition vary continuously along one or more directions. This gradual change can include variations in the material's chemical composition, physical properties, structure, or morphology. Gradient materials are designed to achieve more precise control and optimize their performance to meet the needs of specific applications. Gradient materials can be categorized by the properties they vary, including but not limited to mechanical, optical, thermal, and electromagnetic properties. The following are some common types of gradient materials: Mechanically gradient materials: These materials exhibit a gradual change in hardness, strength, or toughness within the material, thereby optimizing local stress distribution and improving wear resistance and fatigue resistance. Thermally gradient materials: These materials exhibit a gradual change in thermal conductivity along a specific direction and can play an important role in thermal management, such as in thermal barrier coatings or heat energy conversion devices. Optically gradient materials: These materials exhibit a gradual change in refractive index or transparency across a spatial scale and can be used to manufacture optical components such as lenses, prisms, and optical waveguides. Chemically gradient materials: These materials exhibit a gradual change in chemical composition or surface treatment within the material and can be used in surface coatings, biomedical materials, and other fields.

[0040] FDM technology is an additive manufacturing process based on the melting, extrusion, and layer-by-layer deposition of thermoplastic materials. This involves heating filamentary thermoplastic material to a molten state, depositing it layer by layer along a pre-set path through a precisely controlled nozzle system, and then cooling and solidifying it to form a three-dimensional solid model. As one of the earliest 3D printing technologies, FDM has become the most widely used 3D printing technology due to its advantages such as simple equipment structure, easy operation and maintenance, and a wide range of material options. It plays a vital role in product prototyping, education and training, and small-batch production.

[0041] Stereolithography (SLA) technology: SLA technology is based on the principle that photosensitive resin undergoes photopolymerization when exposed to light of a specific wavelength. By controlling a laser beam or projector light source to selectively illuminate the liquid photosensitive resin, it solidifies in specific areas and ultimately forms a three-dimensional solid model through layer-by-layer stacking. As one of the earliest technologies in the field of additive manufacturing, SLA has the advantages of high molding precision, good surface quality, and the ability to realize complex structures. With the continuous advancement of light source technology, resin materials, and control systems, especially the introduction of DLP (digital light processing) technology, SLA equipment has achieved significant improvements in molding efficiency, material properties, and application range.

[0042] The present invention discloses a method for preparing a multi-component structure gradient material, referring to Figure 1 , the steps of the method include S1 to S3.

[0043] Step S1, constructing a component gradient model and a structural gradient model through simulation software, wherein the component gradient model includes multiple single-component discs with different densities, and the structural gradient model includes multiple regulatory structural primitives with the same size.

[0044] In this step, if Figure 2 As shown in the figure, a component gradient model was created in SolidWorks, and the printing path of the gradient model was obtained through slicing software. When constructing multiple identical structural primitive models using simulation software, the Hill function and impedance change function were used to obtain the changing relationship between the thickness of different control structural primitives and the wave impedance value distribution, thereby constructing the control structural primitives.

[0045] The Hill function and impedance change function of the control structure element are:

[0046] f(x)=f(0)+R×(x h ) / (x h +K h )

[0047] Z(x)=k×ρ×C b ×[f(x)] 2

[0048] Wherein, f(x) represents the Hill function of the control structure unit, x represents the thickness coordinate of the structure gradient material from the low-density end, f(0) represents the minimum radius of the tip of the actual prepared structure unit, R represents the control impedance change range, K represents the proportional coefficient of the impedance change span, h represents the Hill coefficient of the control impedance change form, Z(x) represents the impedance change function at the position x thickness away from the initial layer, ρ represents the material density at the position x thickness away from the initial layer, C b represents the sound velocity at constant pressure at a position x thickness away from the initial layer, and k represents the impedance change proportional coefficient.

[0049] Through the organic combination of the Hill function and the impedance change function, a quantitative relationship between structural parameters and performance was established. The Hill function achieves continuous and controllable changes in the size of the structural element by adjusting the Hill coefficient h, proportional coefficient K and R value. The impedance change function takes into account the influence of material density and sound speed, achieving precise regulation of impedance. This multi-parameter collaborative control method not only provides theoretical guidance for structural design and a mathematical basis for performance prediction, but also has good parameter adjustability and engineering applicability.

[0050] In this embodiment, a gradient structure with a wide adjustable range of impedance change is obtained by regulating the gradient structure through mathematical expression, which solves the problem of single structure and limited adjustable range caused by regulating the structure through structural parameters. At the same time, based on mathematical expression, programming code and finite element simulation software are used to directly obtain the stress and strain rate data of the designed structure, avoiding the high cost and low benefit of obtaining data by changing empirical structural parameters, and difficulty in constructing the structure-activity relationship between the structure and the controllable loading waveform and stress-strain rate.

[0051] In this embodiment, the regulating structural unit includes any one of polyurethane acrylic resin, polyester acrylic resin and amino acrylic resin, and the volume density of the regulating structural unit is 0-1.3 g / cm 3 By using polyurethane acrylic resin, polyester acrylic resin or amino acrylic resin as the structural element material, combined with 0-1.3g / cm 3 The controllable density range enables precise regulation of the performance of structural elements; the optionality of three resin materials provides greater design freedom. At the same time, the wide density control range ensures good matching with the matrix material. It not only has excellent processing performance and molding characteristics, but also can meet the performance requirements of different application scenarios, providing a flexible and reliable material selection solution for the practical application of regulating structural elements.

[0052] Furthermore, a single-component disc is prepared by filling a resin-based composite material with metal particles at different contents. The metal particles have a particle size of 1 to 10 μm, are copper particles, and the resin-based composite material is PMMA. The mass fraction of the copper particles is any one of 10 wt.%, 25 wt.%, 40 wt.%, and 60 wt.%, and the mass fraction of PMMA is any one of 90 wt.%, 75 wt.%, 60 wt.%, and 40 wt.%. The thickness of the single-component disc is 50 to 400 μm, and the density of the single-component disc is 1.3 to 4.5 g / cm 3 .

[0053] By adopting a multi-stage ratio combination of copper particles with a particle size of 1 to 10 μm and PMMA resin-based composite materials, precise thickness control and density gradient regulation of single-component wafers are achieved. The micron-sized copper particles ensure good dispersion and interface bonding, the PMMA resin matrix provides excellent processing performance and coating properties, and the multi-stage ratio optimizes the interfacial stress distribution. This not only achieves continuous and controllable changes in material properties, but also has practical advantages such as controllable process flow, predictable performance, and reasonable cost, providing a feasible technical solution for the practical application of functional gradient materials.

[0054] In one example, the component gradient model includes five layers of single-component discs with different densities, and the multiple single-component discs are stacked in order from small to large density to obtain a component gradient model with uniformly increasing component density.

[0055] In step S2, a plurality of regulatory structural primitives are arranged in a preset manner on the upper surface of the component gradient model to form a multi-component gradient structural model, wherein the cross-sectional area of ​​the structural primitive model gradually increases from the direction away from the component gradient model toward the direction close to the component gradient model.

[0056] In this step, the multi-component gradient structure model is composed of multiple structural element models with gradually increasing cross-sectional areas densely arranged on the upper surface of a component gradient model with a certain thickness and diameter. By changing the structure of the structural element, the surface density distribution of the gradient structure is controlled, and then the wave impedance distribution of the gradient structure is controlled. The surface density gradient material is prepared in an integrated manner using additive manufacturing technology. The preparation accuracy is coordinated by controlling the thickness of the resin layer and the degree of polymerization to obtain a gradient structure with excellent interlayer bonding strength, low tip size, and no warping defects.

[0057] Step S3, preparing a multi-component gradient structure corresponding to the multi-component gradient structure model based on printing parameters and 3D printing technology, wherein the printing parameters include single-component disc layer thickness, exposure intensity and printing speed.

[0058] In one example, a composition gradient structure was first obtained by extruding PLA filament through an FDM equipment nozzle (0.2mm and 0.4mm nozzle diameters). The composition gradient structure was then moved to an SLA equipment via a robotic arm for further light curing to obtain a gradient structure densely packed on the composition gradient structure. The composition gradient structure was first obtained by hot pressing a mixed material with different Cu mass fractions to obtain a single-component disc with a single layer thickness of 50 to 400μm. The different single-component discs were then stacked in increasing density and linked by hot pressing to obtain a composition gradient material with uniformly increasing component density.

[0059] This step also includes steps S31 to S33.

[0060] In step S31, an FDM device is used to print a component gradient structure corresponding to the component gradient model, wherein the nozzle temperature of the FDM device is set to 200-230°, the printing speed of the FDM device is set to 25-40 mm, and the layer thickness of the single-component disc is set to 0.05-0.2 mm.

[0061] In this step, the multi-component gradient material is modeled by Solidworks, and the printing path of the component gradient model is obtained by slicing software processing. The FDM device is used to extrude 1.75 mm TPU and PLA filaments, the nozzle temperature is between 200-230 degrees Celsius, the layer thickness is set to 0.05-0.2 mm, the platform temperature is set to 50-70 degrees Celsius, and the printing speed is between 25-40 mm.

[0062] In step S32, the SLA device is used to print a structure gradient corresponding to the structure gradient model on the upper surface of the component gradient structure, wherein the wavelength of the SLA device is 355 nm, the layer thickness of the SLA device is set to 0.01-0.05 mm, and the exposure intensity of the SLA device is set to 20-100 mW / cm 2 .

[0063] In this step, the component gradient model with a density of 1.1-1.3 is clamped by a mechanical arm to the center of the working area of the SLA device. The mechanical arm sends a signal, and the SLA device receives the signal and continues to print the structure gradient model on the component gradient model. The material used by the SLA device is acrylate material, the wavelength of the SLA device is 355 nm, the layer thickness is set to 0.01-0.05 mm, the light intensity is 20-100 mW / cm 2 , and the exposure time is 0.1-2 s.

[0064] Further, 10 wt. % Cu particles (25 wt. %, 40 wt. %, 60 wt. %) and 90 wt. % (75 wt. %, 60 wt. %, 40 wt. %) PMMA are placed in an internal mixer at 200-230 °C, a rotation speed of 60-40 r / min, and internal mixing for 10-30 min. The higher the metal particle content, the higher the temperature setting, the slower the rotation speed, and the longer the internal mixing time. The materials with different metal particle contents obtained by internal mixing are respectively hot-pressed, the materials are heated to 175-200 °C to be in a flowable state, the pressure between the upper and lower platens of the hot press is set to 5-20 MPa, and the hot press is performed at a constant pressure for 20-30 min to obtain single-component circular sheets with a layer thickness of 70-150 microns. The single-component circular sheets with different component contents are hot-pressed to increase the metal content from low to high to obtain a component gradient structure.

[0065] The circular plate of the structure gradient material obtained by additive manufacturing is linked to the end with the lowest metal content of the component gradient material obtained by hot pressing, and epoxy AB glue is used for bonding. The two are linked by AB glue and placed in an environment of 30-50 degrees Celsius for 1-3 hours to complete the linking to obtain a multi-component gradient structure.

[0066] In this embodiment, by precisely controlling the mixing process parameters and hot-pressing process parameters, high-quality preparation of composite materials with different metal contents is achieved. The higher the metal content, the higher the temperature, the lower the speed and the longer the mixing time are used to ensure the uniformity of the material. At the same time, micron-thick single-component wafers are obtained by hot-pressing preparation and the construction of component gradient structure is realized. Then, the epoxy resin AB glue is used to reliably connect the structure gradient material and the component gradient material, forming a multi-component gradient structure with controllable performance and stable structure. The combined hot-pressing, fused deposition and photocuring techniques are used to obtain a multi-component gradient structure material with zero initial impedance, wide range and uniform transition. While ensuring extremely weak initial impact, the problem of single structure gradient material and narrow density range is solved, and a multi-component gradient material with uniform transition from 0 to 4.5 is realized.

[0067] Step S33, the prepared multi-component gradient structure is washed and placed in a curing box with light intensity of 60-80 mW / cm 2 for 15-30 min to complete the secondary curing.

[0068] By designing single-component wafers with different densities in the component gradient model and reasonably configuring the structure gradient model with the same size of structure base units, the dual gradient control of material components and structure characteristics is realized, solving the problem of single structure caused by structure parameter control and the limited adjustable range, thereby improving the impedance adjustable range of the structure gradient material. The gradual design of the cross-sectional area of the structure base unit effectively improves the stress concentration phenomenon and improves the mechanical properties and stability of the structure. By precisely controlling the 3D printing parameters such as layer thickness, exposure intensity and printing speed, the forming quality and manufacturing efficiency are ensured, and the material interface bonding strength is enhanced.

[0069] Please refer to Figure 3 , Figure 3 for the different mathematical function control diagrams of the Hill coefficient for regulating the impedance change range, the impedance change form, and the proportion coefficient of the impedance change span.

[0070] Please continue to refer to Figure 4 and Figure 5 , which are respectively the four kinds of multi-dimensional arrangement forms for realizing controllable stress and strain rate, and the control effect diagrams corresponding to the above four kinds of multi-dimensional arrangement forms.

[0071] Please refer to Figure 6 , Figure 6 for the impedance change trend graph under different mass percentages (wt%). In the graph, the horizontal coordinate represents different concentration conditions from the comparative example to 60wt%, and the vertical coordinate represents the impedance value, with the unit of *10 6 kg / m 2·s. It can be seen from the data that the impedance value presents an obvious upward trend with the increase of wt%. The impedance of the comparative example is 3.4, and it increases to 6.3 at 10 wt%, to 7.8 at 25 wt%, to 9.2 at 40 wt%, and to the highest value 11.1 at 60 wt%. Figure 6 The data points are connected by oblique lines, which intuitively show the gradual change of impedance with the increase of concentration, and reflect the continuous change characteristics of material performance.

[0072] As shown in Figure 7 , Figure 7 The microstructure and structural characteristics of the multi-component structure gradient material are shown in Figure 7 (A) shows the pyramid-shaped microstructure with gradient structure, the ladder-shaped structure with interlayer spacing in the range of 39-41 μm, and the regular hexagonal concentric ring structure with the center area size of 41.2 μm from left to right, Figure 7 (B) on the left side shows the layered structure of different regions by three dashed lines (a, b, c), and the right three columnar structure diagrams (a, b, c) show the gradient change of the material from low density to high density.

[0073] As shown in Figure 8 , Figure 8 The tensile strength curve diagram is shown, and the curve of Example 2 is the highest, with a maximum stress of about 55 MPa, showing the best mechanical properties. The curve of Example 1 is below Example 2, with a maximum stress of about 45 MPa, and the performance is second. The curve of the comparative example is the lowest, with a maximum stress of about 30 MPa, showing the worst mechanical properties. All curves show linear growth at the initial stage, and with the increase of strain, the curve enters the nonlinear region, showing plastic deformation, and finally all samples appear to be broken at about 20-25% strain.

[0074] The above only describes the preferred embodiments of the present application and does not limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a multi-component structural gradient material, characterized in that: The method comprises: Constructing a component gradient model and a structural gradient model using simulation software, wherein the component gradient model includes a plurality of single-component discs with different densities, and the structural gradient model includes a plurality of regulatory structural primitives with the same size; The Hill function and impedance change function of the control structure element are: f ( x )= f (0) +R ×( x h ) / ( x h + K h ) Z ( x )= k × ρ × C b ×[ f ( x )] 2 in, f ( x ) represents the Hill function of the regulatory structural motif, x Represents the thickness coordinate of the structural gradient material from the low-density end, f (0) represents the minimum radius of the tip of the actual prepared structural unit, R Indicates the range of impedance regulation. K The proportional coefficient representing the impedance change span, h The Hill coefficient representing the change in the control impedance, Z ( x ) indicates the distance from the initial layer x Impedance variation function at thickness location, ρ Indicates the distance from the initial layer x Material density at the thickness, C b Indicates the distance from the initial layer x The sound velocity at normal pressure at the thickness position, k Indicates the impedance change proportional coefficient; Arranging a plurality of the regulatory structural primitives in a preset arrangement on the upper surface of the component gradient model to form a multi-component gradient structural model, wherein the cross-sectional area of ​​the structural primitive model gradually increases from a direction away from the component gradient model toward a direction close to the component gradient model; Based on printing parameters and 3D printing technology, a multi-component gradient structure corresponding to the multi-component gradient structure model is prepared, wherein the printing parameters include the thickness of the single-component disc layer, exposure intensity and printing speed.

2. The method for preparing a multi-component structural gradient material according to claim 1, wherein: Based on printing parameters and 3D printing technology, a multi-component gradient structure corresponding to the multi-component gradient structure model is prepared, specifically including: Printing a component gradient structure corresponding to the component gradient model using an FDM device, wherein the nozzle temperature of the FDM device is set to 200-230°, the printing speed of the FDM device is set to 25-40 mm, and the layer thickness of the single-component disc is set to 0.05-0.2 mm; The structure gradient corresponding to the structure gradient model is printed on the upper surface of the component gradient structure using an SLA device, wherein the light wavelength used by the SLA device is 355 nm, the layer thickness of the printing of the SLA device is set to 0.01-0.05 mm, and the exposure intensity of the SLA device is set to 20-100 mW / cm 2 ; The prepared multi-component gradient structure was cleaned and placed under a light intensity of 60-80 mW / cm 2 The secondary curing is completed by irradiating in a curing box for 15 to 30 minutes.

3. The method for preparing a multi-component structural gradient material according to claim 1, wherein: The single-component disc is prepared by filling a resin-based composite material with metal particles of different contents, and the particle size of the metal particles is 1-10 μm.

4. The method for preparing a multi-component structural gradient material according to claim 3, wherein: The metal particles are copper particles, and the resin-based composite material is PMMA.

5. The method for preparing a multi-component structural gradient material according to claim 4, wherein: The mass fraction of the copper particles is any one of 10 wt.%, 25 wt.%, 40 wt.% and 60 wt.%.

6. The method for preparing a multi-component structural gradient material according to claim 1, wherein: The thickness of the single-component disc is 50-400 μm, and the density of the single-component disc is 1.3-4.5 g / cm 3 .

7. The method for preparing a multi-component structural gradient material according to claim 1, wherein: The component gradient model includes five layers of single-component discs with different densities. Multiple single-component discs are stacked in order from small to large density to obtain a component gradient model with uniformly increasing component density.

8. The method for preparing a multi-component structural gradient material according to claim 1, wherein: The regulatory structural unit includes any one of polyurethane acrylic resin, polyester acrylic resin and amino acrylic resin, and the volume density of the regulatory structural unit is 0-1.3 g / cm 3 .

9. The gradient structure of the multi-component structural gradient material obtained by the preparation method according to any one of claims 1 to 8.

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