Analysis method, system and equipment for microstructure of metal additive manufacturing sample piece and medium

Abstract

The invention discloses an analysis method, system and equipment for a microstructure of a metal additive manufacturing sample piece and a medium. The analysis method comprises the steps that a finite element model of ultrasonic propagation is established; in the finite element model of ultrasonic propagation, according to an elastic power time propulsion method, solving a dynamic equilibrium equation to obtain an ultrasonic signal of a time domain; converting the time-domain ultrasonic signals into frequency-domain signals, calculating frequency-domain ultrasonic attenuation values in the X direction, the Y direction and the Z direction under a sample coordinate system, and establishing a relation curve between the frequency-domain ultrasonic attenuation values and microstructure anisotropy indexes, the method, the system, the equipment and the medium can adapt to ultrasonic nondestructive characterization analysis of microstructure characteristics of the metal additive manufacturing sample piece.

Description

Technical Field

[0001] The present invention belongs to the field of material characterization testing, and relates to an analysis method, system, equipment and medium for the microstructure of a metal additive manufacturing sample. Background Art

[0002] In recent years, metal additive manufacturing technology has developed rapidly and has gradually moved from the laboratory to industrial applications. With its flexibility, high efficiency and the ability to process complex and high-performance products, it is widely used in high-end industries such as aerospace, automobiles, and medical care. As key components, the durability and safety of metal additive manufacturing products during service are particularly important, and the microstructure of the material is the core factor affecting the quality and mechanical properties of the component. Therefore, effective characterization of the microstructure of the material has become a key prerequisite for ensuring product quality. Existing microstructure characterization methods mainly include optical microscopy, X-ray related technology, transmission electron microscopy, and scanning electron microscopy. Although these technologies can provide fine organizational information, they usually cause certain damage to the product and it is difficult to obtain internal information. There are limitations in the characterization size and the characterization efficiency is low, which makes it difficult to meet the rapid characterization needs of actual industrial products. Against this background, non-destructive material characterization methods based on ultrasonic technology have emerged.

[0003] Metal additive manufacturing parts are mostly polycrystalline materials. Compared with traditional processing technology, its layer-by-layer manufacturing strategy and complex thermal cycle process make the samples show significant anisotropy and non-uniformity. These characteristics originate from the changes in grain size, shape and orientation, resulting in obvious differences in the mechanical properties of the material in different directions. However, the existing ultrasonic characterization technology of the microstructure of polycrystalline materials does not fully consider the particularity of grain shape and orientation in metal additive manufacturing parts, especially in the analysis of the propagation mechanism of ultrasonic waves in polycrystalline materials, there is a lack of consideration of the complex situation of the existence of texture. To solve these problems, it is urgent to develop an ultrasonic non-destructive characterization analysis method that can adapt to the unique microstructural characteristics of metal additive manufacturing samples. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and to provide a method, system, equipment and medium for analyzing the microstructure of metal additively manufactured samples. The method, system, equipment and medium can be adapted for ultrasonic non-destructive characterization and analysis of the microstructure characteristics of metal additively manufactured samples.

[0005] To achieve the above object, the present invention discloses a method for analyzing the microstructure of a metal additive manufacturing sample, comprising:

[0006] Establish a finite element model of ultrasonic propagation;

[0007] In the finite element model of ultrasonic wave propagation, the dynamic equilibrium equation is solved according to the elastic dynamic time marching method to obtain the ultrasonic signal in the time domain;

[0008] The time domain ultrasonic signal is converted into a frequency domain signal, the frequency domain ultrasonic attenuation values ​​in three directions of XYZ in the sample coordinate system are calculated, and a relationship curve between the frequency domain ultrasonic attenuation value and the microstructure anisotropy index is established.

[0009] Furthermore, the process of establishing the finite element model of ultrasonic propagation is:

[0010] Testing the grain orientation information of the microstructure of metal additive manufacturing samples, and establishing a polycrystalline material model based on the macroscopic statistical characteristics of the grain orientation information;

[0011] Material parameters are set, and according to the Euler angles and rotation matrix in the polycrystalline material model, the stiffness matrix of each grain in the polycrystalline material is calculated using the stiffness matrix of the single crystal material, boundary conditions are set, and a finite element model of ultrasonic propagation is established.

[0012] Furthermore, the rotation matrix T is:

[0013]

[0014] Furthermore, the stiffness matrix C of each grain is:

[0015]

[0016] Among them, c 11 、c 12 and c 44 is the independent elastic constant.

[0017] Furthermore, the frequency domain ultrasonic attenuation values ​​in the three directions of XYZ in the sample coordinate system are calculated according to formula (6);

[0018]

[0019] Among them, Attenuation dB (f) represents the attenuation value at frequency f, h is the distance between the excitation source and the reflecting surface, and A1 and A2 are the amplitudes of the first and second echoes respectively.

[0020] Furthermore, the frequency domain ultrasonic attenuation value directional index and microstructure anisotropy index are:

[0021]

[0022] Among them, Attenuation Elongated Attenuation S h ortenedThey represent the attenuation values ​​in the long axis direction and short axis direction of the grain, AR is the attenuation ratio, TI Elongated and TI Shortened They represent the texture strength in the major axis direction and minor axis direction of the grain respectively, and TIR is the texture intensity ratio.

[0023] The present invention discloses a system for analyzing the microstructure of a metal additive manufacturing sample, comprising:

[0024] Building a module for building a finite element model of ultrasonic propagation;

[0025] A solution module, used for solving the dynamic equilibrium equation in the finite element model of ultrasonic wave propagation according to the elastic dynamic time marching method to obtain an ultrasonic signal in the time domain;

[0026] The calculation module is used to convert the time domain ultrasonic signal into a frequency domain signal, calculate the frequency domain ultrasonic attenuation values ​​in three directions of XYZ in the sample coordinate system, and establish a relationship curve between the frequency domain ultrasonic attenuation value and the anisotropy index of the microstructure.

[0027] Furthermore, the establishment module includes:

[0028] A testing module, used to test the grain orientation information of the microstructure of the metal additive manufacturing sample, and to establish a polycrystalline material model based on the macroscopic statistical characteristics of the grain orientation information;

[0029] The construction module is used to set material parameters, calculate the stiffness matrix of each grain in the polycrystalline material according to the Euler angles and rotation matrix in the polycrystalline material model, use the stiffness matrix of the single crystal material, set boundary conditions, and establish a finite element model of ultrasonic propagation.

[0030] The present invention discloses a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method for analyzing the microstructure of a metal additive manufacturing sample are implemented.

[0031] The present invention discloses a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for analyzing the microstructure of a metal additive manufacturing sample are implemented.

[0032] The present invention has the following beneficial effects:

[0033] The analysis method, system, equipment and medium of the microstructure of metal additive manufacturing samples described in the present invention build a complete propagation mechanism analysis framework during specific operation, establish the correlation between process parameters and organizational anisotropy through crystallographic experiments, analyze the microstructure characteristics of metal additive manufacturing in actual engineering, describe it in the polycrystalline material model, and adopt a model based on the real crystal orientation characteristics, which can better reflect the complexity of the microstructure of metal additive manufacturing parts, and is more convincing and representative; numerical simulation analysis introduces the actual characteristics of the microstructure, while the existing technology fails to keep pace with industrial practice when analyzing the ultrasonic propagation mechanism in polycrystalline materials, and does not simultaneously consider the anisotropy caused by grain morphology and orientation. Therefore, the present invention can effectively and accurately establish a quantitative relationship between ultrasonic attenuation and texture strength through the calculation of the finite element model, and provide a theoretical basis and guidance for non-destructive characterization of the microstructure of metal additive manufacturing parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0035] Figure 1 The 316L sample processed by SEBM additive manufacturing process; (a) is the original molded part, (b) is the cubic sample after wire cutting, and (c) is the sample coordinate system;

[0036] Figure 2 The graphs are the experimental results of electron backscatter diffraction; (a) is the inverse pole figure in the YZ plane, (b) is the inverse pole figure in the XZ plane, (c) is the inverse pole figure in the XY plane, and (d) is the pole figure;

[0037] Figure 3 It is a schematic diagram of the polycrystalline finite element model;

[0038] Figure 4 It is a pole figure representing the microstructure orientation characteristics of the polycrystalline model; among them, (a)-(e) shows that the texture strength in the X and Y directions gradually decreases;

[0039] Figure 5 is a graph showing the relationship between ultrasonic attenuation and frequency based on the finite element model; (a)-(e) are the corresponding Figure 4 (a)-(e) Relationship between ultrasonic attenuation and frequency of the polycrystalline model with microstructural characteristics;

[0040] Figure 6 This is a graph showing the relationship between ultrasonic attenuation ratio and texture strength ratio. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.

[0042] In the description of the present invention, it should be understood that the terms “include” and “comprises” indicate the presence of described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0043] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0044] It should be further understood that the term "and / or" used in the present specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in the present invention generally indicates that the associated objects are in an "or" relationship.

[0045] It should be understood that, although the terms first, second, third, etc. may be used to describe preset ranges, etc. in the embodiments of the present invention, these preset ranges should not be limited to these terms. These terms are only used to distinguish preset ranges from each other. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0046] The word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.

[0047] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings here can usually be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0048] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0049] Embodiment 1

[0050] The method for analyzing the microstructure of a metal additive manufacturing sample of the present invention comprises the following steps:

[0051] 1) Testing the grain orientation information of the microstructure of the metal additive manufacturing sample by electron backscatter diffraction equipment, and establishing a polycrystalline material model based on the macroscopic statistical characteristics of the grain orientation information;

[0052] Selective electron beam melting technology is used to print the frustum sample, such as Figure 1 As shown in (a), the sample is cut into Figure 1 (b) shows a cube with a size of 13 mm × 13 mm × 13 mm. The coordinate system O-XYZ is established according to the sample, as shown in Figure 1 As shown in (c), the direction of the Z axis is set to be consistent with the molding direction of the sample. In the XY, XZ, and YZ planes, a sheet sample with a cross-sectional area of ​​10 mm × 10 mm and a thickness of 3 mm is cut for the electron backscatter diffraction experiment. Figure 2 The EBSD experimental results show that the sample exhibits columnar crystals and strong texture with <1 0 0> orientation along the molding direction, and weak texture with <1 0 0> orientation along the X and Y directions.

[0053] Based on the microstructure feature information obtained through experiments, a random oriented equiaxed polycrystalline model, a random oriented columnar polycrystalline model, an equiaxed polycrystalline model with texture, and a columnar polycrystalline model with texture are generated based on the Voronoi tessellation method. The phase attributes of the model include grain size distribution and orientation information (Euler angle Φ, ).

[0054] 2) setting material parameters, calculating the stiffness matrix of each grain in the polycrystalline material using the stiffness matrix of the single crystal material according to the Euler angles and the rotation matrix in the polycrystalline material model, setting boundary conditions, and establishing a finite element model of ultrasonic propagation;

[0055] The material used for printing samples is 316L. The material parameters are shown in Table 1, including density, i.e., elastic parameters. According to the orientation difference between the sample coordinate system O-XYZ and the crystal coordinate system <1 0 0>-<0 1 0>-<0 0 1>, the stiffness matrix of each grain is obtained by the rotation matrix. The rotation matrix is:

[0056]

[0057] Among them, T Z (φ), T X (φ) are the rotation matrices of the rotation angle φ around the Z axis and the X axis respectively. For the ZXZ rotation axis sequence, the rotation matrix T is:

[0058]

[0059] The selected material 316L is a cubic crystal system. According to the symmetry of the cubic crystal system, the stiffness matrix C of each grain is:

[0060]

[0061] Among them, c 11 、c 12 and c 44 is the independent elastic constant.

[0062] Table 1

[0063]

[0064] The finite element model of ultrasonic propagation is established based on the orientation information, such as Figure 3As shown in the figure, a plane wave is used as the excitation source, and the excitation signal is a 3-cycle tone burst signal with a frequency of 10MHz. A symmetric boundary is applied on the symmetric surface of the model, and the receiving signal node is on the same surface as the excitation source. To ensure the accuracy of the simulation results, a suitable mesh size should be selected when dividing the mesh. The two key factors to be considered are the minimum numerical error in the finite element simulation and the ability to accurately represent the grain geometry. In the specific implementation of the proposed method, the resolution is set to 15μm considering the average grain size.

[0065] The orientation characteristics of the established polycrystalline model are as follows Figure 4 As shown, Figure 4 The texture strength in the X, Y, and Z directions in (a) is 9.8. Figure 4 In (b)-(e), the texture strength in the Z direction is still 9.8, while the texture strength in the X and Y directions gradually decreases to 9.2, 8.3, 6.8, and 5.8.

[0066] 3) According to the elastic dynamic time-marching method, the dynamic equilibrium equation is solved to obtain the plane longitudinal wave displacement data and the ultrasonic signal in the time domain;

[0067] The elastic dynamic time marching method is adopted, and the time step is set to meet the Courant-Friedrichs-Levy condition. The time step is set to 1ns. By solving the dynamic equilibrium equation, the plane wave field is obtained. The node receiving the signal records the displacement in the longitudinal wave propagation direction to obtain the ultrasonic signal in the time domain.

[0068] 4) Perform Fourier transform on the ultrasonic signal in the time domain to obtain the frequency domain signal, calculate the attenuation value of the ultrasound in the three directions of XYZ in the sample coordinate system, and establish the relationship curve between the attenuation value of the ultrasound and the anisotropy index of the microstructure.

[0069] According to the fast Fourier transform, the ultrasonic signal in the time domain is mapped to the frequency domain, and the transformation formula is:

[0070]

[0071] Where x[n] represents the nth discrete sample of the time domain signal, X[k] represents the kth frequency component of the frequency domain signal, and N is the total number of discrete points of the time domain signal.

[0072] The calculation formula for the attenuation value of the frequency domain signal is:

[0073]

[0074] Among them, Attenuation dB (f) represents the attenuation at frequency f, h is the distance between the excitation source and the receiving surface, and A1 and A2 are the amplitudes of the first and second echoes respectively.

[0075] By calculating the attenuation of ultrasound propagating in the long and short axis directions of the grains in the columnar crystal model, the relationship between the attenuation value and the anisotropy of the sample is established. Figure 5 (a)-(e) show the Figure 4 (a)-(e) Attenuation-frequency relationship diagram of the model. The blue and green curves are the attenuation curves in the X and Y directions, respectively, and the red curve is the attenuation curve in the Z direction. As the texture strength in the X and Y directions decreases, the attenuation gradually increases from less than the attenuation in the Z direction to greater than the attenuation in the Z direction.

[0076] In order to quantify the difference in texture strength and compare the relative attenuation between the long axis and short axis directions of the grains, models of different texture strengths were established and two indexes were calculated: attenuation ratio and texture strength ratio. The calculations were as shown in equations (7) and (8), and the relationship curve between the attenuation value and the microstructure anisotropy index was obtained, as shown in Figure 6 shown.

[0077]

[0078] Among them, Attenuation Elongated Attenuation Shortened They represent the attenuation in the long axis direction and short axis direction of the grain, respectively. The attenuation ratio AR describes the relative value of the attenuation. Elongated and TI Shortened They represent the texture strength in the long axis and short axis directions of the grain respectively. The texture intensity ratio TIR quantifies the anisotropy of the texture and reflects the difference in texture strength in the long and short axis directions of the grain.

[0079] Embodiment 2

[0080] The metal additive manufacturing sample microstructure analysis system of the present invention comprises:

[0081] Building a module for building a finite element model of ultrasonic propagation;

[0082] A solution module, used for solving the dynamic equilibrium equation in the finite element model of ultrasonic wave propagation according to the elastic dynamic time marching method to obtain an ultrasonic signal in the time domain;

[0083] The calculation module is used to convert the time domain ultrasonic signal into a frequency domain signal, calculate the frequency domain ultrasonic attenuation values ​​in three directions of XYZ in the sample coordinate system, and establish a relationship curve between the frequency domain ultrasonic attenuation value and the anisotropy index of the microstructure.

[0084] Furthermore, the establishment module includes:

[0085] A testing module, used to test the grain orientation information of the microstructure of the metal additive manufacturing sample, and to establish a polycrystalline material model based on the macroscopic statistical characteristics of the grain orientation information;

[0086] The construction module is used to set material parameters, calculate the stiffness matrix of each grain in the polycrystalline material according to the Euler angles and rotation matrix in the polycrystalline material model, use the stiffness matrix of the single crystal material, set boundary conditions, and establish a finite element model of ultrasonic propagation.

[0087] The division of modules in the embodiments of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation. In addition, each functional module in each embodiment of the present application may be integrated into a processor, or may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated modules may be implemented in the form of hardware or in the form of software functional modules.

[0088] Embodiment 3

[0089] A computer device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the method for analyzing the microstructure of a metal additive manufacturing sample are implemented, for example, comprising: testing the grain orientation information of the microstructure of the metal additive manufacturing sample, and establishing a polycrystalline material model based on the macroscopic statistical characteristics of the grain orientation information; setting material parameters, and calculating the stiffness matrix of each grain in the polycrystalline material using the stiffness matrix of a single crystal material according to the Euler angles and the rotation matrix in the polycrystalline material model, setting boundary conditions, and establishing a finite element model of ultrasonic propagation; in the finite element model of ultrasonic propagation, solving the dynamic equilibrium equation according to the elastic dynamic time marching method to obtain an ultrasonic signal in the time domain; converting the ultrasonic signal in the time domain into a frequency domain signal, calculating the frequency domain ultrasonic attenuation values ​​in the three directions of XYZ in the sample coordinate system, and establishing a relationship curve between the frequency domain ultrasonic attenuation value and the microstructure anisotropy index. The memory may include a memory, such as a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk memory, etc. The processor, network interface, and memory are interconnected through an internal bus, and the internal bus may be an industrial standard architecture bus, a peripheral component interconnection standard bus, an extended industrial standard architecture bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. The memory is used to store programs. Specifically, the program may include a program code, and the program code includes computer operation instructions. The memory may include a memory and a non-volatile memory, and provide instructions and data to the processor.

[0090] Embodiment 4

[0091] A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for analyzing the microstructure of a metal additive manufacturing sample are implemented, for example, including: testing the grain orientation information of the microstructure of the metal additive manufacturing sample, and establishing a polycrystalline material model based on the macroscopic statistical characteristics of the grain orientation information; setting material parameters, and calculating the stiffness matrix of each grain in the polycrystalline material using the stiffness matrix of the single crystal material according to the Euler angle and rotation matrix in the polycrystalline material model, setting boundary conditions, and establishing a finite element model of ultrasonic propagation; in the finite element model of ultrasonic propagation, solving the dynamic equilibrium equation according to the elastic dynamic time marching method to obtain an ultrasonic signal in the time domain; converting the ultrasonic signal in the time domain into a frequency domain signal, calculating the frequency domain ultrasonic attenuation value in the three directions of XYZ in the sample coordinate system, and establishing a relationship curve between the frequency domain ultrasonic attenuation value and the microstructure anisotropy index. Specifically, the computer-readable storage medium includes, but is not limited to, for example, volatile memory and / or non-volatile memory. The volatile memory may include a random access memory (RAM) and / or a cache memory (cache), etc. The non-volatile memory may include a read-only memory (ROM), a hard disk, a flash memory, an optical disk, a magnetic disk, etc.

[0092] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0093] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0094] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0095] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0096] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and disclosure of the invention. This application is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The specification and examples are to be considered exemplary only, and the true scope and spirit of the present invention are indicated by the following claims.

[0097] It should be understood that the present invention is not limited to the exact construction that has been described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

[0098] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A method for analyzing the microstructure of a metal additive manufacturing sample, characterized in that: include: Establish a finite element model of ultrasonic propagation; In the finite element model of ultrasonic wave propagation, the dynamic equilibrium equation is solved according to the elastic dynamic time marching method to obtain the ultrasonic signal in the time domain; The time domain ultrasonic signal is converted into a frequency domain signal, the frequency domain ultrasonic attenuation values ​​in three directions of XYZ in the sample coordinate system are calculated, and a relationship curve between the frequency domain ultrasonic attenuation value and the microstructure anisotropy index is established.

2. The method for analyzing the microstructure of a metal additive manufacturing sample according to claim 1, characterized in that: The process of establishing the finite element model of ultrasonic propagation is as follows: Testing the grain orientation information of the microstructure of metal additive manufacturing samples, and establishing a polycrystalline material model based on the macroscopic statistical characteristics of the grain orientation information; Material parameters are set, and according to the Euler angles and rotation matrix in the polycrystalline material model, the stiffness matrix of each grain in the polycrystalline material is calculated using the stiffness matrix of the single crystal material, boundary conditions are set, and a finite element model of ultrasonic propagation is established.

3. The method for analyzing the microstructure of a metal additive manufacturing sample according to claim 2, characterized in that: The rotation matrix T is:

4. The method for analyzing the microstructure of a metal additive manufacturing sample according to claim 2, characterized in that: The stiffness matrix C of each grain is: Among them, c 11 、c 12 and c 44 is the independent elastic constant.

5. The method for analyzing the microstructure of a metal additive manufacturing sample according to claim 1, characterized in that: According to formula (6), the frequency domain ultrasonic attenuation values ​​in the three directions of XYZ in the sample coordinate system are calculated; Among them, Attenuation dB (f) represents the attenuation value at frequency f, h is the distance between the excitation source and the reflecting surface, and A1 and A2 are the amplitudes of the first and second echoes respectively.

6. The method for analyzing the microstructure of a metal additive manufacturing sample according to claim 1, characterized in that: The frequency domain ultrasonic attenuation value directional index and microstructure anisotropy index are: Among them, Attenuation Elongated Attenuation Shortened They represent the attenuation values ​​in the long axis direction and short axis direction of the grain, AR is the attenuation ratio, TI Elongated and TI Shortened They represent the texture strength in the major axis direction and minor axis direction of the grain respectively, and TIR is the texture intensity ratio.

7. A system for analyzing the microstructure of a metal additive manufacturing sample, characterized in that: include: Building a module for building a finite element model of ultrasonic propagation; A solution module, used for solving the dynamic equilibrium equation in the finite element model of ultrasonic wave propagation according to the elastic dynamic time marching method to obtain an ultrasonic signal in the time domain; The calculation module is used to convert the time domain ultrasonic signal into a frequency domain signal, calculate the frequency domain ultrasonic attenuation value in three directions of XYZ in the sample coordinate system, and establish a relationship curve between the frequency domain ultrasonic attenuation value and the anisotropy index of the microstructure.

8. The metal additive manufacturing sample microstructure analysis system according to claim 7, characterized in that: The establishment module includes: A testing module, used to test the grain orientation information of the microstructure of the metal additive manufacturing sample, and to establish a polycrystalline material model based on the macroscopic statistical characteristics of the grain orientation information; The construction module is used to set material parameters, calculate the stiffness matrix of each grain in the polycrystalline material according to the Euler angles and rotation matrix in the polycrystalline material model, use the stiffness matrix of the single crystal material, set boundary conditions, and establish a finite element model of ultrasonic propagation.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method for analyzing the microstructure of a metal additively manufactured sample as described in any one of claims 1 to 6 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method for analyzing the microstructure of a metal additively manufactured sample as claimed in any one of claims 1 to 6 are implemented.

Images