Orientation and strain field reconstruction method, system, medium and apparatus for three-dimensional neutron diffraction

Abstract

The application provides a three-dimensional neutron diffraction orientation and strain field reconstruction method, system, medium and equipment, including: step S1: according to the principle of three-dimensional neutron diffraction technology, continuously rotating the Euler ring rotation angle to scan the material sample, and obtaining three-dimensional diffraction data; wherein, is the detector coordinate, and is the Euler ring rotation angle; step S2: based on the three-dimensional diffraction data, the two-dimensional rocking curve plane is determined, the two-dimensional rocking curve plane is discretized, the discretized angle unit is obtained, and the center of the angle unit is taken as the representative orientation; step S3: for the discretized angle unit, the diffraction peak curve is obtained by in-plane integration, and the peak position parameter is obtained by using the pseudo Voight model fitting, the crystal plane spacing in the discrete unit is calculated based on the peak position parameter, and the crystal lattice strain in the discrete unit is calculated based on the crystal plane spacing in the discrete unit; step S4: taking all angle units as a pixel grid, reconstructing the segmented constant orientation field and strain field.

Description

Technical Field

[0001] This invention relates to, specifically, to a method, system, medium, and apparatus for reconstructing the orientation and strain field of three-dimensional neutron diffraction. Background Technology

[0002] Three-dimensional neutron diffraction, as a non-destructive characterization method, has been widely used in materials research. In 2025, the CB Larsen team (CB Larsen, S. Samothrakitis, R. Woracek, E. Polatidis, J.) (apek, MV Upadhyay, M. Tovar, S. Schmidt, M. Strobl, Exploring grain-resolved strain tensors and non-uniform lattice deformations with Laue 3DNDT, Acta Materialia 289 (2025) 120869.) A study analyzed grain orientation and strain during deformation of polycrystalline materials using Laue-type three-dimensional neutron diffraction, but the results were mainly grain-scale averages, failing to reveal the fine gradients and non-uniform characteristics within the grains. In contrast, the method presented in this paper can reconstruct the orientation and strain fields within the grains based on orientation discretization. On the other hand, in 2025, SY Zhong's team (P. Sheng, J. Long, N. Li, J. Zhou, Y. Zhao, H. Lin, S. Zhong, Three-dimensional neutron diffraction study of dendrite growth behavior in Ni-based single-crystal turbine blades, ScriptaMaterialia 266 (2025) 116770) used three-dimensional neutron diffraction technology of steady-state neutron source to characterize the strain and orientation deviation of single-crystal blades, but adopted a separate analysis framework. Our method further realizes the reconstruction of the "orientation-strain" co-mapping at the pixel level, establishes a one-to-one correspondence between the two, and thus improves the analytical ability of substructural scale coupling behavior. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method, system, medium, and device for reconstructing the orientation and strain field of three-dimensional neutron diffraction.

[0004] A method for reconstructing the orientation and strain field of three-dimensional neutron diffraction according to the present invention includes:

[0005] Step S1: Based on the principle of three-dimensional neutron diffraction, continuously rotate the Euler ring by the rotation angle. The material sample was scanned to obtain three-dimensional diffraction data. ;in, , For the detector coordinates, The rotation angle of the Euler ring;

[0006] Step S2: Based on three-dimensional diffraction data Define the two-dimensional oscillating curve plane , the two-dimensional rocking curve plane Discretization is performed to obtain discretized angular units, and the center of the angular unit is used as the representative orientation.

[0007] Step S3: Obtain the diffraction peak curve by in-plane integration for the discretized angular unit, and obtain the peak position parameters by fitting with the pseudo-Voight model. Calculate the interplanar spacing within the discrete unit based on the peak position parameters, and calculate the lattice strain within the discrete unit based on the interplanar spacing within the discrete unit.

[0008] Step S4: Reconstruct the piecewise constant orientation field using all angular units as the pixel grid. With strain field .

[0009] Preferably, step S2 includes:

[0010] Step S2.1: Define the discrete angle range , Let the number of grids be respectively and The step size of the angular unit in the plane discretization of the two-dimensional rocking curve is:

[0011] ;

[0012] ;

[0013] Step S2.2: Construct a two-dimensional discretized mesh based on the discrete angle range and the angle element step size. ;

[0014]

[0015] in, ; ; ; ;

[0016] Step S2.3: Center of the angle unit As a representative orientation;

[0017] .

[0018] Preferably, step S3 includes:

[0019] Step S3.1: For each angle unit Extract a one-dimensional curve by averaging within the surface.

[0020] ;

[0021] Step S3.2: The extracted one-dimensional curve is fitted using a pseudo-Voigt model, including peak position parameters;

[0022]

[0023] in, , Peak positions were obtained for Lorentz and Gaussian functions, respectively. parameter;

[0024] Step S3.3: Calculate the interplanar spacing within the discrete unit cell using Bragg's law;

[0025] ;

[0026] in, Indicates the wavelength of a neutron;

[0027] Step S3.4: Based on a relative unstrained reference Calculate the lattice strain within the discrete unit cell;

[0028] .

[0029] Preferably, step S4 includes:

[0030] Step S4.1: Set the center parameters of the angle unit As a representative orientation descriptor for this unit;

[0031] Step S4.2: Establish mapping relationships using the grid as the unit. , ,exist Within the discrete angular range, piecewise constant strain fields are obtained. ;

[0032]

[0033] in, For indicator functions, if The value is 1 if it is positive and 0 otherwise.

[0034] Similarly, orientation field include:

[0035]

[0036] Step S4.3: For The orientation distribution and strain distribution are reconstructed through a global traversal.

[0037] A three-dimensional neutron diffraction orientation and strain field reconstruction system according to the present invention includes:

[0038] Module M1: Based on the principle of three-dimensional neutron diffraction, continuously rotate the Euler ring by an angle. The material sample was scanned to obtain three-dimensional diffraction data. ;in, , For the detector coordinates, The rotation angle of the Euler ring;

[0039] Module M2: Based on 3D diffraction data Define the two-dimensional oscillating curve plane , the two-dimensional rocking curve plane Discretization is performed to obtain discretized angular units, and the center of the angular unit is used as the representative orientation.

[0040] Module M3: For the discretized angular unit, the diffraction peak curve is obtained by in-plane integration, and the peak position parameters are obtained by fitting with the pseudo-Voight model. Based on the peak position parameters, the interplanar spacing within the discrete unit is calculated, and the lattice strain within the discrete unit is calculated based on the interplanar spacing within the discrete unit.

[0041] Module M4: Reconstructs the piecewise constant orientation field using all angular units as the pixel grid. With strain field .

[0042] Preferably, the module M2 includes:

[0043] Module M2.1: Defines the discrete angle range , Let the number of grids be respectively and The step size of the angular unit in the plane discretization of the two-dimensional rocking curve is:

[0044] ;

[0045] ;

[0046] Module M2.2: Constructs a two-dimensional discretized mesh based on the discrete angle range and the angle element step size. ;

[0047]

[0048] in, ; ; ; ;

[0049] Module M2.3: Centered on the angle unit As a representative orientation;

[0050] .

[0051] Preferably, the module M3 includes:

[0052] Module M3.1: For each angle unit Extract a one-dimensional curve by averaging within the surface.

[0053] ;

[0054] Module M3.2: The extracted one-dimensional curve is fitted using a pseudo-Voigt model, including peak position parameters;

[0055]

[0056] in, , Peak positions were obtained for Lorentz and Gaussian functions, respectively. parameter;

[0057] Module M3.3: Calculates the interplanar spacing within discrete units based on Bragg's law;

[0058] ;

[0059] in, Indicates the wavelength of a neutron;

[0060] Module M3.4: Based on a relative unstrained reference Calculate the lattice strain within the discrete unit cell;

[0061] .

[0062] Preferably, the module M4 includes:

[0063] Module M4.1: Transfers the center parameters of the angle unit. As a representative orientation descriptor for this unit;

[0064] Module M4.2: Establishes mapping relationships using a grid as the unit. , ,exist Within the discrete angular range, piecewise constant strain fields are obtained. ;

[0065]

[0066] in, For indicator functions, if The value is 1 if it is positive and 0 otherwise.

[0067] Similarly, orientation field include:

[0068]

[0069] Module M4.3: For The orientation distribution and strain distribution are reconstructed through a global traversal.

[0070] According to an electronic device provided by the present invention, the electronic device includes a memory and at least one processor, wherein the memory stores instructions;

[0071] The at least one processor invokes the instructions in the memory to cause the electronic device to perform the various steps of the orientation and strain field reconstruction method for three-dimensional neutron diffraction as described above.

[0072] According to a computer-readable storage medium provided by the present invention, the computer-readable storage medium stores instructions that, when executed by a processor, implement the various steps of the orientation and strain field reconstruction method for three-dimensional neutron diffraction as described above.

[0073] Compared with the prior art, the present invention has the following beneficial effects:

[0074] 1. This invention solves the problem that existing methods can only obtain overall or regional average parameters and are difficult to present detailed structures by using Euler rings for multi-angle acquisition and high-precision discretization and gridding sampling on a two-dimensional rocking curve plane;

[0075] 2. This invention extracts diffraction peaks from each angular unit and performs fitting analysis to reconstruct the pixel-level strain field based on the orientation distribution, establishing a synergistic mapping relationship between orientation and strain within the material, thus solving the problem of separate analysis of orientation and strain in traditional processes.

[0076] 3. This invention achieves simultaneous acquisition and joint characterization of lattice strain field and orientation field by analyzing diffraction signals pixel by pixel;

[0077] 4. Compared with existing methods that can only obtain average parameters, this invention can reveal the local orientation differences and strain distribution characteristics inside the material, providing a new analytical framework for the accurate characterization of the material microstructure.

[0078] 5. The method of this invention is applied to three-dimensional neutron diffraction experiments and subsequent data analysis. Attached Figure Description

[0079] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0080] Figure 1 This is a flowchart of a method for high-precision reconstruction of orientation and strain fields based on three-dimensional neutron diffraction.

[0081] Figure 2 This is a schematic diagram of the planar discretization of a two-dimensional rocking curve.

[0082] Figure 3 This is a schematic diagram of diffraction peak curve extraction and fitting.

[0083] Figure 4 This is a schematic diagram reconstructing the mapping relationship between high-precision orientation and lattice spacing.

[0084] Figure 5 This is a schematic diagram of the high-precision orientation-strain mapping relationship reconstruction. Detailed Implementation

[0085] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0086] Example 1

[0087] The present invention provides a method, system, medium, and device for reconstructing the orientation and strain field of three-dimensional neutron diffraction, such as... Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, the process includes: acquiring three-dimensional diffraction signals of the material under multi-angle rotation of Euler rings, and preprocessing the raw data to project the diffraction signals onto a two-dimensional rocking curve plane and perform high-precision discretization. Based on the discretized angle units, diffraction peak curves are extracted pixel by pixel, and peak shape fitting analysis is performed using a pseudo-Voigt function to obtain quantitative information on local orientation and lattice strain. Finally, with the orientation represented by the angle unit as the angle center, the orientation-strain pairs of each angle unit are collected to achieve high-precision reconstruction of the piecewise constant strain field and orientation field, establishing a synergistic mapping relationship between "orientation-strain" within the material, and providing a systematic technical framework for the analysis of the microstructure and evolution mechanism of single-crystal materials.

[0088] The method for reconstructing the orientation and strain field of three-dimensional neutron diffraction includes:

[0089] Step 1: Three-dimensional neutron diffraction data acquisition and preprocessing. Based on the principle of three-dimensional neutron diffraction technology, the Euler ring is continuously rotated by an angle. The material sample was scanned to obtain three-dimensional diffraction data. .

[0090]

[0091] in, , For the detector coordinates, For the rotation angle of the Euler ring, , , These represent the angle ranges.

[0092] Step 2: Discretization of the two-dimensional rocking curve plane. The two-dimensional rocking curve plane is discretized and divided into several refined angular units, which serve as the basic calculation units and orientation representatives for subsequent diffraction peak curve extraction.

[0093] Specifically, step 2 includes the following steps:

[0094] Step 2.1: Define the discrete angle range, let... , ;

[0095] Step 2.2: Set the resolution. Let the number of grid cells be... and The step size of the plane discretization angle element for the two-dimensional rocking curve is:

[0096]

[0097]

[0098] Step 2.3: Construct a two-dimensional discretized mesh. Based on the discrete angle range and the angle element step size, a two-dimensional discretized mesh can be constructed. ,Depend on It consists of two-dimensional angular units;

[0099]

[0100] in:

[0101]

[0102]

[0103] , ;

[0104] Step 2.4: Define the angle unit to represent the orientation, with the center of the angle unit as the reference point. As a representative orientation.

[0105] 。

[0106] Step 3: Extraction and fitting analysis of diffraction peak curves within the angular unit. For the discretized angular unit, the diffraction peak curves are obtained by in-plane integration, and the peak position parameters are robustly fitted using the pseudo-Voight model. The interplanar spacing within the discrete unit is calculated based on the peak position parameters, and the lattice strain within the discrete unit is calculated based on the interplanar spacing within the discrete unit.

[0107] Specifically, step 3 includes the following steps:

[0108] Step 3.1: Extraction of diffraction peak curves for each angular unit. Perform in-plane averaging to extract a one-dimensional curve.

[0109]

[0110] Step 3.2: Diffraction peak fitting and parameterization, using a pseudo-Voigt (PV) model for fitting:

[0111]

[0112] in , The peak positions are obtained from Lorentz and Gaussian functions, respectively. ;

[0113] Step 3.4: Calculation of interplanar spacing. According to Bragg's law, calculate the interplanar spacing within the discrete unit cell:

[0114]

[0115] in, Indicates the wavelength of a neutron;

[0116] Step 3.5: Relative Unstrained Reference Calculate the lattice strain within the discrete unit cell;

[0117] .

[0118] Step 4: High-precision orientation and strain mapping relationship reconstruction. Based on the extraction and fitting analysis of diffraction peaks of angular units, the piecewise constant orientation field is reconstructed using all angular units as the pixel grid. With strain field .

[0119] Specifically, step 4 includes the following steps:

[0120] Step 4.1: Define the orientation represented by the discrete 2D mesh element. Set the center parameter of the angle element... As a representative orientation descriptor for this unit;

[0121] Step 4.2: Construct a high-precision orientation-strain mapping relationship, establishing the mapping relationship using the mesh as the unit. :

[0122]

[0123] exist Within the discrete angular range, piecewise constant strain fields are obtained. :

[0124]

[0125] in, For indicator functions, if The value is 1 if it is positive and 0 otherwise.

[0126] Similarly, an orientation field can be defined.

[0127] ;

[0128] Step 4.2: Reconstruct the distribution of the orientation-strain mapping relationship. By traversing the entire domain, high-precision orientation and strain distributions can be reconstructed.

[0129] Specifically, based on Table 1, construct as follows Figure 5 The orientation and strain mapping relationship is shown in Table 1, which contains 61 data items, but only the first 10 are shown here.

[0130] Table 1

[0131]

[0132] The present invention also provides a system for reconstructing the orientation and strain field of three-dimensional neutron diffraction. The system can be implemented by executing the process steps of the method for reconstructing the orientation and strain field of three-dimensional neutron diffraction. That is, those skilled in the art can understand the method for reconstructing the orientation and strain field of three-dimensional neutron diffraction as a preferred embodiment of the system for reconstructing the orientation and strain field of three-dimensional neutron diffraction.

[0133] Those skilled in the art will understand that, in addition to implementing the system, apparatus, and their modules provided by this invention in purely computer-readable program code, the same program can be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system, apparatus, and their modules provided by this invention can be considered a hardware component, and the modules included therein for implementing various programs can also be considered structures within the hardware component; alternatively, modules for implementing various functions can be considered both software programs implementing the method and structures within the hardware component.

[0134] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A method for reconstructing the orientation and strain field of three-dimensional neutron diffraction, characterized in that, include: Step S1: Based on the principle of three-dimensional neutron diffraction, continuously rotate the Euler ring by the rotation angle. The material sample was scanned to obtain three-dimensional diffraction data I( , , );in, , For the detector coordinates, The rotation angle of the Euler ring; Step S2: Based on three-dimensional diffraction data I ( , , ) Define the two-dimensional oscillating curve plane ( , ), the two-dimensional rocking curve plane ( , The angular unit is discretized to obtain the discretized angular unit, and the center of the angular unit is used as the representative orientation. Step S3: Obtain the diffraction peak curve by in-plane integration for the discretized angle unit, and obtain the peak position parameters by fitting with the pseudo-Voight model. Calculate the interplanar spacing within the angle unit based on the peak position parameters, and calculate the lattice strain within the angle unit based on the interplanar spacing within the angle unit. Step S4: Reconstruct the piecewise constant strain field using all angular units as the pixel grid. With orientation field .

2. The method for reconstructing the orientation and strain field of three-dimensional neutron diffraction according to claim 1, characterized in that, Step S2 includes: Step S2.1: Define the discrete angle range , Let the number of grids be respectively and The step size of the angular unit in the plane discretization of the two-dimensional rocking curve is: ； ； Step S2.2: Construct a two-dimensional discretized mesh based on the discrete angle range and the angle element step size. ; in, ; ; ; ; Step S2.3: Center of the angle unit As a representative orientation; 。 3. The method for reconstructing the orientation and strain field of three-dimensional neutron diffraction according to claim 1, characterized in that, Step S3 includes: Step S3.1: For each angle unit Extract a one-dimensional curve by averaging within the surface. ； Step S3.2: The extracted one-dimensional curve is fitted with peak position parameters using a pseudo-Voigt model; in, , These are the Lorentz and Gaussian functions in the pseudo-Voigt model, respectively, and the peak parameters are obtained through fitting. ; Step S3.3: Calculate the interplanar spacing within the angular unit cell according to Bragg's law; ； in, Indicates the wavelength of a neutron; Step S3.4: Based on a relative unstrained reference Calculate the lattice strain within the angular unit cell; 。 4. The method for reconstructing the orientation and strain field of three-dimensional neutron diffraction according to claim 1, characterized in that, Step S4 includes: Step S4.1: Set the center parameters of the angle unit As a representative orientation descriptor for this unit; Step S4.2: Establish mapping relationships using the grid as the unit. , ,exist Within the discrete angular range, piecewise constant strain fields are obtained. ; in, For indicator functions, if The value is 1 if it is positive and 0 otherwise. Similarly, orientation field include: Step S4.3: For The orientation distribution and strain distribution are reconstructed through a global traversal.

5. A three-dimensional neutron diffraction orientation and strain field reconstruction system, characterized in that, include: Module M1: Based on the principle of three-dimensional neutron diffraction, continuously rotate the Euler ring by an angle. The material sample was scanned to obtain three-dimensional diffraction data I( , , );in, , For the detector coordinates, The rotation angle of the Euler ring; Module M2: Based on three-dimensional diffraction data I ( , , ) Define the two-dimensional oscillating curve plane ( , ), the two-dimensional rocking curve plane ( , The angular unit is discretized to obtain the discretized angular unit, and the center of the angular unit is used as the representative orientation. Module M3: For the discretized angular unit, the diffraction peak curve is obtained by in-plane integration, and the peak position parameters are obtained by fitting with the pseudo-Voight model. Based on the peak position parameters, the interplanar spacing within the angular unit is calculated, and the lattice strain within the angular unit is calculated based on the interplanar spacing within the angular unit. Module M4: Reconstructs the piecewise constant strain field using all angular units as the pixel grid. With orientation field .

6. The orientation and strain field reconstruction system for three-dimensional neutron diffraction according to claim 5, characterized in that, The module M2 includes: Module M2.1: Defines the discrete angle range , Let the number of grids be respectively and The step size of the angular unit in the plane discretization of the two-dimensional rocking curve is: ； ； Module M2.2: Constructs a two-dimensional discretized mesh based on the discrete angle range and the angle element step size. ; in, ; ; ; ; Module M2.3: Centered on the angle unit As a representative orientation; 。 7. The orientation and strain field reconstruction system for three-dimensional neutron diffraction according to claim 5, characterized in that, The module M3 includes: Module M3.1: For each angle unit Extract a one-dimensional curve by averaging within the surface. ； Module M3.2: The extracted one-dimensional curve is fitted with peak position parameters using a pseudo-Voigt model; in, , The peak position parameters are obtained by fitting the Lorentz and Gaussian function combinations in the pseudo-Voigt model. ; Module M3.3: Calculates the interplanar spacing within angular units based on Bragg's law; ； in, Indicates the wavelength of a neutron; Module M3.4: Based on a relative unstrained reference Calculate the lattice strain within the angular unit cell; 。 8. The orientation and strain field reconstruction system for three-dimensional neutron diffraction according to claim 5, characterized in that, The module M4 includes: Module M4.1: Transfers the center parameters of the angle unit. As a representative orientation descriptor for this unit; Module M4.2: Establishes mapping relationships using a grid as the unit. , ,exist Within the discrete angular range, piecewise constant strain fields are obtained. ; in, For indicator functions, if The value is 1 if it is positive and 0 otherwise. Similarly, orientation field include: Module M4.3: For The orientation distribution and strain distribution are reconstructed through a global traversal.

9. An electronic device comprising a memory and at least one processor, wherein the memory stores instructions; The at least one processor invokes the instructions in the memory to cause the electronic device to perform the steps of the orientation and strain field reconstruction method for three-dimensional neutron diffraction as described in any one of claims 1-4.

10. A computer-readable storage medium storing instructions thereon, characterized in that, When the instructions are executed by the processor, they implement the various steps of the orientation and strain field reconstruction method for three-dimensional neutron diffraction as described in any one of claims 1-4.

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