Three-dimensional model establishing method based on titanium alloy binary structure EBSD data

Abstract

The invention discloses a three-dimensional model building method based on titanium alloy binary structure EBSD data. The method comprises the steps that firstly, the EBSD data of a titanium alloy material are obtained and stored; 2, separating and storing the two-state organization structure data of the titanium alloy material; 3, changing and storing phase data in the obtained EBSD data of the titanium alloy material; 4, obtaining EBSD original data with two-phase distribution; and 5, obtaining a three-dimensional crystal plasticity finite element model of the titanium alloy binary structure EBSD data. According to the method, the phases with the same crystal structure in the binary structure are distinguished, and the new EBSD data file is formed, so that the related structure parameters of the distinguished phases are kept consistent, and a brand-new method is provided for establishing a model for calculating the crystal plasticity finite element model; the model established by the method is completely consistent with the real microstructure characteristics.

Description

Technical Field

[0001] The invention belongs to the technical field of crystal three-dimensional model reconstruction, and in particular relates to a three-dimensional model establishment method based on titanium alloy dual-state structure EBSD data. Background Art

[0002] Crystal plasticity finite element simulation has become an important tool for studying the plastic deformation behavior of polycrystalline materials. Compared with traditional physical models, crystal plasticity finite element needs to consider the influence of the orientation of each grain in the material and the strain coordination between grains on the deformation behavior. Establishing a crystal plasticity finite element model that is completely consistent with the real microstructure characteristics is the premise of crystal plasticity finite element simulation calculation. For multiphase materials with different crystal structures, such as austenite (FCC) / ferrite (BCC), α (HCP) / β (BCC) and other dual-phase structures, the backscattered electron diffraction technology (Electron Back Scatter Diffraction, EBSD) can be used to identify the crystal structure. The backscattered electron diffraction of the scanning electron microscope can be used to distinguish the crystal structures of each phase and obtain the phase distribution map. However, for materials with the same crystal structure, such as ferrite / bainite structure (BCC structure), β-transformation phase + primary α phase (HCP structure) dual-state structure, etc., the phases cannot be distinguished by the crystal structure, but the mechanical properties of the phases are quite different. The two phases must be distinguished and the two phases with the same crystal structure must be identified during the modeling process, and the material parameters of each phase must be set separately. This brings certain difficulties to the crystal plasticity finite element modeling of this type of multiphase material. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a three-dimensional model establishment method based on the EBSD data of titanium alloy dual-state structure in view of the deficiencies in the above-mentioned prior art. By distinguishing the phases with the same crystal structure in the dual-state structure and forming a new EBSD data file, the relevant structural parameters of the distinguished phases are kept consistent, thereby providing a new method for model establishment for crystal plasticity finite element model calculation. The model established by this method is completely consistent with the real microstructure characteristics.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for establishing a three-dimensional model based on EBSD data of dual-state structure of titanium alloy, characterized in that the method comprises the following steps:

[0005] Step 1: Acquire and store EBSD data of titanium alloy materials;

[0006] Step 2, separating and storing the dual-state organizational structure data of the titanium alloy material;

[0007] Step 3: Change and store the phase data in the acquired EBSD data of titanium alloy material:

[0008] Step 4, obtaining EBSD raw data with two-phase distribution;

[0009] Step 5: Obtain a three-dimensional crystal plasticity finite element model of the titanium alloy dual-state structure EBSD data.

[0010] The above-mentioned three-dimensional model establishment method based on the dual-state structure EBSD data of titanium alloy is characterized in that: in step one, the titanium alloy material is analyzed using backscattered electron diffraction technology to obtain the EBSD data of the titanium alloy material; wherein the EBSD data of the titanium alloy material includes grain information, crystal structure information, and crystal orientation information.

[0011] The above-mentioned three-dimensional model establishment method based on titanium alloy dual-state structure EBSD data is characterized in that: in step 2, the dual-state structure data of the titanium alloy material, that is, the structure data of the β-transformation phase and the primary α-phase, are separated from the EBSD data of step 1; then subsets of the β-transformation phase and the primary α-phase structure data are established and stored respectively.

[0012] The above-mentioned three-dimensional model establishment method based on titanium alloy dual-state structure EBSD data is characterized in that: in step three, a β transformation phase is added to the acquired EBSD data of the titanium alloy material so that the crystal structure parameters of the added β transformation phase are consistent with those of the primary α phase.

[0013] The above-mentioned three-dimensional model establishment method based on titanium alloy dual-state structure EBSD data is characterized in that: in step four, the new phase is redefined by combining the data in steps two and three, and the EBSD original data with the two-phase distribution of β transformation phase and primary α phase can be obtained.

[0014] The above-mentioned three-dimensional model establishment method based on titanium alloy dual-state structure EBSD data is characterized in that: in step five, the EBSD original data with two-phase distribution in step four is processed by DREAM3D software, and the orientation, phase composition, and grain boundary are output to obtain a three-dimensional crystal plasticity finite element model consistent with the measured EBSD data.

[0015] The beneficial effect of the present invention is that by distinguishing the phases with the same crystal structure in the dual-state structure and forming a new EBSD data file, the relevant structural parameters of the distinguished phases are kept consistent, providing a new method for model establishment for crystal plasticity finite element model calculation, and the model established by this method is completely consistent with the real microstructure characteristics.

[0016] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1The figure is a flowchart of the method of the present invention.

[0018] Figure 2 This is the orientation distribution diagram (IPF) and phase distribution diagram before the new phase is defined in the present invention.

[0019] Figure 3 This is the orientation distribution diagram (IPF) and phase distribution diagram after the new phase is defined in the present invention.

[0020] Figure 4 It is the orientation distribution map (IPF) and phase distribution map of the three-dimensional model of the present invention. DETAILED DESCRIPTION

[0021] like Figures 1 to 4 The method for establishing a three-dimensional model based on EBSD data of dual-state structure of titanium alloy shown in the figure comprises the following steps:

[0022] Step 1: Acquire and store EBSD data of titanium alloy materials;

[0023] Step 2, separating and storing the dual-state organizational structure data of the titanium alloy material;

[0024] Step 3: Change and store the phase data in the acquired EBSD data of titanium alloy material:

[0025] Step 4, obtaining EBSD raw data with two-phase distribution;

[0026] Step 5: Obtain a three-dimensional crystal plasticity finite element model of the titanium alloy dual-state structure EBSD data.

[0027] The present invention distinguishes the phases with the same crystal structure in the dual-state structure and forms a new EBSD data file, so that the relevant structural parameters of the distinguished phases remain consistent, providing a new method for model establishment for crystal plasticity finite element model calculation. The model established by this method is completely consistent with the real microstructure characteristics.

[0028] In this embodiment, in step 1, the crystallographic data is mainly obtained by diffraction with a spatial resolution of submicron by a scanning electron microscope. The data contains grain information, crystal structure information, and crystal orientation information. The EBSD data of the titanium alloy material can be stored as .ctf, .cpr, and .h5oina format files. In step 2, the β transformation phase and primary α phase in the titanium alloy are separated from the EBSD data using Channel 5 software, and each phase subset is established and saved as a .sub file; after separating the two phases, the notepad in channel 5 is used to add the relevant information of the β transformation phase, and the HKL Tango interface and the ProjectManager interface are gradually turned off, and finally the notepad is saved. The order of this process cannot be changed.

[0029] From step 1 to step 3, the crystal structures of the β transformation phase and the primary α phase in the dual-state structure of the titanium alloy are almost the same. Therefore, in order to distinguish the two phases, this step mainly establishes a subset manually to pre-distinguish the two phases, and adds the relevant description of the β transformation phase to the EBSD raw data, including the phase name, and makes the crystal structure parameters (a, b, c and α, β, γ) of the added phase consistent with the primary α phase. In particular, use the notepad in channel 5 to add the relevant information of the β transformation phase, and gradually close the HKL Tango interface and the Project Manager interface, and finally save the notepad. The order of saving and closing cannot be changed.

[0030] In step 4, the newly formed .cpr data file is opened using channel 5 software, and the .sub file saved in step 2 is opened, subset is redefined as a new phase, and finally a ctf file is exported; in step 5, the processed .ctf file is imported into DREAM3D software, and after processing by DREAM3D software, the orientation, phase composition, and grain boundary are output to obtain a three-dimensional model that is exactly the same as the measured EBSD data.

[0031] In addition, in step 5, the ctf file is imported into DREAM3D, and the model is output after being processed by DREAM3D software. The processing steps in DREAM3D software are as follows:

[0032] 1) Import Oxford Instr.EBSD data (.ctf);

[0033] 2) Remove noise points and unidentified crystal orientation points;

[0034] 3) Change crystal orientation;

[0035] 4) Segmentation of adjacent unit features by orientation;

[0036] 5) Identify phase characteristics;

[0037] 6) Determine the average orientation of the features;

[0038] 7) Find adjacent relationships;

[0039] 8) Determine the grain size;

[0040] 9) Delete too small grains and features;

[0041] 10) Find defective data;

[0042] 11) Remove or fill in defective data

[0043] 12) Generate IPF map;

[0044] 13) Output DREAM.3D data files (.Xdmf, .dream3d)

[0045] Follow the above steps to set up in DREAM3D software. The process file can be reused by saving it as a .dream3d file. The model IPF diagram and phase distribution diagram obtained through the above steps are shown in Figure 4 shown.

[0046] In this embodiment, in step one, the titanium alloy material is analyzed using backscattered electron diffraction technology to obtain EBSD data of the titanium alloy material; wherein the EBSD data of the titanium alloy material includes grain information, crystal structure information, and crystal orientation information.

[0047] In this embodiment, in step 2, the dual-state structural data of the titanium alloy material, namely the structural data of the β-transformed phase and the primary α-phase, are separated from the EBSD data of step 1; then subsets of the structural data of the β-transformed phase and the primary α-phase are established and stored respectively.

[0048] In this embodiment, subset is used to separate the dual-state tissues with the same crystal structure in step 2.

[0049] In this embodiment, in step three, a β transformation phase is added to the acquired EBSD data of the titanium alloy material so that the crystal structure parameters of the added β transformation phase are consistent with those of the primary α phase.

[0050] In this embodiment, in step 4, the new phase is redefined by combining the data in step 2 and step 3, and EBSD raw data with two-phase distribution of β-transformed phase and primary α-phase can be obtained.

[0051] In this embodiment, in step five, the EBSD raw data with two-phase distribution in step four is processed by DREAM3D software, and the orientation, phase composition, and grain boundary are output to obtain a three-dimensional crystal plasticity finite element model consistent with the measured EBSD data.

[0052] 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 three-dimensional modeling method based on EBSD data of dual-state structure of titanium alloy, characterized in that: The method comprises the following steps: Step 1: Acquire and store EBSD data of titanium alloy materials; Step 2, separating and storing the dual-state organizational structure data of the titanium alloy material; Step 3: Change and store the phase data in the acquired EBSD data of titanium alloy material: Step 4, obtaining EBSD raw data with two-phase distribution; Step 5: Obtain a three-dimensional crystal plasticity finite element model of the titanium alloy dual-state structure EBSD data.

2. The method for establishing a three-dimensional model based on titanium alloy dual-state structure EBSD data according to claim 1, characterized in that: In step one, the titanium alloy material is analyzed using backscattered electron diffraction technology to obtain EBSD data of the titanium alloy material; wherein the EBSD data of the titanium alloy material includes grain information, crystal structure information, and crystal orientation information.

3. The method for establishing a three-dimensional model based on titanium alloy dual-state structure EBSD data according to claim 1, characterized in that: In step 2, the dual-state structural data of the titanium alloy material, namely the structural data of the β-transformation phase and the primary α-phase, are separated from the EBSD data of step 1; then subsets of the β-transformation phase and the primary α-phase structural data are established and stored respectively.

4. The method for establishing a three-dimensional model based on titanium alloy dual-state structure EBSD data according to claim 3, characterized in that: In step three, a β transformation phase is added to the acquired EBSD data of the titanium alloy material so that the crystal structure parameters of the added β transformation phase are consistent with those of the primary α phase.

5. The method for establishing a three-dimensional model based on titanium alloy dual-state structure EBSD data according to claim 4, characterized in that: In step 4, the new phase is redefined by combining the data in steps 2 and 3, and the EBSD raw data with the two-phase distribution of β-transformed phase and primary α-phase can be obtained.

6. The method for establishing a three-dimensional model based on titanium alloy dual-state structure EBSD data according to claim 1, characterized in that: In step five, the original EBSD data with two-phase distribution in step four is processed by DREAM3D software, and the orientation, phase composition, and grain boundary are output to obtain a three-dimensional crystal plasticity finite element model consistent with the measured EBSD data.

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