Construction method of blade dislocation structure
Through stacking two crystals to form a stable bit wrong structure, the problem of difficulty constructing the blade position in existing technologies, the ability to design flexibility or higher hardness, and provide a theoretical model for further research.
Patent Information
- Application Number
- CN202411311790.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-20
- Publication Date
- 2025-01-21
AI Technical Summary
The prior art is difficult to effectively construct a dislocation structure of the blade, limiting the ability to design materials with higher flexibility or hardness.
By stacking two crystals, a stable bitmoring structure is formed. The specific steps include building FCC structure crystals, building bottom and top crystals, lengthening the bottom structure and compressed top structure, and eventually superimposed to form a blade position.
The construction of a stable edge dislocation structure is achieved, which provides a theoretical model for the design of more flexible or harder materials, and promotes the study of edge dislocations with different elemental compositions.
Smart Images
Figure CN119339823A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of molecular dynamics, and in particular relates to a method for constructing an edge dislocation structure. Background Art
[0002] In metal materials, dislocation is an internal microscopic defect of crystal materials, that is, a local irregular arrangement of atoms (crystallographic defect). For some reason, a part of the metal crystal has an extra half-atomic plane relative to the other part. This extra half-atomic plane can be imagined as a blade cutting into the crystal, and the blade edge is the dislocation line, that is, the boundary line between the slipped area and the non-slipped area in the crystal. Dislocation is a kind of line defect, and its existence has a significant effect on the properties of the material, especially the mechanical properties. There are two main forms of ideal dislocations: edge dislocations and screw dislocations.
[0003] The method of constructing edge dislocation structure using face-centered cubic structure (FCC) as an example: The most favorable slip system of FCC metal structure is 1 / 2 <110> {111}, we construct a system containing edge dislocations on the {111} plane perpendicular to the Y axis, which is located on the Z axis of the Cartesian coordinates with the Burgers vector b = 1 / 2
[110] . Dislocations are the main carriers of plastic deformation of materials. Through slip (the movement of dislocations on the crystal plane) and climb (the movement of dislocations over obstacles), dislocations can cause plastic deformation of materials without causing crystal breakage. Understanding the behavior of dislocations can help design more flexible or harder materials, so it is crucial to obtain a method to construct edge dislocations. Summary of the invention
[0004] The technical problem to be solved by the present invention is to provide a method for constructing an edge dislocation structure in view of the deficiencies in the above-mentioned prior art. The present invention forms a stable dislocation structure by superimposing two crystals, which is helpful to design more flexible or harder materials, and provides a mature theoretical model for further research on the construction of edge dislocations of different elemental compositions and dislocations in metals.
[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for constructing an edge dislocation structure, characterized in that the method comprises the following steps:
[0006] Step 1: construct the FCC structure unit cell;
[0007] Step 2: construct the bottom crystal structure and the top crystal structure;
[0008] Step 3: Lengthen the bottom crystal structure;
[0009] Step 4: compress the top crystal structure;
[0010] Step 5: Construct an edge dislocation structure: superimpose the elongated bottom crystal structure and the compressed top crystal structure, and when the superimposed structure is fully relaxed to reach a stable state, an edge dislocation structure is obtained.
[0011] The above-mentioned method for constructing an edge dislocation structure is characterized in that: in step one, the crystal orientation of the constructed FCC structure unit cell is X=
[110] , Y=[-111], Z=
[112] ; wherein the direction of X is the direction of the Burger vector b, and the direction of Y is perpendicular to the slip plane.
[0012] The above-mentioned method for constructing an edge dislocation structure is characterized in that: in step 2, the bottom crystal structure and the top crystal structure are both composed of a plurality of FCC structure cells constructed in step 1; the bottom crystal structure is a crystal structure in which 40 FCC structure cells are repeated in the X-axis direction, 10 FCC structure cells are repeated in the Y-axis direction, and 5 FCC structure cells are repeated in the Z-axis direction;
[0013] The top crystal structure is a crystal structure in which 41 FCC structure units are repeated in the X-axis direction, 10 FCC structure units are repeated in the Y-axis direction, and 5 FCC structure units are repeated in the Z-axis direction.
[0014] The above-mentioned method for constructing an edge dislocation structure is characterized in that: in step three, the X-axis direction of the bottom crystal structure is stretched by half a unit cell along the X-axis direction, and the stretched length of each FCC structure unit cell in the bottom crystal structure is 0.5 / 40=0.0125.
[0015] The above-mentioned method for constructing an edge dislocation structure is characterized in that: in step four, the top crystal structure is compressed by half a unit cell in the X-axis direction, and the compressed length of each FCC structure unit cell in the top crystal structure is 0.5 / 41=0.012195122.
[0016] The above-mentioned method for constructing an edge dislocation structure is characterized in that: in step five, the elongated bottom crystal structure and the compressed top crystal structure are superimposed along the Y-axis direction. Because the top crystal structure contains one more atomic column than the bottom crystal structure, after the top crystal structure is compressed and the bottom crystal structure is elongated, the elongated bottom crystal structure and the compressed top crystal structure have the same length along the X-axis direction.
[0017] The beneficial effect of the present invention is to establish the edge dislocation structure of different metal elements through the molecular dynamics modeling method; due to some reason, a part of the metal crystal has an extra half-atomic plane relative to another part. This extra half-atomic plane can be imagined as a blade that cuts into the crystal, and the blade is the dislocation line, that is, the boundary line between the slipped area and the non-slipped area in the crystal. Dislocation is a kind of line defect, and its existence has a significant effect on the properties of the material, especially the mechanical properties; the method of constructing the edge dislocation structure using the face-centered cubic structure (FCC) as an example, by superimposing two crystals to form a stable dislocation structure, it is helpful to design more flexible or harder materials, and provide a mature theoretical model for the construction of edge dislocations of different elemental compositions and further research on dislocations in metals.
[0018] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 The figure is a flowchart of the method of the present invention.
[0020] Figure 2 Schematic diagram of the initial structure of FCC pure Ni at different viewing angles in the directions of X=
[110] , Y=[-111], and Z=
[112] of the present invention.
[0021] Figure 3 The three-dimensional structure diagram of FCC-Ni at different viewing angles of the bottom crystal structure of the present invention.
[0022] Figure 4 The three-dimensional structure diagram of FCC-Ni at different viewing angles of the top crystal structure of the present invention.
[0023] Figure 5 This is the edge dislocation distribution diagram in the high entropy alloy FeNiCrCoCu of the present invention. DETAILED DESCRIPTION
[0024] like Figures 1 to 5 A method for constructing an edge dislocation structure is shown, the method comprising the following steps: step 1, constructing a FCC structure unit cell;
[0025] Step 2: construct the bottom crystal structure and the top crystal structure;
[0026] Step 3: Lengthen the bottom crystal structure;
[0027] Step 4: compress the top crystal structure;
[0028] Step 5: Construct an edge dislocation structure: superimpose the elongated bottom crystal structure and the compressed top crystal structure, and when the superimposed structure is fully relaxed to reach a stable state, an edge dislocation structure is obtained.
[0029] The present invention establishes the edge dislocation structure of different metal elements through the molecular dynamics modeling method; due to some reason, a part of the metal crystal has an extra half-atomic plane relative to another part. This extra half-atomic plane can be imagined as a blade that cuts into the crystal, and the blade is the dislocation line, that is, the boundary line between the slipped area and the non-slipped area in the crystal. Dislocation is a kind of line defect, and its existence has a significant effect on the properties of the material, especially the mechanical properties; the method of constructing the edge dislocation structure using the face-centered cubic structure (FCC) as an example, by superimposing two crystals to form a stable dislocation structure, it is helpful to design more flexible or harder materials, and provide a mature theoretical model for the construction of edge dislocations of different elemental compositions and further research on dislocations in metals.
[0030] In step 1, taking the high entropy alloy FeNiCrCoCu as an example, a pure Ni-FCC structure unit cell with the following crystal orientation is constructed: X =
[110] , Y = [-111], Z =
[112] , such as Figure 2 shown.
[0031] In step 5, all Ni atoms in the FCC structure unit cell are replaced by five other atomic types, namely Fe, Ni, Cr, Co and Cu atoms, to obtain the FCC high entropy alloy FeNiCrCoCu containing edge dislocation structure. At this time, the system is in a non-equilibrium state, and the structure needs to be fully relaxed to achieve stability and obtain edge dislocation, such as Figure 5 shown.
[0032] In this embodiment, in step 1, the crystal orientation of the constructed FCC structure unit cell is X=
[110] , Y=[-111], Z=
[112] ; wherein the direction of X is the direction of the Burger vector b, and the direction of Y is perpendicular to the slip plane.
[0033] In this embodiment, in step 2, the bottom crystal structure and the top crystal structure are both composed of a plurality of FCC structure cells constructed in step 1; the bottom crystal structure is a crystal structure in which 40 FCC structure cells are repeated in the X-axis direction, 10 FCC structure cells are repeated in the Y-axis direction, and 5 FCC structure cells are repeated in the Z-axis direction;
[0034] The top crystal structure is a crystal structure in which 41 FCC structure units are repeated in the X-axis direction, 10 FCC structure units are repeated in the Y-axis direction, and 5 FCC structure units are repeated in the Z-axis direction.
[0035] In this embodiment, in step three, the bottom crystal structure is stretched along the X-axis direction by half a unit cell, and the stretched length of each FCC structure unit cell in the bottom crystal structure is 0.5 / 40=0.0125.
[0036] In this embodiment, in step 4, the top crystal structure is compressed by half a unit cell in the X-axis direction, and the compressed length of each FCC structure unit cell in the top crystal structure is 0.5 / 41=0.012195122.
[0037] In this embodiment, in step five, the elongated bottom crystal structure and the compressed top crystal structure are superimposed along the Y-axis direction. Because the top crystal structure contains one more atomic column than the bottom crystal structure, after the top crystal structure is compressed and the bottom crystal structure is elongated, the elongated bottom crystal structure and the compressed top crystal structure have the same length along the X-axis direction.
[0038] 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 constructing an edge dislocation structure, characterized in that: The method comprises the following steps: Step 1: construct the FCC structure unit cell; Step 2: construct the bottom crystal structure and the top crystal structure; Step 3: Lengthen the bottom crystal structure; Step 4: compress the top crystal structure; Step 5: Construct an edge dislocation structure: superimpose the elongated bottom crystal structure and the compressed top crystal structure, and when the superimposed structure is fully relaxed to reach a stable state, an edge dislocation structure is obtained.
2. The method for constructing an edge dislocation structure according to claim 1, characterized in that: In step 1, the crystal orientation of the constructed FCC structure unit cell is X=[110], Y=[-111], Z=[112]; wherein the direction of X is the direction of the Burger vector b, and the direction of Y is perpendicular to the slip plane.
3. The method for constructing an edge dislocation structure according to claim 1, characterized in that: In step 2, the bottom crystal structure and the top crystal structure are both composed of a plurality of FCC structure cells constructed in step 1; the bottom crystal structure is a crystal structure in which 40 FCC structure cells are repeated in the X-axis direction, 10 FCC structure cells are repeated in the Y-axis direction, and 5 FCC structure cells are repeated in the Z-axis direction; The top crystal structure is a crystal structure in which 41 FCC structure units are repeated in the X-axis direction, 10 FCC structure units are repeated in the Y-axis direction, and 5 FCC structure units are repeated in the Z-axis direction.
4. The method for constructing an edge dislocation structure according to claim 3, characterized in that: In step three, the bottom crystal structure is stretched along the X-axis direction by half a unit cell, and the stretched length of each FCC structure unit cell in the bottom crystal structure is 0.5 / 40=0.0125.
5. The method for constructing an edge dislocation structure according to claim 4, characterized in that: In step 4, the top crystal structure is compressed by half a unit cell in the X-axis direction, and the compressed length of each FCC structure unit cell in the top crystal structure is 0.5 / 41=0.012195122.
6. The method for constructing an edge dislocation structure according to claim 1, characterized in that: In step five, the elongated bottom crystal structure and the compressed top crystal structure are superimposed along the Y-axis direction. Since the top crystal structure contains one more atomic column than the bottom crystal structure, after the top crystal structure is compressed and the bottom crystal structure is elongated, the elongated bottom crystal structure and the compressed top crystal structure have the same length along the X-axis direction.