Method for simulating gap pair transition

Abstract

The embodiment of the invention relates to the technical field of analysis of diffusion behaviors of interstitial pair atoms in metal materials, in particular to a method for simulating interstitial pair transition, which comprises the following steps: S1, determining position information of an initial position of an interstitial pair; s2, determining a transition mode of the gap pair, and determining a target position of the gap pair after transition according to the transition mode; s3, simulating a gap pair to jump from an initial position to a target position; s4, updating the position information of the gap pair according to the information of the target position; s5, determining the state of the periphery of the updated position of the gap pair; s6, determining continuous transition of the gap pair according to the state of the periphery, and repeating the steps S2-S6; and S7, according to the state of the periphery, determining that the gap pair stops transition. According to the method provided by the embodiment of the invention, the orientation of the gap pair does not need to be distinguished, the applicability is high, and the method can be widely applied to different material systems; and when gap pair transition is simulated, the gap pair does not need to participate in probability sampling, so that the gap pair transition is faster than vacancy transition.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of diffusion behavior analysis of interstitial pair atoms in metal materials, and in particular to a method for simulating interstitial pair transitions. Background Art

[0002] The statements herein merely provide background information related to the present application and do not necessarily constitute prior art.

[0003] Lattice dynamics Monte Carlo simulation methods are often used to simulate the behavior of solute atoms rearranged due to point defect transitions caused by irradiation in reactor materials. Point defects caused by irradiation usually include vacancies and interstitial pairs. The transition of vacancies is relatively easy to handle. For example, in body center cubic (BCC) materials, vacancies can transition to the surrounding 8 1NN (first nearest neighbor) neighbor positions. However, the transition of interstitial pairs is more complicated. This is because interstitial pairs have a certain orientation, and interstitial pairs are two atoms sharing a lattice position. There is no ideal way to handle interstitial pair transitions. Summary of the invention

[0004] A brief overview of the present application is provided below in order to provide a basic understanding of certain aspects of the present application. It should be understood that this overview is not an exhaustive overview of the present application. It is not intended to identify the key or important parts of the present application, nor is it intended to limit the scope of the present application. Its purpose is merely to present certain concepts in a simplified form as a prelude to a more detailed description discussed later.

[0005] An embodiment of the present application provides a method for simulating gap pair transitions, the method comprising the following steps:

[0006] S1: Determine the position information of the initial position of the gap pair;

[0007] S2: determining a transition mode of the gap pair, and determining a target position of the gap pair after the transition according to the transition mode;

[0008] S3: simulate the gap pair jumping from the initial position to the target position;

[0009] S4: updating the position information of the gap pair according to the information of the target position;

[0010] S5: Determine the state of the updated position surrounding the gap pair;

[0011] S6: According to the surrounding state, determine the gap pair to continue the transition and repeat steps S2-S6;

[0012] S7: According to the surrounding state, determine that the gap pair stops transitioning.

[0013] The method provided in the embodiments of the present application does not need to adopt the first-principles method to calculate the energy characteristic parameters of different neighboring atomic environments of different gap pairs. By determining the initial position and transition mode of the gap pair, the transition of the gap pair from the initial position to the target position can be simulated, and then, based on the state around the updated position, it is determined whether the gap pair continues to transition or stops the transition. Such a transition method does not need to distinguish the orientation of the gap pair, has strong applicability, and can be widely used in different material systems; and when simulating the transition of the gap pair, there is no need for the gap pair to participate in probability sampling, which can make the transition of the gap pair faster than the vacancy transition.

[0014] These and other advantages of the present application will become more apparent through the following detailed description of the preferred embodiments of the present application in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to further illustrate the above and other advantages and features of the present application, the specific embodiments of the present application are further described in detail below in conjunction with the accompanying drawings. The accompanying drawings together with the following detailed description are included in this specification and form a part of this specification. Elements with the same function and structure are represented by the same reference numerals. It should be understood that these drawings only describe typical examples of the present application and should not be regarded as limiting the scope of the present application.

[0016] Figure 1 is a schematic flow chart of a method for simulating gap pair transitions provided according to an embodiment of the present application;

[0017] Figure 2a is a schematic diagram of Re atom aggregation caused by interstitial pair transitions in a Mo-Re system at a temperature less than 600K according to one embodiment of the present application;

[0018] Figure 2b is a schematic diagram of Re atom aggregation caused by interstitial pair transitions in a Mo-Re system at a temperature of 600K to 800K provided according to one embodiment of the present application;

[0019] Figure 2c is a schematic diagram of Re atom aggregation caused by interstitial pair transitions in a Mo-Re system at a temperature of 800K to 1100K according to one embodiment of the present application;

[0020] Figure 2d It is a schematic diagram of Re atom aggregation caused by interstitial pair transition in Mo-Re system at a temperature greater than 1100K provided according to one embodiment of the present application.

[0021] It should be noted that the drawings are not necessarily drawn to scale, but are merely shown in a schematic manner that does not affect the reader's understanding. DETAILED DESCRIPTION

[0022] Exemplary embodiments of the present application will be described below in conjunction with the accompanying drawings. For the sake of clarity and conciseness, not all features of the actual implementation are described in the specification. However, it should be understood that many implementation-specific decisions must be made in the process of developing any such actual implementation in order to achieve the developer's specific goals, such as meeting those constraints related to the system and business, and these constraints may vary from implementation to implementation. In addition, it should be understood that although the development work may be very complex and time-consuming, it is only a routine task for those skilled in the art who benefit from the content of this application.

[0023] It is also necessary to explain here that, in order to avoid obscuring the present application due to unnecessary details, only the device structure and / or processing steps closely related to the scheme according to the present application are shown in the accompanying drawings, while other details that are not very relevant to the present application are omitted.

[0024] The disclosure below provides a plurality of different embodiments or examples to implement the present application. In order to simplify the disclosure of the present application, the parts and methods of specific examples are described below. Of course, they are merely examples, and the purpose is not to limit the present application. In the description of the embodiments of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically limited.

[0025] In the related art, interstitial pair transition events, like vacancy transition events, must participate in the probability sampling of the kinetic Monte Carlo method. Probability sampling is related to the probability of transition events. When calculating the probability of interstitial pair transitions, it is necessary to calculate the energy difference between the material system after the interstitial pair transition and before the transition. When calculating the energy of the material system before and after the interstitial pair transition, it is necessary to consider the relative position relationship between the interstitial pair and the surrounding neighboring atoms, and it is necessary to use the first-principles method to calculate and obtain the various neighboring atomic environment energies of different interstitial pairs as a reference. It can be seen from this that the treatment of interstitial pair transition behavior in the lattice dynamics Monte Carlo model is more complicated, and different material systems are treated differently, which is not scalable; at the same time, interstitial pair transitions need to participate in probability sampling, which cannot reflect the characteristics that interstitial pair transitions are faster than vacancy transitions.

[0026] In view of the above problems, the embodiments of the present application provide a method for simulating gap pair transitions, see Figure 1 The method may include the following steps S1 to S7.

[0027] S1: Determine the position information of the initial position of the gap pair.

[0028] S2: Determine a transition mode of the gap pair, and determine a target position of the gap pair after the transition according to the transition mode.

[0029] S3: Simulate the gap pair jumping from the initial position to the target position.

[0030] S4: Update the position information of the gap pair according to the target position information.

[0031] S5: Determine the state of the updated position periphery of the gap pair.

[0032] S6: According to the surrounding state, determine whether the gap pair continues to transition and repeat steps S2-S6.

[0033] S7: According to the surrounding state, determine that the gap pair stops transitioning.

[0034] The method provided in the embodiments of the present application does not need to adopt the first-principles method to calculate the energy characteristic parameters of different neighboring atomic environments of different gap pairs. By determining the initial position and transition mode of the gap pair, the transition of the gap pair from the initial position to the target position can be simulated, and then, based on the state around the updated position, it is determined whether the gap pair continues to transition or stops the transition. Such a transition method does not need to distinguish the orientation of the gap pair, has strong applicability, and can be widely used in different material systems; and when simulating the transition of the gap pair, there is no need for the gap pair to participate in probability sampling, which can make the transition of the gap pair faster than the vacancy transition.

[0035] In some embodiments, in step S1, the position information of the initial position of the gap pair can be expressed as [x 0 ,y 0 ,z 0 ].

[0036] In some embodiments, in step S2, the transition mode of the gap pair may include continuing transition and stopping transition. In the case where the gap pair continues to transition, the transition mode of the gap pair continuing to transition may specifically include three-dimensional transition and one-dimensional transition. If the transition mode of the gap pair continuing to transition is a three-dimensional transition, a lattice position can be randomly selected in the material system, and the lattice position is determined as the target position after the gap pair transition. If the transition mode of the gap pair continuing to transition is a one-dimensional transition, a lattice position can be selected along the transition direction of the gap pair, and the lattice position is determined as the target position after the gap pair transition.

[0037] In some embodiments, the transition behavior of the gap pair can be simulated by first principles or molecular dynamics, and then the transition mode of the gap pair when it continues to transition can be determined by tracking the motion trajectory of the gap pair. If the motion trajectory of the gap pair is an irregular random walk, it is a three-dimensional transition; if the motion trajectory of the gap pair is along a specific direction, it is a one-dimensional transition.

[0038] For example, the target position after the gap pair transition can be expressed as [x 1 ,y 1 ,z 1 ].

[0039] In some embodiments, the next step can be selected based on the state of the surrounding area of ​​the gap pair. If the gap pair can continue to transition, steps S2-S6 can be repeated; if the gap pair no longer continues to transition, the transition processing of the gap pair is terminated.

[0040] In some embodiments, step S7 may also include: determining that there are vacancies around the position of the gap pair, then the gap pair stops transitioning, so that it can be determined that the gap pair and the vacancies are recombined and annihilated so that the gap pair disappears from the material system, thereby terminating the simulation of the gap pair transition and making the gap pair transition faster.

[0041] In some embodiments, whether there is a vacancy around the position of the gap pair may be determined by traversing the perimeter of the position of the gap pair.

[0042] In some embodiments, step S6 may further include: determining that there are no vacancies around the position of the gap pair; determining the number of other gap pairs around the position of the gap pair; and determining that the gap pair performs transition according to the number of other gap pairs.

[0043] In an embodiment of the present application, when there are no vacancies around the position of the gap pair, according to the number of other gap pairs around the position of the gap pair, it can be determined that the gap pair can continue to transition, so that the transition of the gap pair is faster.

[0044] In some embodiments, when it is determined that there is no vacancy around the position of the gap pair, the position around the gap pair can be traversed to determine whether there are other gap pairs around the position of the gap pair, and then determine the number of other gap pairs.

[0045] In some embodiments, the number of other gap pairs around the position of the determined gap pair is less than a first predetermined value, and a first escape probability is determined based on the number of other gap pairs around the position of the gap pair and the first predetermined value; a first random number is generated based on the first escape probability; and the gap pair is determined to transition based on the first escape probability and the first random number.

[0046] Since there is a strong binding effect between gap pairs, when there are other gap pairs in the vicinity of a gap pair, the gap pair and the other gap pairs will combine with each other to form a stable gap pair cluster and no longer continue to transition. The number of other gap pairs that a gap pair can form a stable gap pair cluster after encountering is related to the binding energy between the gap pairs. When the number of other gap pairs around a gap pair is less than a first predetermined value, there is a certain probability that the gap pair escapes from the gap pair cluster. The embodiment of the present application generates a first random number based on the first escape probability, and then determines the gap pair to transition based on the first escape probability and the first random number, which can improve the efficiency of the gap pair transition.

[0047] In some embodiments, the first predetermined value can be calculated based on the first principles or molecular dynamics method. The first predetermined value indicates that when the number of other gap pairs around the position of the gap pair is greater than the first predetermined value, the gap pair will be constrained by other gap pairs and cannot continue to transition.

[0048] According to the first escape probability, a first random number is generated. In some embodiments, the first random number may be randomly generated by a computer.

[0049] In some embodiments, the number of other gap pairs around the position of the gap pair and the first predetermined value determine that the first escape probability meets the following expression:

[0050]

[0051] in, represents the first escape probability, N SIA Indicates the number of other gap pairs around the location of the gap pair, N inter Indicates a first predetermined value.

[0052] The embodiment of the present application determines the first escape probability through the above expression (1), and then determines the transition of the gap pair according to the first escape probability and the first random number, thereby further improving the transition efficiency of the gap pair.

[0053] In some embodiments, if N SIA <N inter , the first escape probability can be calculated using expression (1): Then generate a random number rand1. According to the first escape probability and the random number rand 1, determine the gap pair to transition.

[0054] In some embodiments, according to the first escape probability being greater than the first random number, it is determined that the gap pair is to be transitioned, so as to ensure the transition efficiency of the gap pair.

[0055] In some embodiments, if Then determine the gap pair to stop transition; if It is determined that the gap pair continues to transition.

[0056] In some embodiments, in step S7, it is determined that there is no vacancy around the position of the gap pair; it is determined that the number of other gap pairs around the position of the gap pair is greater than a first predetermined value; and it is determined that the gap pair stops transitioning.

[0057] The gap pair of the embodiment of the present application does not need to participate in probability sampling when it transitions, and when there are no vacancies around the position of the gap pair, it can quickly determine whether the gap pair needs to stop transitioning based on the number of other gap pairs around it and a first predetermined value.

[0058] In some embodiments, when determining that the perimeter of the position of the gap pair does not have a vacancy, if N SIA >N inter , the number of gap pairs is greater than the first predetermined value N inter The other interstitial pairs will combine with each other to form stable interstitial pair clusters and will no longer continue to transition.

[0059] In some embodiments, in step S7, it is determined that there are no vacancies around the position of the gap pair; the number of other gap pairs around the position of the gap pair is determined; the number of other gap pairs around the position of the gap pair is determined to be less than a first predetermined value; a first escape probability is determined based on the number of other gap pairs around the position of the gap pair and the first predetermined value; a first random number is generated based on the first escape probability; and based on the first escape probability being less than the first random number, it is determined that the gap pair does not make a jump.

[0060] In some embodiments, the number of solute atoms around the gap pair is determined; the number of solute atoms around the gap pair is determined to be greater than a second predetermined value; and the gap pair is determined to stop transitioning. This can determine that the gap pair will be held by the surrounding solute atoms and cannot continue to transition, thereby terminating the simulation of the gap pair transition and making the gap pair transition faster.

[0061] In some embodiments, if Then the gap pair can continue to transition, and then the surroundings of the gap pair can be traversed to determine whether there are solute atoms around the gap pair. If there are solute atoms, the number of surrounding solute atoms is recorded.

[0062] In some embodiments, the second predetermined value can be calculated based on first principles or molecular dynamics methods. The second predetermined value indicates that when the number of solute atoms around the position of the interstitial pair is greater than the second predetermined value, the interstitial pair will be bound by the solute atoms and cannot continue to transition.

[0063] In some embodiments, the number of solute atoms around the gap pair is determined; the number of solute atoms around the gap pair is determined to be less than a second predetermined value; a second escape probability is determined based on the number of solute atoms around the gap pair and the second predetermined value; a second random number is generated based on the second escape probability; and the gap pair is determined to undergo a transition based on the second escape probability and the second random number.

[0064] When the number of solute atoms around the gap pair is less than a second predetermined value, the gap pair may not be bound by the surrounding solute atoms and can continue to transition. The embodiment of the present application generates a second random number based on the second escape probability, and then determines the gap pair to transition based on the second escape probability and the second random number, which can improve the transition efficiency of the gap pair.

[0065] In some embodiments, those skilled in the art can understand the implementation manner of generating the second random number according to the second escape probability by generating the first random number according to the first escape probability, which will not be described in detail here for the sake of brevity.

[0066] In some embodiments, according to the number of solute atoms around the gap pair and the second predetermined value, the second escape probability is determined to conform to the following expression:

[0067]

[0068] in, represents the second escape probability, N solute represents the number of solute atoms around the interstitial pair, N trapped Indicates a second predetermined value.

[0069] The embodiment of the present application determines the second escape probability through the above expression (2), and then determines that the gap pair continues to transition according to the second escape probability and the second random number, thereby further improving the transition efficiency of the gap pair.

[0070] In some embodiments, if N solute <N trapped , the second escape probability can be calculated using expression (2): Then generate a random number rand 2. According to the second escape probability and the random number rand 2, determine whether the gap pair continues to transition.

[0071] In some embodiments, according to the second escape probability being greater than the second random number, it is determined that the gap pair is to be transitioned, so as to ensure the transition efficiency of the gap pair.

[0072] The following is a specific example to further illustrate the process of simulating gap pair transitions using the method in the present application.

[0073] Example 1

[0074] Before simulating the gap pair transition, the first predetermined value N is first determined according to the calculation results of the first principle or molecular dynamics method. inter and the second predetermined value N trapped , and then determine the transition path and mode of the interstitial pair based on the first principles or molecular dynamics method.

[0075] The process of gap pair transition mainly includes:

[0076] Step 1: Get the initial position information of the gap pair [x 0 ][y 0 ][z 0 ].

[0077] Step 2: According to the transition mode of the interstitial pair, find the target position [x 1 ][y 1 ][z 1 ].

[0078] Step 3: The gap pair completes the transition, and the position information of the gap pair is updated to [x 1 ][y 1 ][z 1 ].

[0079] Step 4: Determine the surrounding environment of the gap pair's location and decide whether the gap pair has been processed or can continue to transition:

[0080] The interstitial pair position is traversed to see if there is a vacancy around it. If there is a vacancy, the interstitial pair and the vacancy are recombined and annihilated. The interstitial pair and the vacancy disappear from the material system, and the interstitial pair transition process is terminated.

[0081] If there are no empty spaces around the gap pair, check whether there are other gap pairs around the gap pair. If there are other gap pairs, record the number N of other gap pairs around. SIA .

[0082] If N SIA >N inter , then it is determined that the gap pair cannot continue to transition.

[0083] If N SIA <N inter , then use the above expression (1) to calculate the first escape probability And according to the first escape probability Generate a first random number rand 1.

[0084] if It is determined that the gap pair cannot continue to transition.

[0085] if Then determine that the gap pair can continue to transition, then traverse whether there are solute atoms around the gap pair, and record the number of solute atoms around N solute .

[0086] If N solute >N trapped , then it is determined that the gap pair cannot continue to transition.

[0087] As N solute <N trapped , using the above expression (2) to calculate the second escape probability And according to the second escape probability Generate a second random number rand 2.

[0088] if It is determined that the gap pair cannot continue to transition.

[0089] if Then it is determined that the gap pair can continue to transition.

[0090] Step 5: Based on the judgment result of the gap pair, if the gap pair can continue to transition, the operations from the first step to the fourth step are executed in a loop; if the gap pair cannot continue to transition, the transition processing of the gap pair is terminated.

[0091] In some embodiments, Figure 2a to Figure 2d As shown, the interstitial pair transition in the Mo-Re system at different temperatures (T) can lead to the aggregation of Re atoms. By using the method for simulating interstitial pair transitions provided in the embodiments of the present application, the behavior of Re atom aggregation and precipitation induced by interstitial pair transitions in the Mo-Re system can be simulated and studied.

[0092] Regarding the embodiments of the present application, it should also be noted that, in the absence of conflict, the embodiments of the present application and the features therein can be combined with each other to obtain new embodiments.

[0093] The above are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. The protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for simulating gap pair transitions, characterized in that: The method comprises the following steps: S1: Determine the position information of the initial position of the gap pair; S2: Determine a transition mode of the gap pair, and determine a target position of the gap pair after the transition according to the transition mode; S3: simulating the gap pair to jump from the initial position to the target position; S4: updating the position information of the gap pair according to the information of the target position; S5: Determine the state of the updated position periphery of the gap pair; S6: according to the state of the periphery, determine that the gap pair continues to transition, and repeat steps S2-S6; S7: Determine that the gap pair stops transitioning according to the state of the periphery.

2. The method according to claim 1, characterized in that In step S7, it also includes: It is determined that there are vacancies around the positions of the gap pair, and the gap pair stops transitioning.

3. The method according to claim 1, characterized in that In step S6, it also includes: Determining that the perimeter of the position of the gap pair has no vacancies; Determine the number of other gap pairs around the position of the gap pair; According to the number of the other gap pairs, it is determined that the gap pairs are to be transitioned.

4. The method according to claim 3, characterized in that Determine that the number of other gap pairs around the position of the gap pair is less than a first predetermined value, determining a first escape probability according to the number of other gap pairs around the position of the gap pair and the first predetermined value, generating a first random number according to the first escape probability, The gap pair is determined to transition according to the first escape probability and the first random number.

5. The method according to claim 1, characterized in that In step S7, Determining that the perimeter of the position of the gap pair has no empty positions; Determine that the number of other gap pairs around the position of the gap pair is greater than a first predetermined value; It is determined that the gap pair stops transitioning.

6. The method according to claim 4, characterized in that The number of other gap pairs around the position of the gap pair and the first predetermined value determine that the first escape probability meets the following expression: in, represents the first escape probability, N SIA represents the number of other gap pairs around the position of the gap pair, N inter Indicates a first predetermined value.

7. The method according to claim 4, characterized in that According to the first escape probability being greater than the first random number, it is determined that the gap pair is to be transitioned.

8. The method according to claim 1, characterized in that In step S7, Determining that the perimeter of the position of the gap pair has no empty positions; Determine the number of other gap pairs around the position of the gap pair; Determine that the number of other gap pairs around the position of the gap pair is less than a first predetermined value, Determine a first escape probability according to the number of other gap pairs around the position of the gap pair and the first predetermined value, According to the first escape probability, a first random number is generated, According to the first escape probability being less than the first random number, it is determined that the gap pair does not perform a transition.

9. The method according to claim 7, characterized in that: determining the number of solute atoms surrounding the interstitial pair; determining that the number of solute atoms around the interstitial pair is greater than a second predetermined value; It is determined that the gap pair stops transitioning.

10. The method according to claim 7, characterized in that determining the number of solute atoms surrounding the interstitial pair; determining that the number of solute atoms around the interstitial pair is less than a second predetermined value; determining a second escape probability according to the number of solute atoms around the gap pair and the second predetermined value, According to the second escape probability, a second random number is generated, According to the second escape probability and the second random number, it is determined that the gap pair is to be transitioned.

11. The method according to claim 10, characterized in that According to the number of solute atoms around the gap pair and the second predetermined value, it is determined that the second escape probability meets the following expression: in, represents the second escape probability, N solute represents the number of solute atoms around the interstitial pair, N trapped Indicates a second predetermined value.

12. The method according to claim 10, characterized in that According to the second escape probability being greater than the second random number, it is determined that the gap pair is to be transitioned.

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