A method for predicting magnesium / high-nitrogen steel interfacial bonding performance based on first principles

Abstract

The application provides a method for predicting magnesium / high-nitrogen steel interface bonding performance based on first principles, which comprises the following steps: establishing corresponding magnesium crystal structure models, magnesium-based filler metal crystal structure models and high-nitrogen steel crystal structure models based on a welding joint formed by magnesium welding high-nitrogen steel; performing model optimization on each crystal structure model based on a first optimization parameter; splicing cut surfaces of each model-optimized crystal structure model to obtain a magnesium-magnesium-based filler metal-high-nitrogen steel interface composite model; performing interface optimization based on a second optimization parameter to obtain an interface-optimized magnesium-magnesium-based filler metal-high-nitrogen steel interface composite model; adjusting the interface-optimized magnesium-magnesium-based filler metal-high-nitrogen steel interface composite model to obtain magnesium-magnesium-based filler metal-high-nitrogen steel interface composite models corresponding to different magnesium-based filler metals; obtaining bonding performance evaluation results of different interface composite models; and obtaining a target magnesium-based filler metal whose bonding performance evaluation result meets a preset screening condition.

Description

Technical Field

[0001] This application relates to the field of dissimilar material joining technology, and more specifically, to a method for predicting the interfacial bonding performance of magnesium / high-nitrogen steel based on first-principles calculations. Background Technology

[0002] In aerospace, medical, and shipbuilding industries, high-nitrogen steel is widely used due to the non-magnetic, corrosion-resistant, wear-resistant, and excellent mechanical properties resulting from the grain boundary strengthening and solid solution strengthening effects of nitrogen. In the automotive and aerospace industries, magnesium and its alloys, as the lightest metallic structural materials, have been used to replace some other metallic materials in the manufacture of structural components due to their low density, high specific strength and stiffness, and excellent vibration damping performance. However, the corrosion resistance and poor plastic deformation capacity of magnesium and its alloys at room temperature greatly limit their application in aerospace and rail transportation. Therefore, brazing magnesium with high-nitrogen steel can further achieve structural lightweighting and compensate for the functional and performance deficiencies of individual high-nitrogen steel and magnesium alloy components, leveraging the respective performance advantages of the bimetallic materials to obtain a new type of composite structural material with corrosion resistance, low density, and high specific strength, thereby creating greater economic benefits. Therefore, magnesium / high-nitrogen steel brazing has significant application value. However, due to the significant difference in melting and boiling points between magnesium and high-nitrogen steel, as well as the almost complete absence of solid solutions and intermetallic compounds between them, the effective bonding between magnesium and high-nitrogen steel is limited.

[0003] Currently, the main methods to prepare magnesium / high nitrogen steel brazed joints are to optimize the welding forming process of magnesium / high nitrogen steel, add an intermediate alloy layer to achieve metallurgical bonding between magnesium and high nitrogen steel, and use traditional analysis and characterization methods to study the interface structure and bonding performance.

[0004] However, the quality of magnesium / high-nitrogen steel brazed joints prepared by the current trial-and-error method is difficult to guarantee, and the production cycle is long and the manufacturing cost is high, resulting in low production efficiency of magnesium / high-nitrogen steel brazed joints. Moreover, traditional experimental and analytical steps such as brazing connection experiments, microstructure evolution analysis, and physicochemical property testing also bring high R&D costs and long R&D cycles. Summary of the Invention

[0005] In view of this, the purpose of this application is to provide a method for predicting the interfacial bonding performance of magnesium / high-nitrogen steel based on first-principles calculations. This method involves optimizing established magnesium crystal structure models, magnesium-based solder crystal structure models, and high-nitrogen steel crystal structure models, and then assembling the cut crystal faces of each model to obtain a magnesium-magnesium-based solder-high-nitrogen steel interfacial composite model. Further interface optimization is performed on this model, and the target magnesium-based solder is determined based on the bonding performance evaluation results of different magnesium-magnesium-based solder-high-nitrogen steel interfacial composite models. This method can predict the influence of different magnesium-based solders on the interfacial bonding performance of magnesium / high-nitrogen steel, obtaining the composition of the magnesium-based solder with optimal bonding performance. This ensures the quality of magnesium / high-nitrogen steel brazed joints, reduces the production cycle and manufacturing cost of magnesium / high-nitrogen steel brazed joints, and thus improves production efficiency. Simultaneously, because the method predicts the interfacial bonding performance of magnesium / high-nitrogen steel based on first-principles calculations, it reduces the R&D costs and cycle associated with traditional experimental and analytical steps, thereby improving R&D efficiency.

[0006] In a first aspect, embodiments of this application provide a method for predicting the interfacial bonding performance of magnesium / high-nitrogen steel based on first-principles calculations, the method comprising:

[0007] Based on the composition of the weld joint formed by welding high-nitrogen steel with magnesium, various crystal structure models corresponding to the weld joint are established; wherein, the crystal structure models include a magnesium crystal structure model, a magnesium-based brazing filler metal crystal structure model corresponding to magnesium-based brazing filler metal, and a high-nitrogen steel crystal structure model;

[0008] Based on the properties of magnesium, magnesium-based solder, and high-nitrogen steel, corresponding first optimization parameters are determined, and the magnesium crystal structure model, magnesium-based solder crystal structure model, and high-nitrogen steel crystal structure model are optimized based on the first optimization parameters to obtain the optimized magnesium crystal structure model, magnesium-based solder crystal structure model, and high-nitrogen steel crystal structure model.

[0009] The magnesium crystal structure model, the magnesium-based solder crystal structure model, and the high-nitrogen steel crystal structure model, after being cut by the splicing model optimization, yield a magnesium-magnesium-based solder-high-nitrogen steel interface composite model.

[0010] Based on the properties of the magnesium, the magnesium-based brazing filler metal, and the high-nitrogen steel, the corresponding second optimization parameters are determined, and the interface of the magnesium-magnesium-based brazing filler metal-high-nitrogen steel interface composite model is optimized based on the second optimization parameters to obtain the interface-optimized magnesium-magnesium-based brazing filler metal-high-nitrogen steel interface composite model.

[0011] The interface-optimized magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model was adjusted to obtain magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models corresponding to different magnesium-based brazing filler metals.

[0012] The bonding performance evaluation results of the different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models are obtained, and the target magnesium-based brazing filler metal whose bonding performance evaluation results meet the preset screening conditions is obtained.

[0013] In one possible implementation, the first optimization parameters include a description of the inter-electron exchange correlation, k-grid points, plane wave cutoff energy, maximum number of iterations, convergence criterion for system energy, and maximum internal stress; the description of the inter-electron exchange correlation is a generalized gradient functional, the k-grid points are 4×4×1, the plane wave cutoff energy Ecut is 489.9 eV, the maximum number of iterations is 100, the convergence criterion for system energy is 1×10⁻⁶ eV / atom, and the maximum internal stress is less than 0.05 GPa;

[0014] The second optimization parameters include k grid points, plane wave cutoff energy, maximum number of iterations, convergence criterion for system energy, and maximum internal stress; the k grid points are 3×3×1, the plane wave cutoff energy Ecut is 326.5eV, the maximum number of iterations is 75, the convergence criterion for system energy is 2×10-5eV / atom, and the maximum internal stress is less than 0.1Gpa.

[0015] In one possible implementation, the cut crystal planes obtained by splicing the optimized magnesium crystal structure model, the magnesium-based solder crystal structure model, and the high-nitrogen steel crystal structure model yield a magnesium-magnesium-based solder-high-nitrogen steel interface composite model, including:

[0016] Determine the cutting methods corresponding to the magnesium crystal structure model, the magnesium-based solder crystal structure model, and the high-nitrogen steel crystal structure model, respectively. Cut the corresponding crystal structure models based on different cutting methods to obtain the magnesium crystal structure model of the first length, the magnesium-based solder crystal structure model of the second length, and the high-nitrogen steel crystal structure model of the third length.

[0017] Based on the extracted magnesium crystal structure model, the magnesium-based solder crystal structure model, and the high-nitrogen steel crystal structure model, the crystal faces obtained by cutting each crystal structure model are determined, and the crystal faces obtained by cutting each crystal structure model are spliced ​​together to obtain the magnesium-magnesium-based solder-high-nitrogen steel interface composite model. In one possible embodiment, the extracted magnesium unit cell crystal structure model includes multiple magnesium unit cell crystal faces; the extracted magnesium-based solder crystal structure model includes multiple magnesium-based solder crystal faces; the extracted high-nitrogen steel crystal structure model includes multiple high-nitrogen steel crystal faces; the step of determining the crystal faces obtained by cutting each crystal structure model based on the extracted magnesium crystal structure model, the magnesium-based solder crystal structure model, and the high-nitrogen steel crystal structure model, and splicing the crystal faces obtained by cutting each crystal structure model to obtain the magnesium-magnesium-based solder-high-nitrogen steel interface composite model includes:

[0018] Obtain the target magnesium unit cell crystal plane that meets the crystal plane screening conditions from multiple magnesium unit cell crystal planes, the target magnesium-based solder crystal plane that meets the crystal plane screening conditions from multiple magnesium-based solder crystal planes, and the target high-nitrogen steel crystal plane that meets the crystal plane screening conditions from multiple high-nitrogen steel crystal planes.

[0019] The target magnesium cell crystal plane, the target magnesium-based solder crystal plane, and the target high-nitrogen steel crystal plane are spliced ​​together to construct the magnesium-magnesium-based solder-high-nitrogen steel interface composite model.

[0020] In one possible implementation, each crystal plane includes multiple atomic layers; obtaining the target magnesium unit cell crystal plane that meets the crystal plane screening criteria from multiple magnesium unit cell crystal planes, the target magnesium-based solder crystal plane that meets the crystal plane screening criteria from multiple magnesium-based solder crystal planes, and the target high-nitrogen steel crystal plane that meets the crystal plane screening criteria from multiple high-nitrogen steel crystal planes includes:

[0021] Convergence tests were performed on the atomic layers in the multiple magnesium unit cell crystal planes, the multiple magnesium-based solder crystal planes, and the multiple high-nitrogen steel crystal planes respectively, and the convergence test results corresponding to each crystal plane were obtained.

[0022] Based on the convergence test results corresponding to each crystal plane, target magnesium cell crystal planes that meet the convergence requirements, target magnesium-based solder crystal planes that meet the convergence requirements, and target high-nitrogen steel crystal planes that meet the convergence requirements are selected from multiple magnesium cell crystal planes.

[0023] In one possible implementation, the magnesium-based brazing filler metal includes Mg atoms, Al atoms, and Sn atoms; the adjustment of the interface-optimized magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model includes:

[0024] Al atoms are used to replace the Sn atoms of the magnesium-based solder in the interface-optimized magnesium-magnesium-based solder-high nitrogen steel interface composite model to obtain the replaced magnesium-based solder and the corresponding magnesium-magnesium-based solder-high nitrogen steel interface composite model; wherein, the replaced magnesium-based solder includes Mg atoms and Al atoms.

[0025] And / or,

[0026] Sn atoms are used to replace the Al atoms of the magnesium-based solder in the interface-optimized magnesium-magnesium-based solder-high nitrogen steel interface composite model to obtain the replaced magnesium-based solder and the corresponding magnesium-magnesium-based solder-high nitrogen steel interface composite model; wherein, the replaced magnesium-based solder includes Mg atoms and Sn atoms.

[0027] In one possible implementation, obtaining the bonding performance evaluation results of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models includes:

[0028] The interfacial adhesion work of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models is calculated based on a preset interfacial adhesion work calculation formula; the interfacial adhesion work is calculated using the following formula:

[0029] W ad =(E A +E B +E C -E A / B / C ) / 2A

[0030] Among them, W ad E is the work done on interfacial adhesion. A E B E C E represents the total energy of the crystal structure models for the surfaces of metallic magnesium, magnesium-based solder, and high-nitrogen steel, respectively. A / B / C A represents the energy of the interface composite model; A represents the cross-sectional area of ​​the interface composite model.

[0031] The interfacial adhesion work of the different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models was compared to obtain the evaluation results of the bonding performance of the different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models.

[0032] In one possible implementation, obtaining the bonding performance evaluation results of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models further includes:

[0033] Obtain the local electron function plots, Mulliken layout analysis tables, and differential charge density plots of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models;

[0034] Based on the local electron function plots, Mulliken layout analysis tables, and differential charge density plots of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models, the bonding performance evaluation results of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models are obtained.

[0035] Secondly, embodiments of this application also provide an apparatus for predicting the interfacial bonding performance of magnesium / high-nitrogen steel based on first-principles calculations, the prediction apparatus comprising:

[0036] A module is established to create multiple crystal structure models corresponding to the weld joint formed by welding high-nitrogen steel with magnesium, based on the composition of the weld joint; wherein, the crystal structure models include a magnesium crystal structure model, a magnesium-based brazing filler metal crystal structure model corresponding to magnesium-based brazing filler metal, and a high-nitrogen steel crystal structure model;

[0037] The first optimization module is used to determine the corresponding first optimization parameters based on the properties of the magnesium, the magnesium-based solder, and the high-nitrogen steel, and to optimize the magnesium crystal structure model, the magnesium-based solder crystal structure model, and the high-nitrogen steel crystal structure model based on the first optimization parameters, so as to obtain the optimized magnesium crystal structure model, the magnesium-based solder crystal structure model, and the high-nitrogen steel crystal structure model.

[0038] The splicing module is used to splice the cut crystal faces of the optimized magnesium crystal structure model, the magnesium-based brazing filler metal crystal structure model, and the high-nitrogen steel crystal structure model to obtain a magnesium-magnesium-based brazing filler metal-high-nitrogen steel interface composite model.

[0039] The second optimization module is used to determine the corresponding second optimization parameters based on the properties of the magnesium, the magnesium-based brazing filler metal and the high-nitrogen steel, and to perform interface optimization on the magnesium-magnesium-based brazing filler metal-high-nitrogen steel interface composite model based on the second optimization parameters, so as to obtain the interface-optimized magnesium-magnesium-based brazing filler metal-high-nitrogen steel interface composite model.

[0040] The adjustment module is used to adjust the interface-optimized magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model to obtain magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models corresponding to different magnesium-based brazing fillers.

[0041] The acquisition module is used to acquire the bonding performance evaluation results of the different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models, and to obtain the target magnesium-based brazing filler metal whose bonding performance evaluation results meet the preset screening conditions.

[0042] In one possible implementation, the first optimization parameters include a description of the inter-electron exchange correlation, k-grid points, plane wave cutoff energy, maximum number of iterations, convergence criterion for system energy, and maximum internal stress; the description of the inter-electron exchange correlation is a generalized gradient functional, the k-grid points are 4×4×1, the plane wave cutoff energy Ecut is 489.9 eV, the maximum number of iterations is 100, the convergence criterion for system energy is 1×10⁻⁶ eV / atom, and the maximum internal stress is less than 0.05 GPa;

[0043] The second optimization parameters include k grid points, plane wave cutoff energy, maximum number of iterations, convergence criterion for system energy, and maximum internal stress; the k grid points are 3×3×1, the plane wave cutoff energy Ecut is 326.5eV, the maximum number of iterations is 75, the convergence criterion for system energy is 2×10-5eV / atom, and the maximum internal stress is less than 0.1Gpa.

[0044] In one possible implementation, the splicing module is specifically used for:

[0045] Determine the cutting methods corresponding to the magnesium crystal structure model, the magnesium-based solder crystal structure model, and the high-nitrogen steel crystal structure model, respectively. Cut the corresponding crystal structure models based on different cutting methods to obtain the magnesium crystal structure model of the first length, the magnesium-based solder crystal structure model of the second length, and the high-nitrogen steel crystal structure model of the third length.

[0046] Based on the extracted magnesium crystal structure model, magnesium-based solder crystal structure model, and high-nitrogen steel crystal structure model, the crystal faces obtained by cutting each crystal structure model are determined, and the crystal faces obtained by cutting each crystal structure model are spliced ​​together to obtain the magnesium-magnesium-based solder-high-nitrogen steel interface composite model.

[0047] In one possible implementation, the extracted magnesium unit cell crystal structure model includes multiple magnesium unit cell crystal faces; the extracted magnesium-based solder crystal structure model includes multiple magnesium-based solder crystal faces; the extracted high-nitrogen steel crystal structure model includes multiple high-nitrogen steel crystal faces; the splicing module is specifically used for:

[0048] Obtain the target magnesium unit cell crystal plane that meets the crystal plane screening conditions from multiple magnesium unit cell crystal planes, the target magnesium-based solder crystal plane that meets the crystal plane screening conditions from multiple magnesium-based solder crystal planes, and the target high-nitrogen steel crystal plane that meets the crystal plane screening conditions from multiple high-nitrogen steel crystal planes.

[0049] The target magnesium cell crystal plane, the target magnesium-based solder crystal plane, and the target high-nitrogen steel crystal plane are spliced ​​together to construct the magnesium-magnesium-based solder-high-nitrogen steel interface composite model.

[0050] In one possible implementation, each crystal plane comprises multiple atomic layers; the splicing module is specifically used for:

[0051] Convergence tests were performed on the atomic layers in the multiple magnesium unit cell crystal planes, the multiple magnesium-based solder crystal planes, and the multiple high-nitrogen steel crystal planes respectively, and the convergence test results corresponding to each crystal plane were obtained.

[0052] Based on the convergence test results corresponding to each crystal plane, target magnesium cell crystal planes that meet the convergence requirements, target magnesium-based solder crystal planes that meet the convergence requirements, and target high-nitrogen steel crystal planes that meet the convergence requirements are selected from multiple magnesium cell crystal planes.

[0053] In one possible implementation, the magnesium-based brazing filler metal includes Mg atoms, Al atoms, and Sn atoms; the adjustment of the interface-optimized magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model includes:

[0054] Al atoms are used to replace the Sn atoms of the magnesium-based solder in the interface-optimized magnesium-magnesium-based solder-high nitrogen steel interface composite model to obtain the replaced magnesium-based solder and the corresponding magnesium-magnesium-based solder-high nitrogen steel interface composite model; wherein, the replaced magnesium-based solder includes Mg atoms and Al atoms.

[0055] And / or,

[0056] Sn atoms are used to replace the Al atoms of the magnesium-based solder in the interface-optimized magnesium-magnesium-based solder-high nitrogen steel interface composite model to obtain the replaced magnesium-based solder and the corresponding magnesium-magnesium-based solder-high nitrogen steel interface composite model; wherein, the replaced magnesium-based solder includes Mg atoms and Sn atoms.

[0057] In one possible implementation, obtaining the bonding performance evaluation results of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models includes:

[0058] The interfacial adhesion work of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models is calculated based on a preset interfacial adhesion work calculation formula; the interfacial adhesion work is calculated using the following formula:

[0059] W ad =(E A +E B +E C -E A / B / C ) / 2A

[0060] Among them, W ad E is the work done on interfacial adhesion. A EB E C E represents the total energy of the crystal structure models for the surfaces of metallic magnesium, magnesium-based solder, and high-nitrogen steel, respectively. A / B / C A represents the energy of the interface composite model; A represents the cross-sectional area of ​​the interface composite model.

[0061] The interfacial adhesion work of the different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models was compared to obtain the evaluation results of the bonding performance of the different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models.

[0062] In one possible implementation, obtaining the bonding performance evaluation results of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models further includes:

[0063] Obtain the local electron function plots, Mulliken layout analysis tables, and differential charge density plots of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models;

[0064] Based on the local electron function plots, Mulliken layout analysis tables, and differential charge density plots of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models, the bonding performance evaluation results of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models are obtained.

[0065] Thirdly, embodiments of this application provide an electronic device, including: a processor, a storage medium, and a bus. The storage medium stores machine-readable instructions executable by the processor. When the electronic device is running, the processor communicates with the storage medium via the bus, and the processor executes the machine-readable instructions to perform the steps of the method for predicting the interfacial bonding performance of magnesium / high-nitrogen steel based on first principles as described in any of the first aspects.

[0066] This application provides a method for predicting the interfacial bonding performance of magnesium / high-nitrogen steel based on first-principles calculations. Based on the composition of the weld joint formed by welding magnesium to high-nitrogen steel, multiple crystal structure models corresponding to the weld joint are established. These crystal structure models include a magnesium crystal structure model, a magnesium-based solder crystal structure model, and a high-nitrogen steel crystal structure model. First optimization parameters are determined based on the properties of magnesium, magnesium-based solder, and high-nitrogen steel. Based on these first optimization parameters, the magnesium crystal structure model, magnesium-based solder crystal structure model, and high-nitrogen steel crystal structure model are optimized to obtain optimized magnesium crystal structure models, magnesium-based solder crystal structure models, and high-nitrogen steel crystal structure models. The optimized magnesium crystal structure model and magnesium-based solder crystal structure model are then combined. The crystal planes obtained by cutting the crystal structure models of magnesium-based solder and high-nitrogen steel are used to obtain a magnesium-magnesium-based solder-high-nitrogen steel interface composite model. Based on the properties of magnesium, magnesium-based solder, and high-nitrogen steel, the corresponding second optimization parameters are determined. The interface of the magnesium-magnesium-based solder-high-nitrogen steel interface composite model is then optimized based on the second optimization parameters to obtain an interface-optimized magnesium-magnesium-based solder-high-nitrogen steel interface composite model. The interface-optimized magnesium-magnesium-based solder-high-nitrogen steel interface composite model is then adjusted to obtain magnesium-magnesium-based solder-high-nitrogen steel interface composite models corresponding to different magnesium-based solders. The bonding performance evaluation results of different magnesium-magnesium-based solder-high-nitrogen steel interface composite models are obtained, and the target magnesium-based solder whose bonding performance evaluation results meet the preset screening conditions is obtained. This application optimizes established magnesium crystal structure models, magnesium-based solder crystal structure models, and high-nitrogen steel crystal structure models, and then splices the cut crystal faces of each crystal structure model to obtain a magnesium-magnesium-based solder-high-nitrogen steel interface composite model. Further interface optimization is performed on this model, and the target magnesium-based solder is determined based on the bonding performance evaluation results of different magnesium-magnesium-based solder-high-nitrogen steel interface composite models. This allows for the prediction of the impact of different magnesium-based solders on the bonding performance of the magnesium / high-nitrogen steel interface, obtaining the composition of the magnesium-based solder with optimal bonding performance. This ensures the quality of magnesium / high-nitrogen steel brazed joints, reduces the production cycle and manufacturing cost of magnesium / high-nitrogen steel brazed joints, and thus improves production efficiency. Simultaneously, because the magnesium / high-nitrogen steel interface bonding performance is predicted based on first-principles calculations, the research and development costs and cycle time associated with traditional experimental and analytical steps are reduced, thereby improving research and development efficiency.

[0067] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0068] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0069] Figure 1 This is a flowchart of a method for predicting the interfacial bonding performance of magnesium / high nitrogen steel based on first-principles calculations, according to an embodiment of this application.

[0070] Figure 2 These are schematic diagrams of magnesium crystal structure models, magnesium-based solder crystal structure models, and high-nitrogen steel crystal structure models;

[0071] Figure 3 These are schematic diagrams of the magnesium-magnesium-based solder-high nitrogen steel interface composite model and the adjusted magnesium-magnesium-based solder-high nitrogen steel interface composite model.

[0072] Figure 4 This is a flowchart of a method for predicting the interfacial bonding performance of magnesium / high nitrogen steel based on first-principles calculations, according to another embodiment of this application;

[0073] Figure 5 This is a flowchart of a method for predicting the interfacial bonding performance of magnesium / high nitrogen steel based on first-principles calculations, according to another embodiment of this application;

[0074] Figure 6 This is a flowchart of a method for predicting the interfacial bonding performance of magnesium / high nitrogen steel based on first-principles calculations, according to another embodiment of this application;

[0075] Figure 7 These are schematic diagrams of the magnesium-magnesium-based solder-high nitrogen steel interface composite model and another adjusted magnesium-magnesium-based solder-high nitrogen steel interface composite model.

[0076] Figure 8 This is a flowchart of a method for predicting the interfacial bonding performance of magnesium / high nitrogen steel based on first-principles calculations, according to another embodiment of this application;

[0077] Figure 9 This is a flowchart of a method for predicting the interfacial bonding performance of magnesium / high nitrogen steel based on first-principles calculations, according to another embodiment of this application;

[0078] Figure 10 This is a schematic diagram of the first differential charge density map and the second differential charge density map;

[0079] Figure 11 This is a schematic diagram of the first local electron function plot and the second local electron function plot;

[0080] Figure 12 This is a schematic diagram of the device for predicting the interfacial bonding performance of magnesium / high nitrogen steel based on first-principles calculations, according to an embodiment of this application.

[0081] Figure 13 This is a schematic diagram of the structure of an electronic device provided according to an embodiment of this application. Detailed Implementation

[0082] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the accompanying drawings in this application are for illustrative and descriptive purposes only and are not intended to limit the scope of protection of this application. Furthermore, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate operations implemented according to some embodiments of this application. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or implemented simultaneously. In addition, those skilled in the art, guided by the content of this application, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.

[0083] Furthermore, the described embodiments are merely some, not all, of the embodiments of this application. The components of the embodiments of this application described and illustrated herein can typically be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0084] It should be noted that the term "comprising" will be used in the embodiments of this application to indicate the presence of the features declared thereafter, but does not exclude the addition of other features.

[0085] Considering the applications of high-nitrogen steel in aerospace, medical, and shipbuilding industries, where nitrogen's grain boundary strengthening and solid solution strengthening contribute to its non-magnetic properties, corrosion resistance, wear resistance, and excellent mechanical properties, while magnesium and its alloys, as the lightest metallic structural materials, are used in the automotive and aerospace industries due to their low density, high specific strength and stiffness, and excellent vibration damping performance, they have been used to replace some other metallic materials in the manufacture of structural components. However, the corrosion resistance and poor plastic deformation capacity of magnesium and its alloys at room temperature greatly limit their application in aerospace and rail transportation. Therefore, brazing magnesium and high-nitrogen steel can further achieve structural lightweighting and compensate for the functional and performance deficiencies of individual high-nitrogen steel and magnesium alloy components, leveraging the respective performance advantages of the bimetallic materials to obtain a new type of composite structural material with corrosion resistance, low density, and high specific strength, thereby creating greater economic benefits. Therefore, magnesium / high-nitrogen steel brazing has significant application value. However, due to the significant difference in melting and boiling points between magnesium and high-nitrogen steel, as well as the almost complete absence of solid solutions and intermetallic compounds between them, the effective bonding between magnesium and high-nitrogen steel is limited.

[0086] Currently, the main methods to prepare magnesium / high nitrogen steel brazed joints are to optimize the welding forming process of magnesium / high nitrogen steel, add an intermediate alloy layer to achieve metallurgical bonding between magnesium and high nitrogen steel, and use traditional analysis and characterization methods to study the interface structure and bonding performance.

[0087] However, the quality of magnesium / high-nitrogen steel brazed joints prepared by the current trial-and-error method is difficult to guarantee, and the production cycle is long and the manufacturing cost is high, resulting in low production efficiency of magnesium / high-nitrogen steel brazed joints. Moreover, traditional experimental and analytical steps such as brazing connection experiments, microstructure evolution analysis, and physicochemical property testing also bring high R&D costs and long R&D cycles.

[0088] To address this issue, this application provides a method for predicting the interfacial bonding performance of magnesium / high-nitrogen steel based on first-principles calculations. This method involves optimizing established magnesium crystal structure models, magnesium-based solder crystal structure models, and high-nitrogen steel crystal structure models, and then combining the cut crystal faces of each model to obtain a magnesium-magnesium-based solder-high-nitrogen steel interfacial composite model. Further interface optimization is performed on this model, and the target magnesium-based solder is determined based on the bonding performance evaluation results of different magnesium-magnesium-based solder-high-nitrogen steel interfacial composite models. This method can predict the impact of different magnesium-based solders on the interfacial bonding performance of magnesium / high-nitrogen steel, obtaining the composition of the magnesium-based solder with optimal bonding performance. This ensures the quality of magnesium / high-nitrogen steel brazed joints, reduces the production cycle and manufacturing cost of magnesium / high-nitrogen steel brazed joints, and thus improves production efficiency. Furthermore, because the method predicts the interfacial bonding performance of magnesium / high-nitrogen steel based on first-principles calculations, it reduces the R&D costs and cycle time associated with traditional experimental and analytical steps, thereby improving R&D efficiency.

[0089] Figure 1 This is a flowchart of a method for predicting the interfacial bonding performance of magnesium / high-nitrogen steel based on first-principles calculations, according to embodiments of this application. Figure 1 As shown, the method for predicting the interfacial bonding performance of magnesium / high nitrogen steel based on first-principles calculations in this application may specifically include the following steps:

[0090] S101, based on the composition of the welded joint formed by welding high-nitrogen steel with magnesium, establishes multiple crystal structure models corresponding to the welded joint.

[0091] Those skilled in the art will understand that the composition of the weld joint formed by magnesium welding high-nitrogen steel includes magnesium and high-nitrogen steel, specifically magnesium, magnesium-based brazing filler metal, and high-nitrogen steel.

[0092] In this embodiment, the crystal structure model includes a magnesium crystal structure model, a magnesium-based solder crystal structure model corresponding to magnesium-based solder, and a high-nitrogen steel crystal structure model. Based on the composition of the weld joint formed by welding high-nitrogen steel with magnesium, the magnesium crystal structure model, magnesium-based solder crystal structure model, and high-nitrogen steel crystal structure model corresponding to the weld joint are established. For example, the magnesium crystal structure model, magnesium-based solder crystal structure model, and high-nitrogen steel crystal structure model are respectively as follows: Figure 2 As shown, this is for subsequent processing. It should be noted that the magnesium-based solder corresponds to the composition of the magnesium-based solder. The magnesium-based solder includes Mg atoms, Al atoms, and Sn atoms. Specifically, the composition of the magnesium-based solder, by atomic percentage, can be as follows: 75% Mg, 16.67% Al, and 8.33% Sn. This application uses this as an example for description, but it does not constitute a limitation on the composition of the magnesium-based solder; the specific composition can be set according to actual conditions.

[0093] Optionally, magnesium cell models and iron cell models can be obtained based on Material Studio (a crystal library), and magnesium crystal structure models, magnesium-based solder crystal structure models, and high-nitrogen steel crystal structure models can be constructed based on the magnesium cell models and iron cell models.

[0094] S102, based on the properties of magnesium, magnesium-based solder and high-nitrogen steel, determine the corresponding first optimization parameters, and based on the first optimization parameters, optimize the magnesium crystal structure model, magnesium-based solder crystal structure model and high-nitrogen steel crystal structure model to obtain the optimized magnesium crystal structure model, magnesium-based solder crystal structure model and high-nitrogen steel crystal structure model.

[0095] In this embodiment, the properties of magnesium, magnesium-based solder, and high-nitrogen steel, such as material properties and atomic properties, are considered. The first optimization parameter is the optimization parameter used to optimize the magnesium crystal structure model, the magnesium-based solder crystal structure model, and the high-nitrogen steel crystal structure model. The first optimization parameter is determined based on the properties of magnesium, magnesium-based solder, and high-nitrogen steel. Based on the first optimization parameter, the magnesium crystal structure model, the magnesium-based solder crystal structure model, and the high-nitrogen steel crystal structure model are optimized respectively to obtain the optimized magnesium crystal structure model, the optimized magnesium-based solder crystal structure model, and the optimized high-nitrogen steel crystal structure model for subsequent processing.

[0096] It should be noted that the first optimization parameters include the description of the inter-electron exchange correlation, k-grid points, plane wave cutoff energy, maximum number of iterations, convergence criterion of system energy, and maximum internal stress. The description of the inter-electron exchange correlation is the generalized gradient functional, the k-grid points are 4×4×1, the plane wave cutoff energy Ecut is 489.9 eV, the maximum number of iterations is 100, the convergence criterion of system energy is 1×10-6 eV / atom, and the maximum internal stress is less than 0.05 GPa.

[0097] S103, the crystal planes obtained by cutting the optimized magnesium crystal structure model, magnesium-based brazing filler metal crystal structure model, and high-nitrogen steel crystal structure model are used to obtain the magnesium-magnesium-based brazing filler metal-high-nitrogen steel interface composite model.

[0098] In this embodiment, after cutting the optimized magnesium crystal structure model, magnesium-based solder crystal structure model, and high-nitrogen steel crystal structure model to obtain the crystal faces of each crystal structure model, the crystal faces obtained from cutting each crystal structure model are spliced ​​together to construct a magnesium-magnesium-based solder-high-nitrogen steel interface composite model.

[0099] S104. Based on the properties of magnesium, magnesium-based brazing filler metal and high-nitrogen steel, the corresponding second optimization parameters are determined, and the interface of the magnesium-magnesium-based brazing filler metal-high-nitrogen steel interface composite model is optimized based on the second optimization parameters to obtain the interface-optimized magnesium-magnesium-based brazing filler metal-high-nitrogen steel interface composite model.

[0100] In this embodiment, the properties of magnesium, magnesium-based brazing filler metal, and high-nitrogen steel, such as material properties and atomic properties, are considered. The second optimization parameter is the optimization parameter used to optimize the interface of the magnesium-magnesium-based brazing filler metal-high-nitrogen steel interface composite model. The second optimization parameter is determined based on the properties of magnesium, magnesium-based brazing filler metal, and high-nitrogen steel. Based on the second optimization parameter, the interface of the magnesium-magnesium-based brazing filler metal-high-nitrogen steel interface composite model is optimized to obtain the optimized magnesium-magnesium-based brazing filler metal-high-nitrogen steel interface composite model. For example, as shown... Figure 3 As shown on the left, the magnesium surface is the magnesium in this application, and the magnesium surface / magnesium-based brazing filler metal / high nitrogen steel is the magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model in this application.

[0101] It should be noted that the second optimization parameters include k grid points, plane wave cutoff energy, maximum number of iterations, convergence criterion for system energy, and maximum internal stress; k grid points are 3×3×1, plane wave cutoff energy Ecut is 326.5eV, maximum number of iterations is 75, convergence criterion for system energy is 2×10-5eV / atom, and maximum internal stress is less than 0.1Gpa.

[0102] S105, the interface-optimized magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model is adjusted to obtain the magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model corresponding to different magnesium-based brazing filler metals.

[0103] In this embodiment of the application, the interface-optimized magnesium-magnesium-based solder-high nitrogen steel interface composite model obtained in step S104 is adjusted to obtain magnesium-magnesium-based solder-high nitrogen steel interface composite models corresponding to different magnesium-based solders, for example, such as Figure 3 As shown on the right, the magnesium surface / comparison solder 1 / high nitrogen steel is a different magnesium-magnesium-based solder-high nitrogen steel interface composite model in this application.

[0104] Optionally, the magnesium-magnesium-based solder-high nitrogen steel interface composite model can be adjusted based on preset magnesium-based solder compositions. It should be noted that different magnesium-based solders correspond to different magnesium-based solder compositions.

[0105] S106, evaluate the bonding performance of different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models, and obtain the target magnesium-based brazing filler metal whose bonding performance evaluation results meet the preset screening conditions.

[0106] In this embodiment, the preset screening conditions are the conditions for screening the bonding performance evaluation results. The bonding performance of different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models obtained in the above embodiments is evaluated to obtain the bonding performance evaluation results of different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models. The bonding performance evaluation results are screened according to the preset screening conditions, and the magnesium-based brazing filler metal whose bonding performance evaluation results meet the preset screening conditions is determined as the target magnesium-based brazing filler metal, so that the high nitrogen steel / magnesium brazed joint can be prepared in the future according to the target magnesium-based brazing filler metal.

[0107] The method for predicting the interfacial bonding performance of magnesium / high-nitrogen steel based on first-principles calculations provided in this application establishes multiple crystal structure models corresponding to the weld joint formed by welding magnesium to high-nitrogen steel, based on the composition of the weld joint. These crystal structure models include a magnesium crystal structure model, a magnesium-based brazing filler metal crystal structure model, and a high-nitrogen steel crystal structure model. First optimization parameters are determined based on the properties of magnesium, magnesium-based brazing filler metal, and high-nitrogen steel. Based on these first optimization parameters, the magnesium crystal structure model, magnesium-based brazing filler metal crystal structure model, and high-nitrogen steel crystal structure model are optimized to obtain optimized magnesium crystal structure models, magnesium-based brazing filler metal crystal structure models, and high-nitrogen steel crystal structure models. The optimized magnesium crystal structure model and magnesium-based brazing filler metal crystal structure model are then combined. Crystal planes obtained by cutting the crystal structure model and the high-nitrogen steel crystal structure model are used to obtain a magnesium-magnesium-based solder-high-nitrogen steel interface composite model. Based on the properties of magnesium, magnesium-based solder, and high-nitrogen steel, corresponding second optimization parameters are determined. The interface of the magnesium-magnesium-based solder-high-nitrogen steel interface composite model is then optimized based on the second optimization parameters to obtain an interface-optimized magnesium-magnesium-based solder-high-nitrogen steel interface composite model. The interface-optimized magnesium-magnesium-based solder-high-nitrogen steel interface composite model is then adjusted to obtain magnesium-magnesium-based solder-high-nitrogen steel interface composite models corresponding to different magnesium-based solders. The bonding performance evaluation results of different magnesium-magnesium-based solder-high-nitrogen steel interface composite models are obtained, and the target magnesium-based solder whose bonding performance evaluation results meet the preset screening conditions is obtained. This application presents a method for predicting the interfacial bonding performance of magnesium / high-nitrogen steel based on first-principles calculations. This method optimizes established magnesium crystal structure models, magnesium-based solder crystal structure models, and high-nitrogen steel crystal structure models, and then combines the cut crystal faces of each model to obtain a magnesium-magnesium-based solder-high-nitrogen steel interfacial composite model. Further interface optimization is performed on this model, and the target magnesium-based solder is determined based on the bonding performance evaluation results of different magnesium-magnesium-based solder-high-nitrogen steel interfacial composite models. This method can predict the impact of different magnesium-based solders on the interfacial bonding performance of magnesium / high-nitrogen steel, obtaining the composition of the magnesium-based solder with optimal bonding performance. This ensures the quality of magnesium / high-nitrogen steel brazed joints, reduces the production cycle and manufacturing cost of magnesium / high-nitrogen steel brazed joints, and thus improves production efficiency. Furthermore, because the method predicts the interfacial bonding performance of magnesium / high-nitrogen steel based on first-principles calculations, it reduces the R&D costs and cycle time associated with traditional experimental and analytical steps, thereby improving R&D efficiency.

[0108] Furthermore, such as Figure 4 As shown, step S103 in the above embodiment, "splitting the optimized magnesium crystal structure model, magnesium-based solder crystal structure model, and high-nitrogen steel crystal structure model to obtain the crystal planes obtained by cutting, and obtaining the magnesium-magnesium-based solder-high-nitrogen steel interface composite model," may specifically include the following steps:

[0109] S401, determine the cutting methods corresponding to the magnesium crystal structure model, the magnesium-based solder crystal structure model, and the high-nitrogen steel crystal structure model, respectively, and cut the corresponding crystal structure models based on different cutting methods to obtain the first length magnesium crystal structure model, the second length magnesium-based solder crystal structure model, and the third length high-nitrogen steel crystal structure model.

[0110] In this embodiment, the cutting method refers to the method of cutting the crystal structure model. For example, the cutting method may include the cutting direction and the cutting position. The optimized magnesium crystal structure model, magnesium-based solder crystal structure model, and high-nitrogen steel crystal structure model obtained in the above embodiments each correspond to a cutting method. The cutting methods corresponding to the optimized magnesium crystal structure model, magnesium-based solder crystal structure model, and high-nitrogen steel crystal structure model are determined, and the corresponding crystal structure models are cut according to different cutting methods to obtain a magnesium crystal structure model of a first length, a magnesium-based solder crystal structure model of a second length, and a high-nitrogen steel crystal structure model of a third length for subsequent processing. The first length conforms to the corresponding first length cutting range, the second length conforms to the corresponding second length cutting range, and the third length conforms to the corresponding third length cutting range. For example, the first length cutting range of the magnesium crystal structure model is... The second length cutoff range of the magnesium-based solder crystal structure model is The third length cutoff range of the high-nitrogen steel crystal structure model is: At this point, it is possible to intercept Length of magnesium crystal structure model Length of magnesium-based solder crystal structure model and A crystal structure model of high-nitrogen steel of a certain length.

[0111] Optionally, a preset crystal plane index (e.g., 0 1 0) can be selected, and the magnesium crystal structure model, magnesium-based solder crystal structure model, and high-nitrogen steel crystal structure model can be cut based on the crystal plane index and the cutting method.

[0112] S402, based on the extracted magnesium crystal structure model, magnesium-based brazing filler metal crystal structure model and high-nitrogen steel crystal structure model, determine the crystal planes obtained by cutting each crystal structure model, and splice the crystal planes obtained by cutting each crystal structure model to obtain a magnesium-magnesium-based brazing filler metal-high-nitrogen steel interface composite model.

[0113] In this embodiment of the application, after cutting out magnesium crystal structure models, magnesium-based solder crystal structure models and high-nitrogen steel crystal structure models of various lengths in step S402, the crystal planes obtained by cutting each crystal structure model are determined based on the cut-out magnesium crystal structure models, magnesium-based solder crystal structure models and high-nitrogen steel crystal structure models, and these crystal planes are spliced ​​together to obtain a magnesium-magnesium-based solder-high-nitrogen steel interface composite model.

[0114] Among them, the extracted magnesium unit cell crystal structure model includes multiple magnesium unit cell crystal planes; the extracted magnesium-based solder crystal structure model includes multiple magnesium-based solder crystal planes; and the extracted high-nitrogen steel crystal structure model includes multiple high-nitrogen steel crystal planes.

[0115] Furthermore, such as Figure 5 As shown, step S402 in the above embodiment, "determining the crystal planes obtained by cutting each crystal structure model based on the extracted magnesium crystal structure model, magnesium-based solder crystal structure model, and high-nitrogen steel crystal structure model, and splicing the crystal planes obtained by cutting each crystal structure model to obtain a magnesium-magnesium-based solder-high-nitrogen steel interface composite model," may specifically include the following steps:

[0116] S501, obtain the target magnesium cell crystal plane that meets the crystal plane screening conditions from multiple magnesium cell crystal planes, the target magnesium-based solder crystal plane that meets the crystal plane screening conditions from multiple magnesium-based solder crystal planes, and the target high-nitrogen steel crystal plane that meets the crystal plane screening conditions from multiple high-nitrogen steel crystal planes.

[0117] In this embodiment, the crystal plane screening condition refers to the condition for screening target crystal planes. In the above embodiments, the magnesium unit cell crystal structure model, the magnesium-based solder crystal structure model, and the high-nitrogen steel crystal structure model are each screened according to the crystal plane screening condition. This process identifies target magnesium unit cell crystal planes that meet the screening conditions from among the magnesium unit cell crystal planes in the magnesium unit cell crystal structure model, target magnesium-based solder crystal planes that meet the screening conditions from among the magnesium-based solder crystal planes in the magnesium-based solder crystal structure model, and target high-nitrogen steel crystal planes that meet the screening conditions from among the high-nitrogen steel crystal planes in the high-nitrogen steel crystal structure model, for subsequent processing. Each crystal plane includes multiple atomic layers.

[0118] It should be noted that this application does not impose too many restrictions on the specific methods for obtaining the target magnesium cell crystal plane, the target magnesium-based solder crystal plane, and the target high-nitrogen steel crystal plane, and these methods can be set according to the actual situation.

[0119] As one possible implementation, convergence tests are performed on the atomic layers of multiple magnesium unit cell planes, multiple magnesium-based solder planes, and multiple high-nitrogen steel planes to obtain the convergence test results for each plane. Based on the convergence test results for each plane, target magnesium unit cell planes, target magnesium-based solder planes, and target high-nitrogen steel planes that meet the convergence requirements are selected from the multiple magnesium unit cell planes, the multiple magnesium-based solder planes, and the multiple high-nitrogen steel planes. The convergence test results are the results of convergence tests on the number of atomic layers in each plane, and the plane selection criterion is the convergence requirement.

[0120] S502, splicing the target magnesium cell crystal plane, the target magnesium-based solder crystal plane, and the target high-nitrogen steel crystal plane to construct a magnesium-magnesium-based solder-high-nitrogen steel interface composite model.

[0121] In this embodiment of the application, the target magnesium cell crystal plane of the magnesium cell crystal structure model, the target magnesium-based solder crystal plane of the magnesium-based solder crystal structure model, and the target high-nitrogen steel crystal plane of the high-nitrogen steel crystal structure model obtained in step S501 are spliced ​​together to construct a magnesium-magnesium-based solder-high-nitrogen steel interface composite model.

[0122] It should be noted that after performing convergence tests on the atomic layers in the crystal planes, the target parameters of the high-nitrogen steel crystal structure model (e.g., the area of ​​the corresponding crystal plane) are adjusted by redefining the lattice, comparing the lattice parameters to ensure that the mismatch rate is less than a preset mismatch threshold (e.g., 5%). This yields three steady-state crystal structure models. Based on these three steady-state crystal structure models, a magnesium / magnesium-based solder / high-nitrogen steel interface composite model is established. The crystal orientation of the magnesium / magnesium-based solder / high-nitrogen steel interface composite model is consistent with that of the magnesium-based solder, and the lattice parameters of the magnesium / magnesium-based solder / high-nitrogen steel interface composite model are... The initial interlayer spacing is set to Furthermore, a target thickness is set in the direction perpendicular to the construction interface of the magnesium / magnesium-based solder / high-nitrogen steel interface composite model (e.g., A vacuum layer is used to prevent the effects of periodic mirroring.

[0123] Furthermore, such as Figure 6 As shown, step S105 in the above embodiment, "adjusting the interface-optimized magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model," may specifically include the following steps:

[0124] S601, using Al atoms to replace the Sn atoms of the magnesium-based solder in the interface-optimized magnesium-magnesium-based solder-high nitrogen steel interface composite model, to obtain the replaced magnesium-based solder and the corresponding magnesium-magnesium-based solder-high nitrogen steel interface composite model; wherein, the replaced magnesium-based solder includes Mg atoms and Al atoms.

[0125] In this embodiment, Al atoms are selected to replace Sn atoms in the magnesium-based solder in the interface-optimized magnesium-magnesium-based solder-high nitrogen steel interface composite model, resulting in the replaced magnesium-based solder and the corresponding magnesium-magnesium-based solder-high nitrogen steel interface composite model. For example, ... Figure 3The comparative solder 1 shown represents a replacement magnesium-based solder of this application. The solder composition of comparative solder 1, by atomic percentage, is as follows: 75% Mg, 25% Al. At this time, the magnesium-magnesium-based solder-high nitrogen steel interface composite model corresponding to the replacement magnesium-based solder is the magnesium / comparative solder 1 / high nitrogen steel interface composite model.

[0126] S602, Sn atoms are used to replace the Al atoms of the magnesium-based solder in the interface-optimized magnesium-magnesium-based solder-high nitrogen steel interface composite model to obtain the replaced magnesium-based solder and the corresponding magnesium-magnesium-based solder-high nitrogen steel interface composite model; wherein, the replaced magnesium-based solder includes Mg atoms and Sn atoms.

[0127] In this embodiment, Sn atoms are selected to replace Al atoms in the magnesium-based solder in the interface-optimized magnesium-magnesium-based solder-high-nitrogen steel interface composite model, resulting in the replaced magnesium-based solder and the corresponding magnesium-magnesium-based solder-high-nitrogen steel interface composite model. For example, ... Figure 7 The comparative solder 2 shown on the right represents another alternative magnesium-based solder in this application. The solder composition of comparative solder 2, by atomic percentage, is as follows: 75% Mg, 25% Sn. At this time, the magnesium-magnesium-based solder-high nitrogen steel interface composite model corresponding to the alternative magnesium-based solder is the magnesium / comparative solder 2 / high nitrogen steel interface composite model.

[0128] It should be noted that after constructing different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models, structural optimization calculations are also required, which will not be elaborated here.

[0129] Furthermore, such as Figure 8 As shown, the performance evaluation results include interfacial adhesion work. Step S106 in the above embodiment, "obtaining the bonding performance evaluation results of the different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models," specifically includes the following steps:

[0130] S801 calculates the interfacial adhesion work of different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models based on a preset interfacial adhesion work calculation formula.

[0131] In this embodiment, the interface adhesion work calculation formula is a pre-set formula for calculating the interface adhesion work. Based on the interface adhesion work calculation formula, the interface adhesion work of different magnesium-magnesium-based solder-high nitrogen steel interface composite models is calculated for subsequent processing.

[0132] The interfacial adhesion work is calculated using the following formula:

[0133] W ad =(E A +E B +EC -E A / B / C ) / 2A

[0134] Among them, W ad E is the work done on interfacial adhesion. A E B E C E represents the total energy of the crystal structure models for the surfaces of metallic magnesium, magnesium-based solder, and high-nitrogen steel, respectively. A / B / C Let A be the energy of the interface composite model; and let A be the cross-sectional area of ​​the interface composite model.

[0135] For example, based on the above formula for calculating interfacial adhesion work, the unadjusted magnesium-magnesium-based solder-high nitrogen steel interface composite model can be calculated (e.g., Figure 3 The first interfacial adhesion work of the magnesium / magnesium-based solder / high-nitrogen steel interface composite model shown on the left is W. ad =3.91914387 J / m 2 The adjusted magnesium-magnesium-based solder-high nitrogen steel interface composite model (e.g., Figure 3 The adhesion work of the second interface in the magnesium / comparison solder 1 / high nitrogen steel interface composite model shown on the right is W. ad =3.330887741J / m 2 Another adjusted magnesium-magnesium-based solder-high nitrogen steel interface composite model (e.g., Figure 7 The adhesion work of the third interface in the magnesium / comparison solder 2 / high nitrogen steel interface composite model shown on the right is W. ad =2.166383684J / m 2 .

[0136] S802 compares the interfacial adhesion work of different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models to obtain the evaluation results of the bonding performance of different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models.

[0137] In this embodiment, the interfacial adhesion work of different magnesium-magnesium-based solder-high nitrogen steel interface composite models calculated in step S801 is compared to obtain the bonding performance evaluation results of different magnesium-magnesium-based solder-high nitrogen steel interface composite models. For example, as described above, the first interfacial adhesion work of the magnesium-magnesium-based solder-high nitrogen steel interface composite model before adjustment is W. ad =3.91914387 J / m 2 The second interface adhesion work of the adjusted magnesium-magnesium-based solder-high nitrogen steel interface composite model corresponding to solder 1 is W. ad =3.330887741J / m 2 It can be seen that the adhesion work at the first interface is greater than that at the second interface, indicating that the bonding performance of the magnesium-magnesium-based brazing filler metal-high nitrogen steel interface is higher.

[0138] For example, as mentioned above, the first interfacial adhesion work of the magnesium-magnesium-based solder-high nitrogen steel interface composite model before adjustment is W. ad =3.330887741 JJ / m 2 The adhesion work of the third interface in the adjusted magnesium-magnesium-based solder-high nitrogen steel interface composite model corresponding to solder 2 is W. ad =2.166383684J / m 2 It can be seen that the adhesion work at the first interface is greater than that at the third interface, indicating that the bonding performance of the magnesium-magnesium-based brazing filler metal-high nitrogen steel interface is higher.

[0139] Furthermore, such as Figure 9 As shown, step S106 in the above embodiment, "obtaining the bonding performance evaluation results of different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models", may further include the following steps:

[0140] S901, obtain the local electronic function plots, Mulliken layout analysis tables, and differential charge density plots of different atoms under the same functional conditions for different magnesium-magnesium-based solder-high nitrogen steel interface composite models.

[0141] In this embodiment, the performance evaluation results also include local electron function maps, Mulliken layout analysis tables, and differential charge density maps. The differential charge density map represents the differential charge density of different atoms under the same functional conditions. Local electron function maps, Mulliken layout analysis tables, and differential charge density maps of different magnesium-magnesium-based solder-high nitrogen steel interface composite models are obtained for subsequent processing. For example, here the first differential charge density map of the magnesium-magnesium-based solder-high nitrogen steel interface composite model before replacement and the second differential charge density map of the magnesium-magnesium-based solder-high nitrogen steel interface composite model after replacement corresponding to solder 1 are obtained, such as... Figure 10 As shown; obtain the first local electronic function plot of the magnesium-magnesium-based solder-high nitrogen steel interface composite model before replacement and the second local electronic function plot of the magnesium-magnesium-based solder-high nitrogen steel interface composite model corresponding to solder 1 after replacement, as shown. Figure 11 As shown in Table 1 and / or Table 2, the Mulliken layout analysis tables for the magnesium-magnesium-based solder-high nitrogen steel interface composite model before replacement and the magnesium-magnesium-based solder-high nitrogen steel interface composite model after replacement corresponding to the control solder 1 are obtained. Table 1 is the Mulliken layout analysis table of the main chemical bonds of the magnesium / magnesium-based solder / high nitrogen steel interface composite model before and after replacement (magnesium-based solder before replacement and control solder 1); Table 2 is the Mulliken layout analysis table of the main chemical bonds of the magnesium / magnesium-based solder / high nitrogen steel interface composite model before and after replacement (magnesium-based solder before replacement and control solder 2).

[0142] Table 1

[0143]

[0144] Table 2

[0145]

[0146]

[0147] S902, based on the local electron function diagrams, Mulliken layout analysis tables, and differential charge density diagrams of different magnesium-magnesium-based solder-high nitrogen steel interface composite models, the bonding performance evaluation results of different magnesium-magnesium-based solder-high nitrogen steel interface composite models are obtained.

[0148] In this embodiment of the application, based on the local electron function diagrams, Mulliken layout analysis tables, and differential charge density diagrams of different magnesium-magnesium-based solder-high nitrogen steel interface composite models obtained in step S901, the bonding performance evaluation results of different magnesium-magnesium-based solder-high nitrogen steel interface composite models are obtained.

[0149] It should be noted that after determining the bonding performance evaluation results of different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models, it indicates that the magnesium-based brazing filler metal with the best bonding performance has been determined, so that the welded joint can be prepared based on this magnesium-based brazing filler metal (composition) in the future.

[0150] For example, binding performance can be evaluated by comparing differential charge density maps, such as... Figure 10 As shown, for Figure 10 The left-hand model shows a magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model. In the magnesium-based brazing filler metal, Mg atoms share electrons with Mg atoms on the magnesium surface, resulting in significant electron cloud overlap and the formation of Mg-Mg bonds. Electrons near Mg atoms in the magnesium-based brazing filler metal move towards Fe atoms, and Fe exhibits electronegativity towards Mg. Furthermore, Sn atoms share electrons with Fe atoms, forming Sn-Fe bonds. Regarding... Figure 10 The magnesium-comparison solder 1-high nitrogen steel interface composite model on the right shows that, in contrast solder 1, besides the Mg-Mg bond, electrons between Al and Mg atoms move towards the vicinity of Mg, forming an Al-Mg bond. Simultaneously, in contrast solder 1, Mg atoms and Fe atoms form a strong Mg-Fe covalent bond with significant electron cloud overlap. When Al atoms lose charge, Fe atoms gain some charge, forming a weaker Al-Fe bond. However, through comparison... Figure 10 The interface composite model of the left and right parts shows that the charge density between atoms of magnesium-based solder is significantly greater than that of the control solder 1, the electron cloud overlap range is larger, and the bond at the magnesium / magnesium-based solder / high nitrogen steel interface is stronger, thus indicating that the interface bonding performance of the magnesium / magnesium-based solder / high nitrogen steel before replacement is better.

[0151] For example, the bonding characteristics between atoms can be quantitatively described by analyzing the electronic localization function (ELF). In this case, the bonding performance can be evaluated by comparing the localized electron function plots. Figure 11 As shown, for Figure 11 The magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model on the left shows that the ELF value around Fe(4) atoms in the magnesium-based brazing filler metal is in the range of 0 to 0.25, indicating that electrons of Fe atoms are transferred to the nearest neighbor Mg(8) atoms, and the bond between Fe(4) and Mg(8) is an ionic bond. At the same time, the ELF distribution near Sn(1) atoms is uniform, and the ELF value between Sn(1) and Fe(27) atoms is approximately 0.5, indicating that there are both ionic and covalent bonds between Sn(1) and Fe(27). Furthermore, the Mg(25)-Mg(9) bond shows a greater tendency towards covalent bonds, indicating that covalent bonds play a dominant role. Figure 11 In the magnesium-contrast brazing filler metal 1-high nitrogen steel interface composite model on the right, there are obvious lone pairs of electrons between Mg(20) and Mg(6), exhibiting weak covalent bond characteristics. Meanwhile, Fe(28) and Mg(5) show more ionic bond characteristics. Furthermore, the valence electrons of Al(4) and Fe(27) contribute to other surrounding groups, indicating that there are both ionic and covalent bonds between Al(4) and Fe(27). Through comparison... Figure 11 The local electron function plots of the left and right parts show that, compared with the magnesium / comparison solder 1 / high nitrogen steel interface, the average ELF between different atoms in the magnesium / magnesium-based solder / high nitrogen steel interface is larger, and the main chemical bonds are mostly ionic bonds. This indicates that the probability of electron pairs appearing in the magnesium / magnesium-based solder / high nitrogen steel interface is higher, the bonding probability is higher, and the interface has better bonding performance.

[0152] For example, comparing the Mulliken bond layout can reflect the distribution of electrons at the interface and quantify the type and intensity of bonding. At this time, the bonding performance can be evaluated by comparing the Mulliken layout analysis table. As shown in Table 1 above, the Mg(9)-Mg(25) bond at the magnesium / magnesium-based brazing filler metal / high nitrogen steel interface and the Mg(20)-Mg(6) bond at the magnesium / comparison brazing filler metal 1 / high nitrogen steel interface both exhibit strong covalent bond properties with small bond length differences. However, the Fe(27)-Al(1) and Fe(28)-Mg(5) bonds at the magnesium / comparison brazing filler metal 1 / high nitrogen steel interface have longer bond lengths and lower strengths than Sn(1)-Fe(27) and Mg(8)-Fe(4). Therefore, the bonding performance of the magnesium / magnesium-based brazing filler metal / high nitrogen steel interface is higher than that of the magnesium / comparison brazing filler metal 1 / high nitrogen steel interface. As shown in Table 2 above, the Mg(9)-Mg(25) bonds at the magnesium / magnesium-based brazing filler metal / high nitrogen steel interface and the Mg(20)-Mg(6) bonds at the magnesium / comparative brazing filler metal 2 / high nitrogen steel interface both exhibit strong covalent bond properties, with the Mg(9)-Mg(25) bonds having shorter bond lengths and higher strengths. Meanwhile, the Fe(27)-Sn(1) and Fe(28)-Mg(5) bonds at the magnesium / comparative brazing filler metal 2 / high nitrogen steel interface exhibit more ionic bond characteristics. Conversely, the Sn(1)-Fe(27) and Mg(8)-Fe(4) bonds at the magnesium / magnesium-based brazing filler metal / high nitrogen steel interface exhibit more covalent bond characteristics. Therefore, the bonding strength of the magnesium / magnesium-based brazing filler metal / high nitrogen steel interface is higher than that of the magnesium / comparative brazing filler metal 2 / high nitrogen steel interface.

[0153] Clearly, as illustrated in the example above, by comparing the local electron function plots, Mulliken layout analysis tables, and differential charge density plots of different magnesium-magnesium-based solder-high nitrogen steel interface composite models, the optimal bonding performance of the magnesium / magnesium-based solder / high nitrogen steel interface was ultimately determined.

[0154] Figure 12 This is a schematic diagram of the device for predicting the interfacial bonding performance of magnesium / high-nitrogen steel based on first-principles calculations, according to an embodiment of this application. Figure 12 As shown in the embodiment of this application, the apparatus 1200 for predicting the interfacial bonding performance of magnesium / high-nitrogen steel based on first-principles calculations may specifically include:

[0155] Module 1201 is established to create multiple crystal structure models corresponding to the weld joint based on the composition of the weld joint formed by welding high-nitrogen steel with magnesium. The crystal structure models include a magnesium crystal structure model, a magnesium-based brazing filler metal crystal structure model, and a high-nitrogen steel crystal structure model.

[0156] The first optimization module 1202 is used to determine the corresponding first optimization parameters based on the properties of magnesium, magnesium-based solder and high-nitrogen steel, and to optimize the magnesium crystal structure model, magnesium-based solder crystal structure model and high-nitrogen steel crystal structure model based on the first optimization parameters, so as to obtain the optimized magnesium crystal structure model, magnesium-based solder crystal structure model and high-nitrogen steel crystal structure model.

[0157] The splicing module 1203 is used to splice the crystal planes obtained by cutting the optimized magnesium crystal structure model, magnesium-based brazing filler metal crystal structure model and high-nitrogen steel crystal structure model to obtain a magnesium-magnesium-based brazing filler metal-high-nitrogen steel interface composite model.

[0158] The second optimization module 1204 is used to determine the corresponding second optimization parameters based on the properties of magnesium, magnesium-based brazing filler metal and high-nitrogen steel, and to perform interface optimization on the magnesium-magnesium-based brazing filler metal-high-nitrogen steel interface composite model based on the second optimization parameters, so as to obtain the interface-optimized magnesium-magnesium-based brazing filler metal-high-nitrogen steel interface composite model.

[0159] The adjustment module 1205 is used to adjust the interface-optimized magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model to obtain the magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model corresponding to different magnesium-based brazing filler metals.

[0160] The acquisition module 1206 is used to acquire the bonding performance evaluation results of different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models, and obtain the target magnesium-based brazing filler metal whose bonding performance evaluation results meet the preset screening conditions.

[0161] In one possible implementation, the first optimization parameters include a description of the inter-electron exchange correlation, k-grid points, plane wave cutoff energy, maximum number of iterations, convergence criterion for system energy, and maximum internal stress; the description of the inter-electron exchange correlation is a generalized gradient functional, k-grid points are 4×4×1, plane wave cutoff energy Ecut is 489.9 eV, maximum number of iterations is 100, convergence criterion for system energy is 1×10⁻⁶ eV / atom, and maximum internal stress is less than 0.05 GPa;

[0162] The second set of optimization parameters includes k grid points, plane wave cutoff energy, maximum number of iterations, convergence criterion for system energy, and maximum internal stress. The k grid points are 3×3×1, the plane wave cutoff energy Ecut is 326.5eV, the maximum number of iterations is 75, the convergence criterion for system energy is 2×10-5eV / atom, and the maximum internal stress is less than 0.1Gpa.

[0163] In one possible implementation, the splicing module is specifically used for:

[0164] Determine the cutting methods corresponding to the magnesium crystal structure model, the magnesium-based solder crystal structure model, and the high-nitrogen steel crystal structure model, respectively. Cut the corresponding crystal structure models based on different cutting methods to obtain the first length magnesium crystal structure model, the second length magnesium-based solder crystal structure model, and the third length high-nitrogen steel crystal structure model.

[0165] Based on the extracted magnesium crystal structure model, magnesium-based solder crystal structure model, and high-nitrogen steel crystal structure model, the crystal faces obtained by cutting each crystal structure model are determined, and the crystal faces obtained by cutting each crystal structure model are spliced ​​together to obtain a magnesium-magnesium-based solder-high-nitrogen steel interface composite model.

[0166] In one possible implementation, the extracted magnesium unit cell crystal structure model includes multiple magnesium unit cell crystal planes; the extracted magnesium-based solder crystal structure model includes multiple magnesium-based solder crystal planes; the extracted high-nitrogen steel crystal structure model includes multiple high-nitrogen steel crystal planes; the splicing module is specifically used for:

[0167] Obtain the target magnesium unit cell crystal plane that meets the crystal plane screening conditions from multiple magnesium unit cell crystal planes, the target magnesium-based solder crystal plane that meets the crystal plane screening conditions from multiple magnesium-based solder crystal planes, and the target high-nitrogen steel crystal plane that meets the crystal plane screening conditions from multiple high-nitrogen steel crystal planes.

[0168] By splicing together the target magnesium cell crystal plane, the target magnesium-based solder crystal plane, and the target high-nitrogen steel crystal plane, a magnesium-magnesium-based solder-high-nitrogen steel interface composite model is constructed.

[0169] In one possible implementation, each crystal facet includes multiple atomic layers; the splicing module is specifically used for:

[0170] Convergence tests were performed on the atomic layers in multiple magnesium unit cell crystal planes, multiple magnesium-based solder crystal planes, and multiple high-nitrogen steel crystal planes to obtain the convergence test results for each crystal plane.

[0171] Based on the convergence test results corresponding to each crystal plane, target magnesium cell crystal planes that meet the convergence requirements, target magnesium-based solder crystal planes that meet the convergence requirements, and target high-nitrogen steel crystal planes that meet the convergence requirements were selected from multiple magnesium cell crystal planes.

[0172] In one possible implementation, the magnesium-based brazing filler metal includes Mg atoms, Al atoms, and Sn atoms; the interface-optimized magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model is adjusted, including:

[0173] Al atoms were used to replace the Sn atoms of the magnesium-based solder in the interface-optimized magnesium-magnesium-based solder-high nitrogen steel interface composite model to obtain the replaced magnesium-based solder and the corresponding magnesium-magnesium-based solder-high nitrogen steel interface composite model; wherein, the replaced magnesium-based solder includes Mg atoms and Al atoms.

[0174] And / or,

[0175] Sn atoms were used to replace the Al atoms of the magnesium-based solder in the interface-optimized magnesium-magnesium-based solder-high nitrogen steel interface composite model to obtain the replaced magnesium-based solder and the corresponding magnesium-magnesium-based solder-high nitrogen steel interface composite model; wherein, the replaced magnesium-based solder includes Mg atoms and Sn atoms.

[0176] In one possible implementation, the bonding performance evaluation results of different magnesium-magnesium-based solder-high nitrogen steel interface composite models are obtained, including:

[0177] The interfacial adhesion work of different magnesium-magnesium-based solder-high nitrogen steel interface composite models was calculated based on a pre-defined formula. The interfacial adhesion work was calculated using the following formula:

[0178] W ad =(E A +E B +E C -E A / B / C ) / 2A

[0179] Among them, W ad E is the work done on interfacial adhesion. A E B E C E represents the total energy of the crystal structure models for the surfaces of metallic magnesium, magnesium-based solder, and high-nitrogen steel, respectively. A / B / C A represents the energy of the interface composite model; A represents the cross-sectional area of ​​the interface composite model.

[0180] The interfacial adhesion work of different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models was compared to obtain the evaluation results of the bonding performance of different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models.

[0181] In one possible implementation, obtaining the bonding performance evaluation results of different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models further includes:

[0182] Local electron function plots, Mulliken layout analysis tables, and differential charge density plots of different magnesium-magnesium-based solder-high nitrogen steel interface composite models were obtained.

[0183] Based on the local electron function plots, Mulliken layout analysis tables, and differential charge density plots of different magnesium-magnesium-based solder-high nitrogen steel interface composite models, the bonding performance evaluation results of different magnesium-magnesium-based solder-high nitrogen steel interface composite models were obtained.

[0184] The apparatus provided in this application for predicting the interfacial bonding performance of magnesium / high-nitrogen steel based on first-principles calculations establishes multiple crystal structure models corresponding to the weld joint formed by welding high-nitrogen steel with magnesium, based on the composition of the weld joint. These crystal structure models include a magnesium crystal structure model, a magnesium-based brazing filler metal crystal structure model, and a high-nitrogen steel crystal structure model. First optimization parameters are determined based on the properties of magnesium, magnesium-based brazing filler metal, and high-nitrogen steel. Based on these first optimization parameters, the magnesium crystal structure model, magnesium-based brazing filler metal crystal structure model, and high-nitrogen steel crystal structure model are optimized to obtain optimized magnesium crystal structure models, magnesium-based brazing filler metal crystal structure models, and high-nitrogen steel crystal structure models. The optimized magnesium crystal structure model and magnesium-based brazing filler metal crystal structure model are then combined. Crystal planes obtained by cutting the crystal structure model and the high-nitrogen steel crystal structure model are used to obtain a magnesium-magnesium-based solder-high-nitrogen steel interface composite model. Based on the properties of magnesium, magnesium-based solder, and high-nitrogen steel, corresponding second optimization parameters are determined. The interface of the magnesium-magnesium-based solder-high-nitrogen steel interface composite model is then optimized based on the second optimization parameters to obtain an interface-optimized magnesium-magnesium-based solder-high-nitrogen steel interface composite model. The interface-optimized magnesium-magnesium-based solder-high-nitrogen steel interface composite model is then adjusted to obtain magnesium-magnesium-based solder-high-nitrogen steel interface composite models corresponding to different magnesium-based solders. The bonding performance evaluation results of different magnesium-magnesium-based solder-high-nitrogen steel interface composite models are obtained, and the target magnesium-based solder whose bonding performance evaluation results meet the preset screening conditions is obtained. This application presents a device for predicting the interfacial bonding performance of magnesium / high-nitrogen steel based on first-principles calculations. This device optimizes established magnesium crystal structure models, magnesium-based brazing filler metal (BLM) crystal structure models, and high-nitrogen steel crystal structure models, then combines the cut crystal faces of each model to obtain a magnesium-MgLM-High-Nitrogen Steel interfacial composite model. Further interface optimization is performed on this composite model, and the target magnesium-based brazing filler metal is determined based on the bonding performance evaluation results of different composite models. This allows for the prediction of the impact of different magnesium-based brazing fillers on the magnesium / high-nitrogen steel interfacial bonding performance, resulting in the optimal composition of the magnesium-based brazing filler metal for bonding performance. This ensures the quality of magnesium / high-nitrogen steel brazed joints, reduces the production cycle and manufacturing cost, and thus improves production efficiency. Furthermore, because the prediction is based on first-principles calculations, it reduces the R&D costs and time associated with traditional experimental and analytical steps, thereby improving R&D efficiency.

[0185] like Figure 13As shown in the embodiment of this application, an electronic device 1300 includes a processor 1301, a memory 1302, and a bus. The memory 1302 stores machine-readable instructions executable by the processor 1301. When the electronic device is running, the processor 1301 communicates with the memory 1302 via the bus. The processor 1301 executes the machine-readable instructions to perform the steps of the method described above for predicting the bonding performance of magnesium / high nitrogen steel interface based on first principles.

[0186] Specifically, the memory 1302 and processor 1301 mentioned above can be general-purpose memory and processor, without any specific limitations. When the processor 1301 runs the computer program stored in the memory 1302, it can execute the above-mentioned method for predicting the bonding performance of magnesium / high nitrogen steel interface based on first principles.

[0187] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems and devices described above can be referred to the corresponding processes in the method embodiments, and will not be repeated here. In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed mutual coupling or direct coupling or communication connection can be through some communication interfaces; the indirect coupling or communication connection of devices or modules can be electrical, mechanical, or other forms.

[0188] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0189] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0190] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the deployment methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0191] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for predicting the interfacial bonding properties of magnesium / high-nitrogen steel based on first-principles calculations, characterized in that, The method includes: Based on the composition of the weld joint formed by welding high-nitrogen steel with magnesium, various crystal structure models corresponding to the weld joint are established; wherein, the crystal structure models include a magnesium crystal structure model, a magnesium-based brazing filler metal crystal structure model corresponding to magnesium-based brazing filler metal, and a high-nitrogen steel crystal structure model; Based on the properties of magnesium, magnesium-based solder, and high-nitrogen steel, corresponding first optimization parameters are determined, and the magnesium crystal structure model, magnesium-based solder crystal structure model, and high-nitrogen steel crystal structure model are optimized based on the first optimization parameters to obtain the optimized magnesium crystal structure model, magnesium-based solder crystal structure model, and high-nitrogen steel crystal structure model. By splicing the optimized magnesium crystal structure model, the magnesium-based solder crystal structure model, and the high-nitrogen steel crystal structure model and cutting the resulting crystal faces, a magnesium-magnesium-based solder-high-nitrogen steel interface composite model is obtained; wherein, splicing the optimized magnesium crystal structure model, the magnesium-based solder crystal structure model, and the high-nitrogen steel crystal structure model and cutting the resulting crystal faces to obtain the magnesium-magnesium-based solder-high-nitrogen steel interface composite model includes: determining the crystal faces of the magnesium crystal structure model, the magnesium-based solder crystal structure model, and the high-nitrogen steel crystal structure model respectively. The model is cut according to the cutting method corresponding to the crystal structure model. The magnesium crystal structure model of the first length, the magnesium-based solder crystal structure model of the second length, and the high-nitrogen steel crystal structure model of the third length are obtained. Based on the cut magnesium crystal structure model, the magnesium-based solder crystal structure model and the high-nitrogen steel crystal structure model, the crystal facets obtained by cutting each crystal structure model are determined, and the crystal facets obtained by cutting each crystal structure model are spliced ​​together to obtain the magnesium-magnesium-based solder-high-nitrogen steel interface composite model. Based on the properties of the magnesium, the magnesium-based brazing filler metal, and the high-nitrogen steel, the corresponding second optimization parameters are determined, and the interface of the magnesium-magnesium-based brazing filler metal-high-nitrogen steel interface composite model is optimized based on the second optimization parameters to obtain the interface-optimized magnesium-magnesium-based brazing filler metal-high-nitrogen steel interface composite model. The interface-optimized magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model was adjusted to obtain magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models corresponding to different magnesium-based brazing filler metals. The bonding performance evaluation results of the different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models are obtained, and the target magnesium-based brazing filler metal whose bonding performance evaluation results meet the preset screening conditions is obtained.

2. The method according to claim 1, characterized in that, The first optimization parameters include a description of the inter-electron exchange correlation, k-grid points, plane wave cutoff energy, maximum number of iterations, convergence criterion for system energy, and maximum internal stress; the description of the inter-electron exchange correlation is a generalized gradient functional, the k-grid points are 4×4×1, the plane wave cutoff energy Ecut is 489.9 eV, the maximum number of iterations is 100, the convergence criterion for system energy is 1×10⁻⁶ eV / atom, and the maximum internal stress is less than 0.05 GPa; The second optimization parameters include k grid points, plane wave cutoff energy, maximum number of iterations, convergence criterion for system energy, and maximum internal stress; the k grid points are 3×3×1, the plane wave cutoff energy Ecut is 326.5eV, the maximum number of iterations is 75, the convergence criterion for system energy is 2×10-5eV / atom, and the maximum internal stress is less than 0.1Gpa.

3. The method according to claim 2, characterized in that, The extracted magnesium unit cell crystal structure model includes multiple magnesium unit cell crystal faces; the extracted magnesium-based solder crystal structure model includes multiple magnesium-based solder crystal faces; the extracted high-nitrogen steel crystal structure model includes multiple high-nitrogen steel crystal faces; the crystal faces obtained by cutting each crystal structure model are determined based on the extracted magnesium crystal structure model, the magnesium-based solder crystal structure model, and the high-nitrogen steel crystal structure model, and the crystal faces obtained by cutting each crystal structure model are spliced ​​together to obtain a magnesium-magnesium-based solder-high-nitrogen steel interface composite model, including: Obtain the target magnesium unit cell crystal plane that meets the crystal plane screening conditions from multiple magnesium unit cell crystal planes, the target magnesium-based solder crystal plane that meets the crystal plane screening conditions from multiple magnesium-based solder crystal planes, and the target high-nitrogen steel crystal plane that meets the crystal plane screening conditions from multiple high-nitrogen steel crystal planes. The target magnesium cell crystal plane, the target magnesium-based solder crystal plane, and the target high-nitrogen steel crystal plane are spliced ​​together to construct the magnesium-magnesium-based solder-high-nitrogen steel interface composite model.

4. The method according to claim 3, characterized in that, Each crystal plane includes multiple atomic layers; obtaining the target magnesium unit cell crystal plane that meets the crystal plane screening conditions from multiple magnesium unit cell crystal planes, the target magnesium-based solder crystal plane that meets the crystal plane screening conditions from multiple magnesium-based solder crystal planes, and the target high-nitrogen steel crystal plane that meets the crystal plane screening conditions from multiple high-nitrogen steel crystal planes includes: Convergence tests were performed on the atomic layers in the multiple magnesium unit cell crystal planes, the multiple magnesium-based solder crystal planes, and the multiple high-nitrogen steel crystal planes respectively, and the convergence test results corresponding to each crystal plane were obtained. Based on the convergence test results corresponding to each crystal plane, target magnesium cell crystal planes that meet the convergence requirements, target magnesium-based solder crystal planes that meet the convergence requirements, and target high-nitrogen steel crystal planes that meet the convergence requirements are selected from multiple magnesium cell crystal planes.

5. The method according to claim 1, characterized in that, The magnesium-based brazing filler metal includes Mg atoms, Al atoms, and Sn atoms; the adjustment of the interface-optimized magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model includes: Al atoms are used to replace the Sn atoms of the magnesium-based solder in the interface-optimized magnesium-magnesium-based solder-high nitrogen steel interface composite model to obtain the replaced magnesium-based solder and the corresponding magnesium-magnesium-based solder-high nitrogen steel interface composite model; wherein, the replaced magnesium-based solder includes Mg atoms and Al atoms; And / or, Sn atoms are used to replace the Al atoms of the magnesium-based solder in the interface-optimized magnesium-magnesium-based solder-high nitrogen steel interface composite model to obtain the replaced magnesium-based solder and the corresponding magnesium-magnesium-based solder-high nitrogen steel interface composite model; wherein, the replaced magnesium-based solder includes Mg atoms and Sn atoms.

6. The method according to claim 1, characterized in that, The evaluation results of the bonding performance of the different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models include: The interfacial adhesion work of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models is calculated based on a preset interfacial adhesion work calculation formula; the interfacial adhesion work is calculated using the following formula: in, For interfacial adhesion work; , represents the total energy of the crystal structure models of metallic magnesium surface, magnesium-based solder, and high-nitrogen steel surface, respectively. Energy for the interface composite model; The cross-sectional area of ​​the interface composite model; The interfacial adhesion work of the different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models was compared to obtain the evaluation results of the bonding performance of the different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models.

7. The method according to claim 6, characterized in that, The process of obtaining the bonding performance evaluation results of the different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models also includes: Obtain the local electron function plots, Mulliken layout analysis tables, and differential charge density plots of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models; Based on the local electron function plots, Mulliken layout analysis tables, and differential charge density plots of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models, the bonding performance evaluation results of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models are obtained.

8. A device for predicting the interfacial bonding performance of magnesium / high-nitrogen steel based on first-principles calculations, characterized in that, The device includes: A module is established to create multiple crystal structure models corresponding to the weld joint formed by welding high-nitrogen steel with magnesium, based on the composition of the weld joint; wherein, the crystal structure models include a magnesium crystal structure model, a magnesium-based brazing filler metal crystal structure model corresponding to magnesium-based brazing filler metal, and a high-nitrogen steel crystal structure model; The first optimization module is used to determine the corresponding first optimization parameters based on the properties of the magnesium, the magnesium-based solder, and the high-nitrogen steel, and to optimize the magnesium crystal structure model, the magnesium-based solder crystal structure model, and the high-nitrogen steel crystal structure model based on the first optimization parameters, so as to obtain the optimized magnesium crystal structure model, the magnesium-based solder crystal structure model, and the high-nitrogen steel crystal structure model. The splicing module is used to splice the optimized magnesium crystal structure model, the magnesium-based solder crystal structure model, and the high-nitrogen steel crystal structure model by cutting the resulting crystal faces, thereby obtaining a magnesium-magnesium-based solder-high-nitrogen steel interface composite model. Specifically, the splicing module is used to: determine the cutting methods corresponding to the magnesium crystal structure model, the magnesium-based solder crystal structure model, and the high-nitrogen steel crystal structure model, respectively; and cut the corresponding crystal structure models based on different cutting methods to obtain a first-length magnesium crystal structure model, a second-length magnesium-based solder crystal structure model, and a third-length high-nitrogen steel crystal structure model. The model is as follows: Based on the extracted magnesium crystal structure model, magnesium-based solder crystal structure model, and high-nitrogen steel crystal structure model, the crystal faces obtained by cutting each crystal structure model are determined, and the crystal faces obtained by cutting each crystal structure model are spliced ​​together to obtain the magnesium-magnesium-based solder-high-nitrogen steel interface composite model; The second optimization module is used to determine the corresponding second optimization parameters based on the properties of magnesium, magnesium-based solder, and high-nitrogen steel, and to perform interface optimization on the magnesium-magnesium-based solder-high-nitrogen steel interface composite model based on the second optimization parameters to obtain the interface-optimized magnesium-magnesium-based solder-high-nitrogen steel interface composite model; The adjustment module is used to adjust the interface-optimized magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model to obtain magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models corresponding to different magnesium-based brazing fillers. The acquisition module is used to acquire the bonding performance evaluation results of the different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models, and to obtain the target magnesium-based brazing filler metal whose bonding performance evaluation results meet the preset screening conditions.

9. An electronic device, characterized in that, include: The device includes a processor, a memory, and a bus. The memory stores machine-readable instructions executable by the processor. When the electronic device is running, the processor communicates with the memory via the bus. When the machine-readable instructions are executed by the processor, they perform the steps of the method for predicting the interfacial bonding performance of magnesium / high-nitrogen steel based on first-principles calculations as described in any one of claims 1 to 7.

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