Method for predicting magnesium / high-nitrogen steel interface bonding performance based on first principle

Abstract

The invention provides a method for predicting the bonding performance of a magnesium / high-nitrogen steel interface based on a first principle, and the method comprises the steps: building a corresponding magnesium crystal structure model, a magnesium-based brazing filler metal crystal structure model and a high-nitrogen steel crystal structure model based on a welding joint formed by magnesium welding high-nitrogen steel, performing model optimization on each crystal structure model based on the first optimization parameters, and splicing crystal faces obtained by cutting of each crystal structure model after model optimization to obtain a magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model, performing interface optimization based on the second optimization parameter to obtain a magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model after interface optimization, and adjusting the magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model after interface optimization to obtain magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models corresponding to different magnesium-based brazing filler metal; and the binding performance evaluation results of the different interface composite models are obtained, and the target magnesium-based brazing filler metal with the binding performance evaluation results meeting the preset screening conditions is obtained.

Description

Technical Field

[0001] The present application relates to the technical field of dissimilar material connection, and in particular to a method for predicting magnesium / high nitrogen steel interface bonding performance based on first principles. Background Art

[0002] In the fields of aviation, medical treatment, shipbuilding, etc., high nitrogen steel has been used due to its non-magnetic, corrosion-resistant, wear-resistant and excellent mechanical properties brought by the grain boundary strengthening and solid solution strengthening effects of its own nitrogen element. In the automotive and aviation industries, magnesium and its alloys, as the lightest metal structural materials, have been used to replace some other metal materials to manufacture structural parts due to their low density, high specific strength and specific stiffness, and excellent shock absorption performance. However, the corrosion resistance and poor plastic deformation ability of magnesium and its alloys at room temperature have greatly limited their application in the fields of aerospace and rail transportation. Therefore, by brazing magnesium with high nitrogen steel, it is possible to further achieve structural lightweight and make up for the deficiencies in the functions and performance of a single component of high nitrogen steel and magnesium alloy, give full play to the performance advantages of the two metals, and obtain a new type of composite structural material with characteristics such as corrosion resistance, low density, and high specific strength, thereby creating greater economic benefits. Therefore, magnesium / high nitrogen steel brazing connection has important application value. However, due to the large difference in melting and boiling points between magnesium and high nitrogen steel and the almost absence of solid solutions and intermetallic compounds between the two, the effective connection between magnesium and high nitrogen steel is limited.

[0003] At present, the metallurgical bonding of magnesium and high nitrogen steel is mainly achieved by optimizing the magnesium / high nitrogen steel welding forming process and adding an intermediate alloy layer, and traditional analysis and characterization methods are used to study the interface structure and bonding properties to prepare magnesium / high nitrogen steel brazing joints.

[0004] However, the quality of the 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 experiments and analysis links such as brazing connection experiments, microstructure evolution analysis, and physical and chemical performance 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 interface bonding performance of magnesium / high nitrogen steel based on the first principles, by optimizing the established magnesium crystal structure model, magnesium-based brazing filler metal 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 brazing filler metal-high nitrogen steel interface composite model, further optimizing the interface of the magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model, and determining the target magnesium-based brazing filler metal through the bonding performance evaluation results of different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models, and predicting the influence of different magnesium-based brazing fillers on the interface bonding performance of magnesium / high nitrogen steel, and obtaining the components of magnesium-based brazing filler metal with the best bonding performance, thereby ensuring the quality of magnesium / high nitrogen steel brazing joints, reducing the production cycle and manufacturing cost of magnesium / high nitrogen steel brazing joints, and thus improving production efficiency. At the same time, due to the prediction of magnesium / high nitrogen steel interface bonding performance based on the first principles, the R&D cost and R&D cycle brought by traditional experimental and analytical links are reduced, thereby improving R&D efficiency.

[0006] In a first aspect, an embodiment of the present application provides a method for predicting the interfacial bonding properties of magnesium / high nitrogen steel based on first principles, the method comprising:

[0007] Based on the components in the weld joint formed by welding high nitrogen steel with magnesium, multiple crystal structure models corresponding to the weld joint are established; wherein the crystal structure model includes a magnesium crystal structure model, a magnesium-based solder crystal structure model corresponding to the magnesium-based solder, and a high nitrogen steel crystal structure model;

[0008] Determining corresponding first optimization parameters based on the properties of the magnesium, the magnesium-based solder and the high-nitrogen steel, and optimizing 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 to obtain the magnesium crystal structure model, the magnesium-based solder crystal structure model and the high-nitrogen steel crystal structure model after model optimization;

[0009] The crystal planes obtained by cutting the magnesium crystal structure model, the magnesium-based solder crystal structure model and the high nitrogen steel crystal structure model after splicing model optimization are obtained to obtain a magnesium-magnesium-based solder-high nitrogen steel interface composite model;

[0010] Determining corresponding second optimization parameters based on the properties of the magnesium, the magnesium-based solder and the high nitrogen steel, and performing interface optimization on the magnesium-magnesium-based solder-high nitrogen steel interface composite model based on the second optimization parameters to obtain the magnesium-magnesium-based solder-high nitrogen steel interface composite model after interface optimization;

[0011] The magnesium-magnesium-based solder-high nitrogen steel interface composite model after interface optimization is adjusted to obtain magnesium-magnesium-based solder-high nitrogen steel interface composite models corresponding to different magnesium-based solders;

[0012] The bonding performance evaluation results of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models are obtained to obtain a target magnesium-based solder whose bonding performance evaluation results meet the preset screening conditions.

[0013] In a possible implementation, the first optimization parameters include a description of the exchange correlation between electrons, a k grid point, a plane wave cutoff energy, a maximum number of iterations, a convergence criterion for system energy, and a maximum internal stress; the description of the exchange correlation between electrons is a generalized gradient functional, the k grid point is 4×4×1, the plane wave cutoff energy Ecut is 489.9 eV, the maximum number of iterations is 100, the convergence criterion for the 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 of 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 of the system energy is 2×10-5eV / atom, and the maximum internal stress is less than 0.1Gpa.

[0015] In a possible implementation, the crystal planes obtained by splicing the magnesium crystal structure model after the optimization of the model, the magnesium-based solder crystal structure model and the high nitrogen steel crystal structure model to obtain a magnesium-magnesium-based solder-high nitrogen steel interface composite model include:

[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, and obtain the magnesium crystal structure model of a first length, the magnesium-based solder crystal structure model of a second length and the high nitrogen steel crystal structure model of a third length;

[0017] Based on the cut-out magnesium crystal structure model, the magnesium-based solder crystal structure model and the high-nitrogen steel crystal structure model, the crystal planes obtained by cutting each crystal structure model are determined, and the crystal planes obtained by cutting each crystal structure model are spliced ​​to obtain the magnesium-magnesium-based solder-high-nitrogen steel interface composite model. In a possible embodiment, the cut-out magnesium unit cell crystal structure model includes a plurality of magnesium unit cell crystal planes; the cut-out magnesium-based solder crystal structure model includes a plurality of magnesium-based solder crystal planes; the cut-out high-nitrogen steel crystal structure model includes a plurality of high-nitrogen steel crystal planes; the crystal planes obtained by cutting each crystal structure model based on the cut-out magnesium crystal structure model, the magnesium-based solder crystal structure model and the high-nitrogen steel crystal structure model, and the crystal planes obtained by cutting each crystal structure model are spliced ​​to obtain the magnesium-magnesium-based solder-high-nitrogen steel interface composite model, including:

[0018] Obtaining a target magnesium unit cell crystal plane that meets the crystal plane screening condition among a plurality of magnesium unit cell crystal planes, a target magnesium-based solder crystal plane that meets the crystal plane screening condition among a plurality of magnesium-based solder crystal planes, and a target high-nitrogen steel crystal plane that meets the crystal plane screening condition among a plurality of high-nitrogen steel crystal planes;

[0019] The target magnesium unit 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 a possible implementation, each crystal plane includes a plurality of atomic layers; and obtaining a target magnesium crystal cell crystal plane that meets the crystal plane screening conditions among a plurality of magnesium crystal cell crystal planes, a target magnesium-based solder crystal plane that meets the crystal plane screening conditions among a plurality of magnesium-based solder crystal planes, and a target high-nitrogen steel crystal plane that meets the crystal plane screening conditions among a plurality of high-nitrogen steel crystal planes comprises:

[0021] Conducting convergence tests 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, to obtain the convergence test results corresponding to each crystal plane;

[0022] According to the convergence test results corresponding to each crystal plane, target magnesium unit cell crystal planes that meet the convergence requirements among multiple magnesium unit cell crystal planes, target magnesium-based solder crystal planes that meet the convergence requirements among multiple magnesium-based solder crystal planes, and target high-nitrogen steel crystal planes that meet the convergence requirements among multiple high-nitrogen steel crystal planes are screened out respectively.

[0023] In a possible implementation manner, the magnesium-based solder includes Mg atoms, Al atoms and Sn atoms; and the magnesium-magnesium-based solder-high nitrogen steel interface composite model after interface optimization is adjusted, including:

[0024] Using Al atoms to replace Sn atoms of the magnesium-based solder in the magnesium-magnesium-based solder-high nitrogen steel interface composite model after interface optimization, so as to obtain a replaced magnesium-based solder and a magnesium-magnesium-based solder-high nitrogen steel interface composite model corresponding to the replaced magnesium-based solder; wherein the replaced magnesium-based solder includes Mg atoms and Al atoms;

[0025] and / or,

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

[0027] In a possible implementation manner, obtaining the bonding performance evaluation results of the different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models includes:

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

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

[0030] Among them, W ad is the interfacial adhesion work; E A 、E B 、E C E is the total energy of the crystal structure model of the magnesium metal surface, magnesium-based solder, and high nitrogen steel surface; A / B / C is the energy of the interface composite model; A is the cross-sectional area of ​​the interface composite model;

[0031] The interface adhesion works of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models are compared to obtain the bonding performance evaluation results of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models.

[0032] In a possible implementation manner, obtaining the bonding performance evaluation results of the different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models further includes:

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

[0034] Based on the local electron function diagram, Mulliken layout analysis table and differential charge density diagram 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] In a second aspect, the embodiment of the present application further provides a device for predicting the interface bonding performance of magnesium / high nitrogen steel based on first principles, the prediction device comprising:

[0036] Establishing a module for establishing a plurality of crystal structure models corresponding to a welded joint formed by welding high nitrogen steel using magnesium, based on the components in the welded joint; wherein the crystal structure model includes a magnesium crystal structure model, a magnesium-based brazing filler metal crystal structure model corresponding to the magnesium-based brazing filler metal, and a high nitrogen steel crystal structure model;

[0037] A first optimization module, used to determine corresponding first optimization parameters based on the properties of the magnesium, the magnesium-based solder and the high-nitrogen steel, and 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 to obtain the magnesium crystal structure model, the magnesium-based solder crystal structure model and the high-nitrogen steel crystal structure model after model optimization;

[0038] A splicing module, used for splicing the magnesium crystal structure model, the magnesium-based solder crystal structure model and the crystal planes obtained by cutting the high nitrogen steel crystal structure model after model optimization, to obtain a magnesium-magnesium-based solder-high nitrogen steel interface composite model;

[0039] A second optimization module is used to determine corresponding second optimization parameters based on the properties of the magnesium, the magnesium-based solder and the 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 magnesium-magnesium-based solder-high nitrogen steel interface composite model after interface optimization;

[0040] An adjustment module, used for adjusting the magnesium-magnesium-based solder-high nitrogen steel interface composite model after interface optimization to obtain a magnesium-magnesium-based solder-high nitrogen steel interface composite model corresponding to different magnesium-based solders;

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

[0042] In a possible implementation, the first optimization parameters include a description of the exchange correlation between electrons, a k grid point, a plane wave cutoff energy, a maximum number of iterations, a convergence criterion for system energy, and a maximum internal stress; the description of the exchange correlation between electrons is a generalized gradient functional, the k grid point is 4×4×1, the plane wave cutoff energy Ecut is 489.9 eV, the maximum number of iterations is 100, the convergence criterion for the 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 of 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 of the system energy is 2×10-5eV / atom, and the maximum internal stress is less than 0.1Gpa.

[0044] In a 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, and obtain the magnesium crystal structure model of a first length, the magnesium-based solder crystal structure model of a second length and the high nitrogen steel crystal structure model of a third length;

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

[0047] In a possible implementation, the cut-out magnesium unit cell crystal structure model includes a plurality of magnesium unit cell crystal faces; the cut-out magnesium-based solder crystal structure model includes a plurality of magnesium-based solder crystal faces; the cut-out high nitrogen steel crystal structure model includes a plurality of high nitrogen steel crystal faces; the splicing module is specifically used for:

[0048] Obtaining a target magnesium unit cell crystal plane that meets the crystal plane screening condition among a plurality of magnesium unit cell crystal planes, a target magnesium-based solder crystal plane that meets the crystal plane screening condition among a plurality of magnesium-based solder crystal planes, and a target high-nitrogen steel crystal plane that meets the crystal plane screening condition among a plurality of high-nitrogen steel crystal planes;

[0049] The target magnesium unit 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 a possible implementation manner, each crystal plane includes a plurality of atomic layers; and the splicing module is specifically used for:

[0051] Conducting convergence tests 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, to obtain the convergence test results corresponding to each crystal plane;

[0052] According to the convergence test results corresponding to each crystal plane, target magnesium unit cell crystal planes that meet the convergence requirements among multiple magnesium unit cell crystal planes, target magnesium-based solder crystal planes that meet the convergence requirements among multiple magnesium-based solder crystal planes, and target high-nitrogen steel crystal planes that meet the convergence requirements among multiple high-nitrogen steel crystal planes are screened out respectively.

[0053] In a possible implementation manner, the magnesium-based solder includes Mg atoms, Al atoms and Sn atoms; and the magnesium-magnesium-based solder-high nitrogen steel interface composite model after interface optimization is adjusted, including:

[0054] Using Al atoms to replace Sn atoms of the magnesium-based solder in the magnesium-magnesium-based solder-high nitrogen steel interface composite model after interface optimization, so as to obtain a replaced magnesium-based solder and a magnesium-magnesium-based solder-high nitrogen steel interface composite model corresponding to the replaced magnesium-based solder; wherein the replaced magnesium-based solder includes Mg atoms and Al atoms;

[0055] and / or,

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

[0057] In a possible implementation manner, obtaining the bonding performance evaluation results of the different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models includes:

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

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

[0060] Among them, W ad is the interfacial adhesion work; E A 、EB 、E C E is the total energy of the crystal structure model of the magnesium metal surface, magnesium-based solder, and high nitrogen steel surface; A / B / C is the energy of the interface composite model; A is the cross-sectional area of ​​the interface composite model;

[0061] The interface adhesion works of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models are compared to obtain the bonding performance evaluation results of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models.

[0062] In a possible implementation manner, obtaining the bonding performance evaluation results of the different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models further includes:

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

[0064] Based on the local electron function diagram, Mulliken layout analysis table and differential charge density diagram 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] In a third aspect, an embodiment of the present application provides an electronic device, comprising: a processor, a storage medium and a bus, wherein the storage medium stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor communicates with the storage medium through the bus, and the processor executes the machine-readable instructions to perform the steps of the method for predicting the interface bonding performance of magnesium / high nitrogen steel based on first principles as described in any one of the first aspects.

[0066] The embodiment of the present application provides a method for predicting the interfacial bonding properties of magnesium / high nitrogen steel based on first principles. Based on the components in the weld joint formed by welding high nitrogen steel with magnesium, a plurality of crystal structure models corresponding to the weld joint are established. The crystal structure models include a magnesium crystal structure model, a magnesium-based brazing filler metal crystal structure model corresponding to the magnesium-based brazing filler metal, and a high nitrogen steel crystal structure model. Based on the properties of magnesium, magnesium-based brazing filler metal, and high nitrogen steel, the corresponding first optimization parameters are determined. Based on the first optimization parameters, the magnesium crystal structure model, the magnesium-based brazing filler metal crystal structure model, and the high nitrogen steel crystal structure model are optimized to obtain the optimized magnesium crystal structure model, the magnesium-based brazing filler metal crystal structure model, and the high nitrogen steel crystal structure model. The optimized magnesium crystal structure model, the magnesium-based brazing filler metal crystal structure model, and the high nitrogen steel crystal structure model are spliced ​​together. A magnesium-magnesium-based solder-high nitrogen steel interface composite model is obtained by cutting the crystal structure model of the solder and the crystal structure model of the high nitrogen steel, a corresponding second optimization parameter is determined based on the properties of magnesium, the magnesium-based solder and the high nitrogen steel, and the interface of the magnesium-magnesium-based solder-high nitrogen steel interface composite model is optimized based on the second optimization parameter 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 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. In this application, the magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model is obtained by optimizing the established magnesium crystal structure model, magnesium-based brazing filler metal crystal structure model and high nitrogen steel crystal structure model and splicing the crystal planes obtained by cutting each crystal structure model, and the magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model is further optimized, and the target magnesium-based brazing filler metal is determined by the bonding performance evaluation results of different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models. The influence of different magnesium-based brazing fillers on the bonding performance of the magnesium / high nitrogen steel interface can be predicted, and the components of the magnesium-based brazing filler metal with the best bonding performance can be obtained, thereby ensuring the quality of the magnesium / high nitrogen steel brazing joint, reducing the production cycle and manufacturing cost of the magnesium / high nitrogen steel brazing joint, and thus improving the production efficiency. At the same time, due to the prediction of the magnesium / high nitrogen steel interface bonding performance based on the first principle, the R&D cost and R&D cycle brought by the traditional experimental and analysis links are reduced, thereby improving the R&D efficiency.

[0067] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0069] Figure 1 It is a flow chart of a method for predicting magnesium / high nitrogen steel interface bonding performance based on first principles provided in an embodiment of the present application;

[0070] Figure 2 It is a schematic diagram of the crystal structure model of magnesium, the crystal structure model of magnesium-based solder and the crystal structure model of high nitrogen steel;

[0071] Figure 3 It is a schematic diagram of the magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model and the adjusted magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model;

[0072] Figure 4 is a flow chart of a method for predicting magnesium / high nitrogen steel interface bonding properties based on first principles provided according to another embodiment of the present application;

[0073] Figure 5 is a flow chart of a method for predicting magnesium / high nitrogen steel interface bonding properties based on first principles provided according to another embodiment of the present application;

[0074] Figure 6 is a flow chart of a method for predicting magnesium / high nitrogen steel interface bonding properties based on first principles provided according to another embodiment of the present application;

[0075] Figure 7 It is a schematic diagram of a magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model and another adjusted magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model;

[0076] Figure 8 is a flow chart of a method for predicting magnesium / high nitrogen steel interface bonding properties based on first principles provided according to another embodiment of the present application;

[0077] Fig. 9 is a flow chart of a method for predicting magnesium / high nitrogen steel interface bonding properties based on first principles provided according to another embodiment of the present application;

[0078] Fig.10 is a schematic diagram of a first differential charge density map and a second differential charge density map;

[0079] Fig.11 is a schematic diagram of a first localized electron function diagram and a second localized electron function diagram;

[0080] Fig.12 It is a schematic diagram of the structure of a device for predicting the interface bonding performance of magnesium / high nitrogen steel based on first principles provided in an embodiment of the present application;

[0081] Fig.13 It is a structural schematic diagram of an electronic device provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0082] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the drawings in the present application only serve the purpose of explanation and description and are not used to limit the scope of protection of the present application. In addition, it should be understood that the schematic drawings are not drawn in real proportion. The flowchart used in this application shows the operations implemented according to some embodiments of the present application. It should be understood that the operations of the flowchart can be implemented out of sequence, and the steps without logical context can be reversed in order or implemented simultaneously. In addition, those skilled in the art can add one or more other operations to the flowchart under the guidance of the content of the present application, or remove one or more operations from the flowchart.

[0083] In addition, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

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

[0085] Considering that in the fields of aviation, medical treatment, shipbuilding, etc., high nitrogen steel has been used due to its non-magnetic, corrosion-resistant, wear-resistant and excellent mechanical properties brought by the grain boundary strengthening and solid solution strengthening of nitrogen. In the automotive and aviation industries, magnesium and its alloys, as the lightest metal structural materials, have been used to replace some other metal materials to manufacture structural parts due to their low density, high specific strength and specific stiffness, and excellent shock absorption performance. However, the corrosion resistance and poor plastic deformation ability of magnesium and its alloys at room temperature greatly limit their application in the fields of aerospace and rail transportation. Therefore, by brazing magnesium with high nitrogen steel, it is possible to further achieve structural lightweight and make up for the deficiencies in the functions and performance of a single component of high nitrogen steel and magnesium alloy, give full play to the performance advantages of the two metals, and obtain a new composite structural material with characteristics such as corrosion resistance, low density, and high specific strength, thereby creating greater economic benefits. Therefore, magnesium / high nitrogen steel brazing connection has important application value. However, due to the large difference in melting and boiling points between magnesium and high nitrogen steel and the almost absence of solid solutions and intermetallic compounds between the two, the effective connection between magnesium and high nitrogen steel is limited.

[0086] At present, the metallurgical bonding of magnesium and high nitrogen steel is mainly achieved by optimizing the magnesium / high nitrogen steel welding forming process and adding an intermediate alloy layer, and traditional analysis and characterization methods are used to study the interface structure and bonding properties to prepare magnesium / high nitrogen steel brazing joints.

[0087] However, the quality of the 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 experiments and analysis links such as brazing connection experiments, microstructure evolution analysis, and physical and chemical performance testing also bring high R&D costs and long R&D cycles.

[0088] In response to this problem, the present application provides a method for predicting the interface bonding performance of magnesium / high nitrogen steel based on the first principles, by optimizing the established magnesium crystal structure model, magnesium-based brazing filler metal crystal structure model and high nitrogen steel crystal structure model and splicing the crystal faces obtained by cutting each crystal structure model to obtain a magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model, further optimizing the interface of the magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model, and determining the target magnesium-based brazing filler metal through the bonding performance evaluation results of different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models, and predicting the influence of different magnesium-based brazing fillers on the interface bonding performance of magnesium / high nitrogen steel, and obtaining the components of magnesium-based brazing filler metal with the best bonding performance, thereby ensuring the quality of magnesium / high nitrogen steel brazing joints, reducing the production cycle and manufacturing cost of magnesium / high nitrogen steel brazing joints, and thus improving production efficiency. At the same time, due to the prediction of magnesium / high nitrogen steel interface bonding performance based on the first principles, the R&D cost and R&D cycle brought by traditional experimental and analytical links are reduced, thereby improving R&D efficiency.

[0089] Figure 1 is a flow chart of a method for predicting magnesium / high nitrogen steel interface bonding performance based on first principles provided in an embodiment of the present application, such as Figure 1 As shown, the method for predicting the magnesium / high nitrogen steel interface bonding performance based on the first principles in the embodiment of the present application may specifically include the following steps:

[0090] S101, based on the components in the weld joint formed by welding high nitrogen steel with magnesium, multiple crystal structure models corresponding to the weld joint are established.

[0091] It is understood by those skilled in the art that the components of the weld joint formed by welding magnesium to high nitrogen steel include magnesium and high nitrogen steel, specifically, magnesium, magnesium-based brazing filler metal and high nitrogen steel.

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

[0093] Optionally, a magnesium unit cell model and an iron unit cell model are obtained based on Material studio (a crystal library), and a magnesium crystal structure model, a magnesium-based solder crystal structure model and a high nitrogen steel crystal structure model are constructed based on the magnesium unit cell model and the iron unit cell model.

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

[0095] In an embodiment of the present application, the properties of magnesium, magnesium-based solder and high nitrogen steel, such as material properties, atomic properties, etc., the first optimization parameter is the optimization parameter for optimizing 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 respectively optimized to obtain a model-optimized magnesium crystal structure model, a model-optimized magnesium-based solder crystal structure model and a model-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 exchange correlation effect between electrons, k grid points, plane wave cutoff energy, maximum number of iterations, convergence criterion of system energy and maximum internal stress; the description of the exchange correlation effect between electrons is generalized gradient functional, the k grid points are 4×4×1, the plane wave cutoff energy Ecut is 489.9eV, the maximum number of iterations is 100, the convergence criterion of system energy is 1×10-6eV / atom, and the maximum internal stress is less than 0.05GPa.

[0097] S103, splicing the crystal planes obtained by cutting the magnesium crystal structure model, the magnesium-based solder crystal structure model and the high nitrogen steel crystal structure model after model optimization to obtain a magnesium-magnesium-based solder-high nitrogen steel interface composite model.

[0098] In an embodiment of the present application, after the optimized magnesium crystal structure model, magnesium-based solder crystal structure model and high nitrogen steel crystal structure model are cut to obtain the crystal planes of each crystal structure model, the crystal planes obtained by cutting each crystal structure model are spliced ​​to construct a magnesium-magnesium-based solder-high nitrogen steel interface composite model.

[0099] S104, determining corresponding second optimization parameters based on the properties of magnesium, magnesium-based solder and high nitrogen steel, and performing interface optimization on the magnesium-magnesium-based solder-high nitrogen steel interface composite model based on the second optimization parameters to obtain the magnesium-magnesium-based solder-high nitrogen steel interface composite model after interface optimization.

[0100] In the embodiment of the present application, the properties of magnesium, magnesium-based solder and high nitrogen steel, such as material properties, atomic properties, etc., the second optimization parameter is the optimization parameter for interface optimization of the magnesium-magnesium-based solder-high nitrogen steel interface composite model, the second optimization parameter is determined based on the properties of magnesium, magnesium-based solder and high nitrogen steel, and the interface of the magnesium-magnesium-based solder-high nitrogen steel interface composite model is optimized based on the second optimization parameter to obtain the magnesium-magnesium-based solder-high nitrogen steel interface composite model after interface optimization, for example, Figure 3 As shown on the left, the magnesium surface is the magnesium in this application, and the magnesium surface / magnesium-based solder / high nitrogen steel is the magnesium-magnesium-based solder-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 of 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 of system energy is 2×10-5eV / atom, and the maximum internal stress is less than 0.1Gpa.

[0102] S105, adjusting the magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model after interface optimization to obtain magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models corresponding to different magnesium-based brazing fillers.

[0103] In the embodiment of the present application, the magnesium-magnesium-based solder-high nitrogen steel interface composite model after interface optimization 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, Figure 3 As shown on the right, magnesium surface / comparison solder 1 / high nitrogen steel is a different magnesium-magnesium-based solder-high nitrogen steel interface composite model in the present application.

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

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

[0106] In the embodiments of the present application, the preset screening conditions are 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 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 brazing joint can be prepared according to the target magnesium-based brazing filler metal in the future.

[0107] The method for predicting the interfacial bonding properties of magnesium / high nitrogen steel based on first principles provided in an embodiment of the present application establishes a plurality of crystal structure models corresponding to the weld joint based on the components in the weld joint formed by welding high nitrogen steel with magnesium, wherein the crystal structure models include a magnesium crystal structure model, a magnesium-based brazing filler metal crystal structure model corresponding to the magnesium-based brazing filler metal, and a high nitrogen steel crystal structure model; a corresponding first optimization parameter is determined based on the properties of magnesium, the magnesium-based brazing filler metal, and the high nitrogen steel; and the magnesium crystal structure model, the magnesium-based brazing filler metal crystal structure model, and the high nitrogen steel crystal structure model are optimized based on the first optimization parameter to obtain the magnesium crystal structure model, the magnesium-based brazing filler metal crystal structure model, and the high nitrogen steel crystal structure model after model optimization; and the magnesium crystal structure model, the magnesium-based brazing filler metal crystal structure model, and the high nitrogen steel crystal structure model after model optimization are spliced ​​together. The 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, the corresponding second optimization parameters are determined based on the properties of magnesium, magnesium-based solder and high nitrogen steel, and the interface of the magnesium-magnesium-based solder-high nitrogen steel interface composite model is 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 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. The method for predicting the interface bonding performance of magnesium / high nitrogen steel based on the first principles of the present application optimizes the established magnesium crystal structure model, magnesium-based brazing filler metal crystal structure model and high nitrogen steel crystal structure model and splices the crystal faces obtained by cutting each crystal structure model to obtain a magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model, further optimizes the interface of the magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model, and determines the target magnesium-based brazing filler metal through the bonding performance evaluation results of different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models, and can predict the influence of different magnesium-based brazing fillers on the interface bonding performance of magnesium / high nitrogen steel, obtain the components of magnesium-based brazing filler metal with the best bonding performance, ensure the quality of magnesium / high nitrogen steel brazing joints, reduce the production cycle and manufacturing cost of magnesium / high nitrogen steel brazing joints, thereby improving production efficiency. At the same time, due to the prediction of magnesium / high nitrogen steel interface bonding performance based on the first principles, the R&D cost and R&D cycle brought by traditional experimental and analytical links are reduced, thereby improving R&D efficiency.

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

[0109] S401, determining 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, cutting the corresponding crystal structure models based on different cutting methods, and obtaining 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.

[0110] In the embodiments of the present application, the cutting method refers to the method of cutting the crystal structure model. For example, the cutting method may include a cutting direction and a cutting position. The magnesium crystal structure model, magnesium-based solder crystal structure model and high nitrogen steel crystal structure model obtained in the above embodiments after model optimization respectively correspond to a cutting method. The cutting methods corresponding to the magnesium crystal structure model, magnesium-based solder crystal structure model and high nitrogen steel crystal structure model after model optimization 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. Among them, the first length meets the corresponding first length interception range, the second length meets the corresponding second length interception range, and the third length meets the corresponding third length interception range. For example, the first length interception range of the magnesium crystal structure model is The second length interception range of the magnesium-based solder crystal structure model is The third length interception range of the high nitrogen steel crystal structure model is At this point, you can intercept Length of magnesium crystal structure model, Crystal structure model of magnesium-based solder with different lengths and Length of high nitrogen steel crystal structure model.

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

[0112] S402, based on the cut-out magnesium crystal structure model, the magnesium-based solder crystal structure model and the high nitrogen steel crystal structure model, the crystal planes obtained by cutting each crystal structure model are determined, and the crystal planes obtained by cutting each crystal structure model are spliced ​​to obtain a magnesium-magnesium-based solder-high nitrogen steel interface composite model.

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

[0114] Among them, the cut-out magnesium unit cell crystal structure model includes a plurality of magnesium unit cell crystal planes; the cut-out magnesium-based solder crystal structure model includes a plurality of magnesium-based solder crystal planes; and the cut-out high nitrogen steel crystal structure model includes a plurality of high nitrogen steel crystal planes.

[0115] Further, such as Figure 5 As shown, step S402 in the above embodiment, "determining the crystal plane obtained by cutting each crystal structure model based on the cut magnesium crystal structure model, the magnesium-based solder crystal structure model and the 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, obtaining a target magnesium unit cell crystal plane that meets the crystal plane screening condition among a plurality of magnesium unit cell crystal planes, a target magnesium-based solder crystal plane that meets the crystal plane screening condition among a plurality of magnesium-based solder crystal planes, and a target high nitrogen steel crystal plane that meets the crystal plane screening condition among a plurality of high nitrogen steel crystal planes.

[0117] In the embodiment of the present application, the crystal plane screening condition is the condition for screening the target crystal plane. The multiple magnesium crystal planes included in the magnesium crystal cell crystal structure model, the multiple magnesium-based solder crystal planes included in the magnesium-based solder crystal structure model, and the multiple high-nitrogen steel crystal planes included in the high-nitrogen steel crystal structure model are screened according to the crystal plane screening condition, so as to screen out the target magnesium crystal cell crystal planes that meet the crystal plane screening condition among the multiple magnesium crystal cell crystal planes of the magnesium crystal cell crystal structure model, the target magnesium-based solder crystal planes that meet the crystal plane screening condition among the multiple magnesium-based solder crystal planes of the magnesium-based solder crystal structure model, and the target high-nitrogen steel crystal planes that meet the crystal plane screening condition among the multiple high-nitrogen steel crystal planes of the high-nitrogen steel crystal structure model, for subsequent processing. Each crystal plane includes multiple atomic layers.

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

[0119] As a possible implementation method, the atomic layers in multiple magnesium unit cell crystal planes, multiple magnesium-based solder crystal planes, and multiple high-nitrogen steel crystal planes are respectively subjected to convergence tests to obtain the convergence test results corresponding to each crystal plane; and the target magnesium unit cell crystal planes that meet the convergence requirements among the multiple magnesium unit cell crystal planes, the target magnesium-based solder crystal planes that meet the convergence requirements among the multiple magnesium-based solder crystal planes, and the target high-nitrogen steel crystal planes that meet the convergence requirements among the multiple high-nitrogen steel crystal planes are respectively screened out according to the convergence test results corresponding to each crystal plane. Among them, the convergence test results are the results of the convergence test of the number of atomic layers in each crystal plane, and the crystal plane screening condition is the convergence requirement.

[0120] S502, splicing the target magnesium unit 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 the embodiment of the present application, the target magnesium unit cell crystal plane of the magnesium unit cell crystal structure model obtained in step S501, 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 are spliced ​​to construct a magnesium-magnesium-based solder-high-nitrogen steel interface composite model.

[0122] It should be noted that after the convergence test of the atomic layer in the crystal plane, the lattice parameters are compared, and the size of the target parameters of the high nitrogen steel crystal structure model (for example, the area size of the corresponding crystal plane) is adjusted by Redefine Lattice (redefine crystal) so that the mismatch rate is less than the preset mismatch threshold (for example, 5%), and three steady-state crystal structure models are obtained. Based on these three steady-state crystal structure models, a magnesium / magnesium-based solder / high nitrogen steel interface composite model is established. Among them, the crystal direction of the magnesium / magnesium-based solder / high nitrogen steel interface composite model is consistent with the magnesium-based solder, and the lattice parameters of the magnesium / magnesium-based solder / high nitrogen steel interface composite model are consistent with the magnesium-based solder. The initial layer spacing is set to In addition, a target thickness is set in a direction perpendicular to the build interface of the magnesium / magnesium-based brazing filler metal / high nitrogen steel interface composite model (e.g., ) vacuum layer to prevent the influence of periodic mirror images.

[0123] Further, such as Figure 6 As shown, the step S105 in the above embodiment of "adjusting the magnesium-magnesium-based solder-high nitrogen steel interface composite model after interface optimization" may specifically include the following steps:

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

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

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

[0127] In the embodiment of the present application, Sn atoms are selected to replace Al atoms in the magnesium-based solder in the magnesium-magnesium-based solder-high nitrogen steel interface composite model after interface optimization, and the replaced magnesium-based solder and the magnesium-magnesium-based solder-high nitrogen steel interface composite model corresponding to the replaced magnesium-based solder are obtained. For example, Figure 7 The comparison solder 2 shown on the right represents another replaced magnesium-based solder of the present application. The solder composition of the comparison solder 2 is as follows in atomic percentage: 75% Mg, 25% Sn. At this time, the magnesium-magnesium-based solder-high nitrogen steel interface composite model corresponding to the replaced magnesium-based solder is the magnesium / comparison 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] Further, such as Figure 8 As shown, the bonding performance evaluation result includes the interface adhesion work. The step S106 in the above embodiment of "obtaining the bonding performance evaluation results of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models" may specifically include the following steps:

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

[0131] In the embodiment of the present application, 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] Among them, the interfacial adhesion work is calculated by the following formula:

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

[0134] Among them, W ad is the interfacial adhesion work; E A 、E B 、E C E is the total energy of the crystal structure model of the magnesium metal surface, magnesium-based solder, and high nitrogen steel surface; A / B / C is the energy of the interface composite model; A is the cross-sectional area of ​​the interface composite model.

[0135] For example, according to the above-mentioned interface adhesion work calculation formula, the magnesium-magnesium-based solder-high nitrogen steel interface composite model before adjustment can be calculated (for example, Figure 3 The first interface adhesion work of the magnesium / magnesium-based brazing filler metal / high nitrogen steel interface composite model shown on the left is W ad =3.91914387J / m 2 , the adjusted Mg-Mg-based brazing filler metal-high nitrogen steel interface composite model (e.g., Figure 3 The second interface adhesion work of the magnesium / comparative brazing material 1 / high nitrogen steel interface composite model shown on the right is W ad =3.330887741J / m 2 , another adjusted Mg-Mg-based brazing filler metal-high nitrogen steel interface composite model (e.g., Figure 7 The third interface adhesion work of the magnesium / comparative solder 2 / high nitrogen steel interface composite model shown on the right is W ad =2.166383684J / m 2 .

[0136] S802, comparing the interface adhesion work of different magnesium-magnesium-based solder-high nitrogen steel interface composite models, and obtaining the bonding performance evaluation results of different magnesium-magnesium-based solder-high nitrogen steel interface composite models.

[0137] In the embodiment of the present application, the interface adhesion work of different magnesium-magnesium-based solder-high nitrogen steel interface composite models calculated in step S801 are 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 interface adhesion work of the magnesium-magnesium-based solder-high nitrogen steel interface composite model before adjustment is W ad =3.91914387J / m 2 , compared with the adjusted magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model corresponding to brazing filler metal 1, the second interface adhesion work is W ad =3.330887741J / m 2 , it can be seen that the first interface adhesion work is greater than the second interface adhesion work, 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 interface adhesion work of the magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model before adjustment is W ad =3.330887741JJ / m 2 , the third interface adhesion work of the adjusted magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model corresponding to brazing filler metal 2 is W ad =2.166383684J / m 2 , it can be seen that the first interface adhesion work is greater than the third interface adhesion work, indicating that the bonding performance of the magnesium-magnesium-based brazing filler metal-high nitrogen steel interface is higher.

[0139] Further, such as Fig. 9 As shown, the step S106 in the above embodiment of “obtaining the bonding performance evaluation results of different magnesium-magnesium-based solder-high nitrogen steel interface composite models” may further include the following steps:

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

[0141] In the embodiment of the present application, the performance evaluation results also include a local electron function diagram, a Mulliken layout analysis table and a differential charge density diagram, wherein the differential charge density diagram is a differential charge density diagram of different atoms under the same functional conditions, and the local electron function diagram, Mulliken layout analysis table and differential charge density diagram 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 diagram of the magnesium-magnesium-based solder-high nitrogen steel interface composite model before replacement and the second differential charge density diagram of the magnesium-magnesium-based solder-high nitrogen steel interface composite model after replacement corresponding to the comparison solder 1 are obtained, such as Fig.10 As shown; obtain the first local electron function diagram of the magnesium-magnesium-based solder-high nitrogen steel interface composite model before replacement and the second local electron function diagram of the magnesium-magnesium-based solder-high nitrogen steel interface composite model after replacement corresponding to the comparison solder 1, as shown Fig.11 As shown; obtain the Mulliken layout analysis table of the magnesium-magnesium-based solder-high nitrogen steel interface composite model before replacement and the Mulliken layout analysis table of the magnesium-magnesium-based solder-high nitrogen steel interface composite model after replacement corresponding to the comparative solder 1, as shown in Table 1 and / or Table 2 below, 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 comparative 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 comparative solder 2).

[0142] Table 1

[0143]

[0144] Table 2

[0145]

[0146]

[0147] S902, based on the local electron function diagram, Mulliken layout analysis table and differential charge density diagram 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 the embodiment of the present application, based on the local electron function diagram, Mulliken layout analysis table and differential charge density diagram of different magnesium-magnesium-based solder-high nitrogen steel interface composite models obtained in step S901, the combination 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 solder-high nitrogen steel interface composite models, it means that the magnesium-based solder with the best bonding performance is determined, so that the welding joint can be prepared based on the magnesium-based solder (component) in the future.

[0150] For example, the binding performance can be evaluated by comparing the differential charge density maps, such as Fig.10 As shown, for Fig.10 In the magnesium-magnesium-based solder-high nitrogen steel interface composite model on the left, there are shared electrons between the Mg atoms in the magnesium-based solder and the Mg atoms on the magnesium surface, with obvious electron cloud overlap, forming a Mg-Mg bond. The electrons near the Mg atoms in the magnesium-based solder move toward the Fe atoms, and Fe is electronegative to Mg. In addition, there are shared electrons between the Sn atoms and the Fe atoms, forming a Sn-Fe bond. Fig.10 In the magnesium-comparison solder 1-high nitrogen steel interface composite model on the right, in addition to the Mg-Mg bond in comparison solder 1, the electrons between the Al atoms and the Mg atoms move toward the vicinity of Mg to form an Al-Mg bond. At the same time, the Mg atoms and Fe atoms in comparison solder 1 form a strong Mg-Fe covalent bond, and there is an obvious electron cloud overlap between the two. When the Al atoms lose their charge, the Fe atoms gain part of the charge to form a weaker Al-Fe bond. However, by comparing Fig.10 In the interface composite model of the left and right parts, the charge density between atoms of the magnesium-based solder is significantly greater than that of the comparative solder 1, the electron cloud overlap range is larger, and the bond at the magnesium / magnesium-based solder / high nitrogen steel interface is stronger, indicating that the magnesium / magnesium-based solder / high nitrogen steel interface bonding performance before replacement is better.

[0151] For example, the characteristics of interatomic bonding can be quantitatively described by analyzing the electron localization function (ELF). At this time, the bonding performance can be evaluated by comparing the localized electron function diagram, such as Fig.11 As shown, for Fig.11 From the magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model on the left, it can be seen that the ELF value around the Fe(4) atom in the magnesium-based brazing filler metal is in the range of 0 to 0.25, indicating that the electrons of the Fe atom are transferred to the nearest neighbor Mg(8) atom, and the bond between Fe(4) and Mg(8) is an ionic bond. At the same time, the ELF distribution near the Sn(1) atom is uniform, and the ELF value between the Sn(1) atom and the Fe(27) atom is approximately 0.5, indicating that there are both ionic and covalent bonds between Sn(1) and Fe(27), and the Mg(25)-Mg(9) bond shows more covalent bond tendency, indicating that covalent bonds play a major role. Fig.11 In the magnesium-comparison solder 1-high nitrogen steel interface composite model on the right, there are obvious lone pairs of electrons between Mg(20)-Mg(6), showing weak covalent bond characteristics, while Fe(28) and Mg(5) show more ionic bond characteristics. In addition, the valence electrons of Al(4) and Fe(27) are contributed to other surrounding groups, indicating that there are both ionic and covalent bonds between Al(4) and Fe(27). Fig.11 From the local electron function diagrams in the left and right parts, it can be concluded that the average ELF between different atoms at the magnesium / magnesium-based solder / high nitrogen steel interface is larger than that at the magnesium / comparison solder 1 / high nitrogen steel interface, and the main chemical bonds are mostly ionic bonds, indicating that the probability of electron pairs appearing in the magnesium / magnesium-based solder / high nitrogen steel interface is greater, the probability of bonding 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 strength of the 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) bonds at the Mg / Mg-based solder / high nitrogen steel interface and the Mg(20)-Mg(6) at the Mg / comparison solder 1 / high nitrogen steel interface both exhibit strong covalent bond properties with small differences in bond lengths. However, the Fe(27)-Al(1) and Fe(28)-Mg(5) bonds at the Mg / comparison solder 1 / high nitrogen steel interface are longer than the Sn(1)-Fe(27) and Mg(8)-Fe(4) bonds and have lower strength. Therefore, the bonding performance of the Mg / Mg-based solder / high nitrogen steel interface is higher than that of the Mg / comparison solder 1 / high nitrogen steel interface. As shown in Table 2 above, the Mg(9)-Mg(25) bond at the interface of magnesium / magnesium-based solder / high nitrogen steel and the Mg(20)-Mg(6) bond at the interface of magnesium / comparative solder 2 / high nitrogen steel both exhibit strong covalent bond properties, and the bond length of the Mg(9)-Mg(25) bond is shorter and the strength is higher. At the same time, the Fe(27)-Sn(1) and Fe(28)-Mg(5) bonds at the interface of magnesium / comparative solder 2 / high nitrogen steel exhibit more ionic bond characteristics. The Sn(1)-Fe(27) and Mg(8)-Fe(4) bonds at the interface of magnesium / magnesium-based solder / high nitrogen steel exhibit more covalent bond characteristics. Therefore, the bonding strength of the magnesium / magnesium-based solder / high nitrogen steel interface is higher than that of the magnesium / comparative solder 2 / high nitrogen steel interface.

[0153] Obviously, as described in the above example, by comparing the local electron function diagram, Mulliken layout analysis table, and differential charge density diagram of different magnesium-magnesium-based solder-high nitrogen steel interface composite models, it is finally established that the magnesium / magnesium-based solder / high nitrogen steel interface has the best bonding performance.

[0154] Fig.12 is a schematic diagram of the structure of a device for predicting the interface bonding performance of magnesium / high nitrogen steel based on first principles according to an embodiment of the present application, such as Fig.12 As shown, the device 1200 for predicting the interface bonding performance of magnesium / high nitrogen steel based on the first principles in the embodiment of the present application may specifically include:

[0155] Establishing module 1201 is used to establish multiple crystal structure models corresponding to the weld joint based on the components in the weld joint formed by welding high nitrogen steel using magnesium; wherein the crystal structure model includes a magnesium crystal structure model, a magnesium-based brazing filler metal crystal structure model corresponding to the magnesium-based brazing filler metal, 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 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 to obtain the magnesium crystal structure model, the magnesium-based solder crystal structure model and the high nitrogen steel crystal structure model after model optimization.

[0157] The splicing module 1203 is used to splice the cut crystal planes of the magnesium crystal structure model, the magnesium-based solder crystal structure model and the high nitrogen steel crystal structure model after model optimization to obtain a magnesium-magnesium-based solder-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 solder and high nitrogen steel, and perform interface optimization on the magnesium-magnesium-based solder-high nitrogen steel interface composite model based on the second optimization parameters to obtain the magnesium-magnesium-based solder-high nitrogen steel interface composite model after interface optimization.

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

[0160] The acquisition module 1206 is used to obtain 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 exchange correlation between electrons, k grid points, plane wave cutoff energy, a maximum number of iterations, a convergence criterion for system energy, and a maximum internal stress; the description of the exchange correlation between electrons 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;

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

[0163] In a possible implementation, the splicing module is specifically used to:

[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 the different cutting methods, and 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;

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

[0166] In a possible implementation, the cut-out magnesium unit cell crystal structure model includes a plurality of magnesium unit cell crystal faces; the cut-out magnesium-based solder crystal structure model includes a plurality of magnesium-based solder crystal faces; the cut-out high nitrogen steel crystal structure model includes a plurality of high nitrogen steel crystal faces; the splicing module is specifically used for:

[0167] Obtaining a target magnesium unit cell crystal plane that meets the crystal plane screening condition among a plurality of magnesium unit cell crystal planes, a target magnesium-based solder crystal plane that meets the crystal plane screening condition among a plurality of magnesium-based solder crystal planes, and a target high-nitrogen steel crystal plane that meets the crystal plane screening condition among a plurality of high-nitrogen steel crystal planes;

[0168] The target magnesium unit cell crystal planes, target magnesium-based solder crystal planes and target high nitrogen steel crystal planes are spliced ​​together to construct a magnesium-magnesium-based solder-high nitrogen steel interface composite model.

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

[0170] Convergence tests are 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, respectively, to obtain the convergence test results corresponding to each crystal plane;

[0171] According to the convergence test results corresponding to each crystal plane, the target magnesium unit cell crystal planes that meet the convergence requirements among multiple magnesium unit cell crystal planes, the target magnesium-based solder crystal planes that meet the convergence requirements among multiple magnesium-based solder crystal planes, and the target high nitrogen steel crystal planes that meet the convergence requirements among multiple high nitrogen steel crystal planes are screened out respectively.

[0172] In a possible implementation, the magnesium-based solder includes Mg atoms, Al atoms and Sn atoms; the magnesium-magnesium-based solder-high nitrogen steel interface composite model after interface optimization is adjusted, including:

[0173] Using Al atoms to replace Sn atoms of the magnesium-based solder in the magnesium-magnesium-based solder-high nitrogen steel interface composite model after interface optimization, so as to obtain the replaced magnesium-based solder and the magnesium-magnesium-based solder-high nitrogen steel interface composite model corresponding to the replaced magnesium-based solder; wherein the replaced magnesium-based solder includes Mg atoms and Al atoms;

[0174] and / or,

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

[0176] In a possible implementation, obtaining the bonding performance evaluation results of different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models includes:

[0177] The interface adhesion work of different magnesium-magnesium-based solder-high nitrogen steel interface composite models is calculated based on the preset interface adhesion work calculation formula; the interface adhesion work is calculated by the following calculation formula:

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

[0179] Among them, W ad is the interfacial adhesion work; E A 、E B 、E C E is the total energy of the crystal structure model of the magnesium metal surface, magnesium-based solder, and high nitrogen steel surface; A / B / C is the energy of the interface composite model; A is the cross-sectional area of ​​the interface composite model;

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

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

[0182] Obtain local electron function diagrams, Mulliken layout analysis tables and differential charge density diagrams for different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models;

[0183] Based on the local electron function diagram, Mulliken layout analysis table and differential charge density diagram 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 device provided in the embodiment of the present application predicts the magnesium / high nitrogen steel interface bonding performance based on the first principles. Based on the components in the weld joint formed by welding high nitrogen steel with magnesium, a plurality of crystal structure models corresponding to the weld joint are established. The crystal structure models include a magnesium crystal structure model, a magnesium-based brazing filler metal crystal structure model corresponding to the magnesium-based brazing filler metal, and a high nitrogen steel crystal structure model. Based on the properties of magnesium, the magnesium-based brazing filler metal, and the high nitrogen steel, the corresponding first optimization parameters are determined. Based on the first optimization parameters, the magnesium crystal structure model, the magnesium-based brazing filler metal crystal structure model, and the high nitrogen steel crystal structure model are optimized to obtain the magnesium crystal structure model, the magnesium-based brazing filler metal crystal structure model, and the high nitrogen steel crystal structure model after model optimization. The magnesium crystal structure model, the magnesium-based brazing filler metal crystal structure model, and the high nitrogen steel crystal structure model after model optimization are spliced ​​together. The 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, the corresponding second optimization parameters are determined based on the properties of magnesium, magnesium-based solder and high nitrogen steel, and the interface of the magnesium-magnesium-based solder-high nitrogen steel interface composite model is 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 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. The device for predicting the interface bonding performance of magnesium / high nitrogen steel based on the first principles of the present application optimizes the established magnesium crystal structure model, magnesium-based brazing filler metal crystal structure model and high nitrogen steel crystal structure model and splices 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, further optimizes the interface of the magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite model, and determines the target magnesium-based brazing filler metal through the bonding performance evaluation results of different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models, and can predict the influence of different magnesium-based brazing fillers on the interface bonding performance of magnesium / high nitrogen steel, obtain the components of magnesium-based brazing filler metal with the best bonding performance, ensure the quality of magnesium / high nitrogen steel brazing joints, reduce the production cycle and manufacturing cost of magnesium / high nitrogen steel brazing joints, thereby improving production efficiency. At the same time, due to the prediction of magnesium / high nitrogen steel interface bonding performance based on the first principles, the R&D cost and R&D cycle brought by traditional experimental and analytical links are reduced, thereby improving R&D efficiency.

[0185] like Fig.13As shown, an electronic device 1300 provided in an embodiment of the present application includes: a processor 1301, a memory 1302 and a bus, wherein 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 through the bus, and the processor 1301 executes the machine-readable instructions to perform the steps of the method for predicting the interface bonding performance of magnesium / high nitrogen steel based on first principles as described above.

[0186] Specifically, the memory 1302 and the processor 1301 can be general-purpose memories and processors, which are not specifically limited here. When the processor 1301 runs the computer program stored in the memory 1302, the method for predicting the interface bonding performance of magnesium / high nitrogen steel based on first principles can be executed.

[0187] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, the specific working process of the system and device described above can refer to the corresponding process in the method embodiment, and will not be repeated in this application. In the several embodiments provided in this application, it should be understood that the disclosed system, device and method can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation. For example, 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 mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

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

[0189] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0190] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the deployment method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard drives, ROM, RAM, magnetic disks, or optical disks.

[0191] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for predicting the interface bonding performance of magnesium / high nitrogen steel based on first principles, characterized in that: The method comprises: Based on the components in the weld joint formed by welding high nitrogen steel with magnesium, multiple crystal structure models corresponding to the weld joint are established; wherein the crystal structure model includes a magnesium crystal structure model, a magnesium-based solder crystal structure model corresponding to the magnesium-based solder, and a high nitrogen steel crystal structure model; Determining corresponding first optimization parameters based on the properties of the magnesium, the magnesium-based solder and the high-nitrogen steel, and optimizing 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 to obtain the magnesium crystal structure model, the magnesium-based solder crystal structure model and the high-nitrogen steel crystal structure model after model optimization; The crystal planes obtained by cutting the magnesium crystal structure model, the magnesium-based solder crystal structure model and the high nitrogen steel crystal structure model after splicing model optimization are obtained to obtain a magnesium-magnesium-based solder-high nitrogen steel interface composite model; Determining corresponding second optimization parameters based on the properties of the magnesium, the magnesium-based solder and the high nitrogen steel, and performing interface optimization on the magnesium-magnesium-based solder-high nitrogen steel interface composite model based on the second optimization parameters to obtain the magnesium-magnesium-based solder-high nitrogen steel interface composite model after interface optimization; The magnesium-magnesium-based solder-high nitrogen steel interface composite model after interface optimization is 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 the different magnesium-magnesium-based solder-high nitrogen steel interface composite models are obtained to obtain a target magnesium-based solder whose bonding performance evaluation results meet the preset screening conditions.

2. The method according to claim 1, characterized in that: The first optimization parameters include a description of the exchange correlation between electrons, k grid points, plane wave cutoff energy, a maximum number of iterations, a convergence criterion for system energy, and a maximum internal stress; the description of the exchange correlation between electrons 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 the 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 of 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 of the system energy is 2×10-5eV / atom, and the maximum internal stress is less than 0.1Gpa.

3. The method according to claim 1, characterized in that The crystal planes obtained by cutting the magnesium crystal structure model, the magnesium-based solder crystal structure model and the high nitrogen steel crystal structure model after the model optimization are spliced ​​to obtain a magnesium-magnesium-based solder-high nitrogen steel interface composite model, including: 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, and obtain the magnesium crystal structure model of a first length, the magnesium-based solder crystal structure model of a second length and the high nitrogen steel crystal structure model of a third length; Based on the cut-out magnesium crystal structure model, the magnesium-based solder crystal structure model and the high-nitrogen steel crystal structure model, the crystal planes obtained by cutting each crystal structure model are determined, and the crystal planes obtained by cutting each crystal structure model are spliced ​​to obtain the magnesium-magnesium-based solder-high-nitrogen steel interface composite model.

4. The method according to claim 3, characterized in that The cut-out magnesium unit cell crystal structure model includes a plurality of magnesium unit cell crystal faces; the cut-out magnesium-based solder crystal structure model includes a plurality of magnesium-based solder crystal faces; the cut-out high-nitrogen steel crystal structure model includes a plurality of high-nitrogen steel crystal faces; the cut-out magnesium crystal structure model, the magnesium-based solder crystal structure model and the high-nitrogen steel crystal structure model are used to determine the crystal faces obtained by cutting each crystal structure model, and the crystal faces obtained by cutting each crystal structure model are spliced ​​to obtain a magnesium-magnesium-based solder-high-nitrogen steel interface composite model, including: Obtaining a target magnesium unit cell crystal plane that meets the crystal plane screening condition among a plurality of magnesium unit cell crystal planes, a target magnesium-based solder crystal plane that meets the crystal plane screening condition among a plurality of magnesium-based solder crystal planes, and a target high-nitrogen steel crystal plane that meets the crystal plane screening condition among a plurality of high-nitrogen steel crystal planes; The target magnesium unit 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.

5. The method according to claim 4, characterized in that Each crystal plane includes a plurality of atomic layers; the step of obtaining a target magnesium crystal plane that meets the crystal plane screening conditions among a plurality of magnesium crystal planes, a target magnesium-based solder crystal plane that meets the crystal plane screening conditions among a plurality of magnesium-based solder crystal planes, and a target high-nitrogen steel crystal plane that meets the crystal plane screening conditions among a plurality of high-nitrogen steel crystal planes comprises: Conducting convergence tests 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, to obtain the convergence test results corresponding to each crystal plane; According to the convergence test results corresponding to each crystal plane, target magnesium unit cell crystal planes that meet the convergence requirements among multiple magnesium unit cell crystal planes, target magnesium-based solder crystal planes that meet the convergence requirements among multiple magnesium-based solder crystal planes, and target high-nitrogen steel crystal planes that meet the convergence requirements among multiple high-nitrogen steel crystal planes are screened out respectively.

6. The method according to claim 1, characterized in that The magnesium-based solder includes Mg atoms, Al atoms and Sn atoms; the magnesium-magnesium-based solder-high nitrogen steel interface composite model after interface optimization is adjusted, including: Using Al atoms to replace Sn atoms of the magnesium-based solder in the magnesium-magnesium-based solder-high nitrogen steel interface composite model after interface optimization, so as to obtain a replaced magnesium-based solder and a magnesium-magnesium-based solder-high nitrogen steel interface composite model corresponding to the replaced magnesium-based solder; wherein the replaced magnesium-based solder includes Mg atoms and Al atoms; and / or, Sn atoms are used to replace Al atoms of the magnesium-based solder in the magnesium-magnesium-based solder-high nitrogen steel interface composite model after interface optimization to obtain the replaced magnesium-based solder and the magnesium-magnesium-based solder-high nitrogen steel interface composite model corresponding to the replaced magnesium-based solder; wherein the replaced magnesium-based solder includes Mg atoms and Sn atoms.

7. The method according to claim 1, characterized in that The obtaining of the bonding performance evaluation results of the different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models comprises: The interface adhesion work of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models is calculated based on a preset interface adhesion work calculation formula; the interface adhesion work is calculated by the following calculation formula: W ad =(E A +E B +E C -HAVE BEEN A / B / C ) / 2A Among them, W ad is the interfacial adhesion work; E A 、E B 、E C E is the total energy of the crystal structure model of the magnesium metal surface, magnesium-based solder, and high nitrogen steel surface; A / B / C is the energy of the interface composite model; A is the cross-sectional area of ​​the interface composite model; The interface adhesion works of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models are compared to obtain the bonding performance evaluation results of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models.

8. The method according to claim 7, characterized in that The obtaining of the combination performance evaluation results of the different magnesium-magnesium-based brazing filler metal-high nitrogen steel interface composite models also includes: Obtaining local electron function diagrams, Mulliken layout analysis tables and differential charge density diagrams of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models; Based on the local electron function diagram, Mulliken layout analysis table and differential charge density diagram 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.

9. A device for predicting the interface bonding performance of magnesium / high nitrogen steel based on first principles, characterized in that: The device comprises: Establishing a module for establishing a plurality of crystal structure models corresponding to a welded joint formed by welding high nitrogen steel using magnesium, based on the components in the welded joint; wherein the crystal structure model includes a magnesium crystal structure model, a magnesium-based brazing filler metal crystal structure model corresponding to the magnesium-based brazing filler metal, and a high nitrogen steel crystal structure model; A first optimization module, used to determine corresponding first optimization parameters based on the properties of the magnesium, the magnesium-based solder and the high-nitrogen steel, and 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 to obtain the magnesium crystal structure model, the magnesium-based solder crystal structure model and the high-nitrogen steel crystal structure model after model optimization; A splicing module, used for splicing the magnesium crystal structure model, the magnesium-based solder crystal structure model and the crystal planes obtained by cutting the high nitrogen steel crystal structure model after model optimization, to obtain a magnesium-magnesium-based solder-high nitrogen steel interface composite model; A second optimization module is used to determine corresponding second optimization parameters based on the properties of the magnesium, the magnesium-based solder and the 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 magnesium-magnesium-based solder-high nitrogen steel interface composite model after interface optimization; An adjustment module, used for adjusting the magnesium-magnesium-based solder-high nitrogen steel interface composite model after interface optimization to obtain a magnesium-magnesium-based solder-high nitrogen steel interface composite model corresponding to different magnesium-based solders; The acquisition module is used to obtain the bonding performance evaluation results of the different magnesium-magnesium-based solder-high nitrogen steel interface composite models, and obtain the target magnesium-based solder whose bonding performance evaluation results meet the preset screening conditions.

10. An electronic device, characterized in that: include: A processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor and the memory communicate via the bus, and when the machine-readable instructions are executed by the processor, the steps of the method for predicting the interface bonding performance of magnesium / high nitrogen steel based on first principles as claimed in any one of claims 1 to 8 are performed.

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