Metal material current microcell step-by-step scanning processing device and processing method thereof

Abstract

The invention discloses a metal material current micro-area step-by-step scanning processing device and a processing method thereof. The metal material current micro-area step-by-step scanning processing device comprises a PC control system, a current output system, a current micro-area processing device, a workpiece conveying device, a temperature measurement and control system, an insulation module and a high-performance computer system. According to the equipment and the process, the problems that in the traditional heat treatment process, the size of a furnace cavity is limited, and the heat treatment time is long are solved, meanwhile, the structure performance of a specific tiny area of a metal material can be precisely regulated and controlled, the production efficiency is remarkably improved, the production cost is reduced, the comprehensive performance of a product is improved, and the equipment and the process can be used for industrial large-scale production.

Description

Technical Field

[0001] The invention belongs to the technical field of metal material forming, and in particular relates to a metal material electric current micro-area step-by-step processing device and a processing method thereof. Background Art

[0002] With the development of science and technology, the requirements for metal materials in multiple application scenarios are not limited to a single performance. Parts and components in complex environments need to meet the needs of multifunctional integration. One of the important application directions is to meet the different service performances of different parts of the material. For example, in the application of Ti alloy bones, joints are often required to have higher hardness and friction resistance, while the skeleton requires better toughness. Therefore, it is necessary to achieve comprehensive and precise control of material composition, organization, process and performance through new preparation methods and processing technologies.

[0003] To meet the above needs, composite materials can be used or regional processing of materials can be performed. In the preparation process of composite materials, it is necessary to face the welding problem of two or more alloy materials, and the formation of intermetallic compounds is an important problem that must be faced at the composite interface. For example, brittle intermetallic compounds are easily generated at the composite interface of Cu and Al, thereby affecting the overall mechanical properties of the material. At the same time, composite materials with complex components are not friendly to the sustainable development of materials, and the separation of multiple elements during recycling and reuse greatly increases the sustainable cost of materials. For different regional modification technologies of homogeneous materials, there are usually surface modification technologies, that is, through carburizing, nitriding, plating, local heat treatment, local forging and other processes, a new organizational structure is formed on the surface and inside of the parts, thereby achieving performance improvement of a certain area of ​​the metal material. Usually, surface treatment technologies such as carburizing, nitriding, and plating only act on the surface of the material to improve the performance of metal materials, and cannot adjust the internal organization and performance of the material. Local heat treatment and local forging can process the entire material, but it is difficult to process materials with complex shapes and finely control micro-areas, and it is easily affected by equipment size and material size.

[0004] Based on the problems faced in the preparation and processing of the above-mentioned materials, the present invention proposes to gradually process and process the materials in micro areas by designing new processing equipment and processing technology based on the electric pulse processing technology. Among them, the electric pulse processing technology is a new type of heat treatment organization and performance control technology, which applies pulse current to metal materials to obtain excellent mechanical properties. There are two effects in the electric pulse processing process: thermal effect and non-thermal effect. Among them, the thermal effect mainly comes from the Joule heat effect of the current on the metal. The non-thermal effect is mainly the interaction between the current flow and defects such as dislocations, which can promote phase change, dislocation slip, etc. By properly utilizing the coupling effect of the non-thermal effect and thermal effect of the metal, the processing time and manufacturing cost in various traditional heat treatment processes can be effectively reduced. Electric pulse processing technology has been widely studied in the processes of metal aging, stretching, compression, bending, etc. At the same time, certain results have been achieved in the processing fields of magnesium alloys, copper alloys, titanium alloys, steel, etc. For the influence of current on the organization and performance of alloy materials, in addition to factors such as grain coarsening and dislocation slip caused by thermal effects, the influence of non-thermal effects exceeds the influence brought by thermal effects, which can greatly promote element diffusion, recrystallization, defect movement, etc. in the material. The patent document with patent number CN118241019A discloses a duplex stainless steel and a method for regulating its ferrite phase ratio. The method uses the continuous action of the electric and thermal coupling field of the electric pulse to achieve the purpose of rapid grain refinement and preferential growth, and the ferrite phase ratio in the material is regulated by this method, so as to achieve the performance improvement of the duplex stainless steel after the electric pulse treatment. The patent document with patent number CN118241037A discloses a preparation method of copper-containing stainless steel with a double-peak structure using electric pulse technology. The electric pulse treatment technology can make the stainless steel material recrystallize in a short time, thereby significantly improving the mechanical properties of the material. The patent document with patent number CN118186326A discloses an electric pulse toughening treatment method for a linear friction welding joint of a high-toughness titanium alloy. The local regulation of the joint organization is achieved through the electric pulse treatment technology, thereby ensuring the good strength of the joint and greatly improving the toughness of the joint. The above patents show that the electric pulse treatment technology has a significant effect on improving the overall performance of the alloy. However, due to the power supply, the workpiece size is still one of the main factors affecting the processing and processing effect. Therefore, it is very important to solve the problems existing in the existing technology and develop a heat treatment equipment and technology that is not limited by material size and can accurately control the micro-organization properties of different specific areas of the material. Summary of the invention

[0005] In order to solve the deficiencies in the above background, the first purpose of the present invention is to provide a metal material current micro-area step-by-step scanning processing device. The equipment provided by the present invention can realize the intelligent design of metal material micro-area organization, perform current micro-area processing on specific areas of metal plates, strips, pipes and other profiles, and obtain an ideal organizational structure. The device not only solves the problem of being restricted by the furnace chamber size and the long heat treatment time in the traditional heat treatment process, but also can accurately control the organizational properties of specific areas of metal materials, significantly improve production efficiency, reduce production costs, and improve the comprehensive performance of products, and can be used for industrial-scale production.

[0006] The second object of the present invention is to provide a method for step-by-step scanning of electric current micro-regions of metal materials, so as to achieve precise control of the microscopic / mesoscopic structures of different regions of large-sized metal materials.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] The present invention provides a metal material current micro-area step-by-step scanning processing device, the metal material current micro-area step-by-step scanning processing device comprises a current output system, a current micro-area processing device, and two workpiece transmission devices.

[0009] The current output system comprises a power supply for providing current to the current micro-area processing device;

[0010] The current micro-area processing device comprises a current probe No. 1, a current probe No. 2, a current copper plate No. 1, a current copper plate No. 2, a cable fixing copper ring No. 1, a cable fixing copper ring No. 2; a three-axis displacement platform No. 1, and a fixed platform;

[0011] The rear end of the current copper plate No. 1 is connected to the cable fixing copper ring No. 1, and the front end is provided with a current probe No. 1; the rear end of the current copper plate No. 2 is connected to the cable fixing copper ring No. 2, and the front end is provided with a current probe No. 2; the cable fixing copper ring No. 1 and the cable fixing copper ring No. 2 are connected to the positive pole and the negative pole of the power supply respectively.

[0012] The fixed platform is composed of a support and a table located at the top of the support, a limit plate is arranged above the table, and the current copper plate No. 1 is located above the table and below the limit plate, so that it can move freely on the Y axis and move within a limit limit on the X axis; the current copper plate No. 2 is fixed above the three-axis displacement platform No. 1, and the current copper plate No. 2 can move on the X, Y, and Z axes with the movement of the three-axis displacement platform No. 1; the current copper plate No. 2 and the three-axis displacement platform are located below the table, and when working, the current probe No. 1 and the current probe No. 2 are respectively arranged above and below the metal material to be processed, and the current probe No. 1 and the current probe No. 2 are controlled to be centered in the vertical direction.

[0013] The two workpiece transmission devices respectively include a support assembly, a roller assembly, a servo motor, and a three-axis displacement platform No. 2; the support assembly is fixed above the three-axis displacement platform No. 2, and the support assembly is composed of a support box No. 1 and a support box No. 2 that are symmetrically spaced, and the roller assembly includes an upper roller and a lower roller, and the upper roller and the lower roller are vertically symmetrically arranged on the inner side of the support box No. 1 and the support box No. 2, and the servo motor is installed on the outer side of the support box No. 2, and the servo motor drives the upper roller and the lower roller to rotate;

[0014] The two workpiece transmission devices are placed in parallel with each other, the current micro-area processing device is located between the two workpiece transmission devices, the metal material to be processed is clamped between the upper roller and the lower roller of the two workpiece transmission devices, and the upper roller and the lower roller are driven by a servo motor to displace the metal material to be processed in the X-axis direction.

[0015] In the prior art, when current is output to a material, current is usually applied to the material as a whole, while the device provided by the present invention is a device that can continuously and gradually provide current to tiny area partitions of a metal material. The micro-area gradual scanning and processing device provided by the present invention applies current to a workpiece micro-area within the vertical projection range of the probe through current probe No. 1 and current probe No. 2. During the application process, the current micro-area gradual scanning and processing device provided by the present invention transmits the metal material on the X-axis through two workpiece transmission devices. At the same time, the current probe No. 1 and the current probe No. 2 are respectively arranged above and below the metal material to be processed, and the cross-sectional size of the current probe is used to control the area of ​​the metal material to be applied with a single current. At the same time, the current probe No. 1 and the current probe No. 2 are freely moved on the Y-axis and moved with a limit limit on the X-axis to complete continuous micro-area scanning processing of the metal material to be processed.

[0016] Preferably, the current output system further comprises a current output control system and a pure copper cable. The current output control system is used to control the output of current, and the pure copper cable is used to be connected to cable fixing copper ring No. 1 and cable fixing copper ring No. 2.

[0017] The current output system is connected to the current micro-area processing device through the pure copper cable connected to the cable fixing copper ring No. 1 and the cable fixing copper ring No. 2, so that the current output system provides current for the micro-area processing device.

[0018] In a preferred embodiment, the current provided by the power supply is in a form selected from pulse current, constant current, alternating current, and direct current, preferably pulse current.

[0019] Preferably, the current output system further comprises a circuit breaker and a short circuit protector.

[0020] In a preferred solution, the voltage range of the current output system is 0-220V, the current range is 0-20000A, and the duty cycle is 0-100%.

[0021] Further preferably, the voltage range of the current output system is 0-36V, the current range is 0-5000A, and the duty cycle is 0-80%.

[0022] Preferably, the cross-sectional area of ​​the pure copper cable is ≥ 200 mm 2 , preferably ≥800mm 2 By using pure copper cables in the above-mentioned area range, it is possible to apply continuous current to large-sized workpieces.

[0023] In a preferred embodiment, the material of the current probe No. 1 and the current probe No. 2 is selected from one of dispersed copper, chromium bronze, zirconium bronze, tungsten copper, molybdenum copper, pure copper and graphite, preferably dispersed copper. The current probes made of the above materials can avoid electrocorrosion with metal materials.

[0024] In a preferred embodiment, the shape of the head surface of the current probe No. 1 and the current probe No. 2 is selected from a circle, a cone, a cross, and a straight line, and the size of the head surface is 0.01 mm 2 ~10cm 2 , preferably 0.01 mm 2 ~1cm 2 , and further preferably 0.01 mm 2 ~1mm 2 .

[0025] In the present invention, the head surfaces of current probe No. 1 and current probe No. 2 are contact surfaces with the metal material to be processed, and processing of specific areas of the metal workpiece is achieved through probes of specific shapes.

[0026] In a preferred embodiment, the current copper plate No. 1 is connected to the current copper plate No. 2 by a connector that can be extended and retracted on the Z axis. Through the connector, the current copper plate No. 1 and the current copper plate No. 2 remain stationary when moving on the Z axis, and move synchronously on the X and Y axes.

[0027] In a preferred solution, the current micro-area processing device further comprises an infrared thermometer, and the infrared thermometer is installed on the table of the fixed platform.

[0028] In a preferred embodiment, the current micro-area processing device further comprises an atmosphere protection system, which provides a protective atmosphere to prevent the material from being oxidized due to heat during the electric pulse processing.

[0029] In a preferred solution, the two workpiece transmission devices further include a tension sensor and a roller regulator. The tension of the metal material to be processed is adjusted during the transmission of the metal material to be processed by setting the tension sensor and the roller regulator to prevent bending.

[0030] Furthermore, in the present invention, the roller is equipped with a surface temperature unit for detecting the surface temperature of the roller.

[0031] In a preferred solution, the metal material current micro-area step-by-step scanning processing device further comprises an insulating module, which is located between the current copper plate No. 1 and the fixed platform, between the current copper plate No. 2 and the X, Y, Z three-axis displacement platform 1, and between the roller assembly and the metal material to be processed. The insulating module can ensure that the equipment sensor is not affected by the current.

[0032] In addition, in order to detect the health of the insulation module, a local current detection module is also provided.

[0033] In a preferred embodiment, the metal material current micro-area step-by-step scanning processing device further comprises a computer system, wherein the computer system comprises a computer, finite element simulation software, machine learning software, and a temperature feedback control system. The computer is used to design the distribution of the processing area through data-driven and finite element simulation.

[0034] The temperature of the current processing area is measured by an infrared thermometer, and the voltage, current, duty cycle and other parameters are feedback controlled by a temperature feedback control system;

[0035] The present invention discloses a method for step-by-step scanning treatment of metal materials by current micro-areas. The method comprises the following steps: applying a step-by-step scanning treatment device for current micro-areas of metal materials, clamping the metal materials to be treated between upper rollers and lower rollers of two workpiece transmission devices, positioning a current probe No. 1 above the metal materials to be treated, positioning a current probe No. 2 below the metal materials to be treated, and aligning the centers of the current probe No. 1 and the current probe No. 2. The metal materials to be treated are divided into a plurality of treatment areas on the X-axis and Y-axis planes, and the current application process of each treatment area is set. Then, the metal materials to be treated are subjected to step-by-step scanning treatment of current micro-areas by the current probe No. 1 and the current probe No. 2. During the step-by-step scanning treatment of electric pulse micro-areas, a three-axis displacement platform No. 1 moves upward in the Z-axis direction to control the current copper plate No. 2 to move upward, so that the current probe No. 1 and the current probe No. 2 clamp the metal materials to be treated. The upper roller and the lower roller are driven by a servo motor to displace the metal materials to be treated in the X-axis direction. The three-axis displacement platform No. 1 moves to control the displacement of the current copper plate No. 1 and the current copper plate No. 2 in the X-axis and Y-axis directions.

[0036] The method for gradually scanning and processing metal materials by electric current micro-area of ​​the present invention uses the equipment for gradually scanning and processing metal materials by electric pulse micro-area. Different from the prior art that can only apply electric pulse current to the whole material at the same time, the present invention uses a current probe with a specific area to gradually apply current to the metal material in different areas. In the present invention, the metal material to be processed is displaced in the X-axis direction by driving the upper roller and the lower roller in the workpiece transmission device, and the current copper plate 1 and the current copper plate 2 are controlled to be displaced in the Y-axis direction by moving the three-axis displacement platform No. 1, and when necessary, the limit movement is performed in the X-axis, so as to realize the partitioned application of current to the metal material in the X and Y axis directions. Therefore, the present invention can apply different currents to different areas of the metal material to be processed, so as to adjust the microstructure of different areas of the metal material to be processed.

[0037] In a preferred embodiment, the material of the metal material to be processed is selected from non-ferrous metal or ferrous metal, the non-ferrous metal is selected from pure metals or alloys such as aluminum, copper, magnesium, titanium, nickel, etc., and the ferrous metal is an iron alloy. The shape of the sample can be one of a plate, a strip, a foil, a rod, a tube, a wire or a special shape.

[0038] In a preferred embodiment, the metal material to be processed is selected from a cold-processed part A that has been annealed or a cold-processed part B that has been obtained by cold processing a hot-processed part having a structure of columnar crystals in the center and equiaxed crystals in the edge.

[0039] Further preferably, the annealed cold-worked part A is obtained by cold working the cast alloy material, controlling the cold working deformation to be 50% to 98%, and then annealing the cold-worked part.

[0040] More preferably, the as-cast alloy material is a as-cast alloy material having columnar crystals.

[0041] In the actual operation process, cast alloy materials suitable for cold working are selected, such as copper alloys, titanium alloys, aluminum alloys or magnesium alloys, to ensure that the initial microstructure and chemical composition of the material are uniform; then the cold working deformation is set to 50% to 98%, preferably 95%, to achieve plastic deformation of the metal material, refine the grains, and improve the strength and toughness of the material; then cold working is carried out in a controlled environment to ensure the consistency of temperature, speed and lubrication conditions during the processing to avoid introducing additional residual stress or uneven deformation, and then the cold-processed material is appropriately annealed to restore the plasticity of the material and reduce the work hardening effect. Finally, the microstructure and mechanical properties of the cold-processed material are tested to ensure that the requirements of subsequent current micro-area processing are met.

[0042] Further preferably, when the metal material to be processed is selected from a cold-processed part that has been annealed, the metal material to be processed is divided into several processing areas on the X- and Y-axis planes, and the current micro-area step-by-step scanning processing process for each processing area is obtained by: using a computer system, using Thermo-Calc phase diagram calculation software, finite element simulation software, and machine learning calculations to simulate the microstructure and performance of the current micro-area step-by-step scanning processing process after the metal sheet is processed. However, according to different performance requirements, the metal material is divided into several processing areas on the X- and Y-axis planes, and the current micro-area step-by-step scanning processing process for each processing area is set.

[0043] For example, when the as-cast alloy material is a cast alloy material with columnar crystals, high-density dislocations are obtained through large deformation cold working. However, by applying electric current in a specific area, the dislocations in the columnar crystals in the area will be recrystallized to form fine equiaxed crystals, thereby converting the original columnar crystals into equiaxed crystals. Compared with a single columnar crystal, the structure of alternating equiaxed crystals and columnar crystals has higher strength and plasticity.

[0044] More preferably, the phase transformation behavior of the current micro-area step-by-step scanning process after the metal sheet is processed is simulated by using the Thermo-Calc phase diagram calculation software.

[0045] Furthermore, firstly, according to the type of metal sheet and strip, a suitable material database is selected, and the parameters in the current processing process, such as temperature, current, voltage, frequency, etc., are input as the basis for model calculation, and the phase diagram is calculated using Thermo-Calc, including isothermal section, vertical section, time-temperature-transformation (TTT) diagram and cooling-time (CCT) diagram, etc., to predict the phase transformation that may occur under specific conditions. Subsequently, the mechanical properties of the material, such as hardness, tensile strength, yield strength, etc., are predicted through the calculated phase transformation process, and sensitivity analysis is performed to study the influence of different current parameters (such as pulse width, pulse frequency, material composition, etc.) on phase transformation and mechanical properties.

[0046] Furthermore, firstly, the experimental data of the current micro-area treatment of metal materials are collected, including but not limited to the current parameters (such as frequency, amplitude, duration), material properties (such as composition, thickness, initial microstructure), and the regional characteristics after treatment (such as microstructural changes, hardness, conductivity, etc.); then, features are extracted from the collected data, which should be able to represent the key variables and results in the current treatment process. For example, the parameters of the electric pulse can be used as input features, and the microstructural changes of the material can be used as output features. After that, the data is cleaned and standardized, and missing values ​​and outliers are processed. It may also be necessary to normalize or standardize the data for algorithm processing.

[0047] In the actual operation process, choose a machine learning model. For this type of regression problem, use support vector machine (SVM), random forest, gradient boosting tree (such as XGBoost), neural network for model training. By adjusting the model parameters (hyperparameter optimization), the best model performance can be obtained.

[0048] Furthermore, by combining the calculation results of the Thermo-Calc software and the simulation results of the machine learning algorithm, the model is continuously iterated to optimize the prediction accuracy.

[0049] Furthermore, the processing area of ​​the metal material to be processed is selected from a circular, elliptical, linear, and broken line shape, and the area of ​​the processing area is ≤1mm 2 .

[0050] Furthermore, the interval between adjacent processing areas is 0.1 mm to 5 mm.

[0051] In the present invention, the properties include physical properties of metal materials such as mechanical properties and magnetic properties.

[0052] Furthermore, the processing areas are arranged in a dot matrix.

[0053] Further preferably, when the metal material to be processed is selected from cold-processed parts that have been annealed, during the current micro-area step-by-step scanning process, the current is a pulse current, the processing voltage is 2 to 12V, the processing equivalent current is 10 to 1000A, and the pulse current duty cycle is 10 to 80%.

[0054] In a preferred solution, during the step-by-step scanning process of the current micro-area, argon gas is used for atmosphere protection, and the argon gas flow rate is controlled at 12-24 L / min to prevent the material from being oxidized or adversely affected by other environmental factors.

[0055] In the actual operation process, an infrared thermometer is used to monitor the temperature of the processing area in real time, and the temperature control range is adjusted according to the metal type (titanium alloy, copper alloy, aluminum alloy, etc.) to ensure that the treatment process is carried out at the optimal temperature. Real-time monitoring is carried out during the treatment process to ensure the stability of the treatment parameters and the consistency of the processing quality. After the treatment is completed, the microstructure and mechanical properties of the treatment area are tested to evaluate the effect of the current treatment, and the results are compared and analyzed with the simulation results.

[0056] Further preferably, the method for obtaining the hot-worked part with core columnar crystals + edge equiaxed crystals is to select metal raw materials according to the composition of the metal material, smelt them to obtain molten metal, carry out directional crystallization of the molten metal to obtain an ingot with an oblique eight-shaped columnar crystal structure, and carry out hot working treatment on the ingot;

[0057] The process of directional crystallization is as follows: using a continuous casting speed of 1 to 100 mm / s to make the molten metal pass through the rapid cooling section and the slow cooling section of the water-cooled crystallizer in sequence, the length of the rapid cooling section is 50 to 200 mm, the length of the slow cooling section is 20 to 80 mm, the cooling water flow rate of the rapid cooling section is 600 to 2000 L / h, preferably 600 to 1000 L / h, and the cooling water flow rate of the slow cooling section is 100 to 400 L / h;

[0058] The process of the hot working is: firstly heating the ingot to 400-1200°C, preferably 600-1100°C, keeping the temperature for 1-60min, preferably 30-60min, and then performing multiple hot working treatments, controlling the deformation of each pass to be 5%-60%, preferably 10%-30%, performing heat treatment between passes, the heat treatment temperature is 400-1200°C, preferably 600-1100°C, and the holding time is 5-30min, preferably 5-10min;

[0059] During the thermal processing, the processing direction is controlled to be the direction of the temperature gradient.

[0060] The hot working is selected from the group consisting of hot rolling, hot drawing, hot forging, hot rotary forging, hot radial forging, hot extrusion and hot upsetting, preferably hot rolling.

[0061] The preparation principle of the hot-processed parts with columnar crystals in the center and equiaxed crystals in the edge is as follows: by controlling the water flow rate of the water-cooled crystallizer, a cooling temperature gradient of rapid cooling followed by slow cooling is achieved, so that the grains form "epitaxial oblique eight-shaped" columnar crystals. Based on this structure, subsequent hot processing is carried out to allow the "eight-shaped foot" columnar crystals in the outermost circle to be recrystallized, and a structure of columnar crystals in the center + equiaxed crystals in the edge is achieved (the inside of the eight-shaped shape is columnar crystals, and the outside of the eight-shaped shape is equiaxed crystals). This structure has higher mechanical properties than a single equiaxed crystal or parallel columnar crystals, achieving "hard outside and tough inside".

[0062] Further preferably, the direction of the cold working is consistent with the direction during the hot working;

[0063] During the cold working, the deformation of a single pass is controlled to be 5-30%, and the total deformation is controlled to be 70-99%.

[0064] The cold working is selected from one of cold rolling, cold drawing, cold forging, cold rotary forging, cold radial forging, cold extrusion and cold heading, preferably cold rolling.

[0065] In the present invention, after obtaining the structure of core columnar crystals + edge equiaxed crystals through hot working, more dislocations and deformation twins are obtained through cold working with a large deformation amount, so that the material obtains more second phase nucleation sites and better mechanical properties.

[0066] Further preferably, when the metal material to be processed is selected from a cold-processed part B obtained by cold processing a hot-processed part having columnar crystals in the center and equiaxed crystals in the edge, the current micro-area step-by-step scanning processing process is as follows: the metal material is divided into several parallel hardening zones and softening zones along the length direction or the width direction, wherein the hardening zones and the softening zones are alternately distributed, and a blank zone is provided between the hardening zones and the softening zones, and then the hardening zones and the softening zones are subjected to the current micro-area step-by-step scanning processing in turn, wherein the current micro-area step-by-step scanning processing parameters of the hardening zone are: voltage 0.01~8V, current 100~500A, and the current micro-area step-by-step scanning processing parameters of the softening zone are: voltage 8~20V, current 800~2000A.

[0067] In the present invention, by obtaining a metal material with more dislocations and deformation twins during cold working, the metal material is partitioned into hard phase and soft phase, and a high current can cause a large thermal effect on the alloy, and the temperature acting on the alloy area is higher at the instant, and violent recovery and recrystallization occur at the position where the dislocations are accumulated, thereby obtaining a softened micro-region. A low current acts on the alloy area at a lower temperature at the instant, and recovery and precipitation of the second phase occur at the position where the dislocations are accumulated, thereby obtaining a hardened micro-region.

[0068] Further preferably, the width of the blank area (area not treated by current) is greater than 5 mm, preferably 5 to 15 mm. A certain spacing needs to be set in the division between the hardening area and the softening area, and the spacing needs to be controlled. If a smaller spacing is selected, due to metal heat conduction, heat overlap may occur in the target area, resulting in the second phase precipitation and growth rate in the hardening area being too fast, resulting in weakened strengthening effect in the hardening area, and even recovery and recrystallization. If the spacing is too large, the final strengthening effect is weakened.

[0069] Further preferably, the current form in the current micro-area step-by-step scanning process is any one of pulse current, constant current, alternating current and direct current, preferably pulse current.

[0070] Further preferably, the current micro-area step-by-step scanning processing process applies current to the metal material through a movable current probe, firstly places the movable current probe at a certain point in any hardening zone or softening zone of the metal material, applies current once within the area of ​​the current probe, and then moves the current probe in parallel to apply current to the next area of ​​the current probe, until one hardening zone or softening zone is processed, then moves the current probe to another untreated hardening zone or softening zone to repeat the above process; when applying current to the hardening zone, the processing time of any single point is 5 to 120 s, and when applying current to the softening zone, the processing time of any single point is 10 to 300 s.

[0071] By performing a step-by-step scanning process of the current micro-area on the cold-worked part B, a metal material with a multi-phase heterogeneous structure in which softening zones and hardening zones are periodically alternately distributed is obtained, thereby achieving precise performance control.

[0072] Principles and advantages

[0073] The core principle of the present invention relates to a current micro-area step-by-step scanning processing technology for metal materials. Specifically, a pair of electrode probes are symmetrically clamped on both sides of a metal workpiece and operated along the normal direction of the material surface, while the positive and negative poles of the power supply device are connected to the corresponding probes respectively. When the power supply device is activated, a high-energy current is rapidly introduced into the material area contacted by the probe, causing the temperature of the metal material in this area to rise sharply to a predetermined target temperature. The synergistic effect of the thermal effect and non-thermal effect of this high-energy electrical stimulation can quickly induce solid-state phase change processes such as recrystallization and phase precipitation of the metal, thereby achieving precise regulation of the specific micro-area structure of the metal material.

[0074] The present invention uses a computer system to control the current micro-area processing device to ensure that the current probe moves accurately along the y-axis direction, and coordinates the workpiece transmission device to enable the metal material to move accurately along the x-axis direction. In this way, the precise design and precise control of the metal material structure can be achieved.

[0075] Compared with the prior art, the present invention has the beneficial effect that by using a probe to perform current processing on a specific area of ​​a metal material, rapid and precise control of the organizational structure can be achieved, so that different areas of the material have different performance matching.

[0076] (1) Compared with the traditional heat treatment processing method, the present invention adopts the strategy of breaking the whole into parts and simplifying the complex, and adopts the electro-induced step-by-step micro-area scanning process to perform micro-area step-by-step treatment on large-sized special-shaped metal components, thereby achieving precise control of the structure of large-sized special-shaped metal components, and effectively solving the technical problem that the traditional electrical treatment method cannot process large-sized metal components due to insufficient power of the power supply equipment.

[0077] (2) The electric current micro-area microstructure performance control process proposed in the present invention is based on the principle of electric current processing. The microstructure design of metal components is both flexible and precisely controllable. The relative position of the electrode probe and the electric treatment micro-area of ​​the metal component can be precisely controlled by using a computer-controlled mobile platform. According to the design requirements, the path of the electric treatment micro-area is planned, and the precise design and precise control of the electro-induced metal material structure are achieved through a step-by-step micro-area scanning process.

[0078] (3) The current micro-area processing process described in the present invention can realize the preparation and processing of gradient materials. Based on the coupling effect of electric field and thermal field, high energy and large current are input into the micro-area of ​​metal components through electrode probes, so that the metal material in the micro-area quickly reaches the target temperature. By utilizing the strong coupling effect of the Joule heating effect and non-thermal effect generated by electricity, the diffusion, solid-state phase change and recrystallization process of metal material atoms are accelerated at a lower temperature, and the process has the characteristics of rapid organizational transformation and phase transformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Figure 1 This is a schematic diagram of the current micro-area step-by-step scanning processing device of the present invention, in which: 1. workpiece transmission device 1; 2. current micro-area processing device; 3. workpiece to be processed; 4. workpiece transmission device 2.

[0080] Figure 2 Schematic diagram of the structure of the current micro-area processing device in the present invention, in which 5 is a current copper plate No. 1; 6 is a current input connector for installing a current probe 1; 7 is a current output connector for installing a current probe 2; 8 is a three-axis displacement platform 1; 9 is a fixed platform; 10 is an infrared thermometer; 11 is a current copper plate No. 2; 12 is a cable fixing copper ring No. 1; 13 is a cable fixing copper ring No. 2.

[0081] Figure 3 This is a schematic diagram of the structure of the workpiece transmission device in the present invention, in which 14 is a roller assembly; 15 is a roller adjuster; 16 is a servo motor; 17 is a tension sensor; 18 is a three-axis displacement platform 2.

[0082] Figure 4 The circular micro-area of ​​the Ti-6Al-4V alloy plate is processed by the electric pulse micro-area step-by-step scanning in Example 1.

[0083] Figure 5 This is the microstructure diagram of the alloy ingot in Example 4, from which the oblique S-shaped columnar crystal structure can be clearly observed.

[0084] Figure 6 This is a microstructure diagram of the metal material with a multi-phase heterogeneous structure provided in Example 4. From the figure, it can be seen that the left area is a second phase with a large amount of dispersed distribution, the right side is the original structure, the right side is the softening zone, and the left side is the hardening zone. DETAILED DESCRIPTION

[0085] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0086] like Figure 1 As shown, the current micro-area step-by-step scanning processing device provided by the present invention mainly consists of four parts: 1 is a workpiece transmission device 1, 2 is a current micro-area processing device, 3 is a metal workpiece to be processed, and 4 is a workpiece transmission device 2.

[0087] The current output system comprises a power supply for providing current to the current micro-area processing device;

[0088] The current micro-area processing device comprises a current probe No. 1, a current probe No. 2, a current copper plate No. 1, a current copper plate No. 2, a cable fixing copper ring No. 1, a cable fixing copper ring No. 2; a three-axis displacement platform No. 1, and a fixed platform;

[0089] The rear end of the current copper plate No. 1 is connected to the cable fixing copper ring No. 1, and the front end is provided with a current probe No. 1; the rear end of the current copper plate No. 2 is connected to the cable fixing copper ring No. 2, and the front end is provided with a current probe No. 2; the cable fixing copper ring No. 1 and the cable fixing copper ring No. 2 are connected to the positive pole and the negative pole of the power supply respectively.

[0090] The fixed platform is composed of a support and a table located at the top of the support, a limit plate is arranged above the table, and the current copper plate No. 1 is located above the table and below the limit plate, so that it can move freely on the Y axis and move within a limit limit on the X axis; the current copper plate No. 2 is fixed above the three-axis displacement platform No. 1, and the current copper plate No. 2 can move on the X, Y, and Z axes with the movement of the three-axis displacement platform No. 1; the current copper plate No. 2 and the three-axis displacement platform are located below the table, and when working, the current probe No. 1 and the current probe No. 2 are respectively arranged above and below the metal material to be processed, and the current probe No. 1 and the current probe No. 2 are controlled to be centered in the vertical direction.

[0091] The two workpiece transmission devices respectively include a support assembly, a roller assembly, a servo motor, and a three-axis displacement platform No. 2; the support assembly is fixed above the three-axis displacement platform No. 2, and the support assembly is composed of a support box No. 1 and a support box No. 2 that are symmetrically spaced, and the roller assembly includes an upper roller and a lower roller, and the upper roller and the lower roller are vertically symmetrically arranged on the inner side of the support box No. 1 and the support box No. 2, and the servo motor is installed on the outer side of the support box No. 2, and the servo motor drives the upper roller and the lower roller to rotate;

[0092] The two workpiece transmission devices are placed in parallel with each other, the current micro-area processing device is located between the two workpiece transmission devices, and the metal material to be processed is clamped between the upper rollers and the lower rollers of the two workpiece transmission devices.

[0093] In a further preferred case, the current output system further includes a current output control system and a pure copper cable. The current output control system is used to control the output of current, and the pure copper cable is used to be connected to cable fixing copper ring No. 1 and cable fixing copper ring No. 2.

[0094] The current output system is connected to the current micro-area processing device through the pure copper cable connected to the cable fixing copper ring No. 1 and the cable fixing copper ring No. 2, so that the current output system provides current for the current micro-area processing device.

[0095] In a further preferred case, the current provided by the power supply is in a form selected from pulse current, constant current, alternating current, and direct current, preferably pulse current.

[0096] In a further preferred case, the current output system also includes a circuit breaker and a short-circuit protector.

[0097] In a further preferred case, the voltage range of the current output system is 0 to 220 V, the current range is 0 to 20000 A, and the duty cycle is 0 to 100%.

[0098] In a further preferred case, the voltage range of the current output system is 0 to 36V, the current range is 0 to 5000A, and the duty cycle is 0 to 80%.

[0099] In a further preferred case, the cross-sectional area of ​​the pure copper cable is ≥ 200 mm 2 , preferably ≥800mm 2 By using pure copper cables in the above-mentioned area range, it is possible to apply continuous current to large-sized metal workpieces.

[0100] In a further preferred case, the material of the current probe No. 1 and the current probe No. 2 is selected from one of dispersed copper, chromium bronze, zirconium bronze, tungsten copper, molybdenum copper, pure copper, and graphite, preferably dispersed copper. The current probes made of the above materials can avoid electrical corrosion with metal materials.

[0101] In a further preferred embodiment, the shape of the head surface of the current probe No. 1 and the current probe No. 2 is selected from a circle, a cone, a cross, a straight line, etc., and the size of the head surface is 0.01 mm 2 ~10cm 2 , preferably 0.01 mm 2 ~1cm 2 , and further preferably 0.01 mm 2 ~1mm 2 .

[0102] In the present invention, the head surfaces of current probe No. 1 and current probe No. 2 are contact surfaces with the metal material to be processed, and the processing of a specific area of ​​the metal material is achieved through probes of specific shapes.

[0103] In a further preferred case, the current copper plate No. 1 is connected to the current copper plate No. 2 by a connector that can be extended and retracted on the Z axis. Through the connector, the current copper plate No. 1 remains stationary when the current copper plate No. 2 moves on the Z axis, and moves synchronously on the X and Y axes.

[0104] In a further preferred case, the current micro-area processing device further comprises an infrared thermometer, and the infrared thermometer is installed on the table of the fixed platform.

[0105] In a further preferred embodiment, the current micro-area processing device further comprises an atmosphere protection system, which provides a protective atmosphere to prevent the material from being oxidized due to heat during the electric pulse processing.

[0106] In a further preferred embodiment, the two workpiece transmission devices further include a tension sensor and a roller regulator, which are arranged to adjust the tension of the strip during the strip transmission process to prevent bending.

[0107] Furthermore, in the present invention, the roller is equipped with a surface temperature unit for detecting the surface temperature of the roller.

[0108] In a further preferred case, the metal material current micro-area step-by-step scanning processing device further comprises an insulating module, which is located between the current copper plate No. 1 and the fixed platform, between the current copper plate No. 2 and the X, Y, Z three-axis displacement platform 1, and between the roller assembly and the metal material to be processed. The insulating module can ensure that the equipment sensor is not affected by the current.

[0109] In addition, in order to detect the health of the insulation module, a local current detection module is also provided.

[0110] In a further preferred case, the metal material current micro-area step-by-step scanning processing device further includes a computer system for collecting electrical signals, thermal signals, digital signals, etc. in the entire device during the electric pulse micro-area step-by-step scanning processing process, combining real-time feedback and analyzing the entire electric pulse micro-area step-by-step scanning processing process, and the computer system includes a computer, finite element simulation software, machine learning software, and a temperature feedback control system. The computer is used to design the distribution of the processing area through data-driven, finite element simulation.

[0111] A specific example of applying the above-mentioned current micro-area step-by-step scanning processing device to perform current micro-area step-by-step scanning processing on a cold-worked workpiece A that has undergone annealing treatment is as follows:

[0112] Example 1: Current micro-area step-by-step scanning treatment of Ti-6Al-4V alloy plate

[0113] (1): Material preparation and processing

[0114] Vacuum Casting: Ti-6Al-4V alloy is prepared by vacuum casting method to ensure uniform alloy composition.

[0115] Homogenization annealing: Homogenization annealing is carried out at a temperature range of 950°C for 10 hours to eliminate casting stress and microsegregation.

[0116] Hot rolling: hot rolling is carried out at 730°C, with the deformation amount controlled at 15% each time, and finally a 2mm thick plate is obtained.

[0117] (2): Data input and simulation

[0118] Parameter input: The parameters of electric pulse processing such as voltage (2-4V), current (200-400A), temperature (600-900℃) and mechanical properties of Ti-6Al-4V alloy plate (tensile strength 1148MPa, etc.) are input into the high-performance computer system.

[0119] Thermo-Calc software was used to calculate the phase diagram and determine the stable and metastable phases under different temperature and composition conditions. Based on the expected temperature range of the electropulse machining, Thermo-Calc was used to calculate the possible phase changes, such as the α to β phase change. The phase change information calculated by Thermo-Calc was used as the input parameter, combined with the voltage, current, temperature and other parameters of the electropulse machining, and input into the finite element simulation software and machine learning software.

[0120] Finite element simulation: Use finite element simulation software to simulate the thermal and mechanical effects of the electric pulse machining process.

[0121] Machine Learning Simulation: Use machine learning algorithms to combine input parameters and performance data to predict the phase change behavior and mechanical properties of the treated area.

[0122] (3): Optimization of electric pulse machining parameters

[0123] Dot distribution design: According to the simulation results, the dot distribution is designed with a spacing of 0.5 mm between each dot.

[0124] Determination of process parameters: Optimize the electric pulse machining process parameters, such as equivalent voltage 3V, equivalent current 300A, and time 20 seconds.

[0125] (4): Implementation of electric pulse machining

[0126] Plate positioning: Place the Ti-6Al-4V alloy plate on the workpiece conveyor, ensuring that the current probe is in contact with the upper and lower surfaces of the plate and located on the same axis.

[0127] Processing parameter setting: Set the equivalent voltage of the high-energy electric pulse voltage to 3V, and turn on the high-energy electric pulse generating power supply.

[0128] Processing execution: The plate is subjected to 30 seconds of electric pulse processing.

[0129] (5): Processing area movement and repeated processing

[0130] Three-dimensional mobile platform: Use high-precision X, Y, Z-axis three-dimensional mobile platform and workpiece transfer device to move the plate to the next processing position.

[0131] Repeat processing: Repeat steps 3 and 4 to achieve a dot-matrix arranged electric pulse processing area.

[0132] (6) Result analysis and verification

[0133] Microstructure observation: Use a microscope to observe the microstructure of the treated area and analyze the phase change.

[0134] Mechanical properties test: Test the hardness and other mechanical properties of the treated area and compare them with the simulation results.

[0135] Result record: record the processing results, such as Figure 3 As shown, subsequent analysis was performed.

[0136] (7): Iterative Optimization

[0137] Data analysis: Analyze the differences between experimental data and simulation results to identify possible areas for improvement.

[0138] Model adjustment: Adjust the finite element model and machine learning model based on the analysis results to improve prediction accuracy.

[0139] Process parameter optimization: Based on the new model prediction results, the EPM process parameters are further optimized.

[0140] Example 2: Electric pulse micro-area step-by-step scanning treatment of Cu-Zn alloy plate

[0141] (1) Material preparation and processing

[0142] Vacuum casting: Cu-Zn alloy is prepared by traditional casting method to ensure uniform alloy composition.

[0143] Homogenization annealing: Homogenization annealing is carried out at a temperature range of 850-980°C for 4-8 hours to eliminate casting stress and microsegregation.

[0144] Cold rolling: cold rolling is performed, and the deformation amount of each pass is controlled at 15-30%, and finally a Cu-Zn alloy sheet with a thickness of 1-4 mm is obtained.

[0145] (2) Data input and simulation

[0146] Parameter input: Input the voltage (6-10V), current (250-400A), temperature and other parameters of the electric pulse processing and the mechanical properties of the Cu-Zn alloy plate into a high-performance computer system.

[0147] Thermo-Calc Software: Use Thermo-Calc software to perform phase diagram calculations and determine the stable and metastable phases under different conditions.

[0148] Finite element and machine learning simulation: Combined with the EPM machining parameters, the phase change behavior and mechanical properties of the processed area are predicted using finite element simulation software and machine learning algorithms.

[0149] (3) Optimization of EPM parameters

[0150] Dot distribution design: Design dot distribution with a spacing of 0.3 to 0.8 mm between each dot.

[0151] Determination of process parameters: Optimize the electric pulse machining process parameters, such as equivalent voltage 8V, equivalent current, and time.

[0152] (4) Implementation of electric pulse machining

[0153] Plate positioning: Place the Cu-Zn alloy plate on the workpiece conveyor, ensuring that the current probe is in contact with the upper and lower surfaces of the plate and located on the same axis.

[0154] (5) Processing parameter setting: Set the equivalent voltage of the high-energy electric pulse voltage to 8 V, and turn on the high-energy electric pulse generating power supply.

[0155] Processing execution: The plate is subjected to electric pulse processing for 0 to 240 seconds.

[0156] Processing area movement and repeated processing

[0157] Three-dimensional mobile platform: Use high-precision X, Y, Z-axis three-dimensional mobile platform and workpiece transfer device to move the plate to the next processing position.

[0158] Repeat processing: Repeat the processing steps to achieve the electric pulse processing area arranged in a dot matrix.

[0159] Example 3: Electric pulse micro-area step-by-step scanning treatment of Cu-9Ni-6Sn alloy plate

[0160] (1) Material preparation and processing

[0161] Horizontal continuous casting: The Cu-9Ni-6Sn alloy was prepared by horizontal continuous casting method to ensure uniform alloy composition.

[0162] Homogenization annealing: Homogenization annealing is carried out at 900-980°C for 8-12 hours to eliminate casting stress and microsegregation.

[0163] Cold rolling: cold rolling is performed, and the deformation amount of each pass is controlled at 10-35%, so as to obtain a Cu-9Ni-6Sn alloy plate with a thickness of 2-4 mm.

[0164] (2) Data input and simulation

[0165] Parameter input: Input the voltage (4-10V), current (230-320A), temperature and other parameters of the electric pulse machining and the mechanical properties of the Cu-9Ni-6Sn alloy plate.

[0166] Thermo-Calc Software: Use Thermo-Calc software for phase diagram calculations and phase change predictions.

[0167] Finite Element and Machine Learning Simulation: Finite element simulation and machine learning algorithms are used to predict the phase transformation and mechanical properties of the processed area.

[0168] (3) Optimization of EPM parameters

[0169] Dot distribution design: Design dot distribution with a spacing of 0.4 to 1.0 mm between each dot.

[0170] Determination of process parameters: Optimize the electric pulse machining process parameters, such as equivalent voltage 6V, equivalent current, and time.

[0171] (4) Implementation of electric pulse machining

[0172] Plate positioning: Place the Cu-9Ni-6Sn alloy plate on the workpiece conveyor, ensuring that the current probe is in contact with the upper and lower surfaces of the plate and located on the same axis.

[0173] Processing parameter setting: Set the equivalent voltage of the high-energy electric pulse voltage to 6V, and turn on the high-energy electric pulse generating power supply.

[0174] Processing execution: The plate is subjected to electric pulse processing for 60 to 220 seconds.

[0175] (5) Processing area movement and repeated processing

[0176] Three-dimensional mobile platform: Use high-precision X, Y, Z-axis three-dimensional mobile platform and workpiece transfer device to move the plate to the next processing position.

[0177] Repeated processing: Repeat the processing steps to achieve a dot-matrix arranged electric pulse processing area.

[0178] (6) Result analysis and verification

[0179] Microstructure observation: Use a microscope to observe the microstructure of the treated area and analyze the phase change.

[0180] Mechanical properties test: Test the hardness and other mechanical properties of the treated area and compare them with the simulation results.

[0181] Result recording: record the processing results for subsequent analysis.

[0182] (7) Iterative Optimization

[0183] Data analysis: Analyze the differences between experimental data and simulation results to identify areas for improvement.

[0184] Model adjustment: Adjust the finite element model and machine learning model based on the analysis results to improve prediction accuracy.

[0185] Process parameter optimization: Based on the new model prediction results, the EPM process parameters are further optimized.

[0186] A specific example of applying the above-mentioned current micro-area step-by-step scanning processing device to perform current micro-area step-by-step scanning processing on a cold-processed workpiece B obtained by cold processing a hot-processed workpiece having a structure of core columnar crystals + edge equiaxed crystals is as follows:

[0187] Example 4

[0188] The object is Cu-Ni-Sn alloy.

[0189] (1) Electric pulse directional solidification: Prepare electrolytic copper sheets, nickel sheets and tin blocks with a purity of 99.99% or more according to the mass ratio of Ni: Sn: Cu = 15: 8: 77, and put Ni, Cu and Sn into the electric pulse directional solidification crucible in order from high to low according to the melting point, and then put 20g of graphite powder with a particle size of 5 mesh to cover the metal surface. The crucible is induction heated by an electromagnetic coil, and the heating temperature is controlled at 1350°C. After the metal block in the crucible is melted into liquid metal, the electromagnetic stirrer is turned on for mechanical stirring. The magnetic field strength of the electromagnetic stirring is set to 2500Gs and the stirring speed is 200r / min. The temperature is then lowered to 1180°C for insulation. After 5 minutes of insulation, the pulse power supply is turned on, and the pulse frequency is set to 1200Hz and the current density is 2.0A / cm3 through the central controller. After a processing time of 5 minutes, the pulse power supply is turned off to obtain molten metal with uniform composition. The molten metal is then pulled out of the center hole of the crystallizer at a speed of 1mm / s using a robotic arm-linked traction rod. During the pulling process, the molten metal passes through a 150mm rapid cooling section and a 50mm slow cooling section in sequence. The circulating water flow rate of the crystallizer in the rapid cooling section is 800L / h, and the circulating water flow rate of the crystallizer in the slow cooling section is 400L / h, forming a 60×20mm alloy ingot with "oblique eight-shaped" slender columnar crystals.

[0190] (2) Hot working: The ingot is placed in a box-type resistance furnace for heating with the furnace, and the temperature is controlled at 820°C. After keeping warm for 30 minutes, it is taken out and rolled along the temperature gradient direction. The total deformation is 50%, and the deformation of a single pass is 20%. After each pass is completed, it is quickly placed in a box-type resistance furnace for continued insulation. After keeping warm for 10 minutes, it is taken out for the next rolling deformation. After multiple rolling, the thickness of the slab reaches 10 mm.

[0191] (3) Large deformation cold processing: The hot-processed slab is placed in a six-roll rolling mill for cold processing. The deformation direction is consistent with the hot processing direction. The total deformation is 90%, the single-pass deformation is 10%, and the plate thickness reaches 1 mm after multiple rolling.

[0192] (4) Current micro-area step-by-step scanning process: The metal material is divided into parallel hardening zones and softening zones along the X-axis direction, where the hardening zones and softening zones are alternately distributed. At the same time, a blank area is set between the hardening zones and softening zones. The width of the hardening zone and the softening zone is the width of the probe, and the width of the blank area is 10 mm. Then, the cold-processed alloy plate is subjected to current micro-area step-by-step scanning process using an oxygen-free copper current probe. The probe uses a linear contactor with a contact area of ​​0.1 mm. 2, select a low-frequency, high-peak pulse power supply, use a servo motor to drive the upper and lower rollers to displace the metal material to be processed in the X-axis direction, use a current probe to gradually scan the current micro-area, in the hardening area, apply an equivalent voltage of 8V, a current of 200A, and a single processing time of 30s. After the X-direction is processed, move the current probe parallel to the Y-axis by 10mm, and continue to use the servo motor to drive the upper and lower rollers to displace the metal material to be processed in the X-axis direction, and use the current probe to perform micro-area scanning electrical treatment, apply an equivalent voltage of 8V, a current of 1000A, and a single processing time of 30s, until the entire plate and strip is processed.

[0193] The performance indicators of the alloy plate and strip in this implementation case are:

[0194] Tensile strength: 1680MPa

[0195] Elongation at break: 10.6%

[0196] Electrical conductivity: 15.4% IACS

[0197] Embodiment 5:

[0198] This embodiment takes silicon steel alloy as the object.

[0199] (1) Electric pulse directional solidification: prepare iron particles and silicon wafers with a purity of 99.99% or more according to the mass ratio of Fe:Si=96:4, and put Cu and Zn into the electric pulse directional solidification crucible in order from high to low according to the melting point, and then put 20g of graphite powder with a particle size of 5 mesh to cover the metal surface. The crucible is induction heated by an electromagnetic coil, and the heating temperature is controlled at 1580℃. After the metal block in the crucible is melted into molten metal, turn on the electromagnetic stirrer for mechanical stirring. The magnetic field strength of the electromagnetic stirring is set to 1500Gs, and the stirring speed is 200r / min. The temperature is then lowered to 1520°C for insulation. After 5 minutes of insulation, the pulse power supply is turned on, and the pulse frequency is set to 1200Hz and the current density is 1.0A / cm3 through the central controller. After 5 minutes of processing, the pulse power supply is turned off to obtain molten metal with uniform composition. The molten metal is then pulled out of the center hole of the crystallizer at a speed of 10mm / s using a robotic arm-linked traction rod. During the pulling process, the molten metal passes through an 80mm rapid cooling section and a 50mm slow cooling section in sequence. The circulating water flow rate of the crystallizer in the rapid cooling section is 600L / h, and the circulating water flow rate of the crystallizer in the slow cooling section is 300L / h, forming a 60×20mm alloy ingot with "oblique eight-shaped" slender columnar crystals.

[0200] (2) Hot working: The ingot is placed in a box-type resistance furnace for heating with the furnace, and the temperature is controlled at 880°C. After keeping warm for 30 minutes, it is taken out and rolled along the temperature gradient. The total deformation is 70%, and the deformation of a single pass is 30%. After each pass, it is quickly placed in a box-type resistance furnace for continued insulation. After keeping warm for 10 minutes, it is taken out for the next rolling deformation. After multiple rolling, the thickness of the slab reaches 10 mm.

[0201] (3) Large deformation cold processing: The hot-processed slab is placed in a six-roll rolling mill for cold processing. The deformation direction is consistent with the hot processing direction. The total deformation is 90%, the single-pass deformation is 20%, and the slab thickness reaches 1 mm after multiple rolling.

[0202] (4) Current micro-area step-by-step scanning process: The metal material is divided into parallel hardening zones and softening zones along the X-axis direction, where the hardening zones and softening zones are alternately distributed. At the same time, a blank area is set between the hardening zones and softening zones. The width of the hardening zone and the softening zone is the width of the probe, and the width of the blank area is 5 mm. Then, the cold-processed alloy plate is subjected to current micro-area step-by-step scanning process using an oxygen-free copper current probe. The probe uses a linear contactor with a contact area of ​​0.1 mm. 2 , select low-frequency high-peak pulse power supply, use servo motor to drive upper roller and lower roller to displace the metal material to be processed in X-axis direction, use current probe to gradually perform micro-area scanning electrical treatment, in hardening area, apply equivalent voltage of 10V, current of 250A, treatment time of 30s, after X-direction treatment, move current probe parallel to Y-axis by 1mm, use servo motor to drive upper roller and lower roller to displace the metal material to be processed in X-axis direction, use current probe to perform micro-area scanning electrical treatment, apply equivalent voltage of 10V, current of 1200A, treatment time of 30s, until the whole plate and strip is processed.

[0203] The performance indicators of the alloy plate and strip in this implementation case are:

[0204] Tensile strength: 1450MPa

[0205] Elongation at break: 15.6%.

[0206] Comparative Example 1

[0207] The other conditions are the same as those in Example 4, except that the electric pulse aging process is replaced by the step-by-step scanning treatment of the current micro-area: the plate and strip after large deformation cold working are placed in the electric pulse heat treatment circuit for electric pulse aging, and a low-frequency high-peak pulse power supply is selected, with an equivalent voltage of 8V, a current of 200A, and a treatment time of 5mins;

[0208] The performance indicators of the alloy plate and strip in this comparative example are:

[0209] Tensile strength: 1360MPa

[0210] Elongation at break: 5.3%

[0211] Electrical conductivity: 10.6% IACS.

Claims

1. A device for step-by-step scanning of current micro-areas of metal materials, characterized in that: The metal material current micro-area step-by-step scanning processing device comprises a current output system, a current micro-area processing device, and two workpiece transmission devices. The current output system comprises a power supply for providing current to the current micro-area processing device; The current micro-area processing device comprises a current probe No. 1, a current probe No. 2, a current copper plate No. 1, a current copper plate No. 2, a cable fixing copper ring No. 1, a cable fixing copper ring No. 2; a three-axis displacement platform No. 1, and a fixed platform; The rear end of the current copper plate No. 1 is connected to the cable fixing copper ring No. 1, and the front end is provided with a current probe No. 1; the rear end of the current copper plate No. 2 is connected to the cable fixing copper ring No. 2, and the front end is provided with a current probe No. 2; the cable fixing copper ring No. 1 and the cable fixing copper ring No. 2 are connected to the positive pole and the negative pole of the power supply respectively. The fixed platform is composed of a support and a table located at the top of the support, a limit plate is arranged above the table, and the current copper plate No. 1 is located above the table and below the limit plate, so that it can move freely on the Y axis and move within a limit limit on the X axis; the current copper plate No. 2 is fixed above the three-axis displacement platform No. 1, and the current copper plate No. 2 can move on the X, Y, and Z axes with the movement of the three-axis displacement platform No. 1; the current copper plate No. 2 and the three-axis displacement platform are located below the table, and when working, the current probe No. 1 and the current probe No. 2 are respectively arranged above and below the metal material to be processed, and the current probe No. 1 and the current probe No. 2 are controlled to be centered in the vertical direction. The two workpiece transmission devices each include a support assembly, a roller assembly, a servo motor, and a three-axis displacement platform No. 2; The support assembly is fixed above the three-axis displacement platform No. 2, and the support assembly is composed of a support box No. 1 and a support box No. 2 that are symmetrically spaced, and the roller assembly includes an upper roller and a lower roller, and the upper roller and the lower roller are vertically symmetrically arranged on the inner side of the support box No. 1 and the support box No. 2, and the servo motor is installed on the outer side of the support box No. 2, and the servo motor drives the upper roller and the lower roller to rotate; The two workpiece transmission devices are placed in parallel with each other, the current micro-area processing device is located between the two workpiece transmission devices, the metal material to be processed is clamped between the upper roller and the lower roller of the two workpiece transmission devices, and the upper roller and the lower roller are driven by a servo motor to displace the metal material to be processed in the X-axis direction.

2. The device for step-by-step scanning of current micro-areas of metal materials according to claim 1, characterized in that: The current output system further comprises a current output control system and a pure copper cable, wherein the current output control system is used to control the output of the current, and the pure copper cable is used to be connected to the cable fixing copper ring No. 1 and the cable fixing copper ring No. 2; The current provided by the power supply is selected from one of pulse current, constant current, alternating current and direct current; The current output system also includes a circuit breaker and a short circuit protector; The voltage range of the current output system is 0-220V, the current range is 0-20000A, and the duty cycle is 0-100%; The cross-sectional area of ​​the pure copper cable is ≥ 200mm 2 .

3. The device for step-by-step scanning of current micro-areas of metal materials according to claim 1, characterized in that: The material of the current probe No. 1 and the current probe No. 2 is selected from one of dispersed copper, chromium bronze, zirconium bronze, tungsten copper, molybdenum copper, pure copper and graphite; The shape of the head surface of the current probe No. 1 and the current probe No. 2 is selected from one of a circle, a cross, and a straight line, and the size of the head surface is 0.01 mm 2 ~100cm 2 ; The current copper plate No. 1 is connected to the current copper plate No. 2 via a connector that can be extended and retracted on the Z axis; The current micro-area processing device further comprises an infrared thermometer, which is installed on the table of the fixed platform; The current micro-area processing device also includes an atmosphere protection system; The two workpiece transmission devices also include a tension sensor and a roller regulator.

4. The device for step-by-step scanning of current micro-areas of metal materials according to claim 1, characterized in that: The metal material current micro-area step-by-step scanning processing device further comprises an insulating module, which is located between the current copper plate No. 1 and the fixed platform, between the current copper plate No. 2 and the X, Y, Z three-axis displacement platform 1, and between the roller assembly and the metal material to be processed; The metal material current micro-area step-by-step scanning processing device also includes a computer system, which includes a computer, finite element simulation software, machine learning software, and a temperature feedback control system.

5. A method for stepwise scanning of metal material current micro-areas according to any one of claims 1 to 4, characterized in that: A metal material current micro-area step-by-step scanning processing device is used, the metal material to be processed is clamped between the upper roller and the lower roller of two workpiece transmission devices, and the current probe No. 1 is located above the metal material to be processed, the current probe No. 2 is located below the metal material to be processed, and the centers of the current probe No. 1 and the current probe No. 2 are aligned, the metal material to be processed is divided into a plurality of processing areas on the X-axis and Y-axis planes, and the current application process of each processing area is set, and then the metal material to be processed is subjected to current micro-area step-by-step scanning processing by the current probe No. 1 and the current probe No.

2. During the electric pulse micro-area step-by-step scanning processing, the three-axis displacement platform No. 1 moves upward in the Z-axis direction to control the current copper plate No. 2 to move upward, so that the current probe No. 1 and the current probe No. 2 clamp the metal material to be processed, the upper roller and the lower roller are driven by the servo motor to displace the metal material to be processed in the X-axis direction, and the three-axis displacement platform No. 1 moves to control the displacement of the current copper plate 1 and the current copper plate 2 in the X-axis and Y-axis directions.

6. A method for step-by-step scanning of current micro-areas of metal materials according to claim 5, characterized in that: The metal material to be processed is selected from a cold-processed part A that has been annealed or a cold-processed part B that is obtained by cold processing a hot-processed part having a structure of columnar crystals in the center and equiaxed crystals in the edge.

7. A method for step-by-step scanning of metal material current micro-areas according to claim 6, characterized in that: The process of obtaining the annealed cold-worked part A is as follows: cold-work the cast alloy material, control the cold-work deformation to be 50% to 98%, and then anneal the cold-worked part.

8. The method for step-by-step scanning of current micro-areas of a metal material according to claim 6, characterized in that: When the metal material to be processed is selected from the cold-processed parts that have been annealed, the metal material to be processed is divided into several processing areas on the X-axis and Y-axis planes, and the current micro-area step-by-step scanning processing process of each processing area is set to obtain the following method: through a computer system, Thermo-Calc phase diagram calculation software, finite element simulation software, and machine learning calculations are used to simulate the microstructure and performance of the current micro-area step-by-step scanning processing process after the metal sheet is processed. However, according to different performance requirements, the metal material is divided into several processing areas on the X-axis and Y-axis planes, and the current micro-area step-by-step scanning processing process of each processing area is set, and then the current micro-area step-by-step scanning process is performed.

9. The method for step-by-step scanning of metal material current micro-areas according to claim 6, characterized in that: The method for obtaining a hot-worked part with a structure of core columnar crystals + edge equiaxed crystals is as follows: selecting a metal raw material according to the composition of the metal material, smelting the metal liquid to obtain a molten metal, subjecting the molten metal to directional crystallization to obtain an ingot with an oblique eight-shaped columnar crystal structure, and subjecting the ingot to a hot working treatment; The process of directional crystallization is as follows: using a continuous casting speed of 1 to 100 mm / s to make the molten metal pass through the rapid cooling section and the slow cooling section of the water-cooled crystallizer in sequence, the length of the rapid cooling section is 50 to 200 mm, the length of the slow cooling section is 20 to 80 mm, the cooling water flow rate of the rapid cooling section is 600 to 2000 L / h, and the cooling water flow rate of the slow cooling section is 100 to 400 L / h; The process of the heat treatment is as follows: firstly, the ingot is heated to 400-1200°C, kept at the temperature for 1-60 minutes, and then a plurality of heat treatments are performed, the deformation of each pass is controlled to be 5%-60%, and heat treatment is performed between passes, the heat treatment temperature is 400-1200°C, and the holding time is 5-30 minutes; During the thermal processing, the processing direction is controlled to be the direction of the temperature gradient; The direction of the cold working is consistent with the deformation direction during hot working; During the cold working, the deformation of a single pass is controlled to be 5-30%, and the total deformation is controlled to be 70-99.9%.

10. The method for step-by-step scanning of metal material current micro-areas according to claim 6, characterized in that: When the metal material to be processed is selected from a cold-processed part B obtained by cold processing of a hot-processed part having a structure of core columnar crystals + edge equiaxed crystals, the current micro-area step-by-step scanning process is as follows: the metal material is divided into a plurality of parallel hardening zones and softening zones along the length direction or the width direction, wherein the hardening zones and the softening zones are alternately distributed, and a blank zone is provided between the hardening zones and the softening zones, and then the hardening zones and the softening zones are subjected to the current micro-area step-by-step scanning process in turn, wherein the current micro-area step-by-step scanning process parameters of the hardening zone are: voltage 0.01-8V, current 100-500A, and the current micro-area step-by-step scanning process parameters of the softening zone are: voltage 8-20V, current 800-2000A; The width of the blank area>5mm, The current micro-area step-by-step scanning treatment process applies electric current to the metal material through a movable current probe, firstly places the movable current probe at a certain point in any hardening zone or softening zone of the metal material, applies current once within the area of ​​the current probe, then moves the current probe in parallel to apply current to the next area of ​​the current probe, until one hardening zone or softening zone is treated, then moves the current probe to another untreated hardening zone or softening zone to repeat the above process; when applying current to the hardening zone, the treatment time of any single point is 5 to 120 seconds, and when applying current to the softening zone, the treatment time of any single point is 10 to 300 seconds.

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