A metal material current micro-area step-by-step scanning processing device and processing method thereof

Abstract

This invention discloses a device and method for gradually scanning and processing current micro-areas of metal materials. The device comprises a PC control system, a current output system, a current micro-area processing device, a workpiece transfer device, a temperature measurement and control system, an insulation module, and a high-performance computer system. This device and process not only addresses the limitations of furnace chamber size and long heat treatment times in traditional heat treatment processes, but also enables precise control of the microstructure and properties of specific micro-areas of metal materials, significantly improving production efficiency, reducing production costs, and enhancing the overall performance of the product. The device and process can be used for industrial-scale production.

Description

Technical Field

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

[0002] With the advancement of science and technology, the requirements for metal materials in various application scenarios are no longer limited to a single performance. Component materials in complex environments need to meet the needs of multifunctional integration. One important application direction is to meet the different service properties of different parts of the material. For example, in the application of Ti alloy skeletons, joints are often required to have higher hardness and friction resistance, while the skeleton requires better toughness. Therefore, new preparation methods and processing technologies are needed to achieve comprehensive and precise control of material composition, structure, process and performance.

[0003] To meet these needs, composite materials or regional processing of materials can be employed. The preparation of composite materials involves the challenge of welding two or more alloy materials, and the formation of intermetallic compounds is a significant issue that must be addressed at the composite interface. For example, brittle intermetallic compounds are easily formed at the interface between Cu and Al, affecting the overall mechanical properties of the material. Furthermore, complex composite materials pose a challenge to sustainable development, as the separation of multiple elements during recycling and reuse significantly increases the material's sustainability cost. Surface modification techniques are commonly used to modify different regions of homogeneous materials. This involves creating new microstructures on the surface and interior of components through processes such as carburizing, nitriding, plating, localized heat treatment, and localized forging, thereby improving the performance of specific regions of the metal material. Surface treatment techniques such as carburizing, nitriding, and plating typically improve the performance of metal materials only on the surface and are unable to adjust the internal structure and properties of the material. Localized heat treatment and localized forging can process the entire material, but they struggle with processing complex materials and fine-tuning micro-regions. Furthermore, these techniques are susceptible to the effects of equipment and material size.

[0004] To address the challenges encountered during the preparation and processing of these materials, the present invention proposes to utilize electropulse processing technology to incrementally treat and process materials in micro-areas by designing new processing equipment and techniques. Electropulse processing is a novel heat treatment microstructure and property control technology that applies pulsed current to metal materials to achieve superior mechanical properties. Two effects occur during electropulse processing: thermal and non-thermal. The thermal effect primarily stems from the Joule heating of the current on the metal. The non-thermal effect primarily results from the interaction between the current flow and defects such as dislocations, which can promote phase transformations and dislocation slip. By properly leveraging the coupling effect of non-thermal and thermal effects in metals, processing time and manufacturing costs can be effectively reduced in various traditional heat treatment processes. Electropulse processing technology has been extensively studied in metal aging, stretching, compression, and bending processes. It has also achieved significant results in the processing of magnesium alloys, copper alloys, titanium alloys, and steel. Regarding the impact of current on the microstructure and properties of alloy materials, in addition to factors such as grain coarsening and dislocation slip caused by thermal effects, the non-thermal effects outweigh the thermal effects, significantly promoting element diffusion, recrystallization, and defect movement within the material. Patent document CN118241019A discloses a duplex stainless steel and a method for regulating its ferrite phase ratio. This method utilizes the continuous action of the electrical and thermal coupling field of electric pulses to achieve rapid grain refinement and preferential growth. By regulating the ferrite phase ratio in the material, the performance of the duplex stainless steel after electric pulse treatment is improved. Patent document CN118241037A discloses a method for preparing copper-containing stainless steel with a bimodal structure using electric pulse technology. The electric pulse treatment technology can cause the stainless steel material to recrystallize in a short period of time, thereby significantly improving the material's mechanical properties. Patent document CN118186326A discloses a method for electric pulse toughening treatment of high-toughness titanium alloy linear friction welded joints. The electric pulse treatment technology achieves localized control of the joint structure, thereby ensuring good joint strength and significantly improving the joint toughness. The above patents show that electric pulse treatment technology has a significant effect on improving the overall performance of the alloy. However, due to the power supply limit, the workpiece size remains one of the main factors affecting the treatment 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 the material size and can precisely control the micro-regional structural properties of different specific areas of the material. Summary of the Invention

[0005] To address the shortcomings of the above background, the first object of the present invention is to provide a device for step-by-step scanning and processing of metal materials using electric current micro-areas. The equipment provided by the present invention can realize intelligent design of metal material microstructures, perform electric current micro-area processing on specific areas of metal profiles such as metal plates, strips, and tubes, and obtain ideal microstructures. This device not only solves the problems of traditional heat treatment processes that are limited by furnace chamber size and long heat treatment times, but also can precisely control the microstructure and properties of specific areas of metal materials, significantly improving production efficiency, reducing production costs, and improving the overall 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 current micro-regions of metal materials, so as to achieve precise control of the microscopic / mesoscopic structures of different regions of large-scale metal materials.

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

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

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

[0010] The current micro-area processing device comprises current probe No. 1, current probe No. 2, current copper plate No. 1, current copper plate No. 2, cable fixing copper ring No. 1, cable fixing copper ring No. 2; three-axis displacement platform No. 1, 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 and negative poles 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 set above the table. 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 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 as the three-axis displacement platform No. 1 moves; the current copper plate No. 2 and the three-axis displacement platform are located below the table. When working, the current probe No. 1 and the current probe No. 2 are respectively set 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 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; 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 sides 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, and 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. 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. The device provided by the present invention is a device that can continuously and gradually provide current to tiny areas of a metal material. The micro-area gradual scanning and processing device provided by the present invention applies current to a micro-area of ​​a workpiece within the vertical projection range of the probe through current probe No. 1 and current probe No. 2. During application, 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. The cross-sectional size of the current probe is used to control the area of ​​the metal material to which current is applied at a single time. 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 on the X-axis to complete continuous micro-area scanning processing of the metal material to be processed.

[0016] In a preferred embodiment, 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 by connecting the pure copper cable with the cable fixing copper ring No. 1 and the cable fixing copper ring No. 2, so that the current output system provides current to the micro-area processing device.

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

[0019] In a preferred solution, the current output system further includes 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] In a preferred embodiment, the cross-sectional area of ​​the pure copper cable is ≥ 200 mm 2 , preferably ≥800mm 2 By using pure copper cables within the above-mentioned area range, it is possible to apply continuous current to large-sized workpieces.

[0023] Preferably, the material of current probe No. 1 and current probe No. 2 is selected from dispersed copper, chromium bronze, zirconium bronze, tungsten copper, molybdenum copper, pure copper, and graphite, preferably dispersed copper. Current probes made of these materials can avoid galvanic corrosion 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 one of a circle, a cone, a cross, and a straight line, and the size of the head surface is 0.01mm 2 ~10cm 2 , preferably 0.01mm 2 ~1cm 2 , further preferably 0.01mm 2 ~1mm 2 .

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

[0026] In a preferred embodiment, the current copper plate No. 1 and the current copper plate No. 2 are connected 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] Preferably, the two workpiece transmission devices further include a tension sensor and a roller regulator. The tension sensor and the roller regulator are configured to adjust the tension of the metal material to be processed during transmission 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] Preferably, the metal material current micro-area step-by-step scanning processing device further includes an insulation module. The insulation module is located between the current copper plate No. 1 and the fixed platform, between the current copper plate No. 2 and the X, Y, and Z three-axis displacement platform 1, and between the roller assembly and the metal material to be processed. The insulation module ensures 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 stepwise scanning processing device further comprises a computer system comprising 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.

[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 processing of metal materials using current micro-area. The method uses a device for step-by-step scanning processing of metal materials using current micro-area. The metal material to be processed is clamped between upper rollers and lower rollers of two workpiece transmission devices, and current probe No. 1 is located above the metal material to be processed, and current probe No. 2 is located below the metal material to be processed, and the centers of current probe No. 1 and 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 a current application process for each processing area is set. Then, the metal material to be processed is subjected to step-by-step scanning processing of current micro-area by current probe No. 1 and current probe No. 2. During the step-by-step scanning processing of electric pulse micro-area, a three-axis displacement platform No. 1 is moved 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 current probe No. 2 clamp the metal material to be processed, 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, and the three-axis displacement platform No. 1 is moved to control the displacement of current copper plate 1 and current copper plate 2 in the X-axis and Y-axis directions.

[0036] The metal material current micro-area step-by-step scanning processing method of the present invention uses metal material electric pulse micro-area step-by-step scanning processing equipment. Unlike the prior art, which can only apply electric pulse current to the entire 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 a partitioned manner. 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 X-axis is limited and moved, thereby realizing 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, thereby adjusting the microstructure of different areas of the metal material to be processed.

[0037] Preferably, the metal material to be processed is selected from nonferrous metals or ferrous metals. The nonferrous metal is selected from pure metals or alloys such as aluminum, copper, magnesium, titanium, and nickel, and the ferrous metal is an iron alloy. The sample can be in the form of a plate, strip, foil, rod, tube, wire, or a special shape.

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

[0039] More 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 actual operation, cast alloy materials suitable for cold working, such as copper alloys, titanium alloys, aluminum alloys or magnesium alloys, are selected to ensure that the initial microstructure and chemical composition of the material are uniform; then the cold working deformation amount 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-worked 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-worked 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 set. The computer system is used to simulate the microstructure and performance of the current micro-area step-by-step scanning processing process after the metal sheet is processed using Thermo-Calc phase diagram calculation software, finite element simulation software, and machine learning calculations. 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 current to a specific area, the dislocations in the columnar crystals in the area will recrystallize to form fine equiaxed crystals, thereby converting the original columnar crystals into equiaxed crystals. This structure of alternating equiaxed crystals and columnar crystals has higher strength and plasticity than a single columnar crystal.

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

[0045] Furthermore, the method first selects an appropriate material database based on the type of metal sheet or strip. By inputting parameters during the current processing, such as temperature, current, voltage, and frequency, as the basis for model calculations, Thermo-Calc is used to calculate phase diagrams, including isothermal sections, vertical sections, time-temperature-transformation (TTT) diagrams, and cooling-time (CCT) diagrams, to predict the phase transformation that may occur under specific conditions. Subsequently, the calculated phase transformation process is used to predict the material's mechanical properties, such as hardness, tensile strength, and yield strength. A sensitivity analysis is then performed to investigate the effects of different current parameters (such as pulse width, pulse frequency, and material composition) on the phase transformation and mechanical properties.

[0046] Furthermore, first, the experimental data of the current micro-area treatment of metal materials is collected, including but not limited to current parameters (such as frequency, amplitude, duration), material properties (such as composition, thickness, initial microstructure), and regional characteristics after treatment (such as microstructural changes, hardness, conductivity, etc.); then, features are extracted from the collected data. These features should be able to represent the key variables and results of 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. The data is then cleaned and standardized, and missing values ​​and outliers are handled. It may also be necessary to normalize or standardize the data to facilitate algorithm processing.

[0047] In practice, we select a machine learning model. For this type of regression problem, we use support vector machines (SVMs), random forests, gradient boosting trees (such as XGBoost), and neural networks for model training. We adjust the model parameters (hyperparameter optimization) to achieve optimal model performance.

[0048] Furthermore, by combining the calculation results of 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 one of a circle, an ellipse, a straight line, and a broken line, 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] It is further preferred that 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 current micro-area step-by-step scanning process, argon gas is used as an 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] During the actual operation, 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 processing is carried out at the optimal temperature. Real-time monitoring is carried out during the processing to ensure the stability of the processing parameters and the consistency of the processing quality. After the processing is completed, the microstructure and mechanical properties of the processing area are tested to evaluate the effect of the current treatment and compare and analyze it with the simulation results.

[0056] Further preferably, a method for obtaining a hot-worked part with core columnar crystals and 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 directionally crystallizing the molten metal to obtain an ingot with an oblique eight-shaped columnar crystal structure, and then carry out hot working treatment on the ingot.

[0057] The directional crystallization process 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 hot working process is as follows: first, heating the ingot to 400-1200° C., preferably 600-1100° C., holding the temperature for 1-60 minutes, preferably 30-60 minutes, and then performing multiple hot working treatments, controlling the deformation of each pass to be 5%-60%, preferably 10%-30%, and performing heat treatment between passes, the heat treatment temperature is 400-1200° C., preferably 600-1100° C., and the holding time is 5-30 minutes, preferably 5-10 minutes;

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

[0060] The hot working is selected from one 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 outermost circle of "eight-shaped" columnar crystals to be recrystallized, and a structure of columnar crystals in the center and equiaxed crystals on the edge is achieved (the inside of the eight-shaped is columnar crystals, and the outside of the eight-shaped is equiaxed crystals). This structure has higher mechanical properties than a single equiaxed crystal or parallel columnar crystal, 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 and hot-processing a 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 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 cold working a metal material with more dislocations and deformation twins, the metal material is partitioned into hard and soft phases. High currents can cause a significant thermal effect on the alloy, resulting in higher temperatures in the alloy region at the instantaneous application. Vigorous recovery and recrystallization occur at locations where dislocations accumulate, creating softened micro-regions. Low currents, on the other hand, result in lower temperatures in the alloy region at the instantaneous application. Recovery and precipitation of a second phase occur at locations where dislocations accumulate, creating hardened micro-regions.

[0068] Furthermore, preferably, the width of the blank area (the area not treated by current) is greater than 5 mm, preferably 5 to 15 mm. A certain spacing needs to be set between the hardened and softened zones, and the spacing needs to be controlled. If a smaller spacing is selected, heat overlap may occur in the target area due to metal heat conduction, resulting in excessively rapid precipitation and growth of the second phase in the hardened area, weakening the strengthening effect of the hardened area, and even causing 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, first placing the movable current probe at a certain point in any hardened zone or softened zone of the metal material, applying current once within the area of ​​the current probe, and then moving the current probe in parallel to apply current to the next area of ​​the current probe, until one hardened zone or softened zone is processed, and then moving the current probe to another untreated hardened zone or softened zone to repeat the above process; when current is applied to the hardened zone, the processing time of any single point is 5 to 120 s, and when current is applied to the softened 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 workpiece B, a metal material with a multi-phase heterogeneous structure in which softening zones and hardening zones are periodically alternating 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 the 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 quickly 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 realizing precise control 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, ensuring the precise movement of the current probe along the y-axis. Simultaneously, it coordinates the workpiece transfer device to precisely move the metal material along the x-axis. This method enables precise design and control of the metal material structure.

[0075] Compared with the prior art, the present invention has the beneficial effect that by using a probe to perform current treatment on a specific area of ​​a metal material, the tissue structure can be quickly and accurately controlled, 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 processing 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 processing method cannot process large-sized metal components due to insufficient power of the power supply equipment.

[0077] (2) The proposed current micro-area microstructure performance control process is based on the principle of current processing, making the microstructure design of metal components both flexible and precisely controllable. Using a computer-controlled mobile platform, the relative position of the electrode probe and the metal component's electro-processing micro-area can be precisely controlled. Based on design requirements, the path of the electro-processing micro-area is planned, and through a step-by-step micro-area scanning process, precise design and control of the electrically induced metal material microstructure can be achieved.

[0078] (3) The current micro-area processing process described in the present invention can be used to prepare and process gradient materials. Based on the coupling effect of the electric field and the thermal field, high energy and large current are input into the micro-area of ​​the metal component through the electrode probe, so that the metal material in the micro-area quickly reaches the target temperature. By utilizing the strong coupling effect of the electrically generated Joule heating effect and the non-thermal effect, the diffusion of metal material atoms, solid-state phase transformation, and recrystallization process are accelerated at a relatively low temperature, resulting in rapid structural 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 This is a schematic diagram of the structure of the current micro-area processing device in the present invention. In the figure, 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 structural diagram 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; and 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. The oblique S-shaped columnar crystal structure can be clearly observed in the figure.

[0084] Figure 6 This is a microstructure diagram of the metal material with a multiphase heterogeneous structure provided in Example 4. It can be seen from the figure 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 clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall 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 includes a power supply for providing current to the current micro-area processing device;

[0088] The current micro-area processing device comprises current probe No. 1, current probe No. 2, current copper plate No. 1, current copper plate No. 2, cable fixing copper ring No. 1, cable fixing copper ring No. 2; three-axis displacement platform No. 1, 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 and negative poles 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 set above the table. 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 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 as the three-axis displacement platform No. 1 moves; the current copper plate No. 2 and the three-axis displacement platform are located below the table. When working, the current probe No. 1 and the current probe No. 2 are respectively set 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 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; 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 sides 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 roller and the lower roller 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 by connecting the pure copper cable with the cable fixing copper ring No. 1 and the cable fixing copper ring No. 2, so that the current output system provides current to the current micro-area processing device.

[0095] In a further preferred case, the current provided by the power supply is in the 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 0-220V, the current range is 0-20000A, and the duty cycle is 0-100%.

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

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

[0100] In a further preferred embodiment, the material of current probe No. 1 and current probe No. 2 is selected from dispersed copper, chromium bronze, zirconium bronze, tungsten copper, molybdenum copper, pure copper, and graphite, preferably dispersed copper. Current probes made of these materials can avoid galvanic 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 0.01mm. 2 ~10cm 2 , preferably 0.01mm 2 ~1cm 2 , further preferably 0.01mm 2 ~1mm 2 .

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

[0103] In a further preferred embodiment, the current copper plate No. 1 is connected to the current copper plate No. 2 via a connector that is extendable and retractable 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, while moving 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 configured to adjust the tension of the strip during transmission 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 embodiment, the metal material current micro-area step-by-step scanning processing device further includes an insulation 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, and Z three-axis displacement platform 1, and between the roller assembly and the metal material to be processed. The insulation 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 embodiment, 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, and the like from the entire device during the electric pulse micro-area step-by-step scanning processing process, and for analyzing the entire electric pulse micro-area step-by-step scanning processing process in combination with real-time feedback. 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 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℃ 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] Phase diagrams were calculated using Thermo-Calc software to identify stable and metastable phases under various temperature and composition conditions. Based on the expected EPM temperature range, Thermo-Calc was used to calculate potential phase transitions, such as the α-to-β transition. The phase transition information obtained from Thermo-Calc was used as input parameters, along with EPM parameters such as voltage, current, and temperature, and fed into finite element simulation 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: Utilizes machine learning algorithms, combined with 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: Based on 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 mechanical properties of the treated area, such as hardness, 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 using traditional casting methods to ensure uniform alloy composition.

[0143] Homogenization annealing: Homogenization annealing is carried out in the temperature range of 850-980℃ for 4-8 hours to eliminate casting stress and microsegregation.

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

[0145] (2) Data input and simulation

[0146] Parameter 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 are input 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 parameters, finite element simulation software and machine learning algorithms are used to predict the phase transformation behavior and mechanical properties of the processed area.

[0149] (3) Optimization of electric pulse machining 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 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 8V 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 processing steps to achieve a dot-matrix arranged electric pulse processing area.

[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 is prepared by horizontal continuous casting to ensure uniform alloy composition.

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

[0163] Cold rolling: cold rolling is performed, and the deformation of each pass is controlled at 10-35% 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 transition 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 electric pulse machining 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 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 mechanical properties of the treated area, such as hardness, and compare them with the simulation results.

[0181] Result recording: record 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 a cold-processed workpiece B obtained by cold processing a hot-processed workpiece having a structure of core columnar crystals and edge equiaxed crystals is as follows:

[0187] Example 4

[0188] The Cu-Ni-Sn alloy is used as the target.

[0189] (1) Electric pulse directional solidification: Prepare electrolytic copper sheets, nickel sheets, and tin blocks with a purity of 99.99% or above according to the mass ratio of Ni:Sn:Cu=15:8:77, and place Ni, Cu, and Sn into the electric pulse directional solidification crucible in descending order according to their melting points. Then, add 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℃. After the metal block in the crucible is melted into metal liquid, 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 and current density are set to 1200Hz and 2.0A / 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 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 turn. 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℃. 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 working: The hot-processed slab is placed in a six-roll rolling mill for cold working. 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 softening zone is the width of the probe, and the width of the blank area is 10mm. 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 ​​0.1mm. 2, select low-frequency and high-peak pulse power supply, use servo motor to drive upper roller and lower roller to make the metal material to be processed displace in X-axis direction, use current probe to gradually perform current micro-area scanning treatment, in the hardening zone, apply equivalent voltage of 8V, current of 200A, single treatment time of 30s, after X-direction treatment, move current probe parallel to Y-axis by 10mm, continue to use servo motor to drive upper roller and lower roller to make the metal material to be processed displace in X-axis direction, and use current probe to perform micro-area scanning electrical treatment, apply equivalent voltage of 8V, current of 1000A, single treatment time of 30s, until the entire plate and strip is processed.

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

[0194] Tensile strength: 1680MPa

[0195] Elongation at break: 10.6%

[0196] Electrical conductivity: 15.4% IACS

[0197] Example 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 higher according to the mass ratio of Fe:Si = 96:4. Place Cu and Zn into the electric pulse directional solidification crucible in descending order of melting point. Then, place 20g of graphite powder with a particle size of 5 mesh on 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. Then the temperature was lowered to 1520℃ for insulation. After insulation for 5 minutes, the pulse power supply was turned on, and the pulse frequency was set to 1200Hz and the current density to 1.0A / cm3 through the central controller. After the processing time was 5 minutes, the pulse power supply was turned off to obtain molten metal with uniform composition. Then the molten metal was pulled out from the center hole of the crystallizer at a speed of 10mm / s by using a robotic arm linked traction rod. During the pulling process, the molten metal passed through an 80mm rapid cooling section and a 50mm slow cooling section in turn. Among them, the crystallizer circulating water flow rate in the rapid cooling section was 600L / h, and the crystallizer circulating water flow rate in the slow cooling section was 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℃. After keeping warm for 30 minutes, it is taken out and rolled along the temperature gradient direction. The total deformation is 70%, and the deformation of a single pass is 30%. 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.

[0201] (3) Large deformation cold working: The hot-processed slab is placed in a six-roll rolling mill for cold working. 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 softening zone is the width of the probe, and the width of the blank area is 5mm. 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 ​​0.1mm. 2 , select low-frequency and high-peak pulse power supply, use servo motor to drive upper and lower rollers to displace the metal material to be processed in the X-axis direction, use current probe to gradually perform micro-area scanning electrical treatment, in the hardening zone, 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 and lower rollers to displace the metal material to be processed in the 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 entire plate and strip is processed.

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

[0204] Tensile strength: 1450MPa

[0205] Elongation at break: 15.6%.

[0206] Comparative Example 1

[0207] 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 5 minutes;

[0208] The performance indicators of the alloy plates and strips 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 by: The metal material current micro-area step-by-step scanning processing device includes a current output system, a current micro-area processing device, and two workpiece transmission devices. The current output system includes a power supply for providing current to the current micro-area processing device; The current micro-area processing device comprises current probe No. 1, current probe No. 2, current copper plate No. 1, current copper plate No. 2, cable fixing copper ring No. 1, cable fixing copper ring No. 2; three-axis displacement platform No. 1, 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 and negative poles 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 set above the table. 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 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 as the three-axis displacement platform No. 1 moves; the current copper plate No. 2 and the three-axis displacement platform are located below the table. When working, the current probe No. 1 and the current probe No. 2 are respectively set 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 transfer 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. The roller assembly includes an upper roller and a lower roller. The upper roller and the lower roller are vertically symmetrically arranged on the inner sides of the support box No. 1 and the support box No.

2. 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, and 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. 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 a metal material according to claim 1, characterized in that: 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 the current. The pure copper cable is used to connect 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 ≥ 200 mm 2 .

3. The device for step-by-step scanning of current micro-areas of a metal material 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 ~ 100 cm 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 further comprises 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 a metal material 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, and 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 current micro-areas in metal materials, characterized by: A metal material current micro-area step-by-step scanning processing device is applied as described in any one of claims 1-4, 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 current probe No. 1 and current probe No. 2 are aligned, the metal material to be processed is divided into several processing areas on the X 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 current probe No. 1 and current probe No.

2. During the current 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 current copper plate 1 and current copper plate 2 in the X axis and Y axis directions.

6. The method for processing metal materials by current micro-area step-by-step scanning 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 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.

7. The method for processing metal materials by current micro-area step-by-step scanning according to claim 6, characterized in that: 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.

8. The method for processing metal materials by current micro-area step-by-step scanning according to claim 6, characterized in that: 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 a current micro-area step-by-step scanning processing process is set for each processing area. The method is as follows: through 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 metal sheet after processing by the current micro-area step-by-step scanning processing process. However, according to different performance requirements, the metal material is divided into several processing areas on the X- and Y-axis planes, and a current micro-area step-by-step scanning processing process is set for each processing area, and then the current micro-area step-by-step scanning processing is performed.

9. The method for processing metal materials by stepwise scanning of electric current micro-areas according to claim 6, characterized in that: A method for obtaining a hot-worked part having a structure of core columnar crystals and edge equiaxed crystals is as follows: selecting metal raw materials according to the composition of the metal material, smelting the metal to obtain a molten metal, subjecting the molten metal to directionally crystallization to obtain an ingot having an oblique eight-shaped columnar crystal structure, and subjecting the ingot to a hot working treatment. The directional crystallization process is as follows: using a continuous casting speed of 1-100 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 50-200 mm, the length of the slow cooling section is 20-80 mm, the cooling water flow rate of the rapid cooling section is 600-2000 L / h, and the cooling water flow rate of the slow cooling section is 100-400 L / h; The heat treatment process is as follows: first, the ingot is heated to 400-1200°C, kept at this temperature for 1-60 minutes, and then subjected to multiple heat treatments, with the deformation of each pass controlled at 5%-60%, and heat treatment performed between passes, with the heat treatment temperature at 400-1200°C and the holding time at this temperature for 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 processing metal materials by current micro-area step-by-step scanning 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 a hot-processed part having a structure of core columnar crystals + edge equiaxed crystals, the current micro-area step-by-step scanning treatment process is as follows: the metal material is divided into a plurality of parallel hardened zones and softened zones along the length direction or the width direction, wherein the hardened zones and the softened zones are alternately distributed, and a blank zone is provided between the hardened zones and the softened zones, and then the hardened zones and the softened zones are subjected to the current micro-area step-by-step scanning treatment in sequence, wherein the current micro-area step-by-step scanning treatment parameters of the hardened zone are: voltage 0.01-8V, current 100-500A, and the current micro-area step-by-step scanning treatment parameters of the softened zone are: voltage 8-20V, current 800-2000A; The width of the blank area is greater than 5 mm, The current micro-area step-by-step scanning processing process applies electric current to the metal material through a movable current probe. The movable current probe is first placed at a certain point in any hardened area or softened area of ​​the metal material, and current is applied once within the area of ​​the current probe. Then, the current probe is moved parallel to apply current to the next area of ​​the current probe until one hardened area or softened area is processed. The current probe is then moved to another untreated hardened area or softened area to repeat the above process. When current is applied to the hardened area, the processing time of any single point is 5 to 120 seconds, and when current is applied to the softened area, the processing time of any single point is 10 to 300 seconds.

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