An oxygen-free silver-containing copper rod heat treatment process parameter optimization method and system

Abstract

The present application relates to copper rod production technical field, especially to a kind of oxygen-free silver-containing copper rod heat treatment process parameter optimization method and system, comprising: the microstructure characteristics and copper rod characteristic parameters of the oxygen-free silver-containing copper rod to be heat treated are obtained;Microstructure characteristics and copper rod characteristic parameters are used as positioning condition, in the heat treatment process library that is constructed in advance, matching positioning is carried out, initial heat treatment process parameter set is determined, and oxygen-free silver-containing copper rod is heat treated with this;In the heat treatment process, the heat treatment characteristic parameter set of oxygen-free silver-containing copper rod is collected in real time;In response to at least one heat treatment characteristic in heat treatment characteristic parameter set does not reach preset target characteristic index within preset time, the deviation value of all substandard heat treatment characteristics is calculated, and is converted into heat treatment deviation vector.It can respond to the microstructure change of material in heat treatment process in real time, realizes the dynamic adjustment to process parameter.

Description

Technical Field

[0001] This invention relates to the technical field of copper rod production, and in particular to a method and system for optimizing heat treatment process parameters of oxygen-free silver-containing copper rods. Background Technology

[0002] Oxygen-free silver-containing copper rods are widely used as high-performance conductive materials in fields such as superconducting equipment, precision electronic devices, and aerospace cables; their mechanical and electrical properties directly depend on the microstructure characteristics of the material after heat treatment.

[0003] Heat treatment is an important processing technique that alters the microstructure and properties of metallic materials by heating, holding, and cooling them. For oxygen-free silver-containing copper rods, a proper heat treatment process can refine the grains, improve grain boundary characteristics, and adjust the distribution of alloying elements (such as silver), thereby significantly improving the performance of the copper rods, such as enhancing their strength, toughness, and fatigue resistance, while also ensuring their good electrical conductivity and thermal stability.

[0004] Existing heat treatment process parameters for oxygen-free silver-containing copper rods are often based on experience or general standards. However, due to differences in microstructure and copper rod properties, uniform heat treatment process parameters may not achieve optimal results for different oxygen-free silver-containing copper rods. For example, copper rods with different silver contents have different requirements for parameters such as temperature, holding time, and cooling rate during the heat treatment process. Using the same empirical heat treatment process parameters will lead to unsatisfactory performance of some copper rods.

[0005] Meanwhile, in the actual heat treatment process, factors such as the operating status of the heat treatment equipment and subtle differences in the microstructure and composition of the raw materials may cause the heat treatment characteristic parameters to deviate from expectations. However, once the existing heat treatment process parameters are determined, it is difficult to make real-time adjustments during the heat treatment process. For example, if it is found that the rate of change of the microstructure of the copper rod does not meet expectations during the heat preservation process, it is impossible to adjust the heat preservation time or other process parameters in time, which may affect the final performance of the copper rod. Summary of the Invention

[0006] This invention provides a method and system for optimizing process parameters in the heat treatment of oxygen-free silver-containing copper rods, which can respond in real time to changes in the microstructure of the material during heat treatment and dynamically adjust the process parameters, effectively solving the problems in the background art.

[0007] To achieve the above objectives, in a first aspect, the present invention provides a method for optimizing the process parameters of heat treatment of oxygen-free silver-containing copper rods, comprising:

[0008] To obtain the microstructural characteristics and property parameters of the oxygen-free silver-containing copper rod to be heat-treated;

[0009] Using the microstructural features and copper rod characteristic parameters as positioning conditions, the system performs matching and positioning in a pre-built heat treatment process library to determine the initial heat treatment process parameter set, and then uses this set to perform heat treatment on the oxygen-free silver-containing copper rod.

[0010] During the heat treatment process, the heat treatment characteristic parameter set of oxygen-free silver-containing copper rods is collected in real time;

[0011] In response to the fact that at least one heat treatment feature in the set of heat treatment feature parameters fails to meet the preset target feature index within a preset time, the deviation values ​​of all the heat treatment features that fail to meet the target are calculated and converted into a heat treatment deviation vector.

[0012] Based on the heat treatment deviation vector, the initial heat treatment process parameter set is adjusted to obtain the optimal heat treatment process parameter set, and the oxygen-free silver-containing copper rod is then heat-treated accordingly.

[0013] In conjunction with the first aspect, in one possible design, the microstructural features include at least grain size, grain morphology, and grain boundary features;

[0014] The characteristic parameters of the copper rod include at least its specifications and composition.

[0015] In conjunction with the first aspect, in one possible design, the preset time is a dynamic response time window, satisfying the following calculation formula:

[0016] ;

[0017] Among them, t preset The preset time is represented by d; the real-time grain size is represented by d; K0 represents the grain growth rate constant, an intrinsic material parameter characterizing the grain boundary migration rate of the Ag-Cu system; Q represents the grain boundary migration activation energy, reflecting the hindering effect of silver atoms on the recrystallization process of the copper matrix; R represents the gas constant, a universal constant in thermodynamic calculations; T represents the real-time temperature of the copper rod surface in the heat treatment furnace; α represents the thermal hysteresis compensation factor, used to correct the deviation of temperature field fluctuations on grain growth prediction; ΔD represents the absolute difference between the current grain size and the target value; D target The target grain size is the ideal grain diameter set according to the product performance requirements.

[0018] In conjunction with the first aspect, in one possible design, the initial heat treatment process parameter set includes at least heating temperature, holding time, and cooling rate.

[0019] In conjunction with the first aspect, in one possible design, the set of heat treatment characteristic parameters includes temperature field characteristic parameters, microstructure dynamic parameters, physical performance parameters, and process control parameters.

[0020] In conjunction with the first aspect, in one possible design, the temperature field characteristic parameters include at least one of temperature gradient distribution and temperature change rate;

[0021] The microstructure dynamic parameters include at least one of grain size, grain boundary migration rate, and silver element distribution characteristics.

[0022] The physical performance parameters include at least one of the following: residual stress field, dynamic conductivity value, and hardness distribution characteristics.

[0023] The process control parameters include at least one of the following: oxygen content during the heat preservation stage, equipment power, quenching medium flow rate, and quenching medium temperature.

[0024] In conjunction with the first aspect, in one possible design, the heat treatment process library is used to store the initial heat treatment process parameter set under different combinations of microstructural features and copper rod characteristic parameters;

[0025] The heat treatment process library is based on a preset indexing method and retrieves the initial heat treatment process parameter set that matches the input copper rod feature parameters.

[0026] In conjunction with the first aspect, in one possible design, the preset indexing method in the heat treatment process library includes:

[0027] Based on the specifications and characteristics of the copper rod to be processed, a set of initial heat treatment process parameters that match it is selected and marked as the first-order initial heat treatment process parameter set.

[0028] Matching weights are set for grain size, grain morphology and grain boundary characteristics respectively, and the similarity between the copper rod to be processed and all the first-order initial heat treatment process parameter sets is calculated.

[0029] The set of first-order initial heat treatment process parameters with the highest similarity is used as the set of initial heat treatment process parameters for the copper rod to be treated.

[0030] In conjunction with the first aspect, in one possible design, the method for acquiring the temperature gradient distribution in the temperature field characteristic parameters includes:

[0031] A preset number of temperature sensors are installed along the axis of the copper rod inside the heat treatment furnace;

[0032] Based on a preset frequency, the monitored temperatures of each temperature sensor are collected.

[0033] The axial temperature gradient of the copper rod is calculated based on the collected monitoring temperature.

[0034] Secondly, the present invention also provides a system for optimizing process parameters of oxygen-free silver-containing copper rod heat treatment, comprising:

[0035] The parameter acquisition module is used to acquire the microstructural characteristics and property parameters of the oxygen-free silver-containing copper rod to be heat-treated.

[0036] The parameter matching and positioning module is used to match and locate microstructure features and copper rod characteristic parameters as positioning conditions in a pre-built heat treatment process library to determine the initial heat treatment process parameter set.

[0037] The real-time acquisition module is used to acquire the set of heat treatment characteristic parameters of the oxygen-free silver-containing copper rod in real time during the heat treatment process.

[0038] The deviation calculation module is used to determine whether at least one heat treatment feature in the set of heat treatment feature parameters fails to meet the preset target feature index within a preset time. If there is a failure to meet the target, the deviation value of all the failure heat treatment features is calculated and converted into a heat treatment deviation vector.

[0039] The parameter control module is used to control the initial heat treatment process parameter set based on the heat treatment deviation vector obtained by the deviation calculation module, to obtain the optimal heat treatment process parameter set, and to perform heat treatment on the oxygen-free silver-containing copper rod accordingly.

[0040] The technical solution of this invention can achieve the following technical effects: By acquiring the microstructural characteristics and characteristic parameters of the oxygen-free silver-containing copper rod to be heat-treated, and using these as positioning conditions to match and locate the initial heat treatment process parameter set in the heat treatment process library, the previous method of formulating process parameters based on experience or general standards can be changed. This allows for the formulation of more targeted heat treatment processes for copper rods with different characteristics, avoiding the problem that uniform parameters cannot achieve the best treatment effect, and improving the consistency and reliability of copper rod performance. During the heat treatment process, the heat treatment characteristic parameter set is collected in real time. When at least one heat treatment characteristic is found to be not meeting the preset target characteristic index, the deviation value can be calculated and converted into a heat treatment deviation vector. This allows for the adjustment of the initial heat treatment process parameter set to obtain the optimal heat treatment process parameter set. This can effectively cope with the situation where the heat treatment characteristic parameters deviate from the expected value due to factors such as equipment operating status, slight differences in the microstructure and composition of raw materials during the heat treatment process, ensuring that the final performance of the copper rod is not affected.

[0041] In summary, this method achieves bidirectional feedback between microstructure evolution and process parameter formation through coupled optimization of real-time monitoring, dynamic decision-making, and closed-loop control, enabling automatic balance between silver segregation suppression and grain boundary migration rate. Simultaneously, it compresses multi-parameter coupling deviations within the process tolerance range, triggering a cross-scale compensation mechanism during sudden operating conditions, thus achieving a strong robust effect of self-digestion of dynamic disturbances. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a flowchart illustrating the optimization method for oxygen-free silver-containing copper rod heat treatment process parameters in this invention.

[0044] Figure 2 This is a structural block diagram of the oxygen-free silver-containing copper rod heat treatment process parameter optimization system of the present invention. Detailed Implementation

[0045] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0046] This application will now be described with reference to the accompanying drawings.

[0047] like Figure 1 As shown, the method for optimizing the heat treatment process parameters of oxygen-free silver-containing copper rods according to the present invention specifically includes the following steps:

[0048] Step S1: Obtain the microstructure characteristics and copper rod property parameters of the oxygen-free silver-containing copper rod to be heat-treated;

[0049] Step S2: Using the microstructure features and copper rod characteristic parameters as positioning conditions, match and locate them in a pre-constructed heat treatment process library to determine the initial heat treatment process parameter set, and use this to perform heat treatment on the oxygen-free silver-containing copper rod.

[0050] Step S3: During the heat treatment process, the heat treatment characteristic parameter set of the oxygen-free silver-containing copper rod is collected in real time;

[0051] Step S4: In response to at least one heat treatment feature in the heat treatment feature parameter set failing to meet the preset target feature index within a preset time, calculate the deviation values ​​of all non-compliant heat treatment features and convert them into a heat treatment deviation vector.

[0052] Step S5: Based on the heat treatment deviation vector, adjust the initial heat treatment process parameter set to obtain the optimal heat treatment process parameter set, and use it to heat treat the oxygen-free silver-containing copper rod.

[0053] In this embodiment, traditional processes rely on experience and general standards, with fixed process parameters and a lack of flexibility. In contrast, this method dynamically adjusts process parameters by matching and locating microstructural features and copper rod characteristic parameters, combined with real-time acquired heat treatment characteristic parameters, forming a closed-loop optimization system that shifts from "experience-driven" to "data-driven." This not only solves the problem of "one-size-fits-all" process parameters in traditional processes but also achieves adaptive optimization of process parameters. Even when faced with complex material properties and equipment fluctuations, process parameters can automatically adjust to the optimal state, forming intelligent adaptive heat treatment capabilities. This makes the process no longer limited to experience and standards but possesses intelligent and precise capabilities.

[0054] By acquiring heat treatment characteristic parameter sets in real time, and combining deviation value calculation and heat treatment deviation vector analysis, dynamic adjustment of process parameters can be achieved. This dynamic adjustment is carried out throughout the entire heat treatment process, rather than being limited to a fixed stage. The original static process is transformed into dynamic process control, which can respond in real time to changes in the microstructure of the material during heat treatment. For example, when the grain growth rate at a certain stage does not meet expectations, the holding time or cooling rate can be adjusted immediately, avoiding the performance loss caused by delayed adjustment in traditional processes. This makes the process more precise, and the final product has more stable and superior performance.

[0055] By collecting and analyzing heat treatment characteristic parameters in real time, and combining this with the calculation of deviation vectors, process parameters can be controlled from a global perspective. This ensures that the process parameters at each stage have a positive impact on the final performance, achieving a leap from local optimization to global optimization. For example, if the grain growth rate is found to be too slow during the holding stage, not only is the holding time adjusted, but the parameters of the subsequent cooling stage are also comprehensively considered to ensure the continuity and consistency of the entire heat treatment process. This global optimization capability makes the performance of the final product more balanced and excellent, avoiding overall performance shortcomings caused by local optimization.

[0056] By acquiring the microstructural features and characteristic parameters of copper rods, and combining this with matching and positioning within a heat treatment process library, the process parameters are transformed from "process-dependent" to "material-characteristic-driven." This allows the process parameters to better adapt to the differences in material properties. For example, copper rods with different silver contents have different requirements for temperature, holding time, and cooling rate during heat treatment. This method can automatically adjust the process parameters according to the material characteristics, avoiding performance losses caused by a "one-size-fits-all" approach to the process.

[0057] In some embodiments of the present invention, the microstructure features include at least grain size, grain morphology and grain boundary features; the copper rod characteristic parameters include at least specification features and composition features.

[0058] Grain size refers to the average size of grains in the copper rod material. Grain size has a significant impact on the strength, toughness, and conductivity of the material. For example, fine grains can usually improve the strength and toughness of the material, but may have a certain impact on conductivity. The method of obtaining the grain size is to observe it using metallographic microscopy. Samples of the copper rod to be heat-treated are taken, and after grinding, polishing, and etching, the grain morphology is observed under a 100-500x metallographic microscope. The average size of at least 50 grains is measured using image analysis software, or the average grain diameter is calculated using the intercept method to ensure the statistical significance of the data.

[0059] Grain morphology refers to the shape characteristics of grains, such as equiaxed grains, columnar grains, or plate-like grains. Grain morphology affects the distribution of grain boundaries and the mechanical properties of materials. By recording the geometric shape (such as equiaxed grains, columnar grains, irregular grains), surface roughness, and grain boundary integrity through metallographic photographs or scanning electron microscope images, it is possible to determine whether there are abnormal grains and their proportion. Abnormal grains include twins and coarse grains.

[0060] Grain boundary characteristics include the clarity, continuity, and migration rate of grain boundaries. Using scanning electron microscopy combined with electron backscatter diffraction, we can analyze the orientation difference of grain boundaries, the distribution of precipitates at grain boundaries, such as the segregation of silver elements at grain boundaries, as well as the continuity and cleanliness of grain boundaries, and whether there is an oxide film or impurity enrichment.

[0061] The characteristic parameters of copper rods reflect the fundamental properties of the material. These include dimensional characteristics such as geometric parameters and previous processing techniques; and compositional characteristics such as silver content and alloy element distribution. The specific methods for obtaining these parameters are as follows:

[0062] Geometric parameters: Use vernier calipers or laser diameter gauges to measure the diameter, length, cross-sectional shape, and surface defects of the copper rod;

[0063] Previous processing technology: Record the initial processing technology and deformation of the copper rod, as the processing history will affect the initial texture and residual stress state of the material;

[0064] Silver content detection: Inductively coupled plasma atomic emission spectrometry or X-ray fluorescence spectrometry is used to perform elemental quantitative analysis on copper rod samples, accurately determine the mass fraction of silver and the content of impurity elements, and ensure that the composition meets the oxygen-free copper standard;

[0065] Alloy element distribution: The uniformity of silver distribution in the copper matrix is ​​detected by electron probe microanalysis or energy dispersive spectroscopy to determine whether segregation occurs.

[0066] In this embodiment, the parameters obtained through step S1 directly reflect the unique characteristics of oxygen-free silver-containing copper rods. The microstructure characteristics determine the potential for grain refinement and grain boundary optimization during heat treatment. For example, copper rods with initially coarse grains may require higher heating temperatures or longer holding times to promote recrystallization. The characteristic parameters of copper rods (especially silver content and specifications) determine the thermodynamic behavior during heat treatment. For example, copper rods with high silver content need to control the cooling rate to avoid silver phase precipitation, which affects conductivity. Through precise detection methods, the limitations of traditional processes relying on empirical parameters are broken, providing input conditions for subsequent data-driven process optimization, ensuring that the heat treatment schemes for copper rods are tailored to the specific needs, and improving the treatment effect from the source.

[0067] In some embodiments of the present invention, the microstructural features and characteristic parameters of the copper rod are matched and located with a pre-built heat treatment process library to determine the initial heat treatment process parameter set suitable for the copper rod, ensuring that the initial process parameters can meet the specific requirements of the copper rod.

[0068] The heat treatment process library stores sets of heat treatment process parameters corresponding to different microstructure characteristics and copper rod characteristic parameters. The data in the process library is generated through experimental verification, theoretical calculation, or industrial experience accumulation, and is continuously improved through data analysis and optimization algorithms. Specifically, it includes initial heat treatment process parameter sets under different combinations of microstructure characteristics and copper rod characteristic parameters, such as heating temperature, holding time, and cooling rate. For example, for a copper rod with a silver content of 0.1%, a grain size of 100μm, and a diameter of 10mm, the corresponding initial process parameters might be a heating temperature of 800℃, a holding time of 60 minutes, and a cooling rate of 5℃ / min; for a copper rod with a silver content of 0.3%, a grain size of 50μm, and a diameter of 20mm, the corresponding initial process parameters might be a heating temperature of 850℃, a holding time of 90 minutes, and a cooling rate of 3℃ / min.

[0069] Specifically, the method for constructing the heat treatment process library is as follows: Collect a large amount of experimental data, actual production data, and relevant theoretical research results on the heat treatment of oxygen-free silver-containing copper rods under different combinations of microstructural features and copper rod characteristic parameters; the data must cover the correspondence between various process parameters such as heating temperature, holding time, and cooling rate and the final performance of the copper rod; systematically organize, analyze, and classify the collected data; use data mining and machine learning techniques to extract valuable information from the massive data, constructing a heat treatment process library with a certain logical structure and indexing method; the process library can quickly retrieve matching heat treatment process information based on the input copper rod characteristic parameters.

[0070] More specifically, the microstructural features and copper rod characteristic parameters are used as positioning conditions and matched with data in the process library. The output is an initial set of heat treatment process parameters that match the input data, including heating temperature, holding time, and cooling rate. The matching method uses a "layered screening + weighted matching" strategy to ensure positioning accuracy, and the specific implementation is as follows:

[0071] First, process ranges that are obviously mismatched are eliminated based on specifications. For example, copper rods with a diameter >20mm have low thermal conductivity, so the holding time needs to be increased by more than 20%. Process parameter ranges are limited based on composition characteristics. For example, when the silver content is >0.1%, the cooling rate needs to be ≤8℃ / s to avoid the formation of Ag2Cu precipitate, which would affect conductivity.

[0072] Matching weights are set for grain size, grain morphology, and grain boundary characteristics. The Euclidean distance algorithm is used to calculate the similarity between the copper rod to be processed and the samples in the process library. For example, if a copper rod has a grain size of 45μm (corresponding to the 30-50μm range in the process library) and a grain boundary silver segregation degree of 15% (segregation of similar samples in the library is ≤20%), then process parameters with similar segregation degrees in this range will be matched first.

[0073] For feature combinations that are not fully covered, such as novel irregular cross-section copper rods, the rule inference engine is activated: if the grains are coarse (>80μm) and the grain boundary cleanliness is high, the system automatically recommends "heating temperature = recrystallization temperature + 80℃, holding time = normal value × 1.5", which promotes grain breakage through overheating; if silver segregation at the grain boundary is detected to be >25%, the cooling rate is forcibly reduced to below 5℃ / s to delay the precipitation of silver phase.

[0074] Furthermore, after matching and positioning, an initial process plan containing three core parameters is generated:

[0075] Heating temperature: Based on the recrystallization temperature model and combined with grain size correction, for example, the heating temperature is increased by 20℃ for every 10μm coarsening of the initial grains to ensure that the grains are sufficiently refined; for example, the initial grains of a copper rod are 50μm, and the calculated recrystallization temperature is about 450℃. After correction, the heating temperature is set to 620℃, with a 170℃ superheat allowance.

[0076] Holding time: The temperature difference equilibrium time of the cross section is calculated according to the Fourier heat conduction equation and combined with the grain boundary migration kinetic formula to ensure uniform distribution of alloying elements;

[0077] Cooling rate: Based on the critical relationship between silver content and cooling rate, such as when the silver content is 0.08%, the critical cooling rate is 7℃ / s. Step cooling is adopted, with 10℃ / s in the high-temperature section and 5℃ / s in the low-temperature section to avoid precipitation of brittle phase.

[0078] The generated initial parameters are synchronized to the heat treatment equipment via a visual interface. The parameters are automatically verified to ensure their rationality before the heating program is started, such as that the temperature does not exceed the melting point of copper (1083℃) and the cooling rate matches the equipment capacity.

[0079] In this embodiment, a matching mechanism of "data-driven + knowledge fusion" is used to achieve a leap from "experience-dependent" to "precise mapping" in heat treatment process. Compared with traditional general process parameters, the initial parameters are improved to better match the individual characteristics of the copper rod, reducing performance fluctuations caused by parameter mismatch from the source. The "trial and error" debugging of traditional processes is avoided, the process planning time for a single batch is reduced, and production efficiency is improved. Reasonable initial conditions are laid for subsequent real-time dynamic adjustments, forming a closed-loop control of "detection-matching-processing-feedback".

[0080] As a preferred embodiment of the above solution, in the heat treatment process of oxygen-free silver-containing copper rods, due to various factors such as unstable equipment operation and subtle differences in the microstructure and composition of raw materials, the actual heat treatment situation may deviate from the expected result. Therefore, it is necessary to use multi-dimensional sensors and detection technologies to capture key parameters reflecting the evolution of the copper rod's microstructure and the process status in real time, providing real-time data support for subsequent deviation analysis and parameter adjustment.

[0081] Specifically, the heat treatment characteristic parameter set includes temperature field characteristic parameters, microstructure dynamic parameters, physical performance parameters, and process control parameters; the temperature field characteristic parameters include at least one of temperature gradient distribution and temperature change rate; the microstructure dynamic parameters include at least one of grain size, grain boundary migration rate, and silver element distribution characteristics; the physical performance parameters include at least one of residual stress field, dynamic conductivity value, and hardness distribution characteristics; and the process control parameters include at least one of oxygen content during the holding stage, equipment power, quenching medium flow rate, and quenching medium temperature.

[0082] More specifically, temperature gradient distribution is collected by embedding K-type thermocouples along the axial direction (head, middle, and tail) of the copper rod in the heat treatment furnace to form an array of 6-8 temperature measuring points, ensuring coverage of the temperature distribution along the length of the copper rod; the temperature at each point is recorded in real time at a frequency of 10Hz using a data acquisition card, and the axial temperature gradient is calculated.

[0083] Temperature change rate acquisition: During the heating and cooling stages, the real-time temperature change rate is calculated by the temperature difference between adjacent moments; specifically, the temperature change per unit time is calculated with a time interval of 10 seconds.

[0084] Grain size and grain boundary migration data were collected by using a miniature metallographic microscope in the furnace in conjunction with a high-speed camera to capture real-time images of the grains on the surface of the copper rod at 500x magnification. The equivalent diameter of the grains was measured by an image recognition algorithm, and the average grain size was output every 5 minutes. At the same time, feature points were tracked in the continuous image sequence, and the ratio of grain boundary migration distance to time was calculated to obtain the grain boundary migration rate, which directly reflects the grain growth dynamics.

[0085] Silver element distribution characteristics were collected by line scanning of the copper rod surface using X-ray fluorescence spectrometry to detect the real-time concentration distribution of silver element, with a focus on the segregation at grain boundaries; combined with electron backscatter diffraction technique of scanning electron microscopy, the copper rod was scanned periodically to analyze the enrichment degree of silver element in different grain boundary types, providing data support for judging the uniformity of alloy element distribution.

[0086] Residual stress field was acquired using an X-ray stress analyzer, with residual stress detected in three directions: axial, radial, and circumferential, on the surface of the copper rod. The stress values ​​were then calculated using Bragg's equation.

[0087] The conductivity dynamic value is acquired by using the four-probe method to measure the conductivity online. By applying a constant current at both ends of the copper rod and measuring the voltage drop of the middle probe, the real-time conductivity is calculated.

[0088] Hardness distribution characteristics were collected by using an electromagnetic induction hardness tester to scan the surface of the copper rod at 2mm intervals, measuring the Vickers hardness and plotting the distribution curve.

[0089] Oxygen content is collected during the heat treatment stage by installing an infrared oxygen sensor inside the heat treatment furnace to monitor the oxygen content in the furnace in real time.

[0090] Equipment power and energy consumption are collected by installing current and voltage sensors at the heating power supply end to collect the heating equipment power in real time and calculate the unit energy consumption based on the mass of the copper rod.

[0091] Quenching medium parameters are collected by monitoring the flow rate of the quenching medium using an electromagnetic flowmeter and measuring the temperature of the quenching medium using a platinum resistance thermometer.

[0092] By collecting the aforementioned heat treatment characteristic parameter set in real time, we can comprehensively and dynamically understand the actual state of oxygen-free silver-containing copper rods during the heat treatment process. On the one hand, this data can be compared with preset target characteristic indicators. If a deviation is found, step S4 can be triggered in time to calculate the deviation and adjust the parameters accordingly. On the other hand, the long-term accumulation of data helps to further optimize the heat treatment process library, improve the accuracy and reliability of process matching, and provide a more complete reference for the heat treatment of more batches of oxygen-free silver-containing copper rods in the future.

[0093] In some embodiments of the present invention, based on the expected performance of the oxygen-free silver-containing copper rod, specific target characteristic indicators are set for various heat treatment characteristic parameters, such as temperature field characteristic parameters, microstructure dynamic parameters, physical performance parameters, and process control parameters. Simultaneously, a preset time for judging deviations is determined. This preset time is not arbitrarily set, but is determined by comprehensively considering the time characteristics of each stage in the heat treatment process and the general laws of microstructure changes, ensuring that potential deviations can be captured in a timely manner at critical time points.

[0094] Specifically, the preset time is a dynamic response time window, which satisfies the following calculation formula:

[0095] ;

[0096] Among them, t preset The preset time is represented by d; the real-time grain size is represented by d; K0 represents the grain growth rate constant, an intrinsic material parameter characterizing the grain boundary migration rate of the Ag-Cu system; Q represents the grain boundary migration activation energy, reflecting the hindering effect of silver atoms on the recrystallization process of the copper matrix; R represents the gas constant, a universal constant in thermodynamic calculations; T represents the real-time temperature of the copper rod surface in the heat treatment furnace; α represents the thermal hysteresis compensation factor, used to correct the deviation of temperature field fluctuations on grain growth prediction; ΔD represents the absolute difference between the current grain size and the target value; D target The target grain size is the ideal grain diameter set according to the product performance requirements.

[0097] The formula incorporates real-time grain size d, real-time temperature T, and the absolute difference ΔD between the current grain size and the target value. This allows for real-time adjustment of the preset time based on the actual state of grain growth, temperature changes, and the gap with the target during heat treatment, rather than using a fixed value. This makes the preset time more closely match the actual process, improving the flexibility and accuracy of time setting. By using intrinsic material parameters such as the grain growth rate constant K0 and the grain boundary migration activation energy Q, the formula fully considers the grain boundary migration rate of the Ag-Cu system and the hindering effect of silver atoms on the recrystallization of the copper matrix. This ensures that the calculation of the preset time conforms to the principles of materials science and more accurately reflects the inherent laws of grain growth under this system. The thermal hysteresis compensation factor α can correct the deviation of temperature field fluctuations in grain growth prediction, ensuring that the preset time can still be reasonably adjusted when the temperature is unstable. This reduces the time setting error caused by temperature interference and enhances the robustness of the calculation model.

[0098] Furthermore, the preset target characteristic index refers to the ideal value or target range set for the heat treatment characteristic parameter set during the heat treatment process; the preset target characteristic index is determined based on the microstructural characteristics of the copper rod, the characteristic parameters of the copper rod, and the final performance requirements, specifically including:

[0099] Target ranges for temperature gradient distribution; target values ​​for temperature change rates, such as the target heating rate during the heating stage and the target cooling rate during the cooling stage; target ranges for grain size, such as refining to the target grain size; target values ​​for grain boundary migration rates, such as the speed at which grain boundaries migrate to the target location; target values ​​for silver element distribution characteristics, such as the uniformity of silver element distribution at grain boundaries; target values ​​for residual stress fields, such as residual stress approaching zero; target ranges for dynamic conductivity values, such as achieving high conductivity standards; target values ​​for hardness distribution characteristics, such as uniform hardness distribution meeting design requirements; target ranges for oxygen content during the heat preservation stage, such as below a certain threshold to avoid oxidation; target values ​​for equipment power, such as ensuring stable heating power; and target values ​​for quenching medium flow rate and temperature, such as ensuring uniform cooling rate meeting process requirements.

[0100] If a certain heat treatment characteristic parameter fails to meet the preset target characteristic index, it is marked as a non-compliant parameter. For each non-compliant parameter, the deviation value between it and the target value is calculated. The deviation value can be positive (actual value is higher than the target value) or negative (actual value is lower than the target value). The deviation values ​​of all non-compliant features are organized into an n-dimensional vector in a preset order to form a heat treatment deviation vector. The deviation vector is a quantitative description of the deviation from the expected situation during the heat treatment process. If the deviation of a certain feature exceeds twice the allowable range, it is considered a serious anomaly and is marked as an extreme value in the vector, triggering an emergency control mechanism.

[0101] In this embodiment, by quantifying deviations and using structured representation, complex process anomalies are transformed into calculable mathematical vectors, which is beneficial for subsequent precise control. The heat treatment deviation vector covers four dimensions: temperature, structure, performance, and equipment, avoiding the one-sidedness of monitoring a single parameter. For example, by combining grain size deviation and conductivity deviation simultaneously, it is possible to accurately determine whether the performance degradation is caused by grain coarsening or silver segregation. The deviation weight can also be adjusted according to the characteristics of the copper rod to ensure the targeted nature of the control strategy. The deviation vector serves as an intermediate variable, connecting the logical chain of real-time monitoring and parameter adjustment, enabling the control algorithm to be iteratively optimized based on historical deviation data, gradually improving the robustness of the process. This is the core link in realizing the "perception-analysis-decision" closed loop of the heat treatment process. Through precise deviation quantification, the scientific nature and effectiveness of subsequent control actions are ensured, ultimately achieving a stable improvement in the heat treatment quality of oxygen-free silver-containing copper rods.

[0102] In some embodiments of the present invention, based on the heat treatment deviation vector generated in step S4, the initial heat treatment process parameter set is dynamically adjusted to generate an optimal heat treatment process parameter set, and the oxygen-free silver-containing copper rod is heat-treated accordingly, specifically including:

[0103] The heat treatment deviation vector is analyzed, and the signs of the process parameters in the vector are used to determine whether the parameters exceed the target value (positive value) or fail to reach the target value (negative value). For example, a positive deviation in temperature change rate indicates that the actual heating rate is too fast; a negative deviation in grain boundary migration rate indicates that the grain boundary migration speed is too slow. Weights are assigned to different deviation values ​​based on the degree of influence of the process parameters on the copper rod's performance. For example, grain size has a significant impact on the strength and toughness of the copper rod, so its deviation weight is relatively high; oxygen content during the heat treatment stage has a significant impact on conductivity, so its deviation weight is also relatively high.

[0104] Based on the analysis results of the deviation vector, the initial heat treatment process parameter set is adjusted to make the process parameters closer to the target characteristic indicators. The control strategy needs to comprehensively consider the magnitude, weight and severity of the deviation value to ensure that the adjusted process parameters can effectively improve the non-compliant characteristics.

[0105] Specifically, for heating temperature control, adjustments are made based on deviations in the deviation vector, such as those related to the temperature field and microstructure. If the temperature change rate during the heating stage is lower than the target value, such as a negative temperature change rate term in the deviation vector and slow grain size growth with a negative grain size deviation, the heating temperature is appropriately increased to increase superheat and promote grain refinement and grain boundary migration. For example, if the initial heating temperature is 600℃, and the temperature change rate deviation is -1.5℃ / s and the grain size has not reached the target, the temperature can be adjusted to 620℃. If the temperature gradient distribution is abnormal, such as a radial temperature gradient in a certain region being greater than the target value, the heating power is adjusted through zoned temperature control to balance the temperature field, rather than directly changing the overall heating temperature.

[0106] For heat preservation time control, dynamic adjustments are made based on deviations such as grain size and grain boundary migration rate. If the grain size does not meet the target during the heat preservation stage, such as a deviation vector showing a grain size deviation of -5μm and a grain boundary migration rate lower than expected, the heat preservation time is extended, for example, by increasing it by 10%-20% of the original time. For instance, if the initial heat preservation time is 60 minutes, it can be extended to 66-72 minutes to ensure sufficient grain homogenization. If the silver element distribution characteristics do not meet the standard, such as a grain boundary silver segregation deviation of +8%, while extending the heat preservation time, the heating temperature can be reduced by 5-10℃ to slow down the silver element segregation trend and promote its uniform diffusion.

[0107] For cooling rate control, optimization is performed based on deviations such as silver element distribution and residual stress. If the silver element segregation exceeds the standard, such as abnormal silver element distribution characteristic terms in the deviation vector, the cooling rate is reduced to delay the formation of Ag2Cu precipitate phase and improve conductivity. If the residual stress field deviation is large, such as residual stress exceeding the target value of 20MPa, a stepped cooling adjustment is adopted: the high-temperature section maintains the original cooling rate for rapid cooling, and the low-temperature section reduces the cooling rate to release internal stress.

[0108] The adjusted parameters need to be verified for rationality, including physical constraint verification and process compatibility verification; the heating temperature must be lower than the melting point of copper and a safety threshold must be reserved; the cooling rate must be within the equipment's capacity; check whether the adjusted parameter combination conforms to the logic of the heat treatment stage; for example, after the heating temperature is increased, the holding time needs to be adjusted accordingly to ensure sufficient heat conduction; after the cooling rate is changed, the control parameters such as the quenching medium flow rate and temperature need to be matched synchronously; after the verification is passed, the optimal heat treatment process parameter set is transmitted to the heat treatment equipment for execution, and the status of the copper rod is monitored in real time to ensure that the heat treatment process is accurate and controllable.

[0109] In this embodiment, dynamic optimization of the heat treatment process is achieved through a logical chain of "deviation vector - parameter control - verification implementation": differentiated control strategies are formulated for different deviations to avoid the traditional "one-size-fits-all" adjustment. For example, adjusting the cooling rate alone can solve the silver segregation problem without affecting the grain refinement effect during the heating stage. The interaction between heating temperature, holding time, and cooling rate is comprehensively considered. For example, the holding time is shortened after increasing the temperature, or the holding time is extended when the cooling rate is reduced, to ensure the overall coordination of the process. Parameter conflicts are eliminated through a verification mechanism, such as excessively high temperature or cooling rate not supported by the equipment, so that the adjusted parameters meet both quality requirements and engineering feasibility.

[0110] In some solutions, multiple embodiments of this application can be combined, and the combined solution can be implemented. Optionally, some operations in the processes of each method embodiment may be combined, and / or the order of some operations may be changed. Furthermore, the execution order between the steps of each process is merely exemplary and does not constitute a limitation on the execution order between steps; other execution orders are also possible. It is not intended to indicate that the execution order is the only possible order in which these operations can be performed. Those skilled in the art will conceive of various ways to reorder the operations described herein. In addition, it should be noted that the process details involved in one embodiment of this document are similarly applicable to other embodiments, or different embodiments may be combined.

[0111] Furthermore, some steps in the method embodiments can be equivalently replaced with other possible steps. Alternatively, some steps in the method embodiments may be optional and can be deleted in certain use cases. Or, other possible steps may be added to the method embodiments. Moreover, the various method embodiments can be implemented individually or in combination.

[0112] like Figure 2 As shown, the present invention also provides a system for optimizing process parameters of oxygen-free silver-containing copper rod heat treatment, which specifically includes the following modules;

[0113] The parameter acquisition module is used to acquire the microstructure characteristics and copper rod property parameters of the oxygen-free silver-containing copper rod to be heat-treated; wherein, the microstructure characteristics at least cover grain size, grain morphology and grain boundary characteristics; the copper rod property parameters at least include specification characteristics and composition characteristics;

[0114] The parameter matching and positioning module is used to match and locate microstructure features and copper rod characteristic parameters as positioning conditions in a pre-built heat treatment process library to determine the initial heat treatment process parameter set. The initial heat treatment process parameter set includes at least heating temperature, holding time and cooling rate, and this parameter set is used for the heat treatment of oxygen-free silver-containing copper rods.

[0115] The real-time acquisition module is used to acquire the set of heat treatment characteristic parameters of the oxygen-free silver-containing copper rod in real time during the heat treatment process.

[0116] The deviation calculation module is used to determine whether at least one heat treatment feature in the set of heat treatment feature parameters fails to meet the preset target feature index within a preset time. If there is a failure to meet the target, the deviation value of all the failure heat treatment features is calculated and converted into a heat treatment deviation vector.

[0117] The parameter control module is used to control the initial heat treatment process parameter set determined by the parameter matching and positioning module based on the heat treatment deviation vector obtained by the deviation calculation module, to obtain the optimal heat treatment process parameter set, and to use the optimal parameter set to perform heat treatment on the oxygen-free silver-containing copper rod.

[0118] In this embodiment, the parameter acquisition module and the parameter matching and positioning module work together to accurately match the initial heat treatment process parameter set from the process library based on the unique microstructure characteristics and properties of each oxygen-free silver-containing copper rod. This changes the previous extensive approach that relied on experience or general standards, effectively solving the problem that uniform process parameters cannot achieve optimal results due to individual differences in copper rods. It improves the adaptability of the process to different copper rods, ensuring that each copper rod receives a relatively suitable initial heat treatment scheme. The real-time acquisition module and the deviation calculation module work together to monitor the heat treatment characteristic parameters of the copper rod in real time during the heat treatment process. Once a parameter deviation from the preset target is detected, the deviation calculation module quickly calculates the deviation. The deviation is converted into a vector, enabling the parameter control module to adjust the initial process parameters in a timely manner based on the deviation vector to obtain the optimal parameter set. The entire process can dynamically correct parameter deviations caused by factors such as equipment status and raw material differences, effectively ensuring the stability of the final copper rod performance, reducing performance fluctuations caused by process deviations, and improving product quality consistency. The system has a real-time monitoring and adjustment mechanism, which can flexibly respond to complex and ever-changing production environments, whether it is changes in equipment operating status or subtle differences in the microstructure and composition of raw materials. By dynamically adjusting parameters, the heat treatment process is always kept in an optimal state, enhancing the flexibility of the process and its adaptability to different production scenarios.

[0119] This embodiment divides functional modules according to the method example described above. For example, each function can be divided into its own functional modules, or two or more functions can be integrated into one processing module. The integrated modules can be implemented in hardware. It should be noted that the module division in this embodiment is illustrative and only represents one logical functional division; other division methods may be used in actual implementation.

[0120] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for optimizing heat treatment process parameters of oxygen-free silver-containing copper rods, characterized in that, include: The microstructure characteristics and property parameters of the oxygen-free silver-containing copper rod to be heat-treated are obtained; the microstructure characteristics include at least grain size, grain morphology and grain boundary characteristics. The characteristic parameters of the copper rod include at least its specifications and composition. Using the microstructural features and copper rod characteristic parameters as positioning conditions, the system performs matching and positioning in a pre-built heat treatment process library to determine the initial heat treatment process parameter set, and then uses this set to perform heat treatment on the oxygen-free silver-containing copper rod. During the heat treatment process, the heat treatment characteristic parameter set of oxygen-free silver-containing copper rods is collected in real time; In response to the fact that at least one heat treatment feature in the set of heat treatment feature parameters fails to meet the preset target feature index within a preset time, the deviation values ​​of all the heat treatment features that fail to meet the target are calculated and converted into a heat treatment deviation vector. Based on the heat treatment deviation vector, the initial heat treatment process parameter set is adjusted to obtain the optimal heat treatment process parameter set, and the oxygen-free silver-containing copper rod is heat-treated accordingly. The preset time is a dynamic response time window, which satisfies the following calculation formula: ； Among them, t preset This refers to the preset time; d represents the real-time grain size; K0 represents the grain growth rate constant, an intrinsic material parameter characterizing the grain boundary migration rate of the Ag-Cu system; Q represents the grain boundary migration activation energy, reflecting the hindering effect of silver atoms on the recrystallization process of the copper matrix; R represents the gas constant, a universal constant in thermodynamic calculations; T represents the real-time temperature of the copper rod surface in the heat treatment furnace; α represents the thermal hysteresis compensation factor, used to correct the deviation of temperature field fluctuations on grain growth prediction; ΔD represents the absolute difference between the current grain size and the target value; D target The target grain size is the ideal grain diameter set according to the product performance requirements.

2. The method for optimizing the heat treatment process parameters of oxygen-free silver-containing copper rods according to claim 1, characterized in that, The initial heat treatment process parameter set includes at least heating temperature, holding time, and cooling rate.

3. The method for optimizing the heat treatment process parameters of oxygen-free silver-containing copper rods according to claim 1, characterized in that, The set of heat treatment characteristic parameters includes temperature field characteristic parameters, microstructure dynamic parameters, physical performance parameters, and process control parameters.

4. The method for optimizing the heat treatment process parameters of oxygen-free silver-containing copper rods according to claim 3, characterized in that, The temperature field characteristic parameters include at least one of temperature gradient distribution and temperature change rate; The microstructure dynamic parameters include at least one of grain size, grain boundary migration rate, and silver element distribution characteristics. The physical performance parameters include at least one of the following: residual stress field, dynamic conductivity value, and hardness distribution characteristics. The process control parameters include at least one of the following: oxygen content during the heat preservation stage, equipment power, quenching medium flow rate, and quenching medium temperature.

5. The method for optimizing the heat treatment process parameters of oxygen-free silver-containing copper rods according to claim 1, characterized in that, The heat treatment process library is used to store the initial heat treatment process parameter set under different combinations of microstructure features and copper rod characteristic parameters. The heat treatment process library is based on a preset indexing method and retrieves the initial heat treatment process parameter set that matches the input copper rod feature parameters.

6. The method for optimizing the heat treatment process parameters of oxygen-free silver-containing copper rods according to claim 5, characterized in that, The preset indexing methods in the heat treatment process library include: Based on the specifications and characteristics of the copper rod to be processed, a set of initial heat treatment process parameters that match it is selected and marked as the first-order initial heat treatment process parameter set. Matching weights are set for grain size, grain morphology and grain boundary characteristics respectively, and the similarity between the copper rod to be processed and all the first-order initial heat treatment process parameter sets is calculated. The set of first-order initial heat treatment process parameters with the highest similarity is used as the set of initial heat treatment process parameters for the copper rod to be treated.

7. The method for optimizing the heat treatment process parameters of oxygen-free silver-containing copper rods according to claim 3, characterized in that, The method for acquiring the temperature gradient distribution in the temperature field characteristic parameters includes: A preset number of temperature sensors are installed along the axis of the copper rod inside the heat treatment furnace; Based on a preset frequency, the monitored temperatures of each temperature sensor are collected. The axial temperature gradient of the copper rod is calculated based on the collected monitoring temperature.

8. A system for optimizing process parameters of oxygen-free silver-containing copper rod heat treatment, wherein the system is applied to the method for optimizing process parameters of oxygen-free silver-containing copper rod heat treatment as described in claim 1, characterized in that, The system includes: The parameter acquisition module is used to acquire the microstructural characteristics and property parameters of the oxygen-free silver-containing copper rod to be heat-treated. The parameter matching and positioning module is used to match and locate microstructure features and copper rod characteristic parameters as positioning conditions in a pre-built heat treatment process library to determine the initial heat treatment process parameter set. The real-time acquisition module is used to acquire the set of heat treatment characteristic parameters of the oxygen-free silver-containing copper rod in real time during the heat treatment process. The deviation calculation module is used to determine whether at least one heat treatment feature in the set of heat treatment feature parameters fails to meet the preset target feature index within a preset time. If there is a failure to meet the target, the deviation value of all the failure heat treatment features is calculated and converted into a heat treatment deviation vector. The parameter control module is used to control the initial heat treatment process parameter set based on the heat treatment deviation vector obtained by the deviation calculation module, to obtain the optimal heat treatment process parameter set, and to perform heat treatment on the oxygen-free silver-containing copper rod accordingly.

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