A short-process preparation process design and optimization method for brass wire

Abstract

The present invention relates to a brass wire short-process preparation process design and optimization method, including high strain rate compression on a thermal simulator; constructing a brass constitutive equation and thermal deformation processing diagram under high strain rate conditions; constructing a brass wire isothermal reverse extrusion digital simulation system, optimizing the extrusion process and die structure for the digital simulation system; on this basis, performing isothermal reverse extrusion of the brass wire with a large extrusion ratio, repeatedly iterating and correcting through a digital simulation system and experimental measurements, and optimizing the process; collecting a large amount of brass wire isothermal reverse extrusion production data, using neural network mapping to construct a brass wire process-organization-performance correspondence, constructing a brass wire short-process preparation big database, and screening and iteratively optimizing the extrusion process through the big database. The present invention is oriented to a digital integrated optimization process, and produces brass wires with good surface quality, fine and uniform organization, excellent comprehensive performance, high yield rate, and high production efficiency.

Description

Technical Field

[0001] The invention relates to a short-process preparation process design and optimization method for a brass wire, and belongs to the field of nonferrous metal processing and forming. Background Art

[0002] Copper is one of the earliest metal materials known and used by humans. It has a strong alloying ability and can form alloys with most metal elements. It is one of the key engineering materials indispensable for the development of industrial informatization. It has strongly promoted the development of modern science and technology and has attracted great attention from the scientific and technological community and the industrial community. With the practical application of new products and new technologies, there are more and more varieties of copper alloys, the application fields of products are becoming more and more refined, the requirements for performance are getting higher and higher, the production cost requirements are getting lower and lower, and the energy consumption is getting lower and lower. Low-energy green preparation and processing is the eternal driving force for technological updates. The copper industry is developing in the direction of greening, low carbonization, refinement, and conservation.

[0003] Brass is a copper alloy with zinc as the main element. It is also the most important alloy variety among copper alloys and is known for its low cost and high performance. Brass has excellent thermal conductivity, mechanical properties, processing properties, and corrosion resistance. It is widely used in various fields of the national economy, such as water tank belts, water supply and drainage pipes, medals, bellows, serpentine pipes, condensers, shells, and various complex-shaped punching products, small hardware parts, etc. Ordinary brass is a copper-zinc binary alloy. Its zinc content varies in a wide range, so its room temperature structure is also very different. In order to improve the corrosion resistance, strength, hardness and machinability of brass, a small amount of tin, aluminum, manganese, iron, silicon, nickel, lead and other elements are added to the copper-zinc alloy to form a ternary, quaternary, or even quinary alloy, which is a special brass. Adding tin to brass can significantly improve the heat resistance of the alloy, especially the ability to resist seawater corrosion and marine atmospheric corrosion. Brass wire has strong wear resistance, high strength, high hardness, strong chemical corrosion resistance, outstanding cutting mechanical properties, good electrical conductivity and thermal conductivity. It is widely used in the manufacture of wires, cables, brushes, hardware, magnetic instruments that must be protected from magnetic interference, electronic appliances, and instruments such as compasses and aviation instruments.

[0004] At present, the main production processes of brass wire are extrusion + multi-pass drawing, continuous casting + rolling + drawing, and continuous casting + drawing. Among them, the continuous casting + drawing process has the remarkable feature of short process, but the plastic deformation processing of the material in this process is relatively small, the alloy structure refinement effect is limited, and the comprehensive performance of the product is relatively low; the continuous casting + rolling + drawing process adds a rolling process, and the production process is complicated; brass is refined after large extrusion deformation, which significantly improves the comprehensive performance of the material. The extruded rod is drawn through multiple passes to obtain wire, and the preparation process is long and energy consumption is high. The preparation processes of brass wire have their own advantages. Since the extrusion + drawing process shows significant advantages in the comprehensive performance of the product, it is still the mainstream process for the preparation of brass wire. In order to shorten the process and reduce energy consumption, brass wires have been prepared by extrusion + a small amount of drawing or direct extrusion, which greatly shortens the preparation process. Reducing subsequent drawing or directly extruding into wires will inevitably increase the extrusion ratio. A large extrusion ratio obviously increases the extrusion force, resulting in an increase in extrusion energy consumption. The use of a large extrusion ratio and large plastic deformation can theoretically significantly refine the organization; if the extrusion process is not properly controlled, a large extrusion ratio and large plastic deformation will cause a large amount of plastic deformation heat, significantly increase the deformation temperature, and excessively high deformation temperature will cause overheating or even overburning, coarsening the organization and significantly reducing the comprehensive performance of the wire; if the extrusion process is not properly controlled, a large extrusion ratio and large plastic deformation will inevitably cause greater uneven deformation, resulting in poor consistent performance of the wire. Numerical simulation calculations show that during the extrusion process of brass wire with a large extrusion ratio, the material deforms under high strain rate conditions and is formed at the limit edge of the physical deformation of brass. It is very easy to cause unstable deformation, low product dimensional accuracy, and easy to crack, which can easily lead to product scrapping. Research and development of energy-saving, short-process, high-quality brass wire extrusion preparation and processing technology has significant economic and social benefits. A search of existing technical literature found that there are few patents involving systematic research on the design and optimization methods of short-process preparation processes for brass wires.

[0005] Therefore, it is necessary to develop a short-process preparation process design and optimization method for brass wire to solve the problems of coarsening structure, cracking, poor comprehensive performance, etc. of brass wire prepared in the short process, improve the quality and extrusion yield of brass wire, reduce costs, reduce energy consumption, and realize green, low-carbon, refined, economical, and large-scale production of brass wire. Summary of the invention

[0006] The purpose of the present invention is to overcome the technical bottleneck of brass wire short-process preparation and processing, and to provide a brass wire short-process preparation process design and optimization method. The thermal deformation behavior of brass under high strain rate conditions is studied, and the true stress-strain curve of brass under high strain rate conditions is obtained on a thermal simulator, and the constitutive equation of brass under high strain rate conditions is established, and the processing diagram of brass under high strain rate conditions is constructed to determine the thermal deformation process parameters suitable for brass processing under high strain rate conditions; a three-dimensional model of brass high extrusion ratio extrusion numerical simulation is constructed, and simulation calculations are performed to obtain the physical forming limit conditions of brass high extrusion ratio and determine the brass high extrusion ratio forming process window; test points are selected within the process window, and the isothermal reverse extrusion process conditions of brass high extrusion ratio are determined by simulation calculations, and on this basis, a brass wire high extrusion ratio isothermal reverse extrusion test is carried out, and the microstructure of the brass wire is characterized by advanced testing methods such as scanning electron microscopy and transmission electron microscopy, and the conventional mechanical properties, impact properties, fatigue properties, etc. of the brass wire are comprehensively evaluated. Repeated experiments were carried out to collect production process data, microstructure and performance data during the extrusion process, and a database of isothermal reverse extrusion process parameters and wire performance of brass wire with a large extrusion ratio was established. According to customer demand for wire, the extrusion process parameters of isothermal reverse extrusion of brass wire with a large extrusion ratio were screened and optimized through big data, and the production process was monitored and precisely controlled in real time. At the same time, neural network mapping was used to establish the relationship between extrusion process, die structure, die material and product-specific performance, cost and energy consumption. The high strain rate thermal deformation characteristics of brass, numerical calculation simulation, physical forming limit of brass with a large extrusion ratio, online monitoring, big data collection, and advanced material testing and characterization technology were integrated to design a high extrusion ratio isothermal reverse extrusion process for brass wire for digital integrated optimization, to solve the problems of coarsening, cracking, and low dimensional accuracy of brass wire preparation in a short process, to significantly shorten the brass wire preparation process, to improve the quality and yield of brass wire, to reduce costs, and to achieve green large-scale production.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] A brass wire short-process preparation process design and optimization method comprises the following steps:

[0009] (1) Machining horizontal continuous casting brass ingots to prepare high strain rate compression test specimens, performing high strain rate compression on a thermal simulator, and obtaining true stress and true strain curves of brass under high strain rate deformation conditions;

[0010] (2) using the true stress and true response obtained in step (1) to establish the constitutive equation of brass under high strain rate deformation conditions, using the material dynamic model to construct a high strain rate thermal deformation processing diagram, analyzing and characterizing the microstructure of brass under high strain rate conditions, and determining the process conditions suitable for high strain rate deformation;

[0011] (3) According to the wire size specifications, three-dimensional drawing software is used to three-dimensionally graph the high extrusion ratio reverse extrusion process of the brass wire on a computer, and the established three-dimensional graph is imported into the simulation software, and the high strain rate constitutive equation of step (2) is used to simulate and calculate the high extrusion ratio reverse extrusion process of the brass wire, and a digital system for the extrusion process is constructed. In this system, digital characterization is performed under different process parameter conditions to determine the digital extrusion physical forming limit, and the digital brass wire high extrusion ratio isothermal reverse extrusion process parameters are obtained by digitally optimizing the extrusion process and the die structure;

[0012] (4) using the digital extrusion process parameters obtained in step (3), performing isothermal reverse extrusion of the brass wire at a large extrusion ratio, and monitoring the extrusion outlet temperature, wire size fluctuation range, and wire surface quality online in real time, and comparing the extrusion outlet temperature and wire size accuracy with the digitally calculated data, optimizing the process through repeated iterative corrections through digitalization and experimental measurements;

[0013] (5) Use advanced material testing and characterization technology to analyze the microstructure and comprehensive properties of extruded wire and digitize the structure and properties;

[0014] (6) By collecting a large database of extrusion process parameters such as extrusion temperature and speed, die structure parameters, die material performance parameters, wire size, performance, etc., neural network mapping is used to construct the process-structure-performance correspondence of brass wire, and the extrusion process is optimized through screening and iteration through the large database.

[0015] A preferred technical solution is characterized in that: in the brass high strain rate high temperature compression test described in step (1), the temperature range is 500-750°C, the temperature interval is 40-50°C, and the strain rate range is 15s -1 ~50s -1 , strain rate interval is 5s -1 ~10s -1 .

[0016] A preferred technical solution is characterized in that: the specific process of step (2) is: using the Arrhenius model to establish the high strain rate constitutive equation of brass, using the Murty instability criterion of the dynamic material model to obtain the high strain rate thermal deformation processing diagram of the brass component, using advanced testing and characterization methods such as electron backscatter diffraction and transmission electron microscopy to analyze the microstructure of brass under high strain rate thermal deformation conditions, and combining the microstructure and thermal processing diagram to determine the deformation conditions suitable for processing and the occurrence of instability during high strain rate thermal deformation of brass.

[0017] A preferred technical solution is characterized in that: the reverse extrusion of the brass wire described in step (3) adopts a porous extrusion die, and the digital simulation system of the extrusion process constructed on the computer visualizes the entire extrusion process, accurately calculates the distribution of related field quantities such as extrusion force, extrusion temperature field, stress field and strain rate field, and can quantitatively characterize the uniformity of extrusion deformation. Through digital optimization, the deformation uniformity is improved; the digital extrusion physical forming limit can be characterized by an extrusion forming limit curve (extrusion outlet temperature overheating, microstructure coarsening, and low dimensional accuracy).

[0018] A preferred technical solution is characterized in that: the extrusion outlet temperature fluctuation range of the brass wire large extrusion ratio isothermal reverse extrusion process described in step (4) is less than ±10°C, the isothermal reverse extrusion deformation is uniform, the additional stress is significantly reduced, the forming is labor-saving, the load is low, and the energy consumption is low;

[0019] A preferred technical solution is characterized in that: the digital characterization of the organization and performance described in step (5) is that the microstructure of the brass wire is described digitally, such as the grain size is represented by the grain size, the high-angle grain boundary is represented by 15°, the low-angle grain boundary is described by the data between 2 and 15°, and the special grain boundary is described by ∑3, ∑9, ∑27; conventional mechanical properties and impact properties can be represented by specific numerical values ​​of yield strength, tensile strength, elongation, cross-sectional shrinkage, hardness, impact energy, etc.;

[0020] A preferred technical solution is characterized in that: the big database described in step (6) is collected from multiple batches of extrusion production, and the big data includes: composition data of brass billets, ingot heating process data (heating time, insulation time), mold structure parameters, mold material, mold preheating temperature, extrusion pad preheating temperature, extrusion billet temperature, extrusion outlet temperature, brass wire specifications, extrusion ratio, extrusion speed, extrusion pressure, extrusion strain rate, wire structure characteristic data, wire conventional mechanical properties, impact properties, cutting properties, etc.;

[0021] A preferred technical solution is characterized in that: the mold material described in step (6) is a nickel-based high-temperature and cobalt-based high-temperature alloy material with excellent high-temperature performance, which prevents the extrusion mold from deforming under high strain rate, high temperature and high load, thereby ensuring the dimensional accuracy of the wire.

[0022] The advantages of the present invention are:

[0023] The present invention adopts a porous die isothermal reverse extrusion process to prepare brass wire, and is oriented to digital integration of brass high strain rate thermal deformation characteristics, numerical calculation simulation, brass large extrusion ratio physical forming limit, online monitoring, big data collection, and material advanced testing and characterization technology, so as to realize green, low-carbon, refined, economical, low-cost, high-quality large-scale production of brass wire, solve the problems of coarsened structure, cracking, poor comprehensive performance, etc. of brass wire prepared by short process, and improve the quality and extrusion yield of brass wire.

[0024] The extrusion process is most suitable for the preparation and processing of high-quality rods and wires. The wire extrusion process is simple, low in cost, high in production efficiency, and good in surface quality of the extruded wire. Casting defects are eliminated through extrusion with a large extrusion ratio, and the structure is significantly refined. During isothermal forming, the material deformation temperature is uniform, the deformation is uniform, and the prepared wire structure is fine and uniform, which greatly improves the overall performance of the product. During reverse extrusion, the metal flow direction is opposite to the axial movement direction of the extrusion rod. There is no relative sliding between the metal ingot and the extrusion barrel, the friction is small, the required extrusion force is small, and the energy consumption is reduced. During reverse extrusion, the metal flow is mainly concentrated in the area near the die hole, so the deformation of the metal along the length of the wire is relatively uniform, the additional stress is small, and the wire has good consistent performance. The process design and optimization method of the present invention are suitable for large-scale production, and have significant economic and social benefits.

[0025] The present invention is further described below through specific implementation modes, but it is not intended to limit the protection scope of the present invention. DETAILED DESCRIPTION

[0026] Example 1

[0027] The horizontal continuous casting HPb59-1 recycled brass ingot was machined to obtain high temperature compression specimens, and high temperature compression tests were carried out on a thermal simulator. The temperature range of high temperature compression was 550-700℃, the temperature interval was 50℃, and the strain rate was 15s -1 , 20s -1 , 25s -1 , 30s -1 The Arrhenius model is used to establish the high strain rate constitutive equation of brass, and the Murty instability criterion of the dynamic material model is used to obtain the high strain rate thermal deformation processing diagram of brass components. The microstructure of brass under high strain rate thermal deformation conditions is analyzed by advanced test characterization methods such as electron backscatter diffraction and transmission electron microscopy. By combining the microstructure and thermal processing diagram, it is determined that the temperature range for high strain rate thermal processing of HPb59-1 recycled brass is 630-680℃, and the strain rate range is 18-25s. -1 .

[0028] The three-dimensional drawing software is used to visualize the high extrusion ratio reverse extrusion process of brass wire on the computer, and the established three-dimensional graphics are imported into the simulation software to build a digital simulation system for the extrusion process. In this system, digital characterization is performed under different process parameters to determine the physical forming limit of digital extrusion. By digitally optimizing the extrusion process and die structure, the digitally optimized isothermal reverse extrusion process parameters of brass wire with high extrusion ratio are obtained: the extrusion temperature is 655-680℃, the speed is 15-25mm / s, and the extrusion outlet temperature is ±7℃-±10℃; the extrusion die is a 4-hole die, the extrusion material is NiMoWNb high-temperature alloy material, and the length of the die sizing belt is 5mm-7mm. In this extrusion process window, test points are selected for extrusion tests to test and characterize the microstructure and performance of the extruded wire. A large amount of extrusion production data is collected, and the corresponding relationship between the process, microstructure and performance of brass wire is constructed by neural network mapping. The extrusion process is screened and iteratively optimized through a large database. The further optimized extrusion process parameters are: extrusion temperature of 665℃, speed of 18-23mm / s, extrusion outlet temperature of ±9℃; die sizing belt length of 6.5mm-7mm. Under this condition, the surface quality and comprehensive performance of the extruded brass wire are good, and the production efficiency is high; compared with traditional extrusion, the extrusion force can be reduced by 35% and the yield rate can be increased by 35%.

[0029] Example 2

[0030] The horizontal continuous casting H59 recycled brass ingot was machined to obtain high temperature compression specimens, and high temperature compression tests were carried out on a thermal simulator. The temperature range of high temperature compression was 500-660℃, the temperature interval was 40℃, and the strain rate was 20s -1 , 25s -1 , 30s -1 , 35s -1 The Arrhenius model is used to establish the high strain rate constitutive equation of brass, and the Murty instability criterion of the dynamic material model is used to obtain the high strain rate thermal deformation processing diagram of brass components. The microstructure of brass under high strain rate thermal deformation conditions is analyzed by advanced test characterization methods such as electron backscatter diffraction and transmission electron microscopy. By combining the microstructure and thermal processing diagram, it is determined that the temperature range for high strain rate thermal processing of HP62 recycled brass is 600-650℃, and the strain rate range is 24-32s. -1 .

[0031] The three-dimensional drawing software is used to visualize the high extrusion ratio reverse extrusion process of brass wire on the computer, and the established three-dimensional graphics are imported into the simulation software to build a digital simulation system for the extrusion process. In this system, digital characterization is performed under different process parameters to determine the physical forming limit of digital extrusion. By digitally optimizing the extrusion process and die structure, the digitally optimized isothermal reverse extrusion process parameters of brass wire with high extrusion ratio are obtained: the extrusion temperature is 600-660℃, the speed is 18-30mm / s, and the extrusion outlet temperature is ±5℃-±10℃; the extrusion die is a 5-hole die, the extrusion material is NiMoWNbV high-temperature alloy material, and the length of the die sizing belt is 6mm-7.5mm. In this extrusion process window, test points are selected for extrusion tests to test and characterize the microstructure and performance of the extruded wire. A large amount of extrusion production data is collected, and the corresponding relationship between the process, microstructure and performance of brass wire is constructed by neural network mapping. The extrusion process is screened and iteratively optimized through a large database. The further optimized extrusion process parameters are: extrusion temperature of 640℃, speed of 20-27mm / s, extrusion outlet temperature of ±9.5℃; die sizing belt length of 6.8mm-7mm. Under this condition, the surface quality and comprehensive performance of the extruded brass wire are good, and the production efficiency is high; compared with traditional extrusion, the extrusion force can be reduced by 35% and the yield rate can be increased by 30%.

[0032] Example 3

[0033] The horizontal continuous casting HMn58-2 recycled brass ingot was machined to obtain high temperature compression specimens, and high temperature compression tests were carried out on a thermal simulator. The temperature range of high temperature compression was 500-650℃, the temperature interval was 30℃, and the strain rate was 15s -1 , 20s -1 , 25s -1 , 30s -1 , 35s -1 The Arrhenius model was used to establish the high strain rate constitutive equation of brass, and the Murty instability criterion of the dynamic material model was used to obtain the high strain rate thermal deformation processing diagram of brass components. The microstructure of brass under high strain rate thermal deformation conditions was analyzed by advanced test characterization methods such as electron backscatter diffraction and transmission electron microscopy. By combining the microstructure and thermal processing diagram, it was determined that the temperature range for high strain rate thermal processing of HMn58-2 recycled brass is 560-640℃, and the strain rate range is 15-35s. -1 .

[0034] The three-dimensional drawing software is used to visualize the high extrusion ratio reverse extrusion process of brass wire on the computer, and the established three-dimensional graphics are imported into the simulation software to build a digital simulation system for the extrusion process. In this system, digital characterization is performed under different process parameters to determine the physical forming limit of digital extrusion. By digitally optimizing the extrusion process and die structure, the digital optimization of the high extrusion ratio isothermal reverse extrusion process parameters of brass wire are obtained: the extrusion temperature is 580-635℃, the speed is 16-32mm / s, and the extrusion outlet temperature is ±6℃-±10℃; the extrusion die is a 3-hole die, the extrusion material is CoNiCrW high-temperature alloy material, and the length of the die sizing belt is 5.5mm-7mm. In this extrusion process window, test points are selected for extrusion tests to test and characterize the microstructure and performance of the extruded wire. A large amount of extrusion production data is collected, and the process-microstructure-performance correspondence of brass wire is constructed by neural network mapping. The extrusion process is screened and iteratively optimized through a large database. The further optimized extrusion process parameters are: extrusion temperature of 625℃, speed of 25-30mm / s, extrusion outlet temperature of ±8.5℃; die sizing belt length of 6.5mm-6.8mm. Under this condition, the surface quality and comprehensive performance of the extruded brass wire are good, and the production efficiency is high; compared with traditional extrusion, the extrusion force can be reduced by 38% and the yield rate can be increased by 32%.

[0035] The short-process preparation process design and optimization method of brass wire of the present invention is based on the high strain rate thermal deformation characteristics of brass, organically combines digital simulation and extrusion test to optimize the extrusion process and die structure, and is oriented to digital integration of high strain rate thermal deformation characteristics of brass, numerical calculation simulation, physical forming limit of brass with large extrusion ratio, online monitoring, big data collection, and advanced material testing and characterization technology. Neural network mapping is used to establish the relationship between extrusion process, die structure, die material and specific performance, cost, and energy consumption of the product, so as to obtain the optimal extrusion process.

[0036] The method can achieve the optimal matching of all parameters such as process, organization, performance, energy consumption, etc. during the isothermal reverse extrusion of brass wire, and organically unifies digitization, process test, online monitoring, and performance control. The produced brass wire has good surface quality, fine and uniform organization, excellent comprehensive performance, high yield rate, and high production efficiency. The process design and optimization method are suitable for large-scale production, and can achieve green, low-carbon, refined, economical, low-cost, high-quality large-scale production of brass wire, with significant economic and social benefits.

Claims

1. A brass wire short-process preparation process design and optimization method, comprising the following steps: (1) Machining horizontal continuous casting brass ingots to prepare high strain rate compression test specimens, performing high strain rate compression on a thermal simulator, and obtaining true stress and true strain curves of brass under high strain rate deformation conditions; (2) using the true stress and true response obtained in step (1) to establish the constitutive equation of brass under high strain rate deformation conditions, using the material dynamic model to construct a high strain rate thermal deformation processing diagram, analyzing and characterizing the microstructure of brass under high strain rate conditions, and determining the process conditions suitable for high strain rate deformation; (3) According to the wire size specifications, three-dimensional drawing software is used to three-dimensionally graph the high extrusion ratio reverse extrusion process of the brass wire on a computer, and the established three-dimensional graph is imported into the simulation software, and the high strain rate constitutive equation of step (2) is used to simulate and calculate the high extrusion ratio reverse extrusion process of the brass wire, and a digital system for the extrusion process is constructed. In this system, digital characterization is performed under different process parameter conditions to determine the digital extrusion physical forming limit, and the digital brass wire high extrusion ratio isothermal reverse extrusion process parameters are obtained by digitally optimizing the extrusion process and the die structure; (4) using the digital extrusion process parameters obtained in step (3), performing isothermal reverse extrusion of the brass wire at a large extrusion ratio, and monitoring the extrusion outlet temperature, wire size fluctuation range, and wire surface quality online in real time, and comparing the extrusion outlet temperature and wire size accuracy with the digitally calculated data, optimizing the process through repeated iterative corrections through digitalization and experimental measurements; (5) Use advanced material testing and characterization technology to analyze the microstructure and comprehensive properties of extruded wire and digitize the structure and properties; (6) By collecting a large database of extrusion temperature, speed extrusion process parameters, die structure parameters, die material performance parameters, wire size, and performance, neural network mapping is used to construct the process-structure-performance correspondence of brass wire, and the extrusion process is optimized through screening and iteration of the large database.

2. According to the short-process preparation process design and optimization method of brass wire material in claim 1, the brass high strain rate high temperature compression test in step (1) is characterized in that: In the brass high strain rate high temperature compression test described in step (1), the temperature range is 500-750°C, the temperature interval is 40-50°C, and the strain rate range is 15s -1 ~50s -1 , strain rate interval is 5s -1 ~10s -1 .

3. The brass wire short-process preparation process design and optimization method according to claim 1, characterized in that: The specific process of step (2) is as follows: the Arrhenius model is used to establish the high strain rate constitutive equation of brass, the Murty instability criterion of the dynamic material model is used to obtain the high strain rate thermal deformation processing diagram of the brass component, and the electron backscatter diffraction and transmission electron microscopy advanced testing and characterization methods are used to analyze the microstructure of brass under high strain rate thermal deformation conditions. By combining the microstructure and the thermal processing diagram, the deformation conditions suitable for processing and the occurrence of instability during high strain rate thermal deformation of brass are determined.

4. The brass wire short-process preparation process design and optimization method according to claim 1, characterized in that: The reverse extrusion of the brass wire adopts a porous extrusion die, and the digital simulation system of the extrusion process constructed on the computer visualizes the entire extrusion process, accurately calculates the distribution of the extrusion force, extrusion temperature field, stress field and strain rate field related field quantities, can quantitatively characterize the uniformity of the extrusion deformation, and improve the deformation uniformity through digital optimization; the digital extrusion physical forming limit can be characterized by the extrusion forming limit curve, specifically, the extrusion outlet temperature overheating cracking, microstructure coarsening, and dimensional tolerance.

5. The brass wire short-process preparation process design and optimization method according to claim 1, characterized in that: The extrusion outlet temperature fluctuation range of the brass wire large extrusion ratio isothermal reverse extrusion process described in step (4) is less than ±10°C, the isothermal reverse extrusion deformation is uniform, the additional stress is significantly reduced, the forming is labor-saving, the load is low, and the energy consumption is low.

6. The brass wire short-process preparation process design and optimization method according to claim 1, characterized in that: The digital characterization of the organization and performance described in step (5) is that the microstructure of the brass wire is described by numbers, the grain size is represented by grain size, the large-angle grain boundary is described by 15°, the small-angle grain boundary is described by data between 2 and 15°, and the special grain boundary is described by ∑3, ∑9, and ∑27; conventional mechanical properties and impact properties can be represented by specific numerical values ​​of yield strength, tensile strength, elongation, cross-sectional shrinkage, hardness, and impact work.

7. The brass wire short-process preparation process design and optimization method according to claim 1, characterized in that: The big database described in step (6) is collected from multiple batches of extrusion production, and the big data includes: composition data of brass billet, heating time of ingot heating process, holding time, mold structure parameters, mold material, mold preheating temperature, extrusion pad preheating temperature, extrusion billet temperature, extrusion outlet temperature, brass wire specifications, extrusion ratio, extrusion speed, extrusion pressure, extrusion strain rate, wire structure characteristic data, conventional mechanical properties of wire, impact performance, and cutting performance.

8. The brass wire short-process preparation process design and optimization method according to claim 1, characterized in that: The mold material described in step (6) is a nickel-based high-temperature and cobalt-based high-temperature alloy material with excellent high-temperature performance, which prevents the extrusion mold from deforming under high strain rate, high temperature and high load, and ensures the dimensional accuracy of the wire.