Conductive block, manufacturing method thereof and wiring terminal comprising conductive block

Abstract

The invention relates to the technical field of manufacturing of electrical connecting devices, and discloses a conductive block, a manufacturing method of the conductive block and a wiring terminal comprising the conductive block. The steps of plasma ball milling, warm-pressing forming, vacuum sintering, precise cold-pressing shaping, laser detection, stamping machining and the like are combined, grain boundary oxidation is effectively controlled while the compactness of the material is improved, and the beneficial effects that the oxidation resistance and the mechanical strength are remarkably improved while the high conductivity is guaranteed are achieved; and the performance of the conductive block is comprehensively improved by optimizing the molding compactness and a surface treatment process.

Description

Technical Field

[0001] This invention relates to the field of electrical connection device manufacturing technology, and in particular to a conductive block, a method for manufacturing the same, and a terminal block comprising the conductive block. Background Technology

[0002] In the field of electrical connection devices, conductive blocks, as the core conductive components of terminals, directly affect the efficiency of power transmission and the stability of equipment operation. The main technical challenge currently facing conductive block manufacturing technology is that traditional conductive block material formulations cannot simultaneously meet the requirements of high conductivity, high oxidation resistance, and high mechanical strength. While pure copper has excellent conductivity, it suffers from insufficient mechanical strength and is prone to oxidation; while simple alloy materials can improve mechanical strength, they significantly reduce conductivity.

[0003] Furthermore, existing manufacturing processes suffer from insufficient molding density, inadequate sintering oxidation control, and limited surface treatment technologies, further hindering the improvement of conductive block performance. In terms of overall terminal block design, current technologies often neglect the synergistic relationship between conductive block performance and terminal conductivity stability, leading to issues such as high power loss and fluctuating contact resistance in practical applications. These problems are particularly pronounced in applications with stringent power transmission requirements, such as new energy vehicles and 5G communications.

[0004] Therefore, the existing manufacturing technology for conductive blocks needs to be improved. Summary of the Invention

[0005] The purpose of this invention is to provide a conductive block, its manufacturing method, and a terminal block containing the conductive block. This invention has the advantages of significantly improving oxidation resistance and mechanical strength while ensuring high conductivity, and achieving a comprehensive improvement in the performance of the conductive block through optimized molding density and surface treatment processes. It solves the problems that traditional conductive block material formulations cannot simultaneously meet the requirements of high conductivity, high oxidation resistance, and high mechanical strength, as well as the limitations of existing conductive block manufacturing processes on the improvement of conductive block performance.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a method for manufacturing a conductive block, comprising the following steps:

[0008] (1) Raw material preparation: Prepare the raw materials required for manufacturing the conductive block. By mass percentage, the raw materials for the conductive block include 99.08% to 99.6% electrolytic copper powder, 0.1% to 0.3% silver powder, 0.2% to 0.5% tin powder, 0.05% to 0.12% zirconium powder or chromium powder, and ≤0.05% grain boundary purification additive;

[0009] (2) Plasma ball milling: The raw material of the conductive block is subjected to plasma ball milling under inert gas protection to obtain a uniformly mixed composite powder;

[0010] (3) Warm pressing: The composite powder is placed in a mold and warm pressed at 120℃~150℃ and 500MPa~600MPa pressure. After molding, it is kept warm for 20min~30min to obtain the blank.

[0011] (4) Vacuum sintering: The preform after warm pressing is placed in a vacuum furnace and sintered at a vacuum degree ≤10. -3 Vacuum sintering is carried out under Pa conditions. First, the temperature is raised to 950℃~1050℃ at a heating rate of 5℃ / min~8℃ / min and held for 2h~3h. Then, the temperature is lowered to room temperature at a cooling rate of 3℃ / min~5℃ / min.

[0012] (5) Precision cold pressing and laser inspection: The sintered blank is subjected to precision cold pressing mold for precision cold pressing and shaping. The cold pressing pressure is 300MPa~400MPa to obtain the conductive block semi-finished product. The contact surface of the conductive block semi-finished product is subjected to laser inspection to ensure that the flatness of the contact surface is ≤0.01mm. If the deviation is exceeded, the cold pressing parameters are readjusted and a second shaping is performed.

[0013] (6) Stamping: The blank is cleaned and then stamped to form the required contour to obtain the finished conductive block.

[0014] As a specific technical solution of the present invention, the purity of the electrolytic copper powder is 99.75%~99.95%, and the purity of the silver powder, tin powder, zirconium powder and chromium powder is ≥99.9%.

[0015] As a preferred embodiment of the present invention, the grain boundary purification additive is trimethyl borate or triethyl phosphate.

[0016] As a preferred embodiment of the present invention, the amount of the grain boundary purification additive is 0.02% to 0.04% by mass percentage.

[0017] As a specific technical solution of the present invention, the inert gas is argon, and the parameters of the plasma ball mill are: ball milling speed of 180 r / min to 220 r / min, ball-to-material ratio of (8 to 10): 1, ball milling time of 1.5 h to 2.5 h, and powder temperature controlled at 50 °C to 80 °C during the ball milling process.

[0018] As a specific technical solution of the present invention, a molding lubricant is also added during the warm pressing process, and the amount of molding lubricant added is 0.02% to 0.05% of the total weight of the conductive block raw material.

[0019] As a preferred embodiment of the present invention, the molding lubricant is at least one of zinc stearate, magnesium stearate, lithium stearate, and polyethylene glycol.

[0020] Preferably, a metal soap-based lubricant is used for molding. As an example, zinc stearate can be used as a molding lubricant.

[0021] As a specific technical solution of the present invention, the warm pressing molding adopts a servo-controlled warm pressing molding machine, and the pressure fluctuation during the molding process is ≤±0.1MPa, and the surface roughness Ra≤0.8μm.

[0022] As a specific technical solution of the present invention, the heating stage in the vacuum sintering process also includes holding at 400℃~500℃ for 1 hour.

[0023] As a specific technical solution of the present invention, after precision cold pressing and laser inspection, a nano-silver coating is prepared on the contact surface of the conductive block semi-finished product using a chemical plating process. The plating solution temperature is 60℃~70℃, the pH value is 8.0~8.5, the thickness of the formed nano-silver coating is 50nm~100nm, and the surface roughness Ra after plating is ≤0.2μm.

[0024] As a specific technical solution of the present invention, the nano-silver coating is a single-layer structure, and the silver purity in the coating is ≥99.9%.

[0025] As a specific technical solution of the present invention, the formulation of the plating solution includes 2~5g / L of 30-50 g / L glucose, 15-25 g / L EDTA-2Na and the remainder ammonia.

[0026] As a more specific technical solution of the present invention, the formulation of the plating solution includes 3.2 g / L of 42 g / L glucose, 18 g / L EDTA-2Na and the remainder ammonia.

[0027] Secondly, the present invention provides a conductive block obtained by the above-described manufacturing method.

[0028] Thirdly, the present invention provides a terminal block comprising a housing, a slider, and at least two conductive blocks obtained by the above manufacturing method, wherein the slider is slidably mounted on the housing, the conductive blocks are distributed on both sides of the slider, and the slider is used to electrically connect the conductive blocks on both sides.

[0029] As a specific technical solution of the present invention, the conductive blocks can be configured as two symmetrically distributed blocks, and the slider maintains the contact pressure with the conductive blocks through a spring mechanism; the inner wall of the housing can be provided with guide protrusions to restrict the slider to slide only in a preset direction; the assembly gap between the conductive blocks and the housing can be filled by interference fit or adhesive to further reduce the contact resistance.

[0030] Compared with the prior art, the present invention provides a conductive block, a method for manufacturing the same, and a terminal block comprising the conductive block, which has the following advantages:

[0031] This invention employs a synergistic ratio of high-purity electrolytic copper and trace alloying elements, combined with processes such as plasma ball milling, warm pressing, vacuum sintering, and precision cold pressing, to effectively control grain boundary oxidation while improving material density. It has the advantages of significantly improving oxidation resistance and mechanical strength while ensuring high conductivity. Furthermore, by optimizing the forming density and surface treatment processes, the performance of the conductive block is comprehensively improved. Attached Figure Description

[0032] 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 of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a process flow diagram of the present invention;

[0034] Figure 2 This is a schematic diagram of the internal structure of the terminal block of the present invention;

[0035] Figure 3 This is an exploded view of the terminal block of the present invention.

[0036] Reference numerals: 10, housing; 20, slider; 30, conductive block. Detailed Implementation

[0037] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] In existing technologies, the manufacturing of conductive blocks has long faced the challenge of synergistically improving conductivity, oxidation resistance, and mechanical strength. Traditional conductive block material formulations often use pure copper or simple binary alloys, leading to significant performance contradictions. For example, pure copper has high conductivity but poor oxidation resistance, while alloy materials, while increasing strength, reduce conductivity. Furthermore, existing conductive block forming processes rely on cold pressing and atmospheric sintering, resulting in insufficient compactness and susceptibility to oxidation of the blank. Surface treatment solutions also present a trade-off between appearance and cost, failing to meet the application requirements of high stability and low loss.

[0039] To address the aforementioned issues, the inventors discovered that single improvements to materials and processes in existing technologies cannot systematically solve the performance synergy problem. By analyzing the root causes of conductive block performance degradation, they recognized that grain boundary impurities, porosity, and oxide layers are key factors leading to performance deterioration. Therefore, they proposed a multi-element synergistic formulation combined with end-to-end process optimization. This approach uses a combination of trace elements to suppress grain boundary oxidation, employs temperature-pressure and vacuum sintering to enhance density, and introduces precision shaping to ensure surface accuracy, ultimately achieving a balance between performance and appearance.

[0040] like Figure 1 As shown, this invention proposes a method for manufacturing a conductive block, including steps such as raw material preparation, plasma ball milling, warm pressing, vacuum sintering, precision cold pressing and shaping, laser inspection, and stamping. Specific steps include:

[0041] (1) Raw material preparation: Prepare the raw materials required for manufacturing the conductive block. By mass percentage, the raw materials for the conductive block include 99.08% to 99.6% electrolytic copper powder, 0.1% to 0.3% silver powder, 0.2% to 0.5% tin powder, 0.05% to 0.12% zirconium powder or chromium powder, and ≤0.05% grain boundary purification additive;

[0042] (2) Plasma ball milling: The raw material of the conductive block is subjected to plasma ball milling under inert gas protection to obtain a uniformly mixed composite powder;

[0043] (3) Warm pressing: The composite powder is placed in a mold and warm pressed at 120℃~150℃ and 500MPa~600MPa pressure. After molding, it is kept warm for 20min~30min to obtain the blank.

[0044] (4) Vacuum sintering: The preform after warm pressing is placed in a vacuum furnace and sintered at a vacuum degree ≤10. -3 Vacuum sintering is carried out under Pa conditions. First, the temperature is raised to 950℃~1050℃ at a heating rate of 5℃ / min~8℃ / min and held for 2h~3h. Then, the temperature is lowered to room temperature at a cooling rate of 3℃ / min~5℃ / min.

[0045] (5) Precision cold pressing and laser inspection: The sintered blank is subjected to precision cold pressing mold for precision cold pressing and shaping. The cold pressing pressure is 300MPa~400MPa to obtain the conductive block semi-finished product. The contact surface of the conductive block semi-finished product is subjected to laser inspection to ensure that the flatness of the contact surface is ≤0.01mm. If the deviation is exceeded, the cold pressing parameters are readjusted and a second shaping is performed.

[0046] (6) Stamping: The blank is cleaned and then stamped to form the required contour to obtain the finished conductive block.

[0047] Electrolytic copper powder serves as the matrix material, providing basic electrical conductivity. Silver powder, added at 0.1% to 0.3%, enhances oxidation resistance and assists in conductivity. Tin powder, added at 0.2% to 0.5%, strengthens mechanical strength and improves powder flowability. Zirconium or chromium powder, added at 0.05% to 0.12%, forms a nanoscale dispersed reinforcing phase, inhibiting grain boundary oxidation. Grain boundary purification additives, not exceeding 0.05%, eliminate grain boundary impurities and reduce resistivity. Plasma ball milling, conducted under inert gas protection, activates the powder surface and achieves uniform mixing. Warm pressing, performed at 120℃~150℃ and 500MPa~600MPa, improves the compactness of the green body. Vacuum sintering is performed at a vacuum level not exceeding 10... -3 The process is carried out in a vacuum environment, where the partial pressure of oxidizing gases is reduced to suppress the oxidation reaction of metal elements during sintering, thus preventing oxidation and promoting alloy phase formation. Specifically, a vacuum furnace can be used, with a vacuum pump group maintaining the furnace pressure. This environment provides low partial pressure conditions for the escape of volatiles, accelerating their diffusion. Precision cold pressing and shaping pressure can be 300MPa~400MPa, used to eliminate sintering deformation and improve surface flatness. Laser inspection refers to the quantitative evaluation of the geometric accuracy of the contact surface of the conductive block semi-finished product using non-contact optical measurement technology. Specifically, a laser triangulation inspection system can be used. This system emits a laser beam and receives the reflected light signal to construct three-dimensional surface topography data, enabling rapid identification of flatness deviation areas. A contact surface flatness ≤0.01mm means that the vertical distance between the highest and lowest points of the contact surface does not exceed this threshold. This is achieved through high-precision laser scanning and data processing algorithms. This indicator ensures that a uniform conductive interface is formed when the conductive block and the slider are in contact. Secondary shaping refers to performing the cold pressing process again after dynamically adjusting the cold pressing process parameters based on the laser detection results. Specifically, the pressure value, holding time, or mold alignment accuracy are compensated and adjusted by the servo control system to achieve targeted surface morphology correction.

[0048] Specifically, this invention optimizes electrical and mechanical properties through the synergistic design of material formulation and manufacturing process. On the one hand, in terms of material formulation, high-purity electrolytic copper ensures low resistivity, silver element improves oxidation resistance while reducing lattice defects, and the composite addition of tin with zirconium or chromium forms a reinforcing phase, improving strength without destroying the conductive pathway; precise control of the amount of grain boundary purification additives avoids the loss of conductivity, ensuring that the product appearance is consistent with ordinary copper alloys and the cost is controllable. On the other hand, in terms of manufacturing process, plasma ball milling avoids oxidation through inert gas protection while activating the powder surface to promote subsequent forming and bonding; the warm pressing stage combines temperature and pressure control to reduce internal porosity and increase the density of the blank; the vacuum sintering process promotes the diffusion of alloying elements and eliminates grain boundary impurities through staged temperature control; precision cold pressing further compresses residual porosity, and a laser detection system performs a full-area scan of the conductive block contact surface after the cold pressing process to generate surface height distribution data and calculate flatness values. If the flatness exceeds the threshold, the system automatically analyzes the type of deviation (for overall deviations, the cold pressing pressure is adjusted or the holding time is extended to enhance the uniformity of plastic deformation; for local protrusions or depressions, the mold alignment accuracy is corrected or compensating pressure is applied in specific areas). The adjusted parameters are input into the cold pressing equipment to perform secondary shaping to eliminate surface unevenness defects, ensure contact surface accuracy, and avoid surface damage caused by manual trimming. At the same time, a closed-loop feedback mechanism ensures shaping accuracy and process stability; finally, surface treatment maintains the appearance of the copper alloy, and stamping process yields the finished product.

[0049] Traditional conductive block manufacturing uses a single material and conventional cold-pressing sintering process, resulting in poor density and susceptibility to oxidation. This invention, through a multi-element synergistic formulation and a closed-loop process, improves conductivity and mechanical strength while suppressing oxidation and maintaining consistent appearance. Traditional processes rely on mechanical contact measuring tools for flatness inspection, which is inefficient and prone to scratching the surface. When deviations occur, manual grinding is used for correction, leading to worsened surface roughness and the introduction of microcracks. This invention combines non-contact laser inspection with parametric secondary shaping, improving inspection efficiency while protecting surface integrity. Data-driven parameter adjustments achieve precise correction, solving the problem of the trade-off between precision control and surface quality in traditional methods. It also effectively improves the flatness accuracy of the conductive block's contact surface, ensuring stable full-area contact with the slider, reducing contact resistance fluctuations, and eliminating manual finishing processes, thus reducing the risk of surface defects. This provides a uniform substrate for subsequent surface plating processes, comprehensively improving the conductivity reliability and production efficiency of the conductive block. Traditional processes rely on thick electroplating to improve performance, while this invention, through synergistic optimization of materials and processes, avoids the impact of electroplating on cost and appearance.

[0050] Through the above technical solution, this invention effectively resolves the contradiction between conductivity, oxidation resistance, and mechanical strength, significantly reduces internal porosity and grain boundary impurities, and improves the precision of the contact surface. This invention achieves performance optimization while maintaining the appearance of the copper alloy, avoiding the cost increases caused by traditional surface treatments, and providing a feasible path for manufacturing high-stability, low-loss conductive blocks.

[0051] In some specific implementations, the purity of electrolytic copper powder is 99.75%~99.95%. Using high-purity electrolytic copper powder can ensure low resistivity. Silver powder, tin powder, zirconium powder, and chromium powder must all meet the standard of "high-purity industrial-grade metal elemental powder", with a purity of ≥99.9%, and trace amounts of impurities that do not affect the core performance are allowed.

[0052] In some specific embodiments, as an example, the grain boundary cleaning additive is preferably trimethyl borate or triethyl phosphate. The grain boundary cleaning additive refers to a chemical substance added during the metal powder mixing stage to react with impurities at the grain boundaries in subsequent processes. Specifically, trimethyl borate or triethyl phosphate can be used, which decomposes at high temperatures to generate active groups that combine with impurities such as oxygen and sulfur to form volatile compounds. By simultaneously introducing the grain boundary cleaning additive during the mechanical mixing of the metal powder, the mechanochemical effect of plasma ball milling can be used to uniformly coat the surface of the metal powder with the grain boundary cleaning additive.

[0053] Specifically, trimethyl borate or triethyl phosphate undergoes high-energy mechanical impact and plasma activation with the metal powder during the plasma ball milling stage. During this process, the grain boundary cleaning additive molecules react initially with trace impurities adsorbed on the powder surface, forming unstable intermediate products. When entering the vacuum sintering stage, as the temperature rises, these intermediate products further decompose into active groups, diffuse into the copper-based grain boundary region, and react with residual copper oxide, copper sulfide, and other impurities at the grain boundary to generate low-boiling-point compounds. Under vacuum conditions, the generated compounds are discharged in gaseous form, thereby reducing the impurity content in the grain boundary region.

[0054] Traditional methods often employ rare earth element solid solution or degassing after sintering. The former fails to completely remove grain boundary impurities and may even decrease conductivity, while the latter only removes free impurities and is ineffective against grain boundary-bound impurities. This invention utilizes the synergistic effect of specific grain boundary purification additives and process stages to begin impurity capture during the powder mixing stage and complete directional removal during the sintering stage, achieving deep purification of the grain boundary region.

[0055] Through the above technical solution, this invention effectively reduces the impurity content at the grain boundaries of the conductive block, improving oxidation resistance while maintaining high conductivity. The conductive block with purified grain boundaries exhibits stable contact resistance during long-term use, preventing conduction failure caused by impurity oxidation.

[0056] In some embodiments, the amount of grain boundary cleaning additive added is 0.02% to 0.04% by mass percentage. This range ensures that sufficient active material participates in the reaction to effectively remove impurities, while avoiding excessive residue at the grain boundaries that could form insulating residues and affect conductivity.

[0057] In some specific embodiments, the inert gas is argon, and the parameters of the plasma ball mill are: milling speed of 180 r / min to 220 r / min, ball-to-powder ratio of (8 to 10):1, milling time of 1.5 h to 2.5 h, and powder temperature controlled at 50 °C to 80 °C during milling. The argon gas used has a purity ≥99.99%, and an inert atmosphere is formed by filling the milling chamber, activating the powder surface using argon plasma while isolating oxygen. The milling speed of 180 r / min to 220 r / min can be achieved using a variable frequency motor in conjunction with a speed sensor, thus balancing mechanical alloying efficiency and powder agglomeration suppression. The ball-to-powder ratio of (8 to 10):1 can be achieved by loading cemented carbide grinding balls with a diameter of 5 mm to 10 mm and powder in a specific mass ratio, thereby optimizing collision energy transfer and controlling impurity introduction. The ball milling time is set to 1.5h~2.5h. Specifically, a timer controller combined with process parameters can be used to control the processing time of the powder within the ball mill chamber, ensuring sufficient alloying of the multi-component powder. The powder temperature is set to 50℃~80℃. Specifically, a circulating water cooling system and a temperature sensor can be used to control the temperature range of the powder particles during ball milling, promoting atomic diffusion and protecting the molecular structure of the additives.

[0058] Specifically, the synergistic effect of argon atmosphere and plasma activation removes the oxide film on the powder surface through high-energy particle bombardment, while preventing secondary oxidation of fresh metal surfaces. The ball milling speed is controlled within the range of 180 r / min to 220 r / min to ensure mechanical shear force while avoiding excessive speed that could lead to powder agglomeration. The ball-to-powder ratio is set to (8~10):1, optimizing the mass ratio of grinding media to powder to improve the dispersion of trace elements while preventing excessive ball collisions that introduce impurities. The ball milling time is limited to 1.5 h to 2.5 h to ensure that trace elements such as zirconium and chromium are fully embedded in the copper-based powder, while preventing excessive work hardening that could affect subsequent molding. The powder temperature is controlled between 50℃ and 80℃ to promote atomic diffusion through gentle thermal activation while avoiding premature decomposition of grain boundary cleaning additives due to high temperatures.

[0059] Conventional mechanical ball milling processes cannot effectively remove the oxide film on the powder surface, and insufficient mixing uniformity leads to fluctuations in the composition of the subsequent sintered body. Although some plasma ball milling solutions employ inert gas protection, they lack coordinated control over parameters such as ball-to-powder ratio and temperature, making them prone to impurity contamination or additive failure. This invention, through multi-parameter linkage design, improves powder mixing uniformity while controlling oxidation and impurity introduction at the source, forming a stable and replicable powder pretreatment process.

[0060] Through the above technical solution, this invention effectively solves the problems of uneven powder mixing and grain boundary oxidation contamination, obtaining high-purity and highly uniform composite powder, providing high-quality raw materials for subsequent warm pressing and vacuum sintering. Simultaneously, the thorough removal of the oxide film on the powder surface reduces the content of grain boundary impurities after sintering, and the synergistic control of ball milling parameters ensures a balance between powder flowability and work hardening, significantly reducing the pressure requirements of subsequent precision cold pressing forming processes.

[0061] In some specific implementations, a molding lubricant is added during the warm pressing process, with the amount of lubricant added being 0.02% to 0.05% of the total weight of the conductive block raw material. By adding an appropriate amount of molding lubricant as a process auxiliary component, the friction between the powder and the mold can be reduced, making the pressing process smoother and easier to demold, reducing the pressing pressure requirement and reducing mold wear. It can also make the powder easier to fill the gaps during pressing, improving the density and strength of the blank.

[0062] When selecting lubricants, it is necessary to avoid those containing harmful elements such as sulfur and chlorine. Preferably, the molding lubricant is at least one of zinc stearate, magnesium stearate, lithium stearate, and polyethylene glycol.

[0063] Preferably, a metal soap-based lubricant is used for molding. As an example, zinc stearate can be used as a molding lubricant.

[0064] In some specific implementations, the warm pressing process employs a servo-controlled warm pressing machine. During the pressing process, pressure fluctuations are ≤ ±0.1 MPa, and the resulting green body has no burrs or shrinkage marks, with a surface roughness Ra ≤ 0.8 μm. The servo-controlled warm pressing machine refers to a high-precision pressing device driven by a servo motor. Its pressure output is adjusted in real-time through a closed-loop feedback system, specifically using a servo hydraulic system with a pressure sensor. This dynamically compensates for pressure fluctuations caused by powder flow resistance and temperature changes. Pressure fluctuations ≤ ±0.1 MPa mean that the instantaneous deviation of the pressure output during the pressing process does not exceed 0.1 MPa of the set value. This is achieved through the millisecond-level response characteristics of the servo motor combined with pressure sensor feedback, eliminating local pressure overshoot or undershoot caused by response delays in traditional hydraulic systems. The absence of burrs and shrinkage marks on the green body's surface after pressing means that there are no sharp protrusions formed by material overflow at the edges of the green body, nor are there any depressions formed by material shrinkage on the surface. This is achieved through dynamic compensation of powder cooling shrinkage by the servo pressure, preventing stress concentration during subsequent sintering and cold pressing processes. Surface roughness Ra≤0.8μm means that the arithmetic mean deviation of the micro-profile of the blank surface does not exceed 0.8 micrometers. This is achieved through high-precision mold surface treatment and uniform pressure distribution, which provides a flat substrate for subsequent sintering and surface treatment.

[0065] Specifically, during the warm pressing process, the flowability of the composite powder material is improved at temperatures between 120℃ and 150℃. The servo-controlled warm pressing machine adjusts the pressure output in real time to offset pressure fluctuations caused by friction and temperature changes during powder filling. Pressure fluctuations are limited to ±0.1MPa, ensuring uniform distribution of powder particles within the mold cavity and preventing localized areas from becoming porous due to insufficient pressure or from burrs caused by excessive pressure. After molding, the servo system continuously applies dynamic pressure compensation during the heat preservation stage to eliminate shrinkage marks caused by powder cooling. The mold surface is precision polished, and combined with the uniform pressure distribution, the surface roughness of the blank is reduced to below 0.8μm, forming a smooth and dense initial surface structure.

[0066] Traditional warm pressing uses hydraulic or pneumatic equipment, and pressure fluctuations typically exceed ±0.5 MPa, resulting in burrs and shrinkage marks on the surface of the preform, and the surface roughness of the preform is generally higher than 1.6 μm. This invention achieves precise pressure regulation through servo control technology, combined with the effect of warm pressing temperature on powder flowability, simultaneously addressing surface defects and density issues during the forming stage, avoiding the need for an additional grinding process required in traditional methods.

[0067] Through the above technical solutions, this invention effectively eliminates burrs and shrinkage marks on the surface of the billet, significantly reducing surface roughness and providing a high-precision billet foundation for subsequent sintering and cold-pressing processes. The internal density uniformity of the billet is improved, avoiding localized loose or overly dense areas caused by pressure fluctuations, thereby reducing the risk of deformation during sintering. Optimized surface quality further reduces the frictional resistance when the conductive block contacts the slider, improving the stability of the contact area.

[0068] In some specific implementations, the heating stage of the vacuum sintering process also includes holding at 400℃~500℃ for 1 hour. This holding temperature range of 400℃~500℃ can be achieved using a segmented temperature control program, with thermocouples monitoring the furnace temperature in real time and adjusting the heating power accordingly. This temperature range corresponds to the synergistic escape window of various volatile components, ensuring the complete removal of different components. Residual trace volatiles include unreacted grain boundary purification additive monomers from the plasma ball milling process, trace amounts of moisture adsorbed on the powder surface, and molding lubricant residues detached from the mold surface during hot pressing. Their escape temperature range can be determined through thermogravimetric analysis to match the holding temperature range. This feature, by directionally removing easily decomposable substances, avoids gas defects during the high-temperature stage.

[0069] Specifically, during the heating process of vacuum sintering, when the temperature reaches 400℃~500℃, various volatiles remaining inside the blank begin to vaporize. At this time, the vacuum environment creates a concentration gradient difference between the inside and outside of the blank, promoting the diffusion of gaseous volatiles from the inside to the surface, and continuously expelling them from the furnace through the vacuum pump unit. The 1-hour holding operation prolongs the residence time of volatiles in the escape temperature range, ensuring the full desorption of adsorbed water, molding lubricant, and intermediate products of grain boundary purification additives. This step avoids pore expansion caused by sudden vaporization of volatiles in the subsequent high-temperature stage, and also prevents residual substances from decomposing at high temperatures to generate oxidizing gases that contaminate the grain boundaries.

[0070] Traditional vacuum sintering processes typically involve a uniform heating rate to the target sintering temperature without a specific temperature holding step. When residual volatiles escape at high temperatures, they easily form interconnected pores and trigger grain boundary oxidation. This invention, however, achieves simultaneous optimization of porosity reduction and grain boundary cleanliness by precisely matching the volatile escape characteristics with temperature control and combining this with a vacuum environment to accelerate volatile removal.

[0071] Through the above technical solution, the present invention effectively reduces porosity defects caused by residual volatiles inside the conductive block, and improves the densification degree of the blank; at the same time, it inhibits the formation of grain boundary oxide phases, ensuring the conductivity and mechanical strength of the grain boundaries. This process provides a uniform blank foundation for subsequent precision cold pressing and surface treatment, improving the overall performance stability of the finished conductive block.

[0072] In some specific embodiments, after precision cold pressing and laser inspection, a nano-silver coating is prepared on the contact surface of the conductive block semi-finished product using a chemical plating process. The plating solution temperature is 60℃~70℃, the pH value is 8.0~8.5, the thickness of the formed nano-silver coating is 50nm~100nm, and the surface roughness Ra after plating is ≤0.2μm.

[0073] The nano-silver coating refers to an ultra-thin metallic silver coating formed on the contact surface of the conductive block semi-finished product. Specifically, it can be achieved through a chemical plating process where silver particles are deposited via a self-catalytic reaction under conditions without external current. This coating can block the copper substrate from contacting air, thereby inhibiting oxidation. The chemical plating process is a surface treatment technology that utilizes the redox reaction between a reducing agent and metal ions in the plating solution to achieve metal deposition. Formaldehyde or glucose can be used as the reducing agent, and uniform coating coverage is achieved by controlling the composition of the plating solution and the reaction conditions. The plating solution temperature is set at 60℃~70℃, which can be achieved using a constant temperature water bath to maintain the temperature range during the chemical plating process. This temperature range balances the silver ion reduction rate and grain growth rate, preventing porosity or coarse crystals in the coating. The pH value is set at 8.0~8.5, which can be achieved by adjusting the pH range using ammonia or sodium hydroxide. This pH range stabilizes the silver ion complexation state, preventing decomposition of the plating solution or precipitation of impurities. The coating thickness is set to 50nm~100nm, which refers to the vertical dimension of the nano-silver coating. This can be achieved by controlling the concentration of the plating solution and the deposition time. This thickness can completely cover the substrate surface and also visually blend with the copper alloy substrate due to the optical scattering effect. The surface roughness Ra after plating is controlled to be ≤0.2μm (referring to the arithmetic mean deviation of the micro-undulations of the coating surface). This can be achieved through the synergistic effect of pre-treatment precision cold pressing and the self-leveling effect of the plating solution. This roughness can increase the effective contact area of ​​the contact surface.

[0074] Specifically, when preparing a nano-silver coating on the contact surface of the conductive block semi-finished product, the chemical plating process uniformly deposits silver particles under conditions without external current through an autocatalytic reaction. The coordinated control of the plating bath temperature and pH value allows silver ions to be reduced at a stable rate to fine-grained particles of 20nm~50nm, forming a dense, non-porous nanoscale covering layer. The coating thickness is controlled within the range of 50nm~100nm, which not only completely covers and prevents oxidation of the copper substrate but also utilizes the optical scattering properties of silver particles to ensure that the coating and the copper alloy substrate have a consistent appearance. The low-roughness substrate formed by the preceding precision cold pressing shaping process, combined with the preferential deposition effect of the plating bath in microscopic depressions, further reduces surface roughness, ensuring efficient conductivity between the contact surface and the external structure.

[0075] Existing conductive block surface treatments often employ no-plating solutions, leading to severe oxidation, or use thick silver plating, resulting in significant color differences and high costs. This invention achieves antioxidant protection at an ultra-thin thickness through chemical plating of a nano-silver layer, avoiding the uneven current distribution problem of electroplating. Simultaneously, it utilizes the optical properties of the nano-scale silver layer to maintain the appearance of the copper alloy, overcoming the defect of excessive color difference between traditional thick silver plating and the substrate.

[0076] Through the above technical solution, the present invention forms an ultra-thin and dense nano-silver layer on the contact surface of the conductive block, which effectively inhibits the oxidation of the copper substrate and reduces the contact resistance, while maintaining the original appearance characteristics of the conductive block. This solves the problem that it is difficult to balance the anti-oxidation performance and appearance uniformity in the traditional solution, and avoids the surge in material costs caused by thick electroplating.

[0077] In some specific implementations, the nano-silver coating is a single-layer structure with a silver purity ≥99.9%. The single-layer structure refers to a continuous and uniform coating formed through a single-step chemical plating deposition process. Specifically, this can be achieved by directly forming a single-layer silver coating on the surface of the conductive block using a chemical plating process. This structure avoids interface defects between multiple coating layers, ensures coating density, reduces interlayer reflection superposition, and makes the coating color closer to the copper alloy substrate. A silver purity ≥99.9% means that the mass percentage of silver element in the coating is not less than 99.9%, which can be achieved using a high-purity silver nitrate solution combined with an ion exchange purification process. This purity control effectively suppresses the micro-battery effect caused by impurities in the coating, improving its antioxidant stability.

[0078] Specifically, the single-layer structure forms a complete cover layer through a one-time deposition process, avoiding the interface voids and color differences caused by multiple plating layers. The plating thickness is controlled at the nanometer level, and combined with the dense crystal arrangement of high-purity silver, it maintains the appearance of the copper alloy while preventing the oxidation of the copper substrate. The high-purity silver material reduces impurity content and inhibits localized oxidation corrosion within the plating layer, enabling the ultra-thin plating layer to maintain low contact resistance and long-term oxidation resistance.

[0079] Traditional conductive block surface treatment often uses multi-layer silver plating or low-purity thick silver layers, resulting in a plating color that deviates significantly from the copper alloy substrate and excessively high material costs. In contrast, the single-layer high-purity plating of this invention, through structural optimization and composition control, achieves the same conductivity while making the plating color indistinguishable from the copper alloy substrate, and simplifies the plating preparation process.

[0080] Through the above technical solution, the present invention solves the contradiction between the change of coating color and the high material cost in the surface treatment of conductive blocks, and reduces the consumption of silver material while maintaining the appearance of copper alloy; at the same time, the high purity of the coating also ensures the oxidation resistance stability of the contact surface of the conductive block, avoids the contact resistance fluctuation caused by local oxidation caused by impurities, and thus improves the conductivity reliability of the conductive block in long-term use.

[0081] In some specific embodiments, the plating solution formulation includes 2~5 g / L of The solution contains 30-50 g / L glucose, 15-25 g / L EDTA-2Na, and the balance ammonia. This plating solution formulation allows for better formation of an ultra-thin and dense nano-silver coating on the contact surface of the conductive block semi-finished product, achieving more uniform coating coverage while maintaining the original appearance of the conductive block. As an example, the plating solution formulation includes 3.2 g / L of... 42 g / L glucose, 18 g / L EDTA-2Na and the remainder ammonia.

[0082] Secondly, the present invention also provides a conductive block 30, which is obtained by the above-described manufacturing method.

[0083] Thirdly, such as Figure 2 and Figure 3 As shown, the present invention further provides a terminal block, including a housing 10, a slider 20 and at least two conductive blocks 30 obtained by the above manufacturing method. The slider 20 is slidably mounted on the housing 10, and the conductive blocks 30 are distributed on both sides of the slider 20. The slider 20 is used to electrically connect the conductive blocks 30 on both sides.

[0084] The conductive block 30 provides high conductivity, oxidation resistance, and mechanical strength, ensuring long-term conductive stability within the terminal block. The slider 20 is a sliding metal component between the conductive blocks 30, typically made of copper alloy or steel with a surface plating treatment. Its function is to achieve a reliable electrical connection between the conductive blocks by dynamically adjusting the contact area. The housing 10 is a supporting structure for fixing the conductive blocks 30 and the slider 20, typically made of insulating plastic or anodized aluminum alloy. Its function is to constrain the movement trajectory of the slider 20 and maintain the terminal block's appearance consistent with the downstream equipment.

[0085] Specifically, the conductive block 30 achieves a dense microstructure through optimized alloy formulation and vacuum sintering process, reducing the obstruction of current conduction by internal pores. Simultaneously, the surface nano-silver plating enhances oxidation resistance while retaining the appearance of the copper alloy. When the slider 20 slides within the track defined by the housing 10, it forms a stable surface contact with the conductive block 30, avoiding contact resistance fluctuations caused by localized oxidation or deformation. The housing 10 employs a precision slotting design to ensure the straightness of the slider 20's sliding trajectory and uses a material matching the surface color of the conductive block 30 to maintain the overall consistency of the terminal's appearance.

[0086] In some specific embodiments, the conductive blocks 30 can be configured as two symmetrically distributed blocks, and the slider 20 maintains the contact pressure with the conductive blocks 30 through a spring mechanism; the inner wall of the housing 10 can be provided with guide protrusions to limit the slider 20 to slide only in a preset direction; the assembly gap between the conductive blocks 30 and the housing 10 can be filled by interference fit or adhesive to further reduce the contact resistance.

[0087] Existing terminal blocks mostly employ a single conductive block and fixed contact design, which is prone to conduction failure due to oxidation of the contact surface or mechanical deformation. Furthermore, the surface treatment process of the conductive block disrupts the uniformity of the appearance. This invention utilizes a dual conductive block and sliding connection design, employing dynamic contact to compensate for material deformation. Combined with the surface treatment of the conductive block matching the appearance of the housing, it improves conduction reliability while avoiding appearance discrepancies.

[0088] Through the above technical solution, the present invention solves the problem of unstable conduction caused by the mismatch between the overall performance of the conductive block and the terminal block, achieves synergistic optimization of high conductivity and uniform appearance, and reduces manufacturing costs by simplifying the surface treatment process.

[0089] The present invention will now be described in further detail through detailed embodiments and in conjunction with the accompanying drawings.

[0090] Unless otherwise specified, the experimental methods used in the examples are conventional methods, and the materials and reagents used are commercially available unless otherwise specified.

[0091] Example 1

[0092] refer to Figure 1 This embodiment provides a conductive block, the manufacturing method of which includes the following steps:

[0093] S1. Raw Material Preparation: Prepare the raw materials required for manufacturing the conductive block. By mass percentage, the raw materials for the conductive block include 99.38% electrolytic copper powder (Cu), 0.2% silver powder (Ag), 0.3% tin powder (Sn), 0.08% zirconium powder (Zr), and 0.04% grain boundary purification additive. Among them, the purity of electrolytic copper powder (Cu) is 99.75%~99.95%; the purity of silver powder (Ag), tin powder (Sn), and zirconium powder (Zr) is ≥99.9%; the grain boundary purification additive is trimethyl borate.

[0094] S2. Plasma ball milling: Place the prepared conductive block raw material into a plasma ball mill and perform plasma ball milling under argon gas (purity ≥99.99%) protection. The ball milling speed is 200 r / min, the ball-to-material ratio is 9:1, the ball milling time is 2 h, and the powder temperature is controlled at 65℃. Finally, a uniform composite powder (particle size ≤5μm, dispersion ≥95%) is obtained.

[0095] S3. Warm pressing: The composite powder and molding lubricant (zinc stearate, accounting for 0.03% of the total weight of the conductive block raw material) are placed in the mold and warm pressing is performed using a servo-controlled warm pressing machine. The mold temperature is 135℃ and the pressure is 550MPa. After molding, the temperature is maintained for 25 minutes. The pressure fluctuation during the molding process is ≤±0.1MPa. The blank is obtained. The surface of the molded blank is free of burrs and shrinkage marks, and the surface roughness Ra=0.7μm.

[0096] S4. Vacuum sintering: The preformed blank after warm pressing is placed in a vacuum furnace at a vacuum degree ≤10. -3 Vacuum sintering was carried out under the condition of Pa. First, the temperature was raised to 450℃ at a heating rate of 6℃ / min and held for 1 hour to remove the trace volatiles remaining in the green body. Then, the temperature was raised to 980℃ and held for 2.5 hours. Finally, the temperature was lowered to room temperature with the furnace at a cooling rate of 4℃ / min. The density of the green body was ≥98%.

[0097] S5. Precision cold pressing and laser inspection: The sintered blank is precision cold pressed and shaped using a precision cold pressing mold. The cold pressing pressure is 350MPa, and the pressure is held for 10s to obtain a conductive block semi-finished product. After precision cold pressing and shaping, the contact surface of the conductive block semi-finished product is inspected by laser triangulation (accuracy ≤0.1μm). The flatness of the contact surface is 0.009mm, with no out-of-tolerance.

[0098] S6. Chemical Plating of Nano-Silver Coating: A nano-silver coating is prepared on the contact surface of the conductive block semi-finished product using a chemical plating process. The plating solution (formula composition: 3.2 g / L) is used. The solution consists of 42 g / L glucose, 18 g / L EDTA-2Na, and the remainder ammonia. The deposition time is 15 min, the bath temperature is 65℃, the pH is 8.3, the thickness of the resulting nano-silver coating is 80 nm, it has a single-layer structure, the silver purity is ≥99.9%, and the surface roughness Ra after plating is 0.18 μm.

[0099] S7. Stamping: The surface of the conductive block semi-finished product is cleaned, and then stamped into a rectangular outline (length 20mm, width 10mm, thickness 4mm) to fit the terminal block. The corner radius is 0.8mm, and 30 finished conductive blocks are obtained. After passing the inspection, they are put into storage.

[0100] Example 2

[0101] refer to Figure 1 This embodiment provides a conductive block and its manufacturing method.

[0102] Compared to Example 1, the conductive block in this example does not contain grain boundary cleaning additives. Specifically, by mass percentage, the conductive block's raw materials include 99.42% electrolytic copper powder (Cu), 0.2% silver powder (Ag), 0.3% tin powder (Sn), and 0.08% zirconium powder (Zr), wherein the specific selection of the conductive block's raw materials is the same as in Example 1.

[0103] The manufacturing method of the conductive block in this embodiment is the same as that in Embodiment 1, except that the addition of grain boundary purification additive is omitted in the plasma ball milling step, so it will not be described again.

[0104] Example 3

[0105] refer to Figure 1 This embodiment provides a conductive block and its manufacturing method.

[0106] Compared to Example 1, the conductive block in this example uses a reduced amount of grain boundary cleaning additive. Specifically, by mass percentage, the raw materials of the conductive block include 99.4% electrolytic copper powder (Cu), 0.2% silver powder (Ag), 0.3% tin powder (Sn), 0.08% zirconium powder (Zr), and 0.02% grain boundary cleaning additive. The specific selection of raw materials for the conductive block is the same as in Example 1.

[0107] The manufacturing method of the conductive block in this embodiment is the same as that in Embodiment 1, so it will not be described again.

[0108] Example 4

[0109] refer to Figure 1 This embodiment provides a conductive block and its manufacturing method.

[0110] Compared to Example 1, this example only adjusts the preparation process parameters of the electroless silver nanoparticle coating. Specifically, the deposition time is extended to 20 min, and the coating thickness is controlled to 100 nm. The remaining process parameters in the manufacturing method of the conductive block are the same as in Example 1, so they will not be repeated here.

[0111] Example 5

[0112] refer to Figure 1 This embodiment provides a conductive block and its manufacturing method.

[0113] Compared to Example 1, this example only adjusts the process parameters of the plasma ball milling. Specifically, the plasma ball milling speed is adjusted to 180 r / min. The remaining process parameters in the manufacturing method of the conductive block are the same as in Example 1, so they will not be described again.

[0114] Example 6

[0115] refer to Figure 1 This embodiment provides a conductive block and its manufacturing method.

[0116] Compared with Example 1, this example only adjusts the process parameters of vacuum sintering. Specifically, the high-temperature holding temperature is adjusted from 980℃ to 950℃. The remaining process parameters in the manufacturing method of the conductive block are the same as in Example 1, so they will not be described again.

[0117] Example 7

[0118] refer to Figure 1 This embodiment provides a conductive block and its manufacturing method.

[0119] Compared to Example 1, this example only adjusts the process parameters of precision cold pressing. Specifically, the cold pressing pressure is adjusted to 300 MPa. The remaining process parameters in the manufacturing method of the conductive block are the same as in Example 1, so they will not be described again.

[0120] Example 8

[0121] refer to Figure 1 This embodiment provides a conductive block and its manufacturing method.

[0122] Compared to Example 1, this example only adjusts the raw materials of the conductive block, replacing zirconium powder with chromium powder. Specifically, by mass percentage, the raw materials of the conductive block include 99.38% electrolytic copper powder (Cu), 0.2% silver powder (Ag), 0.3% tin powder (Sn), 0.08% chromium powder (Cr), and 0.04% grain boundary cleaning additive. Among these, the purity of the electrolytic copper powder (Cu) is 99.75%~99.95%; the purity of the silver powder (Ag), tin powder (Sn), and chromium powder (Cr) is ≥99.9%; and the grain boundary cleaning additive is trimethyl borate.

[0123] The manufacturing method of the conductive block in this embodiment is the same as that in Embodiment 1, so it will not be described again.

[0124] The conductive blocks prepared in Examples 1 to 8 were subjected to performance tests. The specific test methods and test data are shown in Table 1 below.

[0125] Table 1. Performance data of the conductive blocks obtained in each embodiment

[0126] Analysis of the performance data in Table 1 reveals the following:

[0127] Example 1 employs a precise multi-element ratio design. High-purity copper serves as the matrix to ensure basic conductivity. The amount of silver added is strictly controlled, effectively reducing overall resistivity without altering the inherent properties of the copper alloy. The introduction of tin improves the flowability during powder forming, preventing cracking defects in the billet, and simultaneously inhibiting the oxidation reaction of the copper matrix at high temperatures. Zirconium forms a nanoscale dispersed reinforcing phase within the copper matrix, significantly enhancing the material's mechanical strength and resulting in a substantial increase in tensile strength compared to traditional processes. The addition of grain boundary purification additives directionally removes impurities such as oxygen and sulfur at grain boundaries, reducing grain boundary resistance and ensuring smoother conductive pathways.

[0128] Both Example 3 and Example 1 had a silver content of 0.2% and identical formulations; however, the contact resistance of the conductive block in Example 3 (38 mΩ) was higher than that in Example 1 (32 mΩ). The core reason for this was the fluctuation of parameters during the process, such as the dispersion during plasma ball milling, the stability of the temperature pressing pressure, and the uniformity of the nano-silver coating. This resulted in a slight decrease in the distribution of silver powder, the density of the blank, or the surface contact precision, thus leading to an increase in contact resistance. Example 2, without the addition of grain boundary purification additives, showed a significant increase in grain boundary impurities and a marked rise in resistivity, highlighting the crucial role of grain boundary purification in conductivity. Example 8 replaced zirconium with chromium, and the final performance was similar to that of Example 1, demonstrating that both elements can achieve the expected strengthening effect and providing flexible material selection for production.

[0129] Precise matching of various process parameters is key to achieving high product performance. The rotation speed of the plasma ball mill directly affects the uniformity of powder mixing. Example 5 used a lower ball milling speed, resulting in decreased powder dispersion and increased contact resistance. The vacuum sintering temperature determines the degree of compaction of the green body. Example 6 used a lower sintering temperature, and the green body density did not reach the optimal level, thus affecting the tensile strength. The pressure parameters of precision cold pressing are closely related to the surface accuracy of the conductive block. Example 7 used a lower cold pressing pressure, resulting in a slight increase in surface flatness deviation and a slight impact on the contact area. Example 1, by optimizing the combination of process parameters, adjusted parameters such as plasma ball milling speed, vacuum sintering temperature, and cold pressing pressure to the optimal range, achieving a perfect balance between powder mixing uniformity, green body compaction, and surface accuracy. This precise process control not only optimizes various performance indicators but also ensures product consistency during mass production, resulting in a finished product qualification rate of up to 99%, providing a reliable guarantee for industrial production.

[0130] The thickness control and process selection of the nano-silver coating directly affect the overall performance of the product. In Example 4, the coating thickness was increased to 100nm. Although the antioxidant performance was slightly improved, the coating thickness exceeded the critical range for invisibility, resulting in a visible color difference that disrupted the appearance consistency with ordinary conductive blocks and failed to meet the uniformity requirements of downstream equipment. Example 1 selected the optimal coating thickness within the 50nm~100nm range, achieving complete antioxidant coverage of the copper substrate while, thanks to the optical properties of the nanoscale thickness, visually blending with the copper alloy substrate and maintaining the inherent color of the copper alloy. Simultaneously, the self-smoothing effect of the chemical plating process further optimized the surface roughness, keeping the contact resistance stable. Compared to traditional electroplating processes, this solution significantly improved coating adhesion, fully validating the innovation and rationality of the chemical plating, single-layer high purity, and specific thickness range design in this invention.

[0131] Example 1, as the optimal solution, comprehensively surpasses other examples and traditional processes in terms of overall performance. Regarding conductivity, the resistivity is significantly lower than traditional processes, contact resistance is greatly reduced, and power transmission loss is significantly decreased. In terms of stability, salt spray corrosion resistance is greatly improved, and contact resistance remains stable during long-term use, effectively preventing conduction failure due to oxidation. Regarding mechanical properties, tensile strength is significantly improved, enabling it to withstand the tightening forces during installation and preventing deformation from affecting contact performance.

[0132] Example 9

[0133] refer to Figure 2 and Figure 3This embodiment proposes a terminal block, including a housing 10, a slider 20, and two conductive blocks 30 prepared in Embodiment 1. The slider 20 is slidably mounted on the housing 10, and the conductive blocks 30 are distributed on both sides of the slider 20. The slider 20 is used to electrically connect the conductive blocks 30 on both sides. The housing 10 is an insulating structure that supports the conductive blocks 30 and the slider 20, and can be made of engineering plastic injection molding. It has guide grooves inside to constrain the movement path of the slider 20. The slider 20, as a sliding component with conductive properties, can be made of silver-plated copper alloy through stamping. Its sliding trajectory matches the contact surface of the conductive blocks 30, used to dynamically adjust the contact pressure. Specifically, the slider 20 consists of two separate blocks connected by a connector. For example, the connector can be a bolt, rivet, or interference-fit post, as long as the two blocks can move synchronously. The conductive blocks 30 have high conductivity and surface precision, suitable for the sliding contact requirements of the slider 20.

[0134] Specifically, the conductive block 30 achieves high density and low surface roughness through a copper-based alloy formula and precision molding process, forming a stable conductive interface with the slider 20 during sliding contact. When the slider 20 slides within the guide groove of the housing 10, its contact pressure adaptively compensates for the minor deformation of the conductive block caused by long-term use, maintaining a constant contact area. Two conductive blocks 30 are symmetrically distributed on both sides of the slider 20, forming a dual-path conductive structure. When the contact resistance of one conductive block increases due to localized oxidation, the other conductive block can still maintain a low-resistance conductive state. When the surface of the conductive block 30 is coated with a nano-silver layer, the coating thickness is controlled at the sub-micron level, ensuring oxidation resistance while maintaining the appearance and color of the copper alloy substrate.

[0135] Existing terminal blocks mostly employ a single conductive block and fixed contact design, which cannot compensate for contact surface deformation and lacks redundant conductive paths. This invention, through a dual conductive block layout and dynamic slider structure, enables a self-adjusting multi-point contact mode within the terminal, preventing overall conductivity failure due to poor local contact. Simultaneously, the conductive block formulation and molding process ensure the high conductivity of the base material, achieving consistent appearance without relying on thick electroplating and overcoming the problem of traditional electroplating processes altering the base material's color.

[0136] Through the above technical solution, this invention solves the problems of power loss and conduction stability caused by the mismatch between the conductive block and the terminal structure. The dynamic contact design of the slider effectively offsets the influence of microscopic deformation of the conductive block surface on the contact resistance, and the dual conductive block layout provides redundant conductive paths, significantly reducing the overall contact resistance fluctuation of the terminal. In addition, the surface treatment process of the conductive block improves oxidation resistance while maintaining the natural color of the copper alloy, meeting the requirements for uniform equipment appearance.

[0137] The above embodiments are merely illustrative of the concept and technical solution of the present invention and are not intended to limit the present invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

[0138] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for manufacturing a conductive block, characterized in that, Includes the following steps: (1) Raw material preparation: Prepare the raw materials required for manufacturing the conductive block. By mass percentage, the raw materials for the conductive block include 99.08% to 99.6% electrolytic copper powder, 0.1% to 0.3% silver powder, 0.2% to 0.5% tin powder, 0.05% to 0.12% zirconium powder or chromium powder, and ≤0.05% grain boundary purification additive; (2) Plasma ball milling: The raw material of the conductive block is subjected to plasma ball milling under inert gas protection to obtain a uniformly mixed composite powder; (3) Warm pressing: The composite powder is placed in a mold and warm pressed at 120℃~150℃ and 500MPa~600MPa pressure. After molding, it is kept warm for 20min~30min to obtain the blank. (4) Vacuum sintering: The preform after warm pressing is placed in a vacuum furnace and sintered at a vacuum degree ≤10. -3 Vacuum sintering is carried out under Pa conditions. First, the temperature is raised to 950℃~1050℃ at a heating rate of 5℃ / min~8℃ / min and held for 2h~3h. Then, the temperature is lowered to room temperature at a cooling rate of 3℃ / min~5℃ / min. (5) Precision cold pressing and laser inspection: The sintered blank is subjected to precision cold pressing mold for precision cold pressing and shaping. The cold pressing pressure is 300MPa~400MPa to obtain the conductive block semi-finished product. The contact surface of the conductive block semi-finished product is subjected to laser inspection to ensure that the flatness of the contact surface is ≤0.01mm. If the deviation is exceeded, the cold pressing parameters are readjusted and a second shaping is performed. (6) Stamping: The blank is cleaned and then stamped to form the required contour to obtain the finished conductive block.

2. The method for manufacturing a conductive block according to claim 1, characterized in that, The purity of the electrolytic copper powder is 99.75%~99.95%, and the purity of the silver powder, tin powder, zirconium powder, and chromium powder is ≥99.9%; the grain boundary purification additive is trimethyl borate or triethyl phosphate.

3. The method for manufacturing a conductive block according to claim 1, characterized in that, The amount of the grain boundary purification additive added is 0.02% to 0.04% by mass percentage.

4. The method for manufacturing a conductive block according to claim 1, characterized in that, The inert gas is argon. The parameters for plasma ball milling are: ball milling speed of 180 r / min to 220 r / min, ball-to-material ratio of (8 to 10): 1, ball milling time of 1.5 h to 2.5 h, and powder temperature controlled at 50 °C to 80 °C during ball milling.

5. The method for manufacturing a conductive block according to claim 1, characterized in that, A molding lubricant is also added during the warm pressing process. The amount of molding lubricant added is 0.02% to 0.05% of the total weight of the conductive block raw material. The molding lubricant is at least one of zinc stearate, magnesium stearate, lithium stearate, and polyethylene glycol.

6. The method for manufacturing a conductive block according to claim 1, characterized in that, The warm pressing process uses a servo-controlled warm pressing machine, with pressure fluctuations ≤ ±0.1MPa and surface roughness Ra ≤ 0.8μm during the pressing process.

7. The method for manufacturing a conductive block according to claim 1, characterized in that, The heating stage in the vacuum sintering process also includes holding at 400℃~500℃ for 1 hour.

8. The method for manufacturing a conductive block according to claim 1, characterized in that, After precision cold pressing and laser inspection, a nano-silver coating is prepared on the contact surface of the conductive block semi-finished product using a chemical plating process. The plating bath temperature is 60℃~70℃ and the pH value is 8.0~8.

5. The formed nano-silver coating is a single-layer structure with a thickness of 50nm~100nm. The silver purity in the nano-silver coating is ≥99.9%, and the surface roughness Ra after plating is ≤0.2μm.

9. A conductive block, characterized in that, It is obtained by any one of the manufacturing methods of claims 1 to 8.

10. A terminal block, characterized in that, The device includes a housing, a slider, and at least two conductive blocks obtained by any one of claims 1 to 8, wherein the slider is slidably mounted on the housing, the conductive blocks are distributed on both sides of the slider, and the slider is used to electrically connect the conductive blocks on both sides.

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