A copper alloy material for a terminal and a method for manufacturing the same

Abstract

The application discloses a copper alloy material for a wiring terminal, characterized in that the mass percentage of each component of the copper alloy material for the wiring terminal is as follows: Pb 0.4-0.7, Te 0.1-0.2, Cr 0.05-0.1, Ti 0.05-0.1, O < 10PPm, and the balance is Cu; and the second phase of the copper alloy material for the wiring terminal comprises Pb, Cu2Te, alpha Cu4Ti and Ti2Cr phases. The copper alloy material for the wiring terminal has high tensile strength, electric conductivity and high-temperature softening resistance. The application further discloses a preparation method of the copper alloy material for the wiring terminal.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of copper alloy, and particularly relates to a copper alloy material for wiring terminals and a preparation method thereof. BACKGROUND

[0002] In the field of automobile wiring terminals, the processing technology is drilling, electroplating, putting into wire harness, riveting and pressing, and plugging, so that the material is required to have certain turning performance, excellent electrical conductivity, good ductility, good arc resistance, compared with traditional terminal materials C3601 and C3602 (electrical conductivity 20-30% IACS), C18700 (electrical conductivity greater than or equal to 85% IACS) has excellent electrical conductivity, so it has excellent ability to transmit electrical signals, but its arc resistance, strength and high temperature resistance are poor, which limits its service life and increases the manufacturing cost of enterprises.

[0003] The main production process of C18700 lead bronze material is semi-continuous casting + extrusion, and there are many welded joints after extrusion. Since the strength of the welded joint can only meet the single pass 20% processing rate without breaking, the required strength of the product cannot be reached at 20% processing rate. In mass production of C18700 material, the joint will frequently break, which greatly affects the production efficiency.

[0004] The patent application with the patent number CN116334441A discloses an easy-to-cut high-conductivity oxygen-free lead copper alloy and a preparation method thereof. The mass percentage composition of the lead copper alloy is P: 0.003% to 0.012%, Pb: 0.8% to 1.2%, O: 1 to 10 ppm, the balance being Cu and unavoidable impurities, the content of impurity elements Fe and Si is controlled to be less than or equal to 0.005%, the content of impurity elements Al, Sb, Mn and Ni is controlled to be less than or equal to 0.02%, and the total content of impurity elements is less than or equal to 0.05%. The preparation adopts bottom blowing refining technology, charcoal covering, reducing the number of annealing, increasing the deformation amount of cold working, etc. The process is: melting, casting, extrusion, pickling, cold drawing and annealing, and straightening and sawing. The easy-to-cut high-conductivity oxygen-free lead copper alloy disclosed in the patent meets the current application of wiring terminal materials, but its service life is short. The main reason is that in the long-term current transmission process, the ablation of current to the material becomes more and more obvious, resulting in lower and lower transmission efficiency. Under the action of large current, the temperature of the material rises sharply, causing softening, and finally leading to product failure, increasing the production cost of enterprises, and not fundamentally solving the performance problems required in the application field of products.

[0005] The patent application with the patent number CN117305653A discloses a lead bronze alloy, and the weight percentage of each component of the lead bronze alloy is as follows: Pb: 0.4-0.7%, Si: 0.1-0.2%, Ce: 0.4-0.7%, and the balance is Cu; the microstructure of the lead bronze alloy is composed of alpha, CePb3, Ce5Pb3 and Si phase. The lead bronze alloy rod has good mechanical properties, electrical conductivity and turning performance, and also has a high softening temperature and a low friction coefficient. However, the anti-arc performance of the lead bronze alloy disclosed by the patent is poor, and cannot meet the stable operation of the terminal under the condition of large current, so an alloy material suitable for large current terminal is needed to adapt to the rapid development of terminal materials. SUMMARY

[0006] The application provides a copper alloy material for a terminal, which has high tensile strength, electrical conductivity and high-temperature softening resistance.

[0007] The application provides a copper alloy material for a terminal, and the mass percentage of each component of the copper alloy material for the terminal is as follows: Pb 0.4-0.7, Te 0.1-0.2, Cr 0.05-0.1, Ti 0.05-0.1, O < 10PPm, and the balance is Cu.

[0008] The second phase of the copper alloy material for the terminal includes Pb, Cu2Te, alpha Cu4Ti and Ti2Cr phase.

[0009] Pb is almost insoluble in copper and is uniformly distributed as free particles on the grain boundary, and acts as a chip breaking point in the turning process to improve the turning performance of the material. The content of Pb in the application is 0.4-0.7, if the content is lower than this, the turning performance of the material is weak, and the knife mark on the surface of the material after turning is deep, which cannot meet the use requirements of electroplating. If the content is higher than this, the melting point of lead is 327 DEG C, and aggregation will occur in the aging process, and lead itself is also a soft phase, which is equivalent to a hole existing in the grain boundary, and reduces the ductility of the material, and cracking will occur in the subsequent riveting pressure, resulting in product scrap.

[0010] The solubility of Te in copper is extremely low, and Cu2Te phase is uniformly distributed in the matrix, which acts as a chip breaking point in the turning process to improve the turning performance of the material, and in addition, due to the high ionization energy, it can remain stable in the process of current impact to improve the anti-arc performance of the material. The content of Te in the application is 0.1-0.2, if the content is lower than this, the turning and anti-arc performance of the material is less improved, and if the content is higher than this, Cu2Te phase is a brittle phase, which is distributed in the grain boundary after aging, and cracking will occur after riveting.

[0011] Preferably, the size of the Pb is 1-5um, and the number of Pb+Cu2Te phases is 5000-8000 / mm 2 By controlling the size of the Pb and the number of Pb+Cu2Te phases, a suitable chip breaking point is maintained in the matrix, thereby ensuring high cutting performance, while avoiding the aggregation of the Pb+Cu2Te phases at the grain boundaries after aging due to excessive number of Pb+Cu2Te phases, thereby causing a fracture phenomenon after cold working. In addition, the proper number of Cu2Te enables the copper alloy material for the terminal provided by the application to have good arc resistance.

[0012] In the Cu-Cr alloy, the solubility of Cr is only 0.65% at the eutectic temperature 1072℃, and the solubility continuously decreases with the decrease of temperature. The Cr will produce a supersaturated solid solution in the copper matrix, which will produce solid solution strengthening. The reason is that the lattice distortion is caused, which causes the increase of internal energy and micro stress, hinders the dislocation slip deformation, but increases the scattering rate of electrons, which increases the strength, hardness, softening temperature of the material, and sharply reduces the electrical conductivity. When aging, the supersaturated solid solution decomposes, and the alloying elements are precipitated in a certain way to form the precipitate Ti2Cr, which can effectively prevent the grain boundary and dislocation movement, thereby improving the hardness, tensile strength, electrical conductivity, softening temperature and other properties of the material. The Cr content of the application is 0.05-0.1. If the content is lower than this, the Cr can be completely precipitated after aging, but the aging strengthening effect is weakened, and the strength and high-temperature softening resistance are slightly improved. If the content is higher than this, the aging strengthening effect is enhanced, and the strength and high-temperature softening resistance are improved, but the Cr exists in the form of dispersed particles in the matrix after aging, which increases the scattering of electrons, resulting in a greater decrease in the electrical conductivity of the material. At the same time, the appropriate amount of Cr, solid solution process and aging process can form the precipitate Ti2Cr with strengthening effect, and avoid the formation of other brittle phases.

[0013] Preferably, the size of the Ti2Cr phase is 20-50 nm, the shape of the Ti2Cr phase is spherical or approximately spherical, and the habit plane orientation thereof is {110}. The Ti2Cr phase with a suitable size ensures that a proper amount of Ti2Cr phases are distributed in the matrix phase to prevent the movement of grain boundaries and dislocations, and the Ti2Cr phase with a suitable size can avoid the situation that Ti and Cr cannot be completely precipitated from the matrix during aging, thereby increasing the scattering rate of electrons and affecting the electrical conductivity. The present application fully breaks the grains of the starting material by continuous extrusion, provides more nucleation sites, and then deforms the material by a certain rolling deformation before solid solution, so that the material has a certain deformation storage energy. After solid solution, the grains do not grow due to the large number of nucleation sites, and the Ti2Cr phase is completely dissolved into the copper matrix. After solid solution, the material is drawn by a certain processing rate before aging, so that the grains are broken and have a certain deformation storage energy before aging. After aging, the Ti2Cr phase precipitates and grows, so that the shape of the Ti2Cr phase is spherical or approximately spherical, so that the Ti2Cr phase is more likely to prevent the movement of grain boundaries and dislocations, the habit plane orientation thereof is {110}, the atomic packing degree thereof is the largest in this orientation, the atomic bonding force is the largest, the performance thereof is better, and the material can better hinder dislocation slip, thereby showing higher tensile strength, elongation, and high-temperature softening resistance.

[0014] Ti atoms in the supersaturated solid solution Cu matrix gather along the {100} direction, which makes the Ti-rich solute-rich region undergo an ordering process. Modulation decomposition occurs, forming aCu4Ti which is coherent with the matrix, and the stacking fault energy thereof is low. During aging, annealing twins are formed, and the intersection of the twins increases the nucleation sites, resulting in grain refinement. In addition, the second phase strengthens the material. When the material is deformed, dislocations slip and are uniformly distributed in the matrix, which hinders the dislocation slip and improves the strength. The Ti content of the present application is 0.05-0.1. If the content is lower than this, the aging strengthening effect is weakened, which is not conducive to improving the high-temperature softening resistance of the material. If the content is higher than this, the second phase precipitated during aging not only increases the electron scattering and reduces the electrical conductivity, but also Ti is an element that is easily absorbed by hydrogen and oxygen. Subsequent materials will crack due to hydrogen embrittlement at high temperatures, resulting in failure.

[0015] Preferably, the size of the alpha Cu4Ti phase is 15-40 nm, the shape of the alpha Cu4Ti phase is spherical or approximately spherical, and the habit plane orientation is {100}. Continuous extrusion sufficiently breaks the grains of the above-mentioned blank, provides more nucleation points, and then a certain rolling deformation is performed, so that the material has a certain deformation storage energy before solid solution, the alpha Cu4Ti phase is deformed, after solid solution, due to the large number of nucleation points, the grains are refined, the alpha Cu4Ti phase is grown, after solid solution, a certain processing rate is drawn, so that the material is broken and has a certain deformation storage energy before aging, the alpha Cu4Ti phase is deformed again, after aging, the alpha Cu4Ti phase is grown to become spherical or approximately spherical. Its habit plane orientation is {100}, in which orientation, the atomic close-packed degree is the largest, the atomic binding force is the largest, and the performance is better, which can better hinder dislocation slip, and the tensile strength, elongation, high-temperature softening resistance and other properties are higher.

[0016] Preferably, the grain size of the copper alloy material for the terminal is 10-20 um, and the dislocation density is 3-7*10 14 / m 2 The higher dislocation density and suitable grain size make the copper alloy material for the terminal provided by the application have higher tensile strength and high-temperature softening resistance.

[0017] In another aspect, the application also provides a preparation method of the copper alloy material for the terminal, and the process flow of the preparation method is: smelting→up-casting→electromagnetic stirring→first acid pickling→continuous extrusion→rolling→solid solution→second acid pickling→drawing→aging of finished product.

[0018] According to the mass percentage of each component of the copper alloy material for the terminal, ingredients are prepared and smelting is performed.

[0019] The rolling processing rate is 40-70%.

[0020] The solid solution temperature is 880-940℃, and the time is 20-40 min.

[0021] The drawing processing rate is 20-40%.

[0022] The aging temperature of the finished product is 400-450℃, and the time is 2-4 h.

[0023] Under the alloy component condition, after continuous extrusion, the grains are further broken after 40-70% rolling pre-deformation, the nucleation points and the deformation storage energy inside the material are increased, the temperature required for recrystallization is reduced, the grain quantity is increased, the grains are refined, sufficient energy is provided for solid solution of the second phase alpha Cu4Ti and Ti2Cr phase, the second phase is completely solid-soluted into the copper matrix at the solid-solution temperature of 880-940 DEG C for 20-40 min, and the grain growth is avoided, and after the drawing processing rate of 20-40%, the grains are broken, the energy and grain refinement are provided for the second phase precipitation in the subsequent finished product aging, and the performance of the material is also improved through work hardening, the second phase is completely precipitated at the aging temperature of 400-450 DEG C for 2-4 h, the material reaches the peak aging state, the performance is best, and the grains will not grow.

[0024] The melting provided by the present application: the melting is carried out by using the up-drawing continuous casting furnace, all elements are added according to the weight percentage, the raw materials for the melting are: oxygen-free red copper rod, 1# lead ingot, pure tellurium, copper-titanium intermediate alloy, copper-chromium intermediate alloy, and the melting temperature is 1350-1400 DEG C. Further, the raw materials provided by the present application are: cathode copper ≥ 99.99%, pure tellurium, 1# lead, copper-titanium intermediate alloy 50%, and copper-chromium intermediate alloy 50%.

[0025] After the composition is qualified after melting, the up-drawing continuous casting is started, and the parameters of the up-drawing continuous casting are as follows:

[0026]

[0027] The electromagnetic stirring provided by the present application: through the generated electromagnetic force, the superheat of the copper water in the crystallizer is improved and eliminated, and the copper water is constantly rolling, the dendritic crystals in the molten liquid are broken, the broken dendritic crystals can act as new nucleation points, the grain of the casting blank is refined, and more equiaxed crystal structure is obtained. In particular: the current frequency is 15-20 HZ, and the current intensity is 400-450 A.

[0028] The continuous extrusion provided by the present application: the extrusion is carried out by using the continuous extrusion machine, and the organization of the extruded blank is more dense. The ingot is put into the TJ630 continuous extrusion machine for water-sealed extrusion. In particular: the extrusion speed is 3-5 mm / s, and the overflow thickness is 1-3 mm. If the speed is higher than this, the transverse cracks are easy to appear on the surface of the material, and if the speed is lower than this, the production efficiency is too low. If the overflow thickness is lower than 1 mm, the defects on the surface of the up-drawing blank will enter the material, and the layered defects will be generated, and if the overflow thickness is higher than this, more waste will be caused, and the material yield will be reduced.

[0029] The rolling provided by the application is that the material after continuous extrusion is cold-rolled, and the rolling deformation is 40-70%, if the deformation is lower than this, the degree of grain crushing is not enough, the nucleation point is not enough after solid solution, the grain grows, and the performance is reduced, if the deformation is higher than this, the grain size is finer, and the material has a risk of cracking.

[0030] The second acid pickling provided by the application is that the material after solid solution is put into an acid pickling tank with H2SO4:HNO3:H2O=5.7:1:12.5 for 20-40 min, and the surface oxide is washed away.

[0031] The drawing provided by the application is that a straight bar product is produced by using a combined drawing machine, a certain processing rate is generated, the aging annealing temperature is reduced, and in particular, the processing rate is 20-40%, if the deformation is lower than this, the material strength is less improved, the Cr element is not completely precipitated after aging, and the material conductivity is reduced, if the deformation is higher than this, the grain becomes very small, the grain boundary is more, the defect is more, and riveting cracking occurs.

[0032] The aging provided by the application is that argon is used as a protective gas to make Cr in the copper matrix precipitate, produce precipitation strengthening, and improve the strength, softening temperature and other properties of the material, the finished product is subjected to 400-450 DEG C bright annealing for 2-4 h, the protective gas is argon, the argon flow is 15-20 m 3 / h, when the aging temperature is lower than 400 DEG C and the time is less than 2 h, the Cr element in the copper matrix cannot be completely precipitated, the aging strengthening effect is weakened, the conductivity, strength, elongation and softening temperature of the material are reduced, and the material is in an under-aged state, when the aging temperature is higher than 450 DEG C and the time is more than 4 h, the Cr in the copper matrix is completely precipitated, the Cr precipitated phase and the grain grow, the strength, elongation and softening temperature of the material are greatly reduced, and the material is in an over-aged state.

[0033] Compared with the prior art, the application has the following beneficial effects:

[0034] The application introduces appropriate Te elements to form Cu2Te phase with Cu, improves the turning performance and the arc resistance of the material, introduces appropriate Cr and Ti elements to form alpha Cu4Ti and Ti2Cr phase to improve the high-temperature softening resistance and strength performance of the material, the conductivity of the copper alloy material for wiring terminals provided by the application is greater than or equal to 80% IACS, the tensile strength is greater than or equal to 420 MPa, A100% is greater than or equal to 25%, the softening temperature is greater than or equal to 400 DEG C, and the turning performance can reach 90% of C36000. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 The metallographic structure diagram of the copper alloy material for wiring terminals prepared in Example 1 is shown in the figure.

[0036] Figure 2 Metallographic structure diagram of the copper alloy material for terminal made for Example 2;

[0037] Figure 3 Metallographic structure diagram of the copper alloy material for terminal made for Example 3;

[0038] Figure 4 Metallographic structure diagram of the copper alloy rod provided for Comparative Example 1;

[0039] Figure 5 Metallographic structure diagram of the copper alloy material for terminal made for Comparative Example 2;

[0040] Figure 6 Metallographic structure diagram of the copper alloy material for terminal made for Comparative Example 3;

[0041] Figure 7 TEM diagram of the copper alloy material for terminal made for Example 1;

[0042] Figure 8 TEM diagram of the copper alloy material for terminal made for Example 2;

[0043] Figure 9 TEM diagram of the copper alloy material for terminal made for Example 3;

[0044] Figure 10 TEM diagram of the copper alloy material for terminal made for Comparative Example 2;

[0045] Figure 11 TEM diagram of the copper alloy material for terminal made for Comparative Example 3. DETAILED DESCRIPTION

[0046] The application will be further described in detail below with reference to the accompanying drawings.

[0047] The application provides Examples 1-3 and Comparative Examples 1-3, and the specific components of Examples 1-3 are shown in Table 1.

[0048] Example 1

[0049] Smelting: oxygen-free bar purity ≥ 99.99%, 1# Pb ingot, Cu-Cr intermediate alloy (Cr 50%), Cu-Ti intermediate alloy (Ti content 50%), elemental Te purity ≥ 99.99%, all elements are added according to mass percentage, and the smelting temperature is 1400℃. Up-drawing continuous casting is used for casting, and the casting specification is Φ28mm, and the batching is shown in Table 1.

[0050] Electromagnetic stirring: current intensity 450A, current frequency 20HZ.

[0051] First acid pickling: the blank is pickled for 20 min, and the surface oxide is removed.

[0052] Continuous extrusion: the Tj630 continuous extruder is used for extrusion, the extrusion speed is 3 mm / s, the overflow amount is 1 mm, and the extrusion specification is Φ30 mm.

[0053] Rolling: the Φ30 mm is cold-rolled to Φ20 mm, and the rolling deformation is 55.6%.

[0054] Solution: the Φ20 mm material is solution-treated at 900 DEG C for 30 min.

[0055] Second acid pickling: the Φ20 mm material is pickled for 30 min.

[0056] Drawing: the Φ17 mm drawing is carried out by using the 8t combined drawing machine.

[0057] Finished product aging: the Φ17 mm drawing finished product is subjected to 430 DEG C 3h bright annealing, and the argon flow is 25 m3 / h, and the finished product performance is shown in Table 2.

[0058] Performance test: 10 samples are randomly selected for performance test.

[0059] As shown in Figure 1 and Figure 7 , the metallographic macrostructure diagram is shown in Figure 1 , only Pb and Cu2Te phases can be seen, Pb is distributed at the grain boundary, Cu2Te phase is distributed in the grain or grain boundary, the number of Pb+Cu2Te phases is 6941 / mm 2 , and the grain size is 0.010 mm. Figure 7 The transmission electron microscope photo of the second phase of the product is shown in

[0060] The shape and orientation of Pb, Cu2Te, αCu4Ti and Ti2Cr phases, and the number of Pb+Cu2Te phases can be formed in combination with the drawings.

[0061] Example 2

[0062] Smelting: oxygen-free bar purity ≥ 99.99%, 1# Pb ingot, Cu-Cr intermediate alloy (Cr 50%), Cu-Ti intermediate alloy (Ti content 50%), elemental Te purity ≥ 99.99%, all elements are added according to mass percentage, and the smelting temperature is 1380 DEG C. The up-drawing continuous casting is used for casting, the casting specification is Φ28 mm, and the batching is shown in Table 1.

[0063] Electromagnetic stirring: current intensity 400 A, current frequency 15 HZ.

[0064] Pickling: Pickle the raw blanks by soaking for 20 minutes to remove the surface oxide scale.

[0065] Continuous extrusion: Extrusion is carried out using a Tj630 continuous extruder with an extrusion speed of 3mm / s, an overflow of 2mm, and an extrusion specification of Φ30mm.

[0066] Rolling: Cold rolling Φ30mm to Φ20mm, with a rolling deformation of 55.6%.

[0067] Solution treatment: The Φ20mm material was solution treated at 880℃ for 40 minutes.

[0068] Pickling: Pickle the Φ20mm material and soak it for 30 minutes.

[0069] Drawing: Φ17mm is drawn using an 8t combined drawing machine.

[0070] Finished product aging: The Φ17mm drawn product was subjected to bright annealing at 420℃ for 3 hours with an argon flow rate of 25m3 / h. The properties of the finished product are shown in Table 2.

[0071] Performance testing: Ten samples were randomly selected for performance testing.

[0072] like Figure 2 and Figure 8 As shown, Figure 2 The metallographic macrostructure diagram shows only Pb and Cu2Te phases. Pb is distributed at grain boundaries, while Cu2Te is distributed within or at grain boundaries. Lead distribution analysis shows that the number of Pb+Cu2Te phases is 7266 / mm. 2 The grain size is 0.015 mm. Figure 8 The image shows a transmission electron microscope (TEM) image of the second phase of the product. The αCu4Ti and Ti2Cr phases are approximately spherical in shape. The inertial separation plane of αCu4Ti is {100}, and that of Ti2Cr is {110}.

[0073] Example 3

[0074] Smelting: Oxygen-free rod purity ≥99.99%, #1 Pb ingot, Cu-Cr master alloy (Cr 50%), Cu-Ti master alloy (Ti content 50%), elemental Te purity ≥99.99%, all elements added according to mass percentage, the smelting temperature is 1360℃. Casting is carried out by top-draw continuous casting, casting size Φ28mm, the material composition is shown in Table 1.

[0075] Electromagnetic stirring: current intensity 410A, current frequency 16HZ.

[0076] Pickling: Pickle the raw blanks by soaking for 20 minutes to remove the surface oxide scale.

[0077] Continuous extrusion: Extrusion is carried out using a Tj630 continuous extruder with an extrusion speed of 4 mm / s, an overflow of 3 mm, and an extrusion specification of Φ30 mm.

[0078] Rolling: Cold rolling Φ30mm to Φ20mm, with a rolling deformation of 55.6%.

[0079] Solution treatment: The Φ20mm material was solution treated at 920℃ for 20 minutes.

[0080] Pickling: Pickle the Φ20mm material and soak it for 30 minutes.

[0081] Drawing: Φ17mm is drawn using an 8t combined drawing machine.

[0082] Finished product aging: The Φ17mm drawn product was bright annealed at 430℃ for 4 hours with an argon flow rate of 25m3 / h. The properties of the finished product are shown in Table 2.

[0083] Performance testing: Ten samples were randomly selected for performance testing.

[0084] like Figure 3 and Figure 9 As shown, Figure 2 The macroscopic microstructure diagram shows only Pb and Cu2Te phases. Pb is distributed at grain boundaries, while Cu2Te is distributed within or at grain boundaries. The lead distribution test shows that the number of Pb+Cu2Te phases is 6296 / mm. 2 . Figure 9 The image shows a transmission electron microscope (TEM) image of the second phase of the product. The αCu4Ti and Ti2Cr phases are approximately spherical in shape. The inertial separation plane of αCu4Ti is {100}, and that of Ti2Cr is {110}.

[0085] Comparative Example 1

[0086] Comparative Example 1 provides C18700 Φ17mm bar stock purchased from the market.

[0087] Metallographic structure such as Figure 4 As shown, Pb is uniformly distributed at the grain boundaries, with a lead particle count of 5465 / mm. 2 The grain size is 0.03 mm.

[0088] Comparative Example 2

[0089] The difference from Example 1 is that the solution temperature was 960℃ for 30 minutes, the aging time was 480℃ for 3 hours, and the composition was the same. The metallographic structure is as follows. Figure 5 As shown, due to the high solution temperature, grain growth occurs, resulting in only a slight improvement in work hardening properties and a decrease in the number of lead particles. The number of Pb+Cu2Te phase particles is 4589 / mm. 2, the grain size is 0.05mm. The transmission electron microscope photograph is shown in Figure 10 As shown in the transmission electron microscope photograph shown in

[0090] Comparative Example 3

[0091] The difference between Example 1 and Comparative Example 3 is that Pb: 1%, Te: 0.8%, Cr: 0.3%, Ti: 0.3%, and the process is the same. The metallographic structure is shown in Figure 6 As shown in the transmission electron microscope photograph shown in 2 Figure 11 As shown in the transmission electron microscope photograph shown in

[0092] Performance analysis:

[0093] High temperature softening resistance: GB / T4340.1 is used as the standard.

[0094] Tensile strength: GB / T228.1-2021 is used as the standard.

[0095] Electrical conductivity: a metal eddy current detector is used for detection.

[0096] Turning performance evaluation standard: under the same turning conditions, a piezoelectric turning force meter is used to measure the turning force.

[0097] Arc resistance test standard: the material is placed between two electrode plates, and the voltage and current are continuously increased during the test. The maximum voltage value that the material can withstand before failure is recorded. As shown in Table 4, the copper alloy material provided by the present application has good electrical conductivity, mechanical properties, high softening temperature, turning performance and arc resistance.

[0098] Table 1 Chemical composition of Example and Comparative Example

[0099] No. Pb % Te % Cr％ Ti % O / ppm Cu Example 1 0.63 0.15 0.06 0.07 6 Balance Example 2 0.65 0.16 0.08 0.09 7 Balance Example 3 0.62 0.18 0.09 0.10 5 Balance

[0100] Table 2 Melting parameters

[0101] ​

[0102] Table 3 Process parameters

[0103]

[0104] Table 4 Performance parameters

[0105]

Claims

1. A copper alloy material for terminal blocks, characterized in that, The mass percentages of the components in the copper alloy material used for the terminals are as follows: Pb 0.4-0.7, Te 0.1-0.2, Cr 0.05-0.1, Ti 0.05-0.1, O < 10 ppm, with the balance being Cu. The second phase of the copper alloy material used for the terminals includes Pb, Cu2Te, aCu4Ti and Ti2Cr phases; The Pb phase has a size of 1-5 μm, and the number of Pb+Cu2Te phases is 5000-8000 per mm. 2 .

2. The copper alloy material for the terminal block according to claim 1, characterized in that, The Ti2Cr phase has a size of 20-50 nm and a spherical or near-spherical shape with an orientation of {110}.

3. The copper alloy material for the terminal block according to claim 1, characterized in that, The size of the aCu4Ti phase is 15-40 nm, and the shape of the αCu4Ti phase is spherical or approximately spherical, with an orientation of {100}.

4. The copper alloy material for the terminal block according to claim 1, characterized in that, The copper alloy material used for the terminals has a grain size of 10-20 μm and a dislocation density of (3-7) * 10⁻⁶. 14 / m 2 .

5. A method for preparing a copper alloy material for terminals according to any one of claims 1-4, characterized in that, The process flow of the preparation method is as follows: smelting → upward continuous casting → electromagnetic stirring → first pickling → continuous extrusion → rolling → solution treatment → second pickling → drawing → aging of finished product. The copper alloy material for terminals as described in any one of claims 1-4 is prepared and smelted according to the mass percentages of each component. The solution treatment temperature is 880-940℃, and the time is 20-40 minutes; The drawing rate is 20-40%; The aging temperature of the finished product is 400-450℃, and the time is 2-4 hours.

6. The method for preparing copper alloy material for terminal blocks according to claim 5, characterized in that, The electromagnetic stirring current has a frequency of 15-20 Hz and a current intensity of 400-450 A.

7. The method for preparing copper alloy material for terminal blocks according to claim 5, characterized in that, The extrusion speed of the continuous extrusion is 3-5 mm / s.

8. The method for preparing copper alloy material for terminal blocks according to claim 5, characterized in that, The deformation during rolling is 40-70%.

9. The method for preparing copper alloy material for terminal blocks according to claim 5, characterized in that, The flow rate of the protective gas during aging is 15-20 m³. 3 / h.

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