Ultrahigh-strength elastic copper alloy high-precision strip foil and preparation method thereof

Abstract

The invention provides an ultrahigh-strength elastic copper alloy high-precision strip foil and a preparation method thereof, and relates to the technical field of copper alloys. The ultrahigh-strength elastic copper alloy high-precision strip foil provided by the invention comprises the following components in percentage by mass: 3.5%-6.0% of Ni, 0.7%-1.5% of Si, 0.1%-0.4% of Mn, 0.05%-0.3% of Mg, 0.01%-0.5% of rare earth elements, 0.01%-0.3% of trace elements and the balance of copper. According to the product, the grain size of a copper matrix is smaller than or equal to 10.5 micrometers, the yield strength is larger than or equal to 1000 MPa, the electric conductivity is larger than or equal to 35% IACS, the elastic modulus is larger than or equal to 125 GPa, the room-temperature 100-hour stress relaxation is smaller than or equal to 10%, the 90-degree bending performance is that cracking is avoided in the GW direction and the BW direction under the conditions that R / t is equal to 2.0 and 2.5, and the requirement for high-end connectors used in the fields of aerospace and the like can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of copper alloys, and in particular to an ultra-high-strength elastic copper alloy high-precision strip foil and a preparation method thereof. Background Art

[0002] Ultra-high-strength elastic copper alloys are critical basic materials urgently needed for high-end electrical connectors in fields such as manned spaceflight and lunar exploration, satellite navigation systems, 5G communications, and the next generation of consumer electronics. The elastic copper alloys used in these fields typically operate in environments characterized by high frequency, high power, and extremely harsh environments. Furthermore, as connectors evolve toward miniaturization, wireless connectivity, high speed, high density, and high reliability, stringent requirements are placed on the strength (≥1000MPa), electrical conductivity (≥35% IACS), bending formability, resistance to high-temperature softening, and even long-term stress relaxation properties of ultra-high-strength elastic copper alloys. Furthermore, the copper alloy strips must possess a good flatness and high-precision geometric dimensions.

[0003] The key reason for the heavy reliance on imports of ultra-high-strength elastic copper alloys is that key technologies for the design and processing of high-performance, high-precision copper alloy strips and foils have yet to be broken through. In actual production, a series of common key technologies for high-performance, high-precision copper alloy strips and foils have yet to be broken through, including ultra-fine grain structure control technology, high-strength and formability coordinated control technology, strip and foil shape dimensional accuracy control technology, high-temperature stress relaxation stability structure design and control technology, and reliability technology for use in different application scenarios. This has led to a significant gap between China and foreign countries in terms of dimensional accuracy, shape control accuracy, mechanical and electrical properties, and their stability. This has led to overcapacity for ordinary products, reliance on imports for high-end products, and the control of high-performance copper alloy technology.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The first object of the present invention is to provide an ultra-high-strength elastic copper alloy high-precision strip foil material to solve the above technical problems.

[0006] The second object of the present invention is to provide a method for preparing the above-mentioned ultra-high-strength elastic copper alloy high-precision strip foil.

[0007] In order to achieve the above objectives, the following technical solutions are adopted:

[0008] In a first aspect, the present invention provides an ultra-high-strength elastic copper alloy high-precision strip foil, comprising, by mass percentage, 3.5% to 6.0% Ni, 0.7% to 1.5% Si, 0.1% to 0.4% Mn, 0.05% to 0.3% Mg, 0.01% to 0.5% rare earth elements, 0.01% to 0.3% trace elements, and the balance being copper;

[0009] The mass ratio of the Ni element to the Si element is (4.0-5.4):1;

[0010] The mass ratio of the Mn element to the Ni element is (0.03-0.1):1;

[0011] The rare earth element is at least one of Sc, La or Y;

[0012] The trace element is at least one of Nb, B or Zr.

[0013] In a second aspect, the present invention provides a method for preparing the above-mentioned ultra-high-strength elastic copper alloy high-precision strip foil, comprising the following steps:

[0014] The materials are prepared according to the mass percentage, and then smelting, casting, hot rolling, milling, first cold rolling, pre-aging, second cold rolling, first solution treatment, third cold rolling, second solution treatment, fourth cold rolling, aging and low-temperature tension annealing are carried out in sequence to prepare ultra-high strength elastic copper alloy high-precision strip foil.

[0015] As a further technical solution, the smelting temperature is 1230-1270°C;

[0016] The casting process parameters include: a casting temperature of 1120-1180° C., a casting speed of 55-85 mm / min, and a cooling water flow rate of 50-100 cubic meters / hour.

[0017] As a further technical solution, the hot rolling start temperature is 900-950°C;

[0018] The final rolling temperature of the hot rolling is 760-820°C;

[0019] The total processing rate of the hot rolling is 95% to 98%.

[0020] As a further technical solution, the processing rate of the first cold rolling is 60% to 80%;

[0021] The processing rate of the second cold rolling is 50% to 75%;

[0022] The processing rate of the third cold rolling is 30% to 60%;

[0023] The processing rate of the fourth cold rolling is 10% to 25%.

[0024] As a further technical solution, the pre-aging device includes a bell annealing furnace;

[0025] The pre-aging temperature is 500-600° C., and the holding time is 5-8 hours.

[0026] As a further technical solution, the device for the first solid solution treatment includes a vertical solid solution furnace;

[0027] The process parameters of the first solution treatment include: a solution temperature of 950 to 1050° C., a solution speed of 9 to 12 m / min, cooling through a protective atmosphere, and a cooling speed of 60 to 80° C. / s.

[0028] As a further technical solution, the device for the second solid solution treatment includes a vertical solid solution furnace;

[0029] The process parameters of the second solution treatment include: a solution temperature of 820-950° C., a solution speed of 18-22 m / min, cooling through a protective atmosphere, and a cooling speed of 60-75° C. / s.

[0030] As a further technical solution, the aging device includes a bell annealing furnace;

[0031] The aging temperature is 400-500° C., and the holding time is 3-6 hours.

[0032] As a further technical solution, the annealing temperature of the low-temperature tension annealing is 350-450° C., the annealing tension is 9-10 kg, and the annealing speed is 30-35 m / min.

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

[0034] The ultra-high-strength, elastic copper alloy high-precision strip and foil provided by the present invention is based on Cu-Ni-Si with the addition of alloying elements such as Mn, Mg, rare earth elements, and trace elements. This product has a copper matrix grain size of ≤10.5μm, a yield strength of ≥1000MPa, a conductivity of ≥35%IACS, an elastic modulus of ≥125GPa, a stress relaxation of ≤10% after 100 hours at room temperature, and exhibits no cracking at 90° bends with R / t=2.0 and R / t=2.5 in the G-W and B-W directions, respectively. This material is a key foundation material for high-end connectors used in aerospace, satellite navigation systems, 5G communications, new energy vehicles, and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 This is the thermal processing diagram of Cu-Ni-Si alloy. DETAILED DESCRIPTION

[0037] Below in conjunction with embodiment and example, embodiment of the present invention is described in detail, but those skilled in the art will appreciate that the following embodiment and example are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiment in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work premise all fall within the scope of protection of the present invention. Unspecified conditions are carried out according to the conditions of normal conditions or manufacturer's recommendations. Reagents used or instruments not specified by the manufacturer are conventional products that can be purchased commercially.

[0038] In a first aspect, the present invention provides an ultra-high-strength elastic copper alloy high-precision strip foil material, which is mainly composed of Ni, Si, Mn, Mg, rare earth elements, trace elements and copper.

[0039] Among them, Ni forms Ni2Si precipitation phase with the main Si element and precipitates through aging, which can simultaneously improve the strength and conductivity of the alloy. The higher the Ni content, the more Ni2Si precipitation phase. Therefore, for ultra-high strength elastic copper-nickel-silicon alloy, the Ni content needs to be ≥3.5%. However, when the Ni content is too much, the Ni2Si precipitation phase will aggregate and grow, losing the effect of aging strengthening. If the Si content is too high, it is easy to generate SiO2 phase with oxygen in the melt, which will reduce the melt fluidity and increase casting defects. Therefore, the ratio of Ni and Si elements should be limited. In the present invention, the content of Ni element can be, for example, but not limited to 3.5%, 5.0% or 6.0%; the content of Si element can be, for example, but not limited to 0.7%, 0.9%, 1.1%, 1.3% or 1.5%; the mass ratio of Ni element to Si element can be, for example, but not limited to 4.0:1, 5.0:1 or 5.4:1.

[0040] Mn is easily oxidized and has a high solid solubility in the α phase of copper alloys. Therefore, it has the effect of deoxidation and solid solution strengthening on copper-nickel-silicon-copper alloys. At the same time, Mn has a strong inhibitory effect on the discontinuous precipitation of Ni2Si phase, which is beneficial to improving the yield strength and elastic modulus of the alloy, improving the stress relaxation resistance and hot workability. However, excessive addition of Mn will replace Ni and Si to form a coarse and brittle Mn2Si second phase, causing the alloy to have a tendency to self-crack. Therefore, the ratio of Mn to Ni elements should be limited. In the present invention, the content of Mn element can be, for example, but not limited to 0.1%, 0.2%, 0.3% or 0.4%; the mass ratio of Mn element to Ni element can be, for example, but not limited to 0.03:1, 0.05:1, 0.08:1 or 0.1:1.

[0041] Mg also has a deoxidizing effect. A small amount can also refine the grains, making the particles smaller and more evenly distributed. The addition of trace amounts of Mg can form Keshi gas clusters, which hinder dislocation movement, thereby improving the alloy's high-temperature oxidation resistance, stress relaxation resistance, and heat resistance. In the present invention, the Mg content can be, for example, but not limited to, 0.05%, 0.1%, 0.2%, or 0.3%.

[0042] Rare earth elements Sc, La, or Y can adsorb impurities, purify the melt, and improve melt fluidity. Small additions can also refine grains and promote the precipitation of precipitated phases, achieving a synergistic improvement in the alloy's mechanical properties and electrical conductivity. In the present invention, the rare earth element content can be, for example, but not limited to, 0.01%, 0.05%, 0.1%, 0.3%, or 0.5%.

[0043] Nb, B, or Zr are almost insoluble in copper-nickel-silicon alloys. Adding small amounts can refine the grains, especially Nb. It can also reduce the average precipitation activation energy during aging, promote the formation of precipitates, and improve the alloy's mechanical, electrical, softening temperature, and wear resistance. In the present invention, the content of trace elements can be, for example, but not limited to, 0.01%, 0.05%, 0.1%, or 0.3%.

[0044] Compared with the prior art, the present invention adds Mn elements, which have the effects of deoxidation and solid solution strengthening on copper-nickel-silicon-copper alloys. At the same time, Mn has a strong inhibitory effect on the discontinuous precipitation of Ni2Si phase, which is beneficial to improving the yield strength and elastic modulus of the alloy and improving hot workability. Adding Mg alloy can also deoxidize and form Keshi gas clusters in the alloy, which hinder the movement of dislocations and improve the high-temperature oxidation resistance, stress relaxation resistance and heat resistance of the alloy. Adding one or more of the rare earth elements Sc, La or Y can purify the melt, improve the melt fluidity, and also refine the grains, promote the precipitation of precipitated phases, and achieve a synergistic improvement in the mechanical properties and electrical conductivity of the alloy. Adding one or more of the trace elements Nb, B or Zr can refine the grains, especially Nb element, and can also reduce the average precipitation activation energy during alloy aging, promote the precipitation of precipitated phases, and improve the mechanical, electrical, softening temperature and wear resistance of the alloy.

[0045] The ultra-high-strength elastic copper alloy high-precision strip foil provided by the present invention has a copper matrix grain size of ≤10.5μm, a yield strength of ≥1000MPa, a conductivity of ≥35%IACS, an elastic modulus of ≥125GPa, a stress relaxation of ≤10% after 100 hours at room temperature, and a 90° bending performance: no cracking in the GW and BW directions under R / t=2.0 and R / t=2.5, respectively. It can meet the requirements of key basic materials for high-end connectors used in aerospace, satellite navigation systems, 5G communications, new energy vehicles and other fields.

[0046] In some optional embodiments, the ultra-high-strength elastic copper alloy high-precision strip foil has a thickness of 0.06 to 0.2 mm and a width of ≥600 mm.

[0047] In a second aspect, the present invention provides a method for preparing the above-mentioned ultra-high-strength elastic copper alloy high-precision strip foil, comprising the following steps:

[0048] The materials are prepared according to the mass percentage, and then smelting, casting, hot rolling, milling, first cold rolling, pre-aging, second cold rolling, first solution treatment, third cold rolling, second solution treatment, fourth cold rolling, aging and low-temperature tension annealing are carried out in sequence to prepare ultra-high strength elastic copper alloy high-precision strip foil.

[0049] In some optional embodiments, the smelting temperature may be, for example, but not limited to, 1230° C., 1250° C., or 1270° C.;

[0050] The casting process parameters include: casting temperature, for example, but not limited to, 1120°C, 1150°C or 1180°C, initial casting speed of 60±5mm / min, normal casting speed of 80±5mm / min, initial cooling water flow of 50-60m 3 / h, normal cooling water flow rate 80~100m 3 / h, processed into ingots.

[0051] In some optional embodiments, the ingot has a width of ≥630 mm and a thickness of ≥190 mm.

[0052] In some optional embodiments, the ingot is heated in a walking beam furnace at a temperature in the range of 900-1200° C. at a rate of 10-12° C. / min, followed by hot rolling;

[0053] The hot rolling start temperature may be, for example, but not limited to, 900° C., 930° C., or 950° C.;

[0054] The final rolling temperature of the hot rolling may be, for example, but not limited to, 760°C, 790°C or 820°C;

[0055] The total processing rate of the hot rolling may be, for example, but not limited to, 95%, 96%, 97% or 98%.

[0056] In some optional embodiments, water cooling and milling are performed after the hot rolling is completed. The specific operation method is not limited and methods familiar to those skilled in the art can be used.

[0057] In particular, the inventors have found that, based on the composition of Example 1 of the present invention, a hot compression test was conducted, and the hot working diagram of the copper-nickel-silicon alloy drawn according to the dissipative structure theory and the instability criterion (see Figure 1) shows that the safe area of ​​hot rolling is mainly distributed in high temperature and some low temperature or low strain rate areas. At high temperature (temperature ≥ 900 ° C), the power dissipation coefficient is as high as 0.23, and decreases with increasing temperature. At some low temperature (temperature ≤ 846 ° C, strain rate ≥ 1.32s -1 ) or low strain rate region (870~890℃, strain rate ≤0.1s -1 ), the power dissipation coefficient is less than 0.21. In order to achieve a higher power dissipation coefficient and obtain hot-rolled plates and strips without defects such as thermal cracking, the hot rolling temperature must be strictly controlled at 900-950℃.

[0058] In some optional embodiments, the processing rate of the first cold rolling may be, for example, but not limited to, 60%, 70% or 80%;

[0059] The processing rate of the second cold rolling can be, for example, but not limited to, 50%, 60% or 75%;

[0060] The processing rate of the third cold rolling can be, for example, but not limited to, 30%, 40%, 50% or 60%;

[0061] The processing rate of the fourth cold rolling may be, for example, but not limited to, 10%, 15%, 20% or 25%.

[0062] In some optional embodiments, the pre-aging device includes a bell jar annealing furnace;

[0063] The pre-aging temperature may be, for example, but not limited to, 500° C., 550° C., or 600° C., and the holding time may be, for example, but not limited to, 5 h, 6 h, 7 h, or 8 h.

[0064] In some optional embodiments, the apparatus for the first solution treatment includes a vertical solution furnace;

[0065] The process parameters of the first solution treatment include: the solution temperature can be, for example, but not limited to 950°C, 1000°C or 1050°C, the solution rate can be, for example, but not limited to 9m / min, 10m / min or 12m / min, and cooling is performed by a protective atmosphere (for example, a mixture of hydrogen and nitrogen), and the cooling rate can be, for example, but not limited to 60°C / s, 70°C / s or 80°C / s.

[0066] After the above-mentioned high-temperature online solution treatment, the primary Ni2Si phase of the alloy is dissolved in the matrix, and rolling defects are eliminated at the same time.

[0067] In some optional embodiments, the apparatus for the second solution treatment includes a vertical solution furnace;

[0068] The process parameters of the second solution treatment include: the solution temperature can be, but not limited to, 820°C, 900°C or 950°C, the solution rate can be, but not limited to, 18m / min, 20m / min or 22m / min, and cooling is performed in a protective atmosphere, and the cooling rate can be, but not limited to, 60°C / s, 70°C / s or 75°C / s.

[0069] During the above low-temperature rapid solution treatment process, the grains elongated by the third cold rolling are broken and refined after the temperature rises. Due to the fast solution rate, the grain growth rate is limited, and the grain refinement effect is finally achieved, which improves the bending performance of the alloy strip. At the same time, the solution treatment can also promote the dissolution of some precipitated phases and reduce the segregation of precipitated phases, so that the precipitated phases can be dispersed and precipitated after subsequent rolling and aging, thereby promoting the synergistic improvement of the mechanical properties and conductivity of the alloy.

[0070] In the present invention, continuous high-temperature solution treatment technology and deformation heat treatment technology compatible with the complete set of equipment are used to regulate the alloy structure and properties; combined with the technical effects of two solid solutions, high-temperature online solid solution dissolves the primary Ni2Si phase, and low-temperature rapid solid solution refines the grains, improves the bending performance of the alloy, and promotes the synergistic improvement of the alloy's mechanical properties and conductive properties.

[0071] In some optional embodiments, the aging device includes a bell jar annealing furnace;

[0072] The aging temperature may be, for example, but not limited to, 400° C., 450° C., or 500° C., and the holding time may be, for example, but not limited to, 3 h, 4 h, or 6 h.

[0073] In some optional embodiments, the annealing temperature of the low-temperature tension annealing may be, for example, but not limited to, 350°C, 400°C or 450°C, the annealing tension may be, for example, but not limited to, 9 kg, 9.5 kg or 10 kg, and the annealing speed may be, for example, but not limited to, 30 m / min, 33 m / min or 35 m / min.

[0074] After the third cold rolling, the grains are elongated and broken, and the precipitated phases are precipitated after aging. After low-temperature tension annealing, the grains are recrystallized, which promotes the increase in the number of small-angle grain boundaries, hinders dislocation movement, increases the number of immobile dislocations, and further improves the stress relaxation properties of the alloy.

[0075] In some optional embodiments, after the low-temperature tension annealing is completed, stretch bending straightening is further performed, the unwinding tension is 18-20N, the winding tension is 35-70N, and the inlet extension is 0.01-0.2%.

[0076] In the present invention, low-temperature tension annealing is combined with rolling and stretch-bending straightening technology to control the surface quality, dimensional accuracy and plate shape of the alloy strip, and is beneficial to improving the alloy's anti-stress relaxation performance.

[0077] The present invention is further described below by means of specific examples and comparative examples. However, it should be understood that these examples are merely provided for more detailed description and are not to be construed as limiting the present invention in any form.

[0078] It should be noted that in the following embodiments and comparative examples, initial rolling refers to the first cold rolling, intermediate rolling refers to the second cold rolling, finishing rolling refers to the third cold rolling, secondary finishing rolling refers to the fourth cold rolling, high-temperature online solution treatment refers to the first solution treatment, low-temperature rapid solution treatment refers to the second solution treatment, 30% Cu-Mn intermediate alloy refers to a Cu-Ni intermediate alloy in which Mn accounts for 30% by mass, and the same applies to other alloys.

[0079] Example 1:

[0080] The alloy compositions are shown in Table 1.

[0081] Electrolytic copper, electrolytic nickel, 60% Ni-Si master alloy, 30% Cu-Mn master alloy, 10% Cu-Mg master alloy, 20% Cu-Sc master alloy, 20% Cu-La master alloy, 20% Cu-Y master alloy, 5% Cu-Nb, 4% Cu-B master alloy or 40% Cu-Zr master alloy are added to the alloy raw materials in order according to the mass ratio of the components. After the metals are completely melted, they are stirred to ensure that the metal melts are evenly mixed.

[0082] Melting and casting: weigh the raw materials according to the alloy composition ratio, mix them and then melt and cast them in sequence. The melting temperature is 1250℃, the casting temperature is 1150℃, the initial casting speed is 60mm / min, the normal casting speed is 80mm / min, and the initial cooling water flow is 55m 3 / h, normal cooling water flow rate 90m 3 / h, processed into ingots;

[0083] Hot rolling: The ingot is heated in a walking beam furnace at a temperature of 1000°C at a rate of 11°C / min, with a starting rolling temperature of 930°C and a finishing rolling temperature of 800°C. The total processing rate is 97%. After hot rolling, the ingot is water-cooled and then milled. The specific operation method is not limited and can be used by methods well known to those skilled in the art.

[0084] Initial rolling: The alloy plate after milling is cold rolled with a deformation processing rate of 75%;

[0085] Pre-aging: The alloy plate after initial rolling is rolled into a coil and placed in a bell annealing furnace for pre-aging at an aging temperature of 550°C for 6 hours.

[0086] Intermediate rolling: The pre-aged alloy coil is uncoiled and cold rolled with a deformation rate of 75%;

[0087] High-temperature online solution treatment: The alloy plate and strip after intermediate rolling are placed in a vertical solution furnace for high-temperature online solution treatment. The solution temperature is 1000°C, the solution speed is 10m / min, and the mixture of hydrogen and nitrogen is used for cooling at a cooling speed of 70°C / s.

[0088] Finish rolling: The alloy plate and strip after solid solution is cold rolled with a deformation processing rate of 60%;

[0089] Low-temperature rapid solution treatment: The finished rolled alloy strip is placed in a vertical solution furnace for low-temperature rapid solution treatment. The solution temperature is 900°C, the solution speed is 20 m / min, and the strip is cooled by a mixture of hydrogen and nitrogen at a cooling speed of 65°C / s.

[0090] Secondary finishing rolling: The aged alloy strip is cold rolled with a deformation rate of 25%;

[0091] Aging: The alloy strip after finish rolling is placed in a bell annealing furnace for aging at a temperature of 450°C for 5 hours in a mixture of hydrogen and nitrogen atmosphere.

[0092] Low temperature tension annealing: The aged alloy strip is subjected to low temperature tension annealing treatment at an annealing temperature of 420°C, an annealing tension of 9.6 kg, and an annealing speed of 32 m / min;

[0093] Stretch leveling: unwinding tension 19N, winding tension 50N, inlet extension 0.1%.

[0094] Example 2:

[0095] The alloy compositions are shown in Table 1.

[0096] Electrolytic copper, electrolytic nickel, 60% Ni-Si master alloy, 30% Cu-Mn master alloy, 10% Cu-Mg master alloy, 20% Cu-Sc master alloy, 20% Cu-La master alloy, 20% Cu-Y master alloy, 5% Cu-Nb, 4% Cu-B master alloy or 40% Cu-Zr master alloy are added to the alloy raw materials in order according to the mass ratio of the components. After the metals are completely melted, they are stirred to ensure that the metal melts are evenly mixed.

[0097] Melting and casting: weigh the raw materials according to the alloy composition ratio, mix them and then melt and cast them in sequence. The melting temperature is 1230℃, the casting temperature is 1120℃, the initial casting speed is 55mm / min, the normal casting speed is 75mm / min, and the initial cooling water flow is 50m 3 / h, normal cooling water flow rate 80m 3 / h, processed into ingots;

[0098] Hot rolling: The ingot is heated in a walking beam furnace at a temperature of 1200°C at a rate of 10°C / min, with a starting rolling temperature of 900°C and a finishing rolling temperature of 820°C. The total processing rate is 98%. After hot rolling, the ingot is water-cooled and then milled. The specific operation method is not limited and can be used by methods well known to those skilled in the art.

[0099] Initial rolling: The alloy plate after milling is cold rolled, and the deformation processing rate is 80%;

[0100] Pre-aging: The alloy sheet after initial rolling is rolled into a coil and placed in a bell annealing furnace for pre-aging at a temperature of 500°C for 8 hours.

[0101] Intermediate rolling: The pre-aged alloy coil is uncoiled and cold rolled with a deformation rate of 75%;

[0102] High-temperature online solution treatment: The alloy plate and strip after intermediate rolling are placed in a vertical solution furnace for high-temperature online solution treatment. The solution temperature is 950°C, the solution speed is 9m / min, and the mixture of hydrogen and nitrogen is used for cooling at a cooling speed of 60°C / s.

[0103] Finish rolling: The alloy plate and strip after solid solution is cold rolled with a deformation processing rate of 60%;

[0104] Low-temperature rapid solution treatment: the finished rolled alloy strip is placed in a vertical solution furnace for low-temperature rapid solution treatment. The solution temperature is 820°C, the solution speed is 18 m / min, and the strip is cooled by a mixture of hydrogen and nitrogen at a cooling speed of 60°C / s.

[0105] Secondary finishing rolling: The aged alloy strip is cold rolled with a deformation rate of 20%;

[0106] Aging: The alloy strip after finish rolling is placed in a bell annealing furnace for aging at a temperature of 400°C for 6 hours in a mixed gas of hydrogen and nitrogen.

[0107] Low temperature tension annealing: The aged alloy strip is subjected to low temperature tension annealing treatment at an annealing temperature of 350°C, an annealing tension of 9kg, and an annealing speed of 30m / min;

[0108] Stretch leveling: unwinding tension 18N, winding tension 35N, inlet extension 0.01%.

[0109] Example 3:

[0110] The alloy compositions are shown in Table 1.

[0111] Electrolytic copper, electrolytic nickel, 60% Ni-Si master alloy, 30% Cu-Mn master alloy, 10% Cu-Mg master alloy, 20% Cu-Sc master alloy, 20% Cu-La master alloy, 20% Cu-Y master alloy, 5% Cu-Nb, 4% Cu-B master alloy or 40% Cu-Zr master alloy are added to the alloy raw materials in order according to the mass ratio of the components. After the metals are completely melted, they are stirred to ensure that the metal melts are evenly mixed.

[0112] Melting and casting: weigh the raw materials according to the alloy composition ratio, mix them and then melt and cast them in sequence. The melting temperature is 1270℃, the casting temperature is 1180℃, the initial casting speed is 65mm / min, the normal casting speed is 85mm / min, and the initial cooling water flow is 60m 3 / h, normal cooling water flow rate 100m 3 / h, processed into ingots;

[0113] Hot rolling: The ingot is heated in a walking beam furnace at a temperature of 1200°C, a rate of 12°C / min, a starting rolling temperature of 950°C, a final rolling temperature of 820°C, and a total processing rate of 98%. After hot rolling, the ingot is water-cooled and then milled. The specific operation method is not limited and can be used by methods familiar to those skilled in the art.

[0114] Initial rolling: The alloy plate after milling is cold rolled, and the deformation processing rate is 76%;

[0115] Pre-aging: The alloy sheet after initial rolling is rolled into a coil and placed in a bell annealing furnace for pre-aging at a temperature of 600°C for 5 hours.

[0116] Intermediate rolling: The pre-aged alloy coil is uncoiled and cold rolled with a deformation rate of 50%;

[0117] High-temperature online solution treatment: the alloy plate and strip after intermediate rolling are placed in a vertical solution furnace for high-temperature online solution treatment. The solution temperature is 1020°C, the solution speed is 12m / min, and the mixture of hydrogen and nitrogen is used for cooling at a cooling rate of 80°C / s.

[0118] Finish rolling: cold rolling the alloy plate and strip after solid solution treatment, with a deformation processing rate of 50%;

[0119] Low-temperature rapid solid solution: The alloy strip after finish rolling is placed in a vertical solid solution furnace for low-temperature rapid solid solution. The solid solution temperature is 950°C, the solid solution speed is 22m / min, and it is cooled by a mixed gas of hydrogen and nitrogen at a cooling speed of 72°C / s.

[0120] Secondary finishing rolling: The aged alloy strip is cold rolled with a deformation rate of 10%;

[0121] Aging: The alloy strip after finish rolling is placed in a bell annealing furnace for aging at a temperature of 500°C for 3 hours in a mixed gas of hydrogen and nitrogen.

[0122] Low temperature tension annealing: The aged alloy strip is subjected to low temperature tension annealing treatment at an annealing temperature of 450°C, an annealing tension of 10kg, and an annealing speed of 35m / min;

[0123] Stretch leveling: unwinding tension 20N, winding tension 70N, inlet extension 0.2%.

[0124] Example 4:

[0125] Electrolytic copper, electrolytic nickel, 60% Ni-Si master alloy, 30% Cu-Mn master alloy, 10% Cu-Mg master alloy, 20% Cu-Sc master alloy, 20% Cu-La master alloy, 20% Cu-Y master alloy, 5% Cu-Nb, 4% Cu-B master alloy or 40% Cu-Zr master alloy are added to the alloy raw materials in order according to the mass ratio of the components. After the metals are completely melted, they are stirred to ensure that the metal melts are evenly mixed.

[0126] Melting and casting: weigh the raw materials according to the alloy composition ratio, mix them and then melt and cast them in sequence. The melting temperature is 1250℃, the casting temperature is 1150℃, the initial casting speed is 60mm / min, the normal casting speed is 80mm / min, and the initial cooling water flow is 55m 3 / h, normal cooling water flow rate 90m 3 / h, processed into ingots;

[0127] Hot rolling: The ingot is heated in a walking beam furnace at a temperature of 1200°C, a rate of 11°C / min, a starting rolling temperature of 950°C, a final rolling temperature of 800°C, and a total processing rate of 98%. After hot rolling, the ingot is water-cooled and then milled. The specific operation method is not limited and can be used by methods familiar to those skilled in the art.

[0128] Initial rolling: The alloy plate after milling is cold rolled, and the deformation processing rate is 80%;

[0129] Pre-aging: The alloy plate after initial rolling is rolled into a coil and placed in a bell annealing furnace for pre-aging at an aging temperature of 550°C for 6 hours.

[0130] Intermediate rolling: The pre-aged alloy coil is uncoiled and cold rolled with a deformation rate of 75%;

[0131] High-temperature online solution treatment: the alloy plate and strip after intermediate rolling are placed in a vertical solution furnace for high-temperature online solution treatment. The solution temperature is 1000°C, the solution speed is 10m / min, and the mixture of hydrogen and nitrogen is used for cooling at a cooling speed of 70°C / s.

[0132] Finish rolling: The alloy plate and strip after solid solution is cold rolled with a deformation processing rate of 30%;

[0133] Low-temperature rapid solution treatment: The finished rolled alloy strip is placed in a vertical solution furnace for low-temperature rapid solution treatment. The solution temperature is 900°C, the solution speed is 20 m / min, and the strip is cooled by a mixture of hydrogen and nitrogen at a cooling speed of 65°C / s.

[0134] Secondary finishing rolling: The aged alloy strip is cold rolled with a deformation rate of 10%;

[0135] Aging: The alloy strip after finish rolling is placed in a bell annealing furnace for aging at a temperature of 450°C for 5 hours in a mixture of hydrogen and nitrogen atmosphere.

[0136] Low temperature tension annealing: The aged alloy strip is subjected to low temperature tension annealing treatment at an annealing temperature of 450°C, an annealing tension of 9.6 kg, and an annealing speed of 30 m / min;

[0137] Stretch leveling: unwinding tension 19N, winding tension 50N, inlet extension 0.1%.

[0138] Example 5:

[0139] Electrolytic copper, electrolytic nickel, 60% Ni-Si master alloy, 30% Cu-Mn master alloy, 10% Cu-Mg master alloy, 20% Cu-Sc master alloy, 20% Cu-La master alloy, 20% Cu-Y master alloy, 5% Cu-Nb, 4% Cu-B master alloy or 40% Cu-Zr master alloy are added to the alloy raw materials in order according to the mass ratio of the components. After the metals are completely melted, they are stirred to ensure that the metal melts are evenly mixed.

[0140] Melting and casting: weigh the raw materials according to the alloy composition ratio, mix them and then melt and cast them in sequence. The melting temperature is 1250℃, the casting temperature is 1150℃, the initial casting speed is 60mm / min, the normal casting speed is 80mm / min, and the initial cooling water flow is 55m 3 / h, normal cooling water flow rate 90m 3 / h, processed into ingots;

[0141] Hot rolling: The ingot is heated in a walking beam furnace at a temperature of 900°C and a rate of 11°C / min. The starting rolling temperature is 900°C, the finishing rolling temperature is 760°C, and the total processing rate is 95%. After the hot rolling is completed, the ingot is water-cooled and then milled. The specific operation method is not limited and can be used by methods familiar to those skilled in the art.

[0142] Initial rolling: The alloy plate after milling is cold rolled, and the deformation processing rate is 80%;

[0143] Pre-aging: The alloy plate after initial rolling is rolled into a coil and placed in a bell annealing furnace for pre-aging at an aging temperature of 550°C for 6 hours.

[0144] Intermediate rolling: The pre-aged alloy coil is uncoiled and cold rolled with a deformation rate of 70%;

[0145] High-temperature online solution treatment: The alloy plate and strip after intermediate rolling are placed in a vertical solution furnace for high-temperature online solution treatment. The solution temperature is 1000°C, the solution speed is 10m / min, and the mixture of hydrogen and nitrogen is used for cooling at a cooling speed of 70°C / s.

[0146] Finish rolling: The alloy plate and strip after solid solution is cold rolled with a deformation processing rate of 60%;

[0147] Low-temperature rapid solution treatment: The finished rolled alloy strip is placed in a vertical solution furnace for low-temperature rapid solution treatment. The solution temperature is 900°C, the solution speed is 20 m / min, and the strip is cooled by a mixture of hydrogen and nitrogen at a cooling speed of 65°C / s.

[0148] Secondary finishing rolling: The aged alloy strip is cold rolled with a deformation rate of 25%;

[0149] Aging: The alloy strip after finish rolling is placed in a bell annealing furnace for aging at a temperature of 450°C for 5 hours in a mixture of hydrogen and nitrogen atmosphere.

[0150] Low temperature tension annealing: The aged alloy strip is subjected to low temperature tension annealing treatment at an annealing temperature of 420°C, an annealing tension of 9.6 kg, and an annealing speed of 32 m / min;

[0151] Stretch leveling: unwinding tension 19N, winding tension 50N, inlet extension 0.1%.

[0152] Example 6:

[0153] The alloy compositions are shown in Table 1.

[0154] Electrolytic copper, electrolytic nickel, 60% Ni-Si master alloy, 30% Cu-Mn master alloy, 10% Cu-Mg master alloy, 20% Cu-Sc master alloy, 20% Cu-La master alloy, 20% Cu-Y master alloy, 5% Cu-Nb, 4% Cu-B master alloy or 40% Cu-Zr master alloy are added to the alloy raw materials in order according to the mass ratio of the components. After the metals are completely melted, they are stirred to ensure that the metal melts are evenly mixed.

[0155] Melting and casting: weigh the raw materials according to the alloy composition ratio, mix them and then melt and cast them in sequence. The melting temperature is 1250℃, the casting temperature is 1150℃, the initial casting speed is 60mm / min, the normal casting speed is 80mm / min, and the initial cooling water flow is 55m 3 / h, normal cooling water flow rate 90m 3 / h, processed into ingots;

[0156] Hot rolling: The ingot is heated in a walking beam furnace at a temperature of 1000°C, a rate of 11°C / min, a starting rolling temperature of 930°C, a final rolling temperature of 800°C, and a total processing rate of 98%. After hot rolling, the ingot is water-cooled and then milled. The specific operation method is not limited and can be used by methods familiar to those skilled in the art.

[0157] Initial rolling: The alloy plate after milling is cold rolled with a deformation rate of 60%;

[0158] Pre-aging: The alloy plate after initial rolling is rolled into a coil and placed in a bell annealing furnace for pre-aging at an aging temperature of 550°C for 6 hours.

[0159] Intermediate rolling: The pre-aged alloy coil is uncoiled and cold rolled with a deformation rate of 75%;

[0160] High-temperature online solution treatment: The alloy plate and strip after intermediate rolling are placed in a vertical solution furnace for high-temperature online solution treatment. The solution treatment temperature is 1050°C, the solution treatment speed is 10m / min, and the mixture of hydrogen and nitrogen is used for cooling at a cooling speed of 70°C / s.

[0161] Finish rolling: The alloy plate and strip after solid solution is cold rolled with a deformation processing rate of 60%;

[0162] Low-temperature rapid solid solution: The alloy strip after finish rolling is placed in a vertical solid solution furnace for low-temperature rapid solid solution. The solid solution temperature is 900°C, the solid solution speed is 20m / min, and it is cooled by a mixed gas of hydrogen and nitrogen at a cooling speed of 75°C / s.

[0163] Secondary finishing rolling: The aged alloy strip is cold rolled with a deformation rate of 25%;

[0164] Aging: The alloy strip after finish rolling is placed in a bell annealing furnace for aging at a temperature of 450°C for 5 hours in a mixture of hydrogen and nitrogen atmosphere.

[0165] Low temperature tension annealing: The aged alloy strip is subjected to low temperature tension annealing treatment at an annealing temperature of 420°C, an annealing tension of 9.6 kg, and an annealing speed of 32 m / min;

[0166] Stretch leveling: unwinding tension 19N, winding tension 50N, inlet extension 0.1%.

[0167] Comparative Example 1:

[0168] The difference from Example 1 is that an excessive amount of Ni element is added, the addition amount is 7%, the Ni:Si ratio is 8.6 (>5), and the element composition is shown in Table 1.

[0169] Comparative Example 2:

[0170] The difference from Example 1 is that no Mn element is added.

[0171] Comparative Example 3:

[0172] The difference from Example 1 is that an excessive amount of Mn element is added, the addition amount is 0.5%, the Mn:Ni ratio is 0.14 (>0.1), and the element composition is shown in Table 1.

[0173] Comparative Example 4:

[0174] The difference from Example 1 is that no Mg element is added.

[0175] Comparative Example 5:

[0176] The difference from Example 1 is that no rare earth element (Sc element) is added.

[0177] Comparative Example 6:

[0178] The difference from Example 1 is that no trace element (Nb element) is added.

[0179] Comparative Example 7:

[0180] The difference from Example 1 is that the solution temperature of the high-temperature online solution is 900°C.

[0181] Comparative Example 8:

[0182] The difference from Example 1 is that the low-temperature rapid solution speed is 12 m / min.

[0183] Comparative Example 9:

[0184] The difference from Example 1 is that the secondary finishing rolling deformation processing rate is 5%.

[0185] Comparative Example 10:

[0186] The difference from Example 1 is that there is no low-temperature tension annealing.

[0187] Comparative Example 11

[0188] The difference from Example 1 is that more Si element is added, the addition amount is 1.5%, the Ni:Si ratio is 2.3 (<4), and the element composition is shown in Table 1.

[0189] Comparative Example 12

[0190] The difference from Example 1 is that more Mn element is added, the addition amount is 0.4%, the Mn:Ni ratio is 0.11 (>0.1), and the element composition is shown in Table 1.

[0191] Table 1 Alloy compositions of Examples and Comparative Examples

[0192]

[0193]

[0194] The properties of the strips provided in the above examples and comparative examples were tested, and the results are shown in Table 2.

[0195] Table 2 Performance and organizational structure of alloys in Examples and Comparative Examples

[0196]

[0197]

[0198] It can be seen from the test results that the foil provided by the embodiment of the present invention has the best comprehensive performance and can meet the demand for key basic materials of high-end connectors used in aerospace, satellite navigation systems, 5G communications, new energy vehicles and other fields.

[0199] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An ultra-high-strength elastic copper alloy high-precision strip foil, characterized in that: Calculated by mass percentage, it includes: Ni 3.5% to 6.0%, Si 0.7% to 1.5%, Mn 0.1% to 0.4%, Mg 0.05% to 0.3%, rare earth elements 0.01% to 0.5%, trace elements 0.01% to 0.3%, and the balance is copper; The mass ratio of the Ni element to the Si element is (4.0-5.4):1; The mass ratio of the Mn element to the Ni element is (0.03-0.1):1; The rare earth element is at least one of Sc, La or Y; The trace element is at least one of Nb, B or Zr.

2. The method for preparing the ultra-high-strength elastic copper alloy high-precision strip foil according to claim 1, characterized in that: The following steps are involved: The ingredients are prepared according to the mass percentage, and then smelting, casting, hot rolling, milling, first cold rolling, pre-aging, second cold rolling, first solution treatment, third cold rolling, second solution treatment, fourth cold rolling, aging and low-temperature tension annealing are carried out in sequence to prepare ultra-high strength elastic copper alloy high-precision strip foil.

3. The preparation method according to claim 2, characterized in that: The smelting temperature is 1230-1270°C; The casting process parameters include: a casting temperature of 1120-1180° C., a drawing speed of 55-85 mm / min, and a cooling water flow rate of 50-100 m3 / h.

4. The preparation method according to claim 2, characterized in that: The hot rolling start temperature is 900-950°C; The final rolling temperature of the hot rolling is 760-820°C; The total processing rate of the hot rolling is 95% to 98%.

5. The preparation method according to claim 2, characterized in that: The processing rate of the first cold rolling is 60% to 80%; The processing rate of the second cold rolling is 50% to 75%; The processing rate of the third cold rolling is 30% to 60%; The processing rate of the fourth cold rolling is 10% to 25%.

6. The preparation method according to claim 2, characterized in that: The pre-aging device includes a bell annealing furnace; The pre-aging temperature is 500-600° C., and the insulation time is 5-8 hours.

7. The preparation method according to claim 2, characterized in that: The first solution treatment device comprises a vertical solution furnace; The process parameters of the first solution treatment include: a solution temperature of 950 to 1050° C., a solution speed of 9 to 12 m / min, cooling through a protective atmosphere, and a cooling speed of 60 to 80° C. / s.

8. The preparation method according to claim 2, characterized in that: The second solution treatment device comprises a vertical solution furnace; The process parameters of the second solution treatment include: a solution temperature of 820-950° C., a solution speed of 18-22 m / min, cooling through a protective atmosphere, and a cooling speed of 60-75° C. / s.

9. The preparation method according to claim 2, characterized in that: The aging device includes a bell annealing furnace; The aging temperature is 400-500° C., and the insulation time is 3-6 hours.

10. The preparation method according to claim 2, characterized in that: The annealing temperature of the low-temperature tension annealing is 350-450° C., the annealing tension is 9-10 kg, and the annealing speed is 30-35 m / min.

Images