Synergistic modified Cu-Ti alloy and preparation method thereof

Abstract

The invention provides a synergistically modified Cu-Ti alloy and a preparation method thereof. The synergistic modified Cu-Ti alloy comprises the following components in percentage by mass: 3.0-3.5 wt% of a Ti element, less than or equal to 0.01 wt% of a B element, less than or equal to 0.01 wt% of a Zr element and the balance of a Cu element, wherein the synergistic modified Cu-Ti alloy comprises a beta '-Cu4Ti precipitated phase with the size of 3 to 5 nm, a beta'-Cu4Ti precipitated phase with the size of 6 to 15 nm and a beta '-Cu4Ti precipitated phase with the size of 16 to 26 nm. The multi-scale precipitation phases jointly act on an alloy matrix, so that the strength, plasticity and conductivity of the synergistically modified Cu-Ti alloy material are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of Cu-Ti alloy preparation technology, and more specifically, to a synergistically modified Cu-Ti alloy and its preparation method. Background Technology

[0002] Although various high-strength conductive copper alloys are widely used in instruments, elastic elements, and conductive and heat-conducting components, such as various current-carrying elastic elements and contact springs, the increasing integration of electronic components due to the rapid pace of informatization, automation, and intelligentization in recent years has led to a trend towards miniaturization, thinning, and special-shaped high-strength conductive copper alloy elastic components. This places higher demands on the mechanical, conductive, and processing properties of high-strength conductive copper alloys. While Cu-Be alloys are renowned for their excellent conductivity and mechanical properties, and can achieve high strength and hardness after appropriate solution-aging treatment, exhibiting excellent corrosion resistance and cold workability—ranking among copper alloys—their high production cost, relatively complex processes, high sensitivity to heat treatment, poor high-temperature stress relaxation resistance, and unstable alloy properties make them unsuitable for prolonged high-temperature operation. Furthermore, beryllium and its compounds are toxic, posing a threat to human health and the environment. These shortcomings severely limit the further widespread application of this alloy. Furthermore, with the increasing awareness of environmental protection and conservation, non-toxic, pollution-free, low-energy-consumption, green, and recyclable materials have become the main development direction for flexible copper alloy materials. To address the shortcomings of traditional materials, researchers have sought and developed a series of new be-free flexible copper alloy materials, such as Cu-Ni-Si alloys, Cu-Ni-Sn alloys, and Cu-Ti alloys.

[0003] Similar to Cu-Be alloys, Cu-Ti alloys are also high-strength, high-elasticity copper alloys. With proper process control, Cu-Ti alloys can achieve strengths similar to Cu-Be alloys, and they also possess good wear resistance, machinability, and high-temperature stress relaxation resistance, and are non-toxic during production and use. Therefore, Cu-Ti alloys are ideal alternatives to Cu-Be alloys. However, a key issue with this alloy system is that achieving high strength generally does not lead to a simultaneous improvement in electrical conductivity. Whether produced by leading international Japanese companies or domestically produced Cu-Ti alloy sheets and strips from various Chinese companies, when the tensile strength reaches over 1000 MPa, the corresponding electrical conductivity is generally below 15% IACS. The key reason for the difficulty in effectively improving the alloy's conductivity is that even trace amounts of Ti dissolved in the alloy matrix significantly reduce the conductivity of Cu-Ti alloys. Therefore, how to effectively improve the conductivity of this alloy system without compromising strength is an urgent problem to be solved.

[0004] To address the poor electrical conductivity of high-strength Cu-Ti alloys, extensive research has been conducted both domestically and internationally. For example, aging in a H2 atmosphere promotes Ti precipitation within the Cu-Ti alloy matrix, leading to the formation of Cu4Ti and δ-TiH2 phases, which improves both conductivity and elongation, but reduces strength. Additionally, studies have investigated the effect of introducing ultra-low temperature cold rolling deformation before aging of Cu-1.5wt%Ti alloys on precipitation behavior. These studies found that after 90% deformation followed by aging, the hardness, yield strength, and tensile strength of Cu-1.5wt%Ti alloys with lower Ti content were all improved to some extent. Furthermore, alloying is a common method for improving the properties of copper alloys; the interaction between different alloying elements can also enhance strength and conductivity to some extent. Therefore, to better induce effective Ti precipitation from the alloy matrix, research has been conducted on improving alloy conductivity by adding a third element, such as Fe, Ni, Al, Sn, Zr, Co, Cr, Cd, B, and Mg. The results show that the addition of these elements does have some influence on the precipitation of alloys, but the effect is not significant and still cannot effectively solve the common key problem of synergistic improvement of the strong and electrical properties of this series of alloys. For example, after aging control, the Cu-3Ti-0.5Cr alloy prepared by adding Cr was found to delay the precipitation and amplitude-modulated decomposition of discontinuous precipitates and reduce the volume fraction of precipitated phases. Although a maximum hardness of 320 HV can be obtained after cold rolling deformation at 450℃ and 90%, the increase in conductivity is still very small. In addition, under certain aging conditions, the addition of Al can improve the conductivity of Cu-3wt%Ti alloy, but the peak hardness will decrease by 35%. Furthermore, after peak aging treatment, the Cu-4.5Ti-0.5Co alloy achieves a hardness of 320 HV, a yield strength of 610 MPa, and a tensile strength of 710 MPa, but its conductivity only increases to 8% IACS. It is evident that while the addition of the third component has a positive effect on improving the conductivity of the alloy to some extent, its overall impact on the increase in conductivity is not significant. Based on the control of the third component, there has been considerable research on further improving the strength and conductivity of the alloy through deformation heat treatment, ultimately hoping to achieve a significant increase in the strength and conductivity of this alloy system through the synergistic effect of deformation strengthening and precipitation strengthening. However, to date, most research on deformation heat treatment processes focuses more on directly cold rolling (room temperature cold rolling or ultra-low temperature cold rolling) the solution-quenched alloy, followed by isothermal aging, or on this basis, secondary cold rolling deformation + isothermal aging control. This not only results in poor coupling distribution of precipitated phases and dislocations, but also makes it difficult to effectively improve the conductivity when the alloy strength reaches above 1000 MPa.Furthermore, when the tensile strength of Cu-Ti alloys exceeds 1000 MPa, their elongation is generally low, sometimes even only around 1%. This results in insufficient bending performance and susceptibility to cracking in high-strength Cu-Ti alloy strips. This is particularly true for 0.1 mm thick Cu-Ti alloy strips used in ultra-thin, irregularly shaped components, where higher elongation is required to meet bending performance requirements. Therefore, while further improving conductivity, how to further improve the plasticity of this alloy strip system is also a key issue in recent times.

[0005] Based on the performance requirements of next-generation high-strength conductive copper alloy elastic components, and considering that the key factors affecting the improvement of alloy strength, conductivity, and other properties remain composition and processing, especially processing, it is necessary to break away from traditional microstructure design and control approaches to achieve a synergistic improvement in the overall performance of this alloy system. Only through the development of new microstructure design and control processes can breakthroughs in the synergistic improvement of the overall performance of this alloy system be achieved. Therefore, it is essential to develop a high-strength conductive Cu-Ti alloy sheet / strip and its preparation technology that does not increase alloy production costs while possessing excellent comprehensive performance, thereby better meeting the urgent needs of high-tech fields for this type of material. Furthermore, this novel Cu-Ti alloy material and its preparation process will also provide important inspiration and impetus for the further development of other novel metallic materials. Summary of the Invention

[0006] The main objective of this invention is to provide a synergistically modified Cu-Ti alloy and its preparation method, so as to solve the problem in the prior art that Cu-Ti alloy materials are difficult to simultaneously achieve excellent strength and conductivity.

[0007] To achieve the above objectives, according to one aspect of the present invention, a synergistically modified Cu-Ti alloy is provided, comprising, by mass percentage: 3.0 to 3.5 wt% Ti, ≤0.01 wt% B, ≤0.01 wt% Zr, and the balance being Cu; wherein the synergistically modified Cu-Ti alloy comprises a β'-Cu4Ti precipitate phase with a size of 3 to 5 nm, a β'-Cu4Ti precipitate phase with a size of 6 to 15 nm, and a β'-Cu4Ti precipitate phase with a size of 16 to 26 nm.

[0008] Furthermore, the dislocation density of the aforementioned synergistically modified Cu-Ti alloy is (8–10) × 10⁻⁶. 14 ·m -2 .

[0009] Furthermore, the spacing between adjacent particles of the β'-Cu4Ti precipitate phase with a size of 3-5 nm is 7-9 nm; and / or the spacing between adjacent particles of the β'-Cu4Ti precipitate phase with a size of 6-15 nm is 11-14 nm; and / or the spacing between adjacent particles of the β'-Cu4Ti precipitate phase with a size of 16-26 nm is 20-26 nm.

[0010] According to another aspect of the present invention, a method for preparing the aforementioned synergistically modified Cu-Ti alloy is provided, the method comprising the following steps performed sequentially: batching, casting, homogenization heat treatment, hot rolling deformation, cold rolling deformation, solution treatment, cooling pre-aging treatment, first cold rolling, first cooling aging, second cold rolling, second cooling aging, third cold rolling, isothermal aging, and third cooling aging.

[0011] Furthermore, the solution temperature is 800–900°C. After solution treatment for 2–5 hours, the solution is cooled to the initial temperature of the cooling pre-aging treatment at a cooling rate greater than 100°C / min, and / or the temperature of the cooling pre-aging treatment is reduced from 410°C to 350°C. The cooling rate during the cooling pre-aging treatment is 0.4–1.5°C / h. After the cooling pre-aging treatment is completed, the solution is air-cooled to 25–30°C.

[0012] Furthermore, the temperature of the first cold rolling is 25-30℃, the total deformation is 40-60%, the deformation method is unidirectional synchronous rolling, and the deformation per pass is 5-20%; and / or the temperature of the first cooling aging is reduced from 500℃ to 350℃, the cooling rate is 1.5-2.0℃ / min, and air cooling is performed when the temperature of the first cooling aging is 350℃.

[0013] Furthermore, the temperature of the second cold rolling is 25-30℃, the total deformation is 40-60%, the deformation method is unidirectional synchronous rolling, and the deformation per pass is 5-20%; and / or the temperature of the second cooling aging is reduced from 500℃ to 350℃, the cooling rate is 1.5-2.0℃ / min, and air cooling is performed when the temperature of the second cooling aging is 350℃.

[0014] Furthermore, the temperature of the third cold rolling is 25-30°C, the total deformation is 35-55%, the deformation method is unidirectional synchronous rolling, and the deformation per pass is 5-15%.

[0015] Furthermore, the isothermal aging temperature is 400–420°C, and the heating rate is greater than 100°C / min during the process of raising the temperature to the isothermal aging temperature. After isothermal aging for 1–7 hours, the temperature is raised to the highest temperature of the third cooling aging at a rate greater than 100°C / min, and the third cooling aging is carried out. The third cooling aging is performed from 500°C to 400°C at a cooling rate of 1.5–2.0°C / min. When the temperature of the third cooling aging is 400°C, air cooling is performed.

[0016] Furthermore, the homogenization heat treatment temperature is 750–850℃, the time is 0.5–4h, and the heating rate during the process of heating to the homogenization heat treatment temperature is 20–80℃ / min; and / or the total deformation of hot rolling deformation is 60–80%, the deformation method is unidirectional synchronous rolling, and the deformation per pass is 10–20%; and / or the cold rolling deformation temperature is 25–30℃, and the total deformation is 40–55%.

[0017] By applying the technical solution of this invention, the synergistic modification of Cu-Ti alloys in this application optimizes the distribution of multi-scale precipitate phases without affecting the basic properties of the alloy. These precipitate phases include microstructures with sizes ranging from 3 to 5 nm, 6 to 15 nm, and 16 to 26 nm, respectively. They work together on the alloy matrix, resulting in significantly improved strength, plasticity, and electrical conductivity of the synergistically modified Cu-Ti alloy material. This is because the multi-scale precipitate phases not only increase the alloy's ability to coordinate deformation and allow for multiple deformation heat treatments, but also further induce the precipitation of more multi-scale precipitate phases. Furthermore, when the multi-scale precipitate phases and dislocations exhibit suitable coupling distribution characteristics, they can synergistically improve the alloy's strength, electrical conductivity, and plasticity. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0019] Figure 1 A process flow diagram for preparing synergistically modified Cu-Ti alloys according to this application is shown;

[0020] Figure 2 The diagram shows the hardness change pattern of the alloy in the second cold-rolled state during the second cooling aging process according to Example 1 of this application;

[0021] Figure 3 The diagram shows the change in electrical conductivity of the alloy in the second cold-rolled state during the second cooling aging process according to Example 1 of this application;

[0022] Figure 4The diagram shows the hardness change pattern of the alloy in the second cold-rolled state during the second cooling aging process according to Example 3 of this application;

[0023] Figure 5 The diagram shows the change in electrical conductivity of the alloy in the second cold-rolled state during the second cooling aging process according to Example 3 of this application;

[0024] Figure 6 The diagram shows the hardness change pattern of the alloy in the second cold-rolled state during the second cooling aging process according to Example 5 of this application;

[0025] Figure 7 The diagram shows the change in electrical conductivity of the alloy in the second cold-rolled state during the second cooling aging process according to Example 5 of this application;

[0026] Figure 8 The diagram shows the hardness variation of the alloys in the third cold-rolled state after isothermal aging and third cooling aging according to Examples 1, 3 and 5 of this application.

[0027] Figure 9 The diagram shows the hardness variation of the alloys in the third cold-rolled state after isothermal aging and third cooling aging according to Examples 2, 4 and 6 of this application. Detailed Implementation

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0029] As analyzed in the background section of this application, the existing technology has the problem that Cu-Ti alloy materials cannot simultaneously achieve excellent strength and conductivity. In order to solve the above problems, this application provides a synergistically modified Cu-Ti alloy and its preparation method.

[0030] In a typical embodiment of this application, a synergistically modified Cu-Ti alloy is provided, comprising, by mass percentage: 3.0–3.5 wt% Ti, ≤0.01 wt% B, ≤0.01 wt% Zr, with the balance being Cu; wherein the synergistically modified Cu-Ti alloy comprises β'-Cu4Ti precipitates with a size of 3–5 nm, β'-Cu4Ti precipitates with a size of 6–15 nm, and β'-Cu4Ti precipitates with a size of 16–26 nm.

[0031] In this application, the synergistic modification of Cu-Ti alloys optimizes the distribution of multi-scale precipitated phases without affecting the alloy's fundamental properties. These precipitated phases include microstructures with sizes ranging from 3 to 5 nm, 6 to 15 nm, and 16 to 26 nm. They work together on the alloy matrix, resulting in significantly improved strength, plasticity, and electrical conductivity in the synergistically modified Cu-Ti alloy. This is because the multi-scale precipitated phases not only increase the alloy's ability to coordinate deformation and allow for controlled deformation through multiple heat treatments, but also further induce the precipitation of more multi-scale precipitated phases. Furthermore, when the multi-scale precipitated phases and dislocations exhibit suitable coupling distribution characteristics, they can synergistically enhance the alloy's strength, electrical conductivity, and plasticity.

[0032] In one embodiment of this application, the dislocation density of the synergistically modified Cu-Ti alloy is (8~10)×10⁻⁶. 14 ·m -2 .

[0033] Smaller precipitate phases help pin dislocations more effectively, preventing them from slipping and annihilating, while larger precipitate phases help reduce electron scattering and improve electrical conductivity. The preferred dislocation density helps balance the overall performance of the synergistically modified Cu-Ti alloy.

[0034] In one embodiment of this application, the spacing between adjacent particles of the β'-Cu4Ti precipitate phase with a size of 3-5 nm is 7-9 nm; and / or the spacing between adjacent particles of the β'-Cu4Ti precipitate phase with a size of 6-15 nm is 11-14 nm; and / or the spacing between adjacent particles of the β'-Cu4Ti precipitate phase with a size of 16-26 nm is 20-26 nm.

[0035] By setting the spacing between adjacent precipitate particles of 3–5 nm, 6–15 nm, and 16–26 nm within the aforementioned ranges, the aggregation of coarse precipitate phases was effectively suppressed, avoiding potential performance degradation. At the same time, the uniformity and stability of the alloy's internal structure were ensured, further improving the alloy's performance.

[0036] In another typical embodiment of this application, a method for preparing the aforementioned synergistically modified Cu-Ti alloy is provided, such as... Figure 1 As shown, the preparation method includes the following steps performed in sequence: batching, casting, homogenization heat treatment, hot rolling deformation, cold rolling deformation, solution treatment, cooling pre-aging treatment, first cold rolling, first cooling aging, second cold rolling, second cooling aging, third cold rolling, isothermal aging, and third cooling aging.

[0037] Considering that precipitation-strengthened alloys commonly precipitate during hot working, high-temperature solution treatment is required before aging. Therefore, if rapid cooling to a suitable temperature after solution treatment is performed and the cooling rate is controlled for pre-aging, not only can the residual heat of the alloy sheet / strip after high-temperature solution treatment be fully utilized for pre-aging, significantly reducing energy consumption, but also multi-scale precipitates can be induced in the alloy matrix through pre-aging. The formation of multi-scale precipitates not only increases the alloy's ability to coordinate deformation, facilitating multiple deformation heat treatments, but also further induces the precipitation of more multi-scale precipitates. Furthermore, when the multi-scale precipitates and dislocations exhibit suitable coupling distribution characteristics, they can synergistically improve the alloy's strength, conductivity, and plasticity. Therefore, this invention breaks away from the traditional deformation heat treatment process routes for controlling the microstructure and properties of Cu-Ti alloys, such as solution quenching → cold deformation → isothermal aging, or solution → cold deformation → isothermal aging → cold deformation → isothermal aging. Instead, it innovatively proposes and develops the following novel control process route: solution treatment followed by rapid cooling to a suitable temperature for pre-aging → first cold rolling → first cooling aging → second cold rolling → second cooling aging → third cold rolling → isothermal aging + third cooling aging. This process route first uses rapid cooling to a suitable temperature after solution treatment for pre-aging, which promotes the rapid precipitation of a large number of multi-scale precipitates within the alloy matrix. This not only synergistically influences the degree of dislocation slip, pile-up, and annihilation during subsequent cold rolling, but also actively affects the diffusion, enrichment, and growth and distribution of solute elements and precipitates during aging, resulting in the precipitation of more multi-scale precipitates within the alloy matrix. Ultimately, this effectively improves both the alloy's strength and electrical conductivity. Furthermore, building upon the initial introduction of cooling pre-aging control, this invention further breaks away from traditional deformation heat treatment control methods (cold rolling + isothermal aging control process). It innovatively proposes a novel method for synergistically controlling the precipitation, growth, and coupling distribution of multi-scale precipitate phases with dislocations through a multi-process, multi-stage non-isothermal heat treatment involving a first cold rolling + first cooling aging, a second cold rolling + second cooling aging, and a third cold rolling + isothermal aging + third cooling aging. This process not only allows for the reasonable coarsening of the multi-scale precipitate phases precipitated by rapid cooling to a suitable temperature after solution treatment for pre-aging, but also induces the precipitation of more multi-scale precipitate phases and influences dislocation slip, pile-up, annihilation, and distribution. Ultimately, based on the formation of multi-scale precipitate phases and their coupling distribution with dislocations, the strength and electrical conductivity of the alloy can be significantly improved.

[0038] In one embodiment of this application, the solution temperature is 800-900°C, and after solution treatment for 2-5 hours, the temperature is cooled to the initial temperature of the cooling pre-aging treatment at a cooling rate greater than 100°C / min, and / or the temperature of the cooling pre-aging treatment is reduced from 410°C to 350°C. The cooling rate during the cooling pre-aging treatment is 0.4-1.5°C / h, and after the cooling pre-aging treatment is completed, the temperature is air-cooled to 25-30°C.

[0039] This application, through careful design of the temperature, cooling rate, and time parameters of the pre-aging cooling treatment, facilitates the rapid precipitation of a large number of multi-scale precipitates in the alloy matrix, thereby reasonably influencing the degree of dislocation slip, pile-up, and annihilation during the subsequent cold rolling process.

[0040] In one embodiment of this application, the temperature of the first cold rolling is 25-30°C, the total deformation is 40-60%, the deformation method is unidirectional synchronous rolling, and the deformation per pass is 5-20%; and / or the temperature of the first cooling aging is reduced from 500°C to 350°C, the cooling rate is 1.5-2.0°C / min, and air cooling is performed when the temperature of the first cooling aging is 350°C.

[0041] This application specifies in detail the conditions for the first cold rolling and the first cooling aging. This method, combining cold rolling and cooling aging, not only effectively utilizes the residual thermal stress within the alloy to promote dislocation rearrangement and optimize the distribution of precipitated phases, but also prevents performance degradation caused by excessive heat treatment. During the first cooling aging process, as the temperature decreases, dislocation activity decreases, and the growth rate of the precipitated phase is controlled, thus forming a unique microstructure within the alloy—a multi-scale coupled distribution of precipitated phases and dislocations. This provides an ideal strengthening mechanism for the alloy while maintaining good plasticity and electrical conductivity.

[0042] In one embodiment of this application, the temperature of the second cold rolling is 25-30°C, the total deformation is 40-60%, the deformation method is unidirectional synchronous rolling, and the deformation per pass is 5-20%; and / or the temperature of the second cooling aging is reduced from 500°C to 350°C, the cooling rate is 1.5-2.0°C / min, and air cooling is performed when the temperature of the second cooling aging is 350°C.

[0043] This application specifies in detail the conditions for the second cold rolling and the second cooling aging. This method of combining cold rolling and cooling aging helps to further utilize the residual thermal stress inside the alloy to promote the rearrangement of dislocations and optimize the distribution of precipitated phases, thus preventing performance deterioration caused by excessive heat treatment.

[0044] In one embodiment of this application, the temperature of the third cold rolling is 25-30°C, the total deformation is 35-55%, the deformation method is unidirectional synchronous rolling, and the deformation per pass is 5-15%.

[0045] By controlling the specific conditions of the third cold rolling within the aforementioned range, the microstructure of the alloy was further refined, resulting in a more uniform size distribution of the previously formed precipitated phases. This also increased the alloy's deformation energy storage, providing greater flexibility for subsequent heat treatment. Through this step, the alloy not only withstands more processing deformation but also exhibits better performance stability during subsequent heat treatment.

[0046] In one embodiment of this application, the isothermal aging temperature is 400-420°C, and the heating rate is greater than 100°C / min during the process of heating to the isothermal aging temperature. After isothermal aging for 1-7 hours, the temperature is increased to the highest temperature of the third cooling aging at a rate greater than 100°C / min, and the third cooling aging is performed. The third cooling aging decreases from 500°C to 400°C at a cooling rate of 1.5-2.0°C / min. When the temperature of the third cooling aging is 400°C, air cooling is performed.

[0047] This application employs a combined isothermal aging and third cooling aging method to further optimize the microstructure of the alloy. First, by controlling the isothermal aging temperature and time within the aforementioned range, the growth of fine precipitate phases is promoted, while dislocation density is reduced, achieving a purifying effect on the matrix. Then, during the third cooling aging process, the continuous cooling from high to low temperature not only reduces the adverse risks caused by sudden temperature changes but also promotes the growth of larger-scale precipitate phases, further improving the alloy's strength and toughness.

[0048] In one embodiment of this application, the homogenization heat treatment temperature is 750–850°C, the time is 0.5–4 h, and the heating rate during the process of heating to the homogenization heat treatment temperature is 20–80°C / min; and / or the total deformation of hot rolling deformation is 60–80%, the deformation method is unidirectional synchronous rolling, and the deformation per pass is 10–20%; and / or the cold rolling deformation temperature is 25–30°C, and the total deformation is 40–55%.

[0049] By controlling the conditions of homogenization heat treatment, hot rolling deformation, cold rolling deformation, and subsequent solution treatment within the aforementioned ranges, these pretreatment steps aim to minimize compositional segregation and microstructural defects in the alloy ingot, laying a solid foundation for subsequent cooling pre-aging and deformation heat treatment. The combination of homogenization heat treatment and hot rolling deformation optimizes the original microstructure of the alloy through high-temperature dissolution and dynamic recrystallization, reducing initial dislocation density and thus improving the overall homogeneity of the alloy and the effectiveness of subsequent heat treatment. Solution treatment, through rapid cooling, retains a large number of supersaturated solute atoms, providing the necessary preconditions for cooling pre-aging treatment and ensuring optimized formation and distribution of subsequent precipitated phases.

[0050] The beneficial effects of this application will be further illustrated below with reference to the embodiments.

[0051] The following examples are based on Figure 1 The process flow diagram for preparing synergistically modified Cu-Ti alloys is shown below.

[0052] Example 1

[0053] First, the alloy is prepared according to the designed composition values ​​and then melted and cast. The raw materials used for melting and casting are 99.9 wt% electrolytic high-purity Cu, sponge Ti, and intermediate alloys. First, a Cu-3.3 wt% Ti alloy is prepared and placed in a medium-frequency induction melting furnace. Once the vacuum degree is less than 0.1 Pa, the temperature is raised directly using high-power heating until the melt is completely melted and the temperature reaches 1250℃. This temperature is held for 5 minutes, and then the melt is stirred electromagnetically for 60 seconds. After the melt temperature stabilizes at around 1250℃, casting begins, controlling the casting speed to minimize shrinkage cavities. Then, the ingot undergoes homogenization treatment and subsequent multi-process control, specifically as follows: homogenization heat treatment + hot rolling deformation (homogenization heat treatment). Temperature: 800℃, Time: 2h; Heating rate: 60℃ / min, Homogenized hot rolling deformation: 70%, Pass deformation: 15%, Deformation method: Unidirectional synchronous rolling) → Cold rolling deformation (Deformation temperature: room temperature, Deformation amount: 50%) → Solution treatment + cooling pre-aging composite treatment (Solution temperature: 850℃, Time: 3h, followed by rapid cooling to 410℃ at a cooling rate of 180℃ / min for cooling pre-aging, Cooling pre-aging temperature range: 410→350℃, Cooling rate: 1.2℃ / min, After pre-aging, air... (Cooled to room temperature) → First cold rolling + cooling aging (Deformation temperature: room temperature, deformation amount: 50%, deformation method: unidirectional synchronous rolling, deformation amount per pass: 15%, cooling aging temperature range: 500→350℃, cooling rate: 1.8℃ / min, after cooling to the minimum temperature, directly air cooling) → Second cold rolling + cooling aging (Deformation temperature: room temperature, deformation amount: 50%, deformation method: unidirectional synchronous rolling, deformation amount per pass: 15%, cooling aging temperature range: 500→350℃, cooling rate: 1.8℃ / min) After cooling to the minimum temperature, the alloy is directly air-cooled → third cold rolling (deformation temperature: room temperature, deformation amount: 45%, per pass deformation amount: 10%, deformation method: unidirectional synchronous rolling) → isothermal aging + cooling aging (isothermal temperature: 410℃, heating rate: 180℃ / min, time: 3h, then directly heating at a rate of 180℃ / min to the highest cooling aging temperature for cooling aging, cooling aging temperature range: 500→400℃, cooling rate: 1.8℃ / min, after cooling to the minimum temperature, the alloy is directly air-cooled). Finally, the microhardness, electrical conductivity and tensile properties of typical aged alloys are characterized, as shown in Tables 1 and 2, and... Figure 2 As shown in 3 and 8.

[0054] Example 2

[0055] First, the alloy is prepared according to the designed composition values ​​and then melted and cast. The raw materials used for melting and casting are 99.9 wt% electrolytic high-purity Cu, sponge Ti, and intermediate alloys. First, a Cu-3.3 wt% Ti alloy is prepared and placed in a medium-frequency induction melting furnace. Once the vacuum level is less than 0.1 Pa, the temperature is raised directly using high power. After the melt is completely melted and the temperature reaches 1200℃, it is held for 3 minutes. Then, the melt is stirred electromagnetically for 30-90 seconds. After the melt temperature stabilizes at around 1250℃, casting begins, controlling the casting speed to minimize shrinkage cavities. Then, the ingot undergoes homogenization treatment and subsequent multi-process control, specifically as follows: homogenization heat treatment + hot rolling deformation (homogenization). Heat treatment temperature: 750℃, time: 0.5h; heating rate: 20℃ / min, hot rolling deformation after homogenization: 60%, deformation per pass: 10%, deformation method: unidirectional synchronous rolling) → cold rolling deformation (deformation temperature: room temperature, deformation amount: 40%) → solution treatment + cooling pre-aging composite treatment (solution temperature: 800℃, time: 2h, followed by rapid cooling to a suitable temperature at a cooling rate of 150℃ / min for cooling pre-aging, cooling pre-aging temperature range: 410→350℃, cooling rate: 0.9℃ / min, pre-aging) The process is as follows: (air cooling to room temperature) → First cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 40%, deformation method: unidirectional synchronous rolling, deformation per pass: 5%, cooling aging temperature range: 500→350℃, cooling rate: 1.5℃ / min, air cooling is performed directly after cooling to the minimum temperature) → Second cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 60%, deformation method: unidirectional synchronous rolling, deformation per pass: 20%, cooling aging temperature range: 500→350℃, cooling rate: 2.0℃ / min) The process involves several steps: first, aging to the minimum temperature followed by direct air cooling; then, a third cold rolling process (deformation temperature: room temperature, deformation amount: 55%, per pass deformation amount: 15%, deformation method: unidirectional synchronous rolling); second, isothermal aging + cooling aging (isothermal temperature: 420℃, heating rate: 150℃ / min, time: 7h, then directly heating at a rate of 150℃ / min to the maximum cooling aging temperature for cooling aging, cooling aging temperature range: 500→400℃, cooling rate: 2.0℃ / min, cooling to the minimum temperature followed by direct air cooling). Finally, the microhardness, electrical conductivity, and tensile properties of typical aged alloys are characterized, as shown in Tables 1 and 2. Figure 9 As shown.

[0056] Example 3

[0057] First, the alloy was prepared according to the designed composition values ​​and then melted and cast. The raw materials used for melting and casting included 99.9 wt% electrolytic high-purity Cu, sponge Ti, and intermediate alloys. First, a Cu-3.3 wt% Ti alloy was prepared and placed in a medium-frequency induction melting furnace. Once the vacuum level was less than 0.1 Pa, the temperature was raised directly using high-power heating until the melt was completely melted and the temperature reached 1300℃. This temperature was held for 7 minutes, and then the melt was stirred electromagnetically for 90 seconds. After the melt temperature stabilized at around 1250℃, casting began, controlling the casting speed to minimize shrinkage cavities. Then, the ingot underwent homogenization treatment and subsequent multi-process control, specifically as follows: homogenization heat treatment + hot rolling deformation (homogenization heat treatment...). Treatment temperature: 850℃, time: 4h; heating rate: 80℃ / min, hot rolling deformation after homogenization: 80%, deformation per pass: 20%, deformation method: unidirectional synchronous rolling) → cold rolling deformation (deformation temperature: room temperature, deformation amount: 55%) → solution treatment + cooling pre-aging composite treatment (solution temperature: 900℃, time: 5h, followed by rapid cooling to a suitable temperature at a cooling rate of 150℃ / min for cooling pre-aging, cooling pre-aging temperature range: 410→350℃, cooling rate: 1.5℃ / min, after pre-aging) (Air cooling to room temperature) → First cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 60%, deformation method: unidirectional synchronous rolling, deformation per pass: 20%, cooling aging temperature range: 500→350℃, cooling rate: 2.0℃ / min, after cooling to the minimum temperature, air cooling is performed directly) → Second cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 4%, deformation method: unidirectional synchronous rolling, deformation per pass: 5%, cooling aging temperature range: 500→350℃, cooling rate: 1.5℃ / min) After cooling to the minimum temperature, the alloy is directly air-cooled → third cold rolling (deformation temperature: room temperature, deformation amount: 35%, deformation per pass: 5%, deformation method: unidirectional synchronous rolling) → isothermal aging + cooling aging (isothermal temperature: 400℃, heating rate: 150℃ / min, time: 1h, then directly heating at a rate of 150℃ / min to the highest cooling aging temperature for cooling aging, cooling aging temperature range: 500→400℃, cooling rate: 1.0℃ / min, after cooling to the minimum temperature, the alloy is directly air-cooled). Finally, the microhardness, electrical conductivity and tensile properties of typical aged alloys are characterized, as shown in Tables 1 and 2, and... Figure 4 As shown in 5 and 8.

[0058] Example 4

[0059] First, the alloy was prepared according to the designed composition values ​​and then melted and cast. The raw materials used for melting and casting included 99.9 wt% electrolytic high-purity Cu, sponge Ti, and intermediate alloys. First, a Cu-3.3 wt% Ti alloy was prepared and placed in a medium-frequency induction melting furnace. Once the vacuum level was less than 0.1 Pa, the temperature was raised directly using high-power heating until the melt was completely melted and the temperature reached 1300℃. This temperature was held for 4 minutes, followed by high-power electromagnetic stirring of the melt for 50 seconds. Then, once the melt temperature stabilized at approximately 1250℃, casting began, controlling the casting speed to minimize shrinkage cavities. The ingot then underwent homogenization treatment and subsequent multi-process control, specifically: homogenization heat treatment + hot rolling deformation (homogenization heat treatment temperature...). Temperature: 780℃, Time: 3.2h; Heating rate: 65℃ / min, Homogenized hot rolling deformation: 68%, Pass deformation: 15%, Deformation method: Unidirectional synchronous rolling) → Cold rolling deformation (Deformation temperature: room temperature, Deformation amount: 50%) → Solution treatment + cooling pre-aging composite treatment (Solution temperature: 850℃, Time: 3.4h, followed by rapid cooling to a suitable temperature at a cooling rate of 180℃ / min for cooling pre-aging, Cooling pre-aging temperature range: 410→350℃, Cooling rate: 1.0℃ / min, After pre-aging, ... (Air cooling to room temperature) → First cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 45%, deformation method: unidirectional synchronous rolling, deformation per pass: 15%, cooling aging temperature range: 500→350℃, cooling rate: 2.0℃ / min, air cooling directly after cooling to the minimum temperature) → Second cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 60%, deformation method: unidirectional synchronous rolling, deformation per pass: 10%, cooling aging temperature range: 500→350℃, cooling rate: 1.8℃ / min) The process involves several steps: first, aging to the minimum temperature followed by direct air cooling; then, a third cold rolling process (deformation temperature: room temperature, deformation amount: 55%, per pass deformation amount: 15%, deformation method: unidirectional synchronous rolling); second, isothermal aging + cooling aging (isothermal temperature: 400℃, heating rate: 180℃ / min, time: 6h, then directly heating at a rate of 180℃ / min to the maximum cooling aging temperature for cooling aging, cooling aging temperature range: 500→400℃, cooling rate: 2.0℃ / min, cooling to the minimum temperature followed by direct air cooling). Finally, the microhardness, electrical conductivity, and tensile properties of typical aged alloys are characterized, as shown in Tables 1 and 2. Figure 9 As shown.

[0060] Example 5

[0061] First, the alloy was prepared according to the designed composition values ​​and then melted and cast. The raw materials used for melting and casting included 99.9 wt% electrolytic high-purity Cu, sponge Ti, and intermediate alloys. First, a Cu-3.3 wt% Ti alloy was prepared and placed in a medium-frequency induction melting furnace. Once the vacuum level was less than 0.1 Pa, the temperature was raised directly using high-power heating until the melt was completely melted and the temperature reached 1300℃. This temperature was held for 3 minutes, followed by high-power electromagnetic stirring of the melt for 30 seconds. Then, once the melt temperature stabilized at approximately 1250℃, casting began, controlling the casting speed to minimize shrinkage cavities. The ingot then underwent homogenization treatment and subsequent multi-process control, specifically: homogenization heat treatment + hot rolling deformation (homogenization heat treatment temperature...). Temperature: 850℃, Time: 2h; Heating rate: 50℃ / min, Homogenized hot rolling deformation: 75%, Pass deformation: 10%, Deformation method: Unidirectional synchronous rolling) → Cold rolling deformation (Deformation temperature: room temperature, Deformation amount: 45%) → Solution treatment + cooling pre-aging composite treatment (Solution temperature: 900℃, Time: 5h, followed by rapid cooling to a suitable temperature at a cooling rate of 180℃ / min for cooling pre-aging, Cooling pre-aging temperature range: 410→350℃, Cooling rate: 1.2℃ / min, Air cooling after pre-aging) (To room temperature) → First cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 60%, deformation method: unidirectional synchronous rolling, deformation amount per pass: 10%, cooling aging temperature range: 500→350℃, cooling rate: 2.0℃ / min, after cooling to the minimum temperature, air cooling is performed directly) → Second cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 40~60%, deformation method: unidirectional synchronous rolling, deformation amount per pass: 10%, cooling aging temperature range: 500→350℃, cooling rate: 1.5℃ / min) The process involves several steps: first, aging to the minimum temperature followed by direct air cooling; then, a third cold rolling process (deformation temperature: room temperature, deformation amount: 55%, per pass deformation amount: 5%, deformation method: unidirectional synchronous rolling); second, isothermal aging + cooling aging (isothermal temperature: 420℃, heating rate: 150℃ / min, time: 1h, then directly heating at a rate of 150℃ / min to the maximum cooling aging temperature for cooling aging, cooling aging temperature range: 500→400℃, cooling rate: 1.8℃ / min, cooling to the minimum temperature followed by direct air cooling). Finally, the microhardness, electrical conductivity, and tensile properties of typical aged alloys are characterized, as shown in Tables 1 and 2. Figure 6 As shown in 7 and 8.

[0062] Example 6

[0063] First, the alloy is prepared according to the designed composition values ​​and then melted and cast. The raw materials used for melting and casting are 99.9 wt% electrolytic high-purity Cu, sponge Ti, and intermediate alloys. First, a Cu-3.3 wt% Ti alloy is prepared and placed in a medium-frequency induction melting furnace. Once the vacuum level is less than 0.1 Pa, the temperature is raised directly using high-power heating until the melt is completely melted and the temperature reaches 1200℃. This temperature is held for 6 minutes, and then the melt is stirred electromagnetically for 35 seconds. After the melt temperature stabilizes at around 1250℃, casting begins, controlling the casting speed to minimize shrinkage cavities. Then, the ingot undergoes homogenization treatment and subsequent multi-process control, specifically as follows: homogenization heat treatment + hot rolling deformation (homogenization heat treatment). Temperature: 850℃, Time: 4h; Heating rate: 54℃ / min, Homogenized hot rolling deformation: 75%, Pass deformation: 15%, Deformation method: Unidirectional synchronous rolling) → Cold rolling deformation (Deformation temperature: room temperature, Deformation amount: 50%) → Solution treatment + cooling pre-aging composite treatment (Solution temperature: 800℃, Time: 5h, followed by rapid cooling to a suitable temperature at a cooling rate of 120℃ / min for cooling pre-aging, Cooling pre-aging temperature range: 410→350℃, Cooling rate: 1.2℃ / min, After pre-aging, air... Cooling to room temperature) → First cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 60%, deformation method: unidirectional synchronous rolling, deformation amount per pass: 20%, cooling aging temperature range: 500→350℃, cooling rate: 2.0℃ / min, after cooling to the minimum temperature, air cooling is performed directly) → Second cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 60%, deformation method: unidirectional synchronous rolling, deformation amount per pass: 20%, cooling aging temperature range: 500→350℃, cooling rate: 1.5℃ / min) After aging to the minimum temperature, the alloy is directly air-cooled → third cold rolling (deformation temperature: room temperature, deformation amount: 35%, deformation per pass: 15%, deformation method: unidirectional synchronous rolling) → isothermal aging + cooling aging (isothermal temperature: 400℃, heating rate: 180℃ / min, time: 7h, then directly heating at a rate of 180℃ / min to the highest cooling aging temperature for cooling aging, cooling aging temperature range: 500→400℃, cooling rate: 2.0℃ / min, after cooling to the minimum temperature, the alloy is directly air-cooled). Finally, the microhardness, electrical conductivity and tensile properties of typical aged alloys are characterized, as shown in Tables 1 and 2, and... Figure 9 As shown.

[0064] Example 7

[0065] The difference from Example 1 is as follows: Homogenization heat treatment + hot rolling deformation (homogenization heat treatment temperature: 800℃, time: 2h; heating rate: 60℃ / min, hot rolling deformation after homogenization: 70%, deformation per pass: 15%, deformation method: unidirectional synchronous rolling) → cold rolling deformation (deformation temperature: room temperature, deformation amount: 50%) → solution treatment + cooling pre-aging composite treatment (solution temperature: 850℃, time: 3h, followed by rapid cooling to 410℃ at a cooling rate of 180℃ / min for cooling pre-aging, cooling pre-aging temperature range: 410→350℃, cooling rate: 2.0℃ / min, followed by air cooling to room temperature) → first cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 50%, deformation method: unidirectional synchronous rolling, deformation per pass: 15%, cooling aging temperature range: 500→350℃, cooling rate: 180℃ / min ... 1.8℃ / min, cooling aging to the minimum temperature followed by direct air cooling) → Second cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 50%, deformation method: unidirectional synchronous rolling, deformation amount per pass: 15%, cooling aging temperature range: 500→350℃, cooling rate: 1.8℃ / min, cooling aging to the minimum temperature followed by direct air cooling) → Third cold rolling (deformation temperature: room temperature, deformation amount: 45%, deformation amount per pass: 10%, deformation method: unidirectional synchronous rolling) → Isothermal aging + cooling aging (isothermal temperature: 410℃, heating rate: 180℃ / min, time: 3h, then directly heating at a rate of 180℃ / min to the highest cooling aging temperature for cooling aging, cooling aging temperature range: 500→400℃, cooling rate: 1.8℃ / min, cooling aging to the minimum temperature followed by direct air cooling). Finally, the microhardness, electrical conductivity and tensile properties of typical aged alloys were characterized.

[0066] Example 8

[0067] The difference from Example 1 is as follows: Homogenization heat treatment + hot rolling deformation (homogenization heat treatment temperature: 800℃, time: 2h; heating rate: 60℃ / min, hot rolling deformation after homogenization: 70%, deformation per pass: 15%, deformation method: unidirectional synchronous rolling) → cold rolling deformation (deformation temperature: room temperature, deformation amount: 50%) → solution treatment + cooling pre-aging composite treatment (solution temperature: 850℃, time: 3h, followed by rapid cooling to 410℃ at a cooling rate of 180℃ / min for cooling pre-aging, cooling pre-aging temperature range: 410→350℃, cooling rate: 1.2℃ / min, followed by air cooling to room temperature) → first cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 50%, deformation method: unidirectional synchronous rolling, deformation per pass: 15%, cooling aging temperature range: 500→350℃, cooling rate: 1.2℃ / min, after pre-aging, air cooling to room temperature) → first cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 50%, deformation method: unidirectional synchronous rolling, deformation per pass: 15%, cooling aging temperature range: 500→350℃, cooling rate: 1.2℃ / min, after pre-aging, air cooling to room temperature) 1.2℃ / min, cooling aging to the minimum temperature followed by direct air cooling) → Second cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 50%, deformation method: unidirectional synchronous rolling, deformation amount per pass: 15%, cooling aging temperature range: 500→350℃, cooling rate: 1.8℃ / min, cooling aging to the minimum temperature followed by direct air cooling) → Third cold rolling (deformation temperature: room temperature, deformation amount: 45%, deformation amount per pass: 10%, deformation method: unidirectional synchronous rolling) → Isothermal aging + cooling aging (isothermal temperature: 410℃, heating rate: 180℃ / min, time: 3h, then directly heating at a rate of 180℃ / min to the highest cooling aging temperature for cooling aging, cooling aging temperature range: 500→400℃, cooling rate: 1.8℃ / min, cooling aging to the minimum temperature followed by direct air cooling). Finally, the microhardness, electrical conductivity and tensile properties of typical aged alloys were characterized.

[0068] Example 9

[0069] The difference from Example 1 is as follows: Homogenization heat treatment + hot rolling deformation (homogenization heat treatment temperature: 800℃, time: 2h; heating rate: 60℃ / min, hot rolling deformation after homogenization: 70%, deformation per pass: 15%, deformation method: unidirectional synchronous rolling) → cold rolling deformation (deformation temperature: room temperature, deformation amount: 50%) → solution treatment + cooling pre-aging composite treatment (solution temperature: 850℃, time: 3h, followed by rapid cooling to 410℃ at a cooling rate of 180℃ / min for cooling pre-aging, cooling pre-aging temperature range: 410→350℃, cooling rate: 1.2℃ / min, followed by air cooling to room temperature) → first cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 50%, deformation method: unidirectional synchronous rolling, deformation per pass: 15%, cooling aging temperature range: 500→350℃, cooling rate: 1.2℃ / min, after pre-aging, air cooling to room temperature) → first cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 50%, deformation method: unidirectional synchronous rolling, deformation per pass: 15%, cooling aging temperature range: 500→350℃, cooling rate: 1.2℃ / min, after pre-aging, air cooling to room temperature) 1.8℃ / min, cooling aging to the minimum temperature followed by direct air cooling) → Second cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 50%, deformation method: unidirectional synchronous rolling, deformation amount per pass: 15%, cooling aging temperature range: 500→350℃, cooling rate: 1.2℃ / min, cooling aging to the minimum temperature followed by direct air cooling) → Third cold rolling (deformation temperature: room temperature, deformation amount: 45%, deformation amount per pass: 10%, deformation method: unidirectional synchronous rolling) → Isothermal aging + cooling aging (isothermal temperature: 410℃, heating rate: 180℃ / min, time: 3h, then directly heating at a rate of 180℃ / min to the highest cooling aging temperature for cooling aging, cooling aging temperature range: 500→400℃, cooling rate: 1.8℃ / min, cooling aging to the minimum temperature followed by direct air cooling). Finally, the microhardness, electrical conductivity and tensile properties of typical aged alloys were characterized.

[0070] Example 10

[0071] The difference from Example 1 is as follows: Homogenization heat treatment + hot rolling deformation (homogenization heat treatment temperature: 800℃, time: 2h; heating rate: 60℃ / min, hot rolling deformation after homogenization: 70%, deformation per pass: 15%, deformation method: unidirectional synchronous rolling) → cold rolling deformation (deformation temperature: room temperature, deformation amount: 50%) → solution treatment + cooling pre-aging composite treatment (solution temperature: 850℃, time: 3h, followed by rapid cooling to 410℃ at a cooling rate of 180℃ / min for cooling pre-aging, cooling pre-aging temperature range: 410→350℃, cooling rate: 1.2℃ / min, followed by air cooling to room temperature) → first cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 50%, deformation method: unidirectional synchronous rolling, deformation per pass: 15%, cooling aging temperature range: 500→350℃, cooling rate: 1.2℃ / min, after pre-aging, air cooling to room temperature) → first cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 50%, deformation method: unidirectional synchronous rolling, deformation per pass: 15%, cooling aging temperature range: 500→350℃, cooling rate: 1.2℃ / min, after pre-aging, air cooling to room temperature) 1.8℃ / min, cooling aging to the minimum temperature followed by direct air cooling) → Second cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 50%, deformation method: unidirectional synchronous rolling, deformation amount per pass: 15%, cooling aging temperature range: 500→350℃, cooling rate: 1.8℃ / min, cooling aging to the minimum temperature followed by direct air cooling) → Third cold rolling (deformation temperature: room temperature, deformation amount: 45%, deformation amount per pass: 10%, deformation method: unidirectional synchronous rolling) → Isothermal aging + cooling aging (isothermal temperature: 410℃, heating rate: 180℃ / min, time: 3h, then directly heating at a rate of 180℃ / min to the highest cooling aging temperature for cooling aging, cooling aging temperature range: 500→400℃, cooling rate: 1.2℃ / min, cooling aging to the minimum temperature followed by direct air cooling). Finally, the microhardness, electrical conductivity and tensile properties of typical aged alloys were characterized.

[0072] Comparative Example 1

[0073] The difference from Example 1 is that no cooling pre-aging is performed. The process is as follows: homogenization heat treatment + hot rolling deformation (homogenization heat treatment temperature: 800℃, time: 2h; heating rate: 60℃ / min, hot rolling deformation after homogenization: 70%, deformation per pass: 15%, deformation method: unidirectional synchronous rolling) → cold rolling deformation (deformation temperature: room temperature, deformation: 50%) → solution treatment (solution temperature: 850℃, time: 3h, followed by air cooling to room temperature) → first cold rolling + cooling aging (deformation temperature: room temperature, deformation: 50%, deformation method: unidirectional synchronous rolling, deformation per pass: 15%, cooling aging temperature range: 500→350℃, cooling rate: 1.8℃ / min, after cooling aging to the minimum temperature, direct air cooling) → second cold rolling + cooling The aging process involved three stages: warm aging (deformation temperature: room temperature, deformation amount: 50%, deformation method: unidirectional synchronous rolling, deformation per pass: 15%, cooling aging temperature range: 500→350℃, cooling rate: 1.8℃ / min, followed by direct air cooling after reaching the minimum temperature) → third cold rolling (deformation temperature: room temperature, deformation amount: 45%, deformation per pass: 10%, deformation method: unidirectional synchronous rolling) → isothermal aging + cooling aging (isothermal temperature: 410℃, heating rate: 180℃ / min, time: 3h, then directly heating at a rate of 180℃ / min to the maximum cooling aging temperature for cooling aging, cooling aging temperature range: 500→400℃, cooling rate: 1.8℃ / min, followed by direct air cooling after reaching the minimum temperature). Finally, the microhardness, electrical conductivity, and tensile properties of the typical aged alloy were characterized.

[0074] Comparative Example 2

[0075] The difference from Example 1 is that the first cooling aging is omitted. The process is as follows: homogenization heat treatment + hot rolling deformation (homogenization heat treatment temperature: 800℃, time: 2h; heating rate: 60℃ / min, hot rolling deformation after homogenization: 70%, deformation per pass: 15%, deformation method: unidirectional synchronous rolling) → cold rolling deformation (deformation temperature: room temperature, deformation amount: 50%) → solution treatment + cooling pre-aging composite treatment (solution temperature: 850℃, time: 3h, followed by rapid cooling to 410℃ at a cooling rate of 180℃ / min for cooling pre-aging, cooling pre-aging temperature range: 410→350℃, cooling rate: 1.2℃ / min, air cooling to room temperature after pre-aging) → first cold rolling (deformation temperature: room temperature, deformation amount: 50%, deformation method: unidirectional synchronous rolling, deformation per pass: 15%). Then, the process proceeds directly to air cooling) → Second cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 50%, deformation method: unidirectional synchronous rolling, deformation per pass: 15%, cooling aging temperature range: 500→350℃, cooling rate: 1.8℃ / min, after cooling aging to the minimum temperature, it is directly air-cooled) → Third cold rolling (deformation temperature: room temperature, deformation amount: 45%, deformation per pass: 10%, deformation method: unidirectional synchronous rolling) → Isothermal aging + cooling aging (isothermal temperature: 410℃, heating rate: 180℃ / min, time: 3h, then directly heating at a rate of 180℃ / min to the maximum cooling aging temperature for cooling aging, cooling aging temperature range: 500→400℃, cooling rate: 1.8℃ / min, after cooling aging to the minimum temperature, it is directly air-cooled). Finally, the microhardness, electrical conductivity, and tensile properties of the typical aged alloy are characterized.

[0076] Comparative Example 3

[0077] The difference from Example 1 is that a second cooling aging is not performed. The process is as follows: homogenization heat treatment + hot rolling deformation (homogenization heat treatment temperature: 800℃, time: 2h; heating rate: 60℃ / min, hot rolling deformation after homogenization: 70%, deformation per pass: 15%, deformation method: unidirectional synchronous rolling) → cold rolling deformation (deformation temperature: room temperature, deformation amount: 50%) → solution treatment + cooling pre-aging composite treatment (solution temperature: 850℃, time: 3h, followed by rapid cooling to 410℃ at a cooling rate of 180℃ / min for cooling pre-aging, cooling pre-aging temperature range: 410→350℃, cooling rate: 1.2℃ / min, followed by air cooling to room temperature) → first cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 50%, deformation method: unidirectional synchronous rolling, deformation per pass: 70%) ...%) → first cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 50%) → first cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 50%) → first cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 50%) → first cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 50%) → first cold rolling + cooling aging (deformation temperature: room temperature, deformation amount: 50%) → The process involves several stages: First, a second cold rolling process (deformation temperature: room temperature, deformation amount: 50%, deformation method: unidirectional synchronous rolling, deformation per pass: 15%, then direct air cooling) → second cold rolling (deformation temperature: room temperature, deformation amount: 45%, deformation per pass: 10%, deformation method: unidirectional synchronous rolling) → isothermal aging + cooling aging (isothermal temperature: 410℃, heating rate: 180℃ / min, time: 3h, then directly heating at a rate of 180℃ / min to the highest cooling aging temperature for cooling aging, cooling temperature range: 500→400℃, cooling rate: 1.8℃ / min, then direct air cooling after cooling to the lowest temperature). Finally, the microhardness, electrical conductivity, and tensile properties of the typical aged alloy were characterized.

[0078] Comparative Example 4

[0079] The difference from Example 1 is that a third cooling aging is not performed. The process is as follows: homogenization heat treatment + hot rolling deformation (homogenization heat treatment temperature: 800℃, time: 2h; heating rate: 60℃ / min, hot rolling deformation after homogenization: 70%, deformation per pass: 15%, deformation method: unidirectional synchronous rolling) → cold rolling deformation (deformation temperature: room temperature, deformation: 50%) → solution treatment + cooling pre-aging composite treatment (solution temperature: 850℃, time: 3h, followed by rapid cooling to 410℃ at a cooling rate of 180℃ / min for cooling pre-aging, cooling pre-aging temperature range: 410→350℃, cooling rate: 1.2℃ / min, air cooling to room temperature after pre-aging) → first cold rolling + cooling aging (deformation temperature: room temperature, deformation: 50%). Deformation method: unidirectional synchronous rolling, deformation per pass: 15%, cooling aging temperature range: 500→350℃, cooling rate: 1.8℃ / min, air cooling directly after cooling to the minimum temperature) → second cold rolling + cooling aging (deformation temperature: room temperature, deformation: 50%, deformation method: unidirectional synchronous rolling, deformation per pass: 15%, cooling aging temperature range: 500→350℃, cooling rate: 1.8℃ / min, air cooling directly after cooling to the minimum temperature) → third cold rolling (deformation temperature: room temperature, deformation: 45%, deformation per pass: 10%, deformation method: unidirectional synchronous rolling) → isothermal aging (isothermal temperature: 410℃, heating rate: 180℃ / min, time: 3h, then air cooling directly). Finally, the microhardness, electrical conductivity and tensile properties of the typical aged alloy were characterized.

[0080] Performance testing:

[0081] Dislocation density: The dislocation density in the alloy matrix was measured using XRD on an Empyrean diffractometer.

[0082] β'-Cu4Ti precipitate phase and its size: The microstructure was characterized by TEM on a JEM-F200 transmission electron microscope.

[0083] Spacing between adjacent precipitate particles of various sizes: characterized by TEM structure on a JEM-F200 transmission electron microscope.

[0084] Hardness: Tested on EAM-3A-500 microhardness scale, with 10 values ​​measured each time and the average value taken.

[0085] Conductivity: Tested using a SIGMATEST 2.070 eddy current conductivity meter, with 10 values ​​measured each time and the average value taken.

[0086] Tensile strength and yield strength: measured on an AG-Xplus tensile testing machine according to international standard E8 / E8M-16a.

[0087] Elongation: Tested according to international standard GB / T 228.1-2021.

[0088] Data for all the above embodiments and comparative examples are shown in Tables 1 to 3.

[0089] Table 1. Hardness and electrical conductivity of alloys in the pre-aged state, third cold-rolled state, and third cold-rolled + isothermal aging state.

[0090]

[0091]

[0092] Table 2 Tensile and electrical properties of the inventive alloy in its final state

[0093]

[0094] Table 3. Spacing and dislocation density between adjacent particles of precipitates of various sizes

[0095]

[0096] As shown in Table 1, the effect of different cooling rates on pre-aging of precipitated phases is complex. Especially with changes in the cooling rate, the size distribution, number density, and distribution characteristics of the multi-scale precipitated phases all change, ultimately leading to different hardness and electrical conductivity. Because different multi-scale precipitated phases are formed in the alloy matrix, after the first cold rolling + cooling aging process, the multi-scale precipitated phases and dislocation coupling distribution characteristics in the matrix are significantly different, resulting in different increases in hardness and electrical conductivity. If a second cold rolling + cooling aging process is performed, the hardness and electrical conductivity of the alloy will inevitably change more significantly. As shown in Example 1, the changes in hardness and electrical conductivity of the alloy in the second cold-rolled state during the cooling aging process are as follows... Figure 2 and 3 As shown in the figure, after secondary cooling and aging, when the cooling and aging temperature is above 470℃, the hardness of the alloy is higher than that of the initial state. The highest hardness occurs at 470℃, corresponding to a hardness range of 328-355 HV. However, the electrical conductivity at this point decreases to its lowest value, around 14.4% IACS. The decrease in electrical conductivity is likely due to the combined effect of the multi-scale precipitated phase and dislocation coupling distribution characteristics. Furthermore, it is worth noting that the different multi-scale particle sizes and distribution densities inevitably lead to differences in hardness within micro-regions. Ultimately, high-hardness and low-hardness micro-regions will appear in the alloy matrix. Therefore, the hardness measurement results all show a large range of measured hardness values ​​(e.g., ...). Figure 2(As shown in subsequent embodiments). Subsequently, as the aging temperature further decreased until 350°C, the hardness distribution range at several temperatures was relatively similar, all within the range of 313-335 HV. However, the electrical conductivity gradually increased with decreasing aging temperature, reaching a maximum value of approximately 19.5% IACS at 350°C. Figure 3 As shown. Subsequently, the second cold-rolled alloy regulated in Example 3 was also subjected to cooling and aging control. It was found that the changes in hardness and electrical conductivity were not significantly different from those in Example 1. Figure 4 and 5 As shown in the figure, the alloy also exhibits a peak hardness at 470℃, ranging from 330-350 HV. As the temperature decreases, the hardness rapidly drops below the initial value. Furthermore, the hardness at temperatures decreasing from 450℃ to 350℃ remains relatively consistent, generally ranging from 315-340 HV. This is primarily due to the synergistic effect of multi-scale precipitation and effective dislocation pinning. In addition, the variation and maximum value of the alloy's electrical conductivity are essentially the same as those of the alloy regulated in Example 1, with the maximum value also appearing at 350℃, at 19.5% IACS. In contrast, with a further reduction in the cooling rate used for pre-aging, the hardness variation during the second cold-rolled alloy regulated in Example 5 undergoes different characteristics during cooling aging. Figure 6 As shown in the figure, the hardness of the alloy immediately decreases after cooling aging, and the hardness at all temperatures is generally lower than the initial state. This indicates that the precipitation driving force in the alloy matrix has significantly decreased, and the contribution of precipitation strengthening is no longer sufficient to compensate for the strength reduction caused by dislocation annihilation. Therefore, the hardness gradually decreases as the cooling aging temperature decreases, but it begins to increase again at 350℃, especially in the high hardness range, which is basically close to the initial state, indicating that a large amount of precipitated phase still precipitated in the later stage. In addition, from Figure 7 The corresponding conductivity variation pattern shows that during the cooling aging process, the conductivity of the alloy first decreases as the aging temperature decreases, then gradually increases, and finally reaches a maximum value of 19.5% IACS at 350℃.

[0097] Although the multi-scale precipitate phase and dislocation coupling distribution characteristics of the alloys in the second cold-rolled state, as regulated in several embodiments, differ after further cooling and aging, leading to significant differences in hardness and electrical conductivity, especially the hardness variation pattern, the alloy can still undergo a third cold rolling process precisely because of the formation of the multi-scale precipitate phase and dislocation coupling distribution characteristics constructed in this invention. The hardness and electrical conductivity of the alloy after the third cold rolling are shown in Table 1. Table 1 shows that compared to the hardness after the second cold rolling and cooling aging, the hardness after the third cold rolling did not increase significantly; in fact, it decreased to some extent. This is likely because the dislocation density in the alloy matrix is ​​already saturated, and further increasing the cold rolling deformation will only exacerbate dislocation annihilation, resulting in a slight decrease. In addition to the decrease in hardness, the electrical conductivity of the alloy after cold rolling also decreased to some extent, as shown in Table 1. Therefore, if a certain period of low-temperature isothermal aging is performed based on the multi-scale precipitate phase and dislocation coupling distribution characteristics of the alloy in the third cold-rolled state, not only will the dislocation density not decrease rapidly, but more precipitate phases will also be induced, thus better pinning dislocations and preventing their rapid annihilation. Table 1 shows that after isothermal aging, the hardness and electrical conductivity of the alloys in several examples increased significantly, and the electrical conductivity was close to the level after secondary cold rolling + cooling aging, as shown in Table 1. Based on isothermal aging, further cooling aging at a suitable rate and temperature range can further promote the precipitation of precipitate phases in the alloy matrix, which already has low precipitation kinetics. Moreover, with reasonable control of the cooling aging rate, the dislocation annihilation rate can also be effectively controlled under the action of multi-scale precipitate phases, ultimately leading to a significant improvement in the overall performance of the alloy. As... Figure 8 The hardness changes of Examples 1, 3, and 5 after three cold-rolled states undergoing isothermal aging and slow-rate cooling aging show that the hardness of the alloys regulated by the three cooling pre-aging methods all decreased to varying degrees, falling to the range of 290-320 HV. However, the electrical conductivity increased significantly, reaching a maximum of 22.0% IACS, as shown in Table 2. This indicates that the different cooling rates used in these alloys after cooling pre-aging have a certain impact on the final state of the alloy's electrical conductivity, while the impact on hardness is relatively small. Tensile property tests revealed that the tensile strength of Examples 1, 3, and 5 in the final state is in the range of 900-950 MPa, and the elongation of these alloys is relatively high, reaching a maximum of 8.5%, significantly higher than the elongation of alloys with similar strength levels reported in the literature. With the increase of the cooling rate used in the cooling aging after isothermal aging, such as... Figure 9As shown, the hardness of the alloys in several examples also decreased, but the decrease was small. The hardness distribution ranges of the different alloys also showed some differences, especially in the low hardness range. However, according to Table 2, the alloys developed in Examples 2, 4, and 6 all achieved tensile strengths exceeding 1000 MPa, and their elongation and electrical conductivity were also excellent. The elongation reached 8.3%, and the electrical conductivity was all above 20% IACS. The alloy controlled in Example 6 achieved a maximum electrical conductivity of 20.7% IACS, all exhibiting very excellent overall performance.

[0098] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0099] In this application, the synergistic modification of Cu-Ti alloys optimizes the distribution of multi-scale precipitated phases without affecting the alloy's fundamental properties. These precipitated phases include microstructures with sizes ranging from 3 to 5 nm, 6 to 15 nm, and 16 to 26 nm. They work together on the alloy matrix, resulting in significantly improved strength, plasticity, and electrical conductivity in the synergistically modified Cu-Ti alloy. This is because the multi-scale precipitated phases not only increase the alloy's ability to coordinate deformation and allow for controlled deformation through multiple heat treatments, but also further induce the precipitation of more multi-scale precipitated phases. Furthermore, when the multi-scale precipitated phases and dislocations exhibit suitable coupling distribution characteristics, they can synergistically enhance the alloy's strength, electrical conductivity, and plasticity.

[0100] The above are merely embodiments of the present invention and are not intended to limit the invention. Those skilled in the art will recognize that the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A synergistically modified Cu-Ti alloy, characterized in that, The synergistically modified Cu-Ti alloy comprises, by mass percentage: 3.0 to 3.5 wt% Ti, ≤0.01 wt% B, ≤0.01 wt% Zr, with the balance being Cu. The synergistically modified Cu-Ti alloy includes β'-Cu4Ti precipitates with a size of 3-5 nm, β'-Cu4Ti precipitates with a size of 6-15 nm, and β'-Cu4Ti precipitates with a size of 16-26 nm.

2. The synergistically modified Cu-Ti alloy according to claim 1, characterized in that, The dislocation density of the synergistically modified Cu-Ti alloy is (8~10)×10 14 ·m -2 .

3. The synergistically modified Cu-Ti alloy according to claim 1 or 2, characterized in that, The spacing between adjacent particles of the β'-Cu4Ti precipitate phase with a size of 3-5 nm is 7-9 nm; and / or the spacing between adjacent particles of the β'-Cu4Ti precipitate phase with a size of 6-15 nm is 11-14 nm; and / or the spacing between adjacent particles of the β'-Cu4Ti precipitate phase with a size of 16-26 nm is 20-26 nm.

4. A method for preparing the synergistically modified Cu-Ti alloy according to any one of claims 1 to 3, characterized in that, The preparation method includes the following steps performed in sequence: batching, casting, homogenization heat treatment, hot rolling deformation, cold rolling deformation, solution treatment, cooling pre-aging treatment, first cold rolling, first cooling aging, second cold rolling, second cooling aging, third cold rolling, isothermal aging, and third cooling aging.

5. The preparation method according to claim 4, characterized in that, The solution treatment temperature is 800-900℃. After the solution treatment is carried out for 2-5 hours, the temperature is cooled to the initial temperature of the cooling pre-aging treatment at a cooling rate greater than 100℃ / min, and / or the temperature of the cooling pre-aging treatment is reduced from 410℃ to 350℃. The cooling rate during the cooling pre-aging treatment is 0.4-1.5℃ / h. After the cooling pre-aging treatment is completed, the temperature is air-cooled to 25-30℃.

6. The preparation method according to claim 4, characterized in that, The temperature of the first cold rolling is 25-30℃, the total deformation is 40-60%, the deformation method is unidirectional synchronous rolling, and the deformation per pass is 5-20%; and / or the temperature of the first cooling aging is reduced from 500℃ to 350℃, the cooling rate is 1.5-2.0℃ / min, and air cooling is performed when the temperature of the first cooling aging is 350℃.

7. The preparation method according to claim 4, characterized in that, The second cold rolling temperature is 25-30℃, the total deformation is 40-60%, the deformation method is unidirectional synchronous rolling, and the deformation per pass is 5-20%; and / or the temperature of the second cooling aging is reduced from 500℃ to 350℃, the cooling rate is 1.5-2.0℃ / min, and air cooling is performed when the temperature of the second cooling aging is 350℃.

8. The preparation method according to claim 4, characterized in that, The temperature of the third cold rolling is 25-30℃, the total deformation is 35-55%, the deformation method is unidirectional synchronous rolling, and the deformation per pass is 5-15%.

9. The preparation method according to claim 4, characterized in that, The isothermal aging temperature is 400–420°C, and the heating rate is greater than 100°C / min during the process of raising the temperature to the isothermal aging temperature. After the isothermal aging is performed for 1–7 hours, the temperature is raised to the highest temperature of the third cooling aging at a rate greater than 100°C / min, and the third cooling aging is performed. The third cooling aging is performed from 500°C to 400°C at a cooling rate of 1.5–2.0°C / min. When the temperature of the third cooling aging is 400°C, air cooling is performed.

10. The preparation method according to claim 4, characterized in that, The homogenization heat treatment is performed at a temperature of 750–850°C for 0.5–4 hours, with a heating rate of 20–80°C / min during the process of heating to the homogenization heat treatment temperature; and / or the total deformation of the hot rolling deformation is 60–80%, the deformation method is unidirectional synchronous rolling, and the deformation per pass is 10–20%; and / or the cold rolling deformation is performed at a temperature of 25–30°C, with a total deformation of 40–55%.

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