Preparation method of oriented structure Cu-Ag composite material

Abstract

The application discloses a preparation method of an oriented structure Cu-Ag composite material, adopts directional solidification and directional annealing process, controls Ag nano precipitated phase of the alloy to become an oriented arrangement structure, and prepares Cu-Ag in-situ composite material with high strength and high conductivity; the composite material is composed of 2-10% Ag, 0.1-1% Cr, 0.05-0.15% Zr and Cu; first, a slab with an oriented solidification structure is prepared under the action of a magnetic field and a gradient temperature field, longitudinal long grains are formed in the matrix, and Cr particles are pinned in the grain boundary; after solid solution treatment and rolling of the slab, directional annealing is carried out under the gradient temperature field, recrystallization is controlled to be carried out along the longitudinal temperature gradient direction, Ag nano precipitated phase is arranged along the longitudinal direction, and finally, the composite material slab is prepared through multi-pass rolling; through control of grain orientation, Cr particle distribution and Ag phase precipitation direction, the composite material has excellent tensile strength and conductivity.

Description

Technical Field

[0001] This invention belongs to the field of metallic materials and relates to the preparation technology of high-strength and high-conductivity Cu-Ag composite materials, specifically a method for preparing an oriented Cu-Ag composite material. Background Technology

[0002] Copper-based alloys are widely used in electronics, power, aerospace, and other fields due to their excellent electrical, thermal, and mechanical properties. However, traditional copper alloys present a trade-off between strength and electrical conductivity, making it difficult to simultaneously meet the requirements of high strength and high conductivity. In recent years, age-hardening precipitation-type copper-based alloys have become a research hotspot due to their ability to improve strength while maintaining high electrical conductivity through a nanophase precipitation strengthening mechanism. Ag, as a common alloying element, can significantly improve the performance of copper-based alloys through solid solution and age-hardening precipitation mechanisms. Ag can be completely integrated into the Cu matrix during the solid solution heat treatment stage and precipitates nanophases during the aging process, strengthening the alloy. However, it is difficult to precisely control the microstructure orientation of Cu-Ag alloys using existing melting and processing technologies, resulting in limited alloy properties and restricting their widespread application in industrial fields.

[0003] Researchers have conducted extensive research on optimizing the performance of Cu-Ag alloys, including various combinations of melting, heat treatment, and deformation processing steps, as well as the addition of other alloying elements. For example, patent application CN 202011617275.1 discloses a method for preparing high-strength, high-conductivity copper-silver alloy wire. This alloy mainly consists of 0.2-8.0 wt.% Ag, with a total impurity content of no more than 0.1%, and the balance being Cu. The preparation method includes vacuum melting, vacuum continuous casting, aging, and multi-pass drawing. Patent application CN 202410106033.8 discloses a Cu-Ag alloy wire reinforced with endogenous Ag fibers and its preparation method. A copper-silver alloy rod is prepared by vacuum continuous casting, and the copper-silver alloy rod is then solution-treated, aged, and drawn to prepare the initial copper-silver alloy wire. Patent application CN 201910401815.3 discloses a high-strength, high-conductivity Cu-Ag-Sc alloy and its preparation method. The alloy's composition, by mass percentage, contains 1-10% Ag, 0.05-0.5% Sc, and the balance Cu. The process includes vacuum melting, solution heat treatment, and aging treatment. However, the above patented technology suffers from limitations in precisely controlling the microstructure orientation, resulting in limited alloy properties. The strength of Cu-Ag composite materials produced using conventional methods is difficult to exceed 700 MPa. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention aims to provide an oriented Cu-Ag alloy and its preparation method. Through processes such as directional solidification under a stable magnetic field, solution heat treatment, forging, directional annealing, rolling deformation processing, and final heat treatment, the microstructure of the alloy is precisely controlled to prepare a Cu-Ag-Cr alloy with high strength and high conductivity. Directional solidification forms a long-grained Cu matrix, and the addition of Cr elements forms Cr particles, while Zr elements further refine the Cr particle effect. The long-grained structure is maintained by Cr particle pinning, and the orientation of the Ag precipitates is achieved through directional annealing. Ultimately, a microstructure is achieved where the Ag precipitates and Cu grain boundaries are parallel to each other in the same direction, thus improving the mechanical and electrical properties of the alloy.

[0005] To achieve the above-mentioned objective, this invention provides a method for preparing an oriented Cu-Ag composite material (aging precipitation type Cu-Ag-Cr alloy). The composite material is composed of the following components with the following mass content: Ag: 2%–10%, Cr: 0.1%–1.0%, Zr: 0.05%–0.15%, with the balance being Cu. In the composite material, the Cu grains are long grains arranged longitudinally, the Ag phase is a longitudinally arranged fibrous nanophase, and the Cr phase is a dispersed particle distributed near the grain boundaries.

[0006] The preparation method of the oriented Cu-Ag composite material includes the following steps:

[0007] ① Using pure metal Cu, pure metal Ag, Cu-Cr master alloy, and Cu-Zr master alloy as raw materials, under an inert atmosphere, the metal Cu, Ag, Cu-Cr master alloy, and Cu-Zr master alloy are placed in a crucible of a directional solidification apparatus. The inner cavity of the crucible is slab-shaped. The mixture is heated to complete melting using a high-frequency induction furnace and held at 1100℃~1300℃ for 10 minutes to obtain a molten alloy. The inert atmosphere is either argon or nitrogen.

[0008] ② The alloy liquid is directionally solidified under the action of a steady magnetic field (magnetic induction intensity 0.1~1.0T) (e.g. Figure 1 As shown, the crucible is pulled downwards into the Ga-In-Sn liquid pool. The temperature gradient for directional solidification is set to 10–50 K / cm, and the pulling speed is 10–100 μm / s. This produces a Cu-Ag-Cr alloy slab ingot with Cu dendrites oriented longitudinally along the temperature gradient direction. Long Cu grains are arranged longitudinally, and Ag eutectic phase and Cr particles are dispersed at the Cu dendrite grain boundaries.

[0009] Furthermore, the magnetic induction intensity of the steady magnetic field is preferably 1.0T, the temperature gradient is preferably 20K / cm, and the pulling speed is preferably 50μm / s.

[0010] ③ Under an inert atmosphere, the Cu-Ag-Cr alloy slab ingot is subjected to solution heat treatment, which allows Ag to completely dissolve into the Cu matrix, while Cr particles with higher solution temperatures remain distributed at the grain boundaries. The inert atmosphere is an argon atmosphere or a nitrogen atmosphere.

[0011] Furthermore, the solution heat treatment temperature is 780℃~950℃, and the time is 2~10h; the preferred solution heat treatment temperature is 900℃, and the preferred time is 4h.

[0012] Directional solidification technology generates a longitudinally aligned columnar grain structure. During solidification, careful control ensures that primary Cr particles are dispersed at the grain boundaries; this distribution characteristic plays a crucial role in subsequent heat treatment, effectively controlling Cu grain growth and coarsening through particle pinning. Furthermore, the addition of Zr generates fine compound particles that not only promote nucleation but also refine Cr particles and promote their dispersed distribution, further enhancing the role of Cr particles. Utilizing the difference in solution temperatures between Ag and Cr in the Cu matrix, precise control of the solution temperature ensures that Ag completely dissolves into the Cu matrix, while Cr particles remain ideally distributed at the grain boundaries.

[0013] ④ The Cu-Ag-Cr alloy slab ingot after solution heat treatment is forged with a deformation of 30% to 70% to reduce the thickness of the alloy slab.

[0014] ⑤ Under an inert atmosphere, the forged Cu-Ag-Cr alloy slab ingot is directionally annealed using a directional annealing device. Recrystallization is controlled to proceed along the longitudinal temperature gradient, causing the Ag nano-precipitates to align longitudinally. The alloy slab is then pulled upwards from the Ga-In-Sn liquid bath into the heating coil region (e.g., Figure 2 As shown in the figure); combined with the pinning effect of the longitudinal temperature field and the Cr grains at the grain boundaries, Cu dendrites recrystallize and grow longitudinally, while the Ag aging precipitates are oriented (longitudinally) along the temperature gradient direction, consistent with the long grain arrangement direction of Cu.

[0015] Furthermore, the directional annealing device has a directional annealing temperature of 350℃~600℃ and a pulling speed of 2~100μm / s; the preferred directional annealing temperature is 450℃ and the preferred pulling speed is 50μm / s.

[0016] A progressive heating directional annealing process was employed, in which the sample passed through a hot zone at a predetermined speed. During this process, the grains underwent directional growth as they passed through the hot zone (e.g., Figure 2As shown in the diagram, recrystallized grains grow along the longitudinal direction. Simultaneously, the pinning effect of Cr particles is fully utilized to suppress lateral migration of grain boundaries, ensuring that the migration direction is mainly concentrated in the longitudinal direction, thus guaranteeing that Cu grains maintain a slender morphology. Ag precipitates have the characteristic of migrating and aligning with grain boundaries; this characteristic can be used to form longitudinally aligned Ag precipitates.

[0017] ⑥ The alloy after directional annealing is subjected to multi-pass rolling (70% to 95% deformation) to further improve the mechanical properties of Cu-Ag-Cr material.

[0018] ⑦ The rolled alloy is heat-treated at 200℃~300℃ for 2~4h to further improve the conductivity and optimize the alloy properties; finally, an oriented Cu-Ag composite material is obtained.

[0019] Furthermore, the oriented Cu-Ag composite material is composed of the following components by mass content: Ag: 5%–7%, Cr: 0.4%–0.6%, Zr: 0.08%–0.12%, with the balance being Cu.

[0020] Furthermore, the Ag content in the Cu-Ag composite material is preferably 6%, the Cr content is preferably 0.5%, and the Zr content is preferably 0.1%.

[0021] By employing a microstructure control technique combining directional solidification and directional recrystallization, and further refining the microstructure and mechanical properties through deformation processing, a structure with longitudinally aligned Cu long grains and longitudinally aligned Ag nanoprecipitates was prepared. This unique structure significantly improves the material's strength, while the parallel-aligned Cu long grains optimize electron transport paths and reduce interface scattering, thus helping the material maintain high conductivity. By designing and implementing the aforementioned longitudinally aligned microstructure, this technique significantly enhances the strengthening effect of Cu-Ag composite materials while minimizing the negative impact on conductivity, thereby improving the overall performance of the material.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] This invention employs a combination of directional solidification and directional annealing processes to regulate the Ag nano-precipitates in the alloy into an oriented structure, thereby preparing a Cu-Ag deformation in-situ composite material with high strength and high conductivity. This composite material consists of 2–10% Ag, 0.1–1% Cr, 0.05–0.15% Zr, and Cu. First, a slab with an oriented solidification structure is prepared under the influence of a magnetic field and a gradient temperature field, causing the matrix to form longitudinally long grains, with Cr particles pinned to the grain boundaries. After solution treatment and rolling, the slab undergoes directional annealing under a gradient temperature field, controlling recrystallization along the longitudinal temperature gradient direction, causing the Ag nano-precipitates to align longitudinally. Finally, the composite material slab is produced through multiple rolling passes.

[0024] This invention regulates the grain size and distribution of an alloy through directional solidification, optimizing the morphology and orientation of Ag precipitates to improve the alloy's strength and conductivity. Solution heat treatment and forging ensure complete Ag solution dissolution, and grain refinement through deformation further enhances the alloy's mechanical properties. Directional annealing and rolling deformation processing precisely control grain boundary migration, recrystallized grains, texture evolution, and precipitate morphology, optimizing the alloy's overall performance. The Cu-Ag composite material with an oriented structure prepared by this invention exhibits high strength and high conductivity, making it suitable for leadframes, power, electronics, and strong magnetic field conductors. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the directional solidification device under a steady magnetic field in this invention.

[0026] Figure 2 This is a schematic diagram of the directional annealing device in this invention;

[0027] Figure 3 The image shows the microstructure of the Cu-6%Ag-0.5%Cr-0.1%Zr alloy prepared in Example 3.

[0028] Figure 4 The image shows the microstructure of the Cu-8%Ag-0.8%Cr-0.1%Zr alloy prepared in Example 4.

[0029] Figure 5 Microstructure diagram of Cu-6%Ag alloy prepared for Comparative Example 1. Detailed Implementation

[0030] The present invention will be further described below with reference to specific embodiments, but this does not limit the invention in any way. To avoid redundancy, unless otherwise specified, the raw materials used in the following embodiments are all commercially available products, and the methods used are all conventional methods unless otherwise specified.

[0031] A method for preparing an oriented Cu-Ag composite material, wherein the composite material is composed of the following components in terms of mass content: Ag: 2%–10%, Cr: 0.1%–1.0%, Zr: 0.05%–0.15%, with the balance being Cu; in the composite material, Cu grains are long grains arranged longitudinally, Ag phase is a longitudinally arranged fibrous nanophase, and Cr phase is a dispersed particle distributed near the grain boundaries.

[0032] The preparation method of the oriented Cu-Ag composite material includes the following steps:

[0033] ① Under an inert atmosphere, the raw material is placed in the crucible of a directional solidification device, heated to complete melting using a high-frequency induction furnace, and held at 1100℃~1300℃ for 10 minutes to obtain an alloy liquid;

[0034] ②The alloy liquid is directionally solidified under the action of a steady magnetic field to prepare Cu-Ag-Cr alloy slab ingots with Cu dendrites longitudinally oriented along the temperature gradient direction.

[0035] The structure of the directional solidification device is as follows: Figure 1 As shown, the alloy raw material is placed in a crucible and then placed in a sealed device consisting of a flange and a protective sleeve. The protective gas (argon or nitrogen) is introduced through the inlet and discharged through the outlet. The alloy is heated to a set temperature by a heating coil, melted, and held at that temperature. Then, the crucible is gradually drawn into the Ga-In-Sn alloy liquid by pulling down the pull rod at a set speed. At the same time, the temperature at the top of the crucible is maintained by the graphite sleeve, so that the alloy solidifies in a directional manner.

[0036] ③ Under an inert atmosphere, the Cu-Ag-Cr alloy slab ingot is subjected to solution heat treatment;

[0037] ④ The Cu-Ag-Cr alloy slab ingot after solution heat treatment is subjected to forging deformation treatment.

[0038] ⑤ Under the protection of an inert atmosphere, the forged Cu-Ag-Cr alloy slab ingot is oriented annealed using a directional annealing device to control recrystallization along the longitudinal temperature gradient direction, so that the Ag nano-precipitates are oriented along the longitudinal direction.

[0039] The structure of the directional annealing device is as follows: Figure 2As shown, during directional annealing, the Cu-Ag-Cr alloy slab is connected to the pull rod and placed into a sealed device consisting of a flange and a protective sleeve. The protective gas (argon or nitrogen) is introduced through the inlet and discharged through the outlet. A hot zone of a certain temperature is formed by heating with a heating coil. The Cu-Ag-Cr alloy slab is pulled upwards at a set speed through the pull rod, gradually rising out of the Ga-In-Sn alloy liquid and gradually entering the hot zone formed by the heating coil in sections. The local temperature of a section of the Cu-Ag-Cr alloy slab in the heating zone is maintained by a graphite sleeve, thus performing directional annealing of the alloy.

[0040] ⑥ Perform multi-pass rolling processing on the alloy after directional annealing;

[0041] ⑦ The rolled alloy is heat-treated at 200℃~300℃ for 2~4h to obtain an oriented Cu-Ag composite material.

[0042] Any aspects not described in the following embodiments are the same as those described in the specific embodiments above.

[0043] Example 1

[0044] A method for preparing an oriented Cu-Ag composite material, wherein the composite material is composed of the following components with the following mass content: Ag: 2%, Cr: 0.1%, Zr: 0.05%, and the balance being Cu.

[0045] The preparation method of the oriented Cu-Ag composite material includes the following steps:

[0046] ① Under the protection of argon atmosphere, the raw materials (pure metal Cu, pure metal Ag, Cu-Cr master alloy and Cu-Zr master alloy) are placed in the crucible of the directional solidification device. The inner cavity of the crucible is in the shape of a slab. The material is heated to complete melting using a high frequency induction furnace and held at 1100℃ for 10 minutes to obtain alloy liquid.

[0047] ②The alloy liquid was directionally solidified under the action of a constant magnetic field (magnetic induction intensity 0.1T), and the temperature gradient was set to 10K / cm and the pulling speed was 10μm / s to prepare Cu-Ag-Cr alloy slab ingots with Cu dendrites longitudinally oriented along the temperature gradient direction. Its composition was Cu-2%Ag-0.1%Cr-0.05%Zr.

[0048] ③ Under the protection of argon atmosphere, the Cu-Ag-Cr alloy slab ingot after directional solidification is subjected to solution heat treatment at 780℃ for 2 hours to ensure complete Ag solution while retaining Cr particles with higher solution temperature at the grain boundaries.

[0049] ④ The Cu-Ag-Cr alloy slab ingot after solution heat treatment is forged with a 30% deformation to reduce the thickness of the alloy slab.

[0050] ⑤ Under the protection of argon atmosphere, the forged Cu-Ag-Cr alloy slab ingot is oriented annealed using an oriented annealing device. The recrystallization is controlled to proceed along the longitudinal temperature gradient direction, so that the Ag nano-precipitates are oriented along the longitudinal direction. The oriented annealing system parameters are set to 350℃ and 2μm / s, so that the precipitates are oriented along the temperature gradient direction, consistent with the long grain arrangement direction of Cu.

[0051] ⑥ The alloy after directional annealing is subjected to multi-pass rolling processing, with a deformation of 70%;

[0052] ⑦ The rolled alloy was heat-treated at 200℃ for 4 hours to obtain an oriented Cu-Ag composite material, which further improved the conductivity and optimized the alloy performance.

[0053] Example 1 shows a Cu-Ag alloy composite material with an oriented structure. In the composite material, Cu grains are long grains arranged in the longitudinal direction, Ag phase is a fibrous nanophase arranged in the longitudinal direction, and Cr phase is a dispersed particle distributed near the grain boundary. The Vickers hardness of this Cu-Ag alloy composite material is 236 HV, the maximum tensile strength is 650 MPa, and the electrical conductivity is 79.6 IACS.

[0054] Example 2

[0055] A method for preparing an oriented Cu-Ag composite material, wherein the composite material is composed of the following components with the following mass content: Ag: 4%, Cr: 0.4%, Zr: 0.08%, and the balance being Cu.

[0056] The preparation method of the oriented Cu-Ag composite material includes the following steps:

[0057] ① Under the protection of argon atmosphere, the raw materials (pure metal Cu, pure metal Ag, Cu-Cr master alloy and Cu-Zr master alloy) are placed in the crucible of the directional solidification device. The inner cavity of the crucible is in the shape of a slab. The material is heated to complete melting using a high frequency induction furnace and held at 1150℃ for 10 minutes to obtain alloy liquid.

[0058] ②The alloy liquid was directionally solidified under the action of a constant magnetic field (magnetic induction intensity 0.2T), and the temperature gradient was set to 20K / cm and the pulling speed was 20μm / s to prepare Cu-Ag-Cr alloy slab ingots with Cu dendrites longitudinally oriented along the temperature gradient direction. Its composition was Cu-4%Ag-0.4%Cr-0.08%Zr.

[0059] ③ Under the protection of argon atmosphere, the Cu-Ag-Cr alloy slab ingot after directional solidification is subjected to solution heat treatment at 800℃ for 4 hours to ensure complete Ag solution while retaining Cr particles with higher solution temperature at the grain boundaries.

[0060] ④ The Cu-Ag-Cr alloy slab ingot after solution heat treatment was forged with a deformation of 40% to analyze the effect of deformation on grain morphology, texture and precipitates.

[0061] ⑤ Under the protection of argon atmosphere, the forged Cu-Ag-Cr alloy slab ingot was directionally annealed using a directional annealing device. The recrystallization was controlled to proceed along the longitudinal temperature gradient direction, so that the Ag nano-precipitates were aligned longitudinally. The directional annealing system parameters were set to 400℃ and 20μm / s. The influence mechanism of key parameters such as temperature gradient and pulling speed on microstructure characteristics such as grain boundary migration, recrystallized grains, texture evolution, interface properties, morphology and orientation of precipitates was investigated.

[0062] ⑥ The alloy after directional annealing is subjected to multi-pass rolling with a deformation of 75% to prepare Cu-Ag-Cr-Zr composite material;

[0063] ⑦ The rolled alloy was heat-treated at 220℃ for 2 hours to obtain an oriented Cu-Ag composite material, which further controlled the microstructure and optimized the alloy properties.

[0064] Example 2 shows a Cu-Ag alloy composite material with an oriented structure. In the composite material, Cu grains are long grains arranged in the longitudinal direction, Ag phase is a fibrous nanophase arranged in the longitudinal direction, and Cr phase is a dispersed particle distributed near the grain boundary. The Vickers hardness of this Cu-Ag alloy composite material is 245 HV, the maximum tensile strength is 765 MPa, and the electrical conductivity is 77.5 IACS.

[0065] Example 3

[0066] A method for preparing an oriented Cu-Ag composite material, wherein the composite material is composed of the following components with the following mass content: Ag: 6%, Cr: 0.5%, Zr: 0.10%, and the balance being Cu.

[0067] The preparation method of the oriented Cu-Ag composite material includes the following steps:

[0068] ① Under the protection of argon atmosphere, the raw materials (pure metal Cu, pure metal Ag, Cu-Cr master alloy and Cu-Zr master alloy) are placed in the crucible of the directional solidification device. The inner cavity of the crucible is in the shape of a slab. The material is heated to complete melting using a high frequency induction furnace and held at 1200℃ for 10 minutes to obtain alloy liquid.

[0069] ②The alloy liquid was directionally solidified under the action of a constant magnetic field (magnetic induction intensity 1.0T), and the temperature gradient was set to 20K / cm and the pulling speed was 50μm / s to prepare Cu-Ag-Cr alloy slab ingots with Cu dendrites longitudinally oriented along the temperature gradient direction. Its composition was Cu-6%Ag-0.5%Cr-0.1%Zr.

[0070] ③ Under the protection of argon atmosphere, the Cu-Ag-Cr alloy slab ingot after directional solidification is subjected to solution heat treatment at 900℃ for 4 hours to ensure complete Ag solution while retaining Cr particles with higher solution temperature at the grain boundaries.

[0071] ④ The Cu-Ag-Cr alloy slab ingot after solution heat treatment is forged with a deformation of 50%.

[0072] ⑤ Under the protection of argon atmosphere, the forged Cu-Ag-Cr alloy slab ingot is oriented annealed using an oriented annealing device. The recrystallization is controlled to proceed along the longitudinal temperature gradient direction, so that the Ag nano-precipitates are oriented along the longitudinal direction. The oriented annealing system parameters are set to 450℃ and 50μm / s, so that the precipitates are oriented along the temperature gradient direction, consistent with the long grain arrangement direction of Cu.

[0073] ⑥ The alloy after directional annealing is subjected to multi-pass rolling with a deformation of 95% to prepare Cu-Ag-Cr-Zr composite material.

[0074] ⑦ The rolled alloy was heat-treated at 240℃ for 2 hours to obtain an oriented Cu-Ag composite material, which further controlled the microstructure and optimized the alloy properties.

[0075] The Cu-Ag alloy composite material with an oriented structure prepared in Example 3 has the following microstructure: Cu-6%Ag-0.5%Cr-0.1%Zr alloy. Figure 3 As shown, the Cu grains in the composite material are long grains arranged longitudinally, the Ag phase is a longitudinally arranged fibrous nanophase, and the Cr phase is a dispersed particle distributed near the grain boundaries. The Vickers hardness of this Cu-Ag alloy composite material is 266 HV, the maximum tensile strength is 980 MPa, and the electrical conductivity is 73.4 IACS.

[0076] Example 4

[0077] A method for preparing an oriented Cu-Ag composite material, wherein the composite material is composed of the following components with the following mass content: Ag: 8%, Cr: 0.8%, Zr: 0.10%, and the balance being Cu.

[0078] The preparation method of the oriented Cu-Ag composite material includes the following steps:

[0079] ① Under the protection of argon atmosphere, the raw materials (pure metal Cu, pure metal Ag, Cu-Cr master alloy and Cu-Zr master alloy) are placed in the crucible of the directional solidification device. The inner cavity of the crucible is in the shape of a slab. The material is heated to complete melting using a high frequency induction furnace and held at 1250℃ for 10 minutes to obtain alloy liquid.

[0080] ②The alloy liquid was directionally solidified under the action of a constant magnetic field (magnetic induction intensity 0.5T), and the temperature gradient was set to 40K / cm and the pulling speed was 50μm / s to prepare Cu-Ag-Cr alloy slab ingots with Cu dendrites longitudinally oriented along the temperature gradient direction. Its composition was Cu-8%Ag-0.8%Cr-0.1%Zr.

[0081] ③ Under the protection of argon atmosphere, the Cu-Ag-Cr alloy slab ingot after directional solidification is subjected to solution heat treatment at 900℃ for 8 hours to ensure complete Ag solution while retaining Cr particles with higher solution temperature at the grain boundaries.

[0082] ④ The Cu-Ag-Cr alloy slab ingot after solution heat treatment is forged with a deformation of 60%.

[0083] ⑤ Under the protection of argon atmosphere, the forged Cu-Ag-Cr alloy slab ingot is oriented annealed using an oriented annealing device. The recrystallization is controlled to proceed along the longitudinal temperature gradient direction, so that the Ag nano-precipitates are oriented along the longitudinal direction. The oriented annealing system parameters are set to 500℃ and 70μm / s, so that the precipitates are oriented along the temperature gradient direction, consistent with the long grain arrangement direction of Cu.

[0084] ⑥ The alloy after directional annealing is subjected to multi-pass rolling with a deformation of 85% to prepare Cu-Ag-Cr-Zr composite material.

[0085] ⑦ The rolled alloy was heat-treated at 260℃ for 2 hours to obtain an oriented Cu-Ag composite material, which further controlled the microstructure and optimized the alloy properties.

[0086] The Cu-Ag alloy composite material with an oriented structure prepared in Example 4 has the following microstructure: Cu-8%Ag-0.8%Cr-0.1%Zr alloy. Figure 4 As shown, the Cu grains in the composite material are long grains arranged longitudinally, the Ag phase is a longitudinally arranged fibrous nanophase, and the Cr phase is a dispersed particle distributed near the grain boundaries. The Vickers hardness of this Cu-Ag alloy composite material is 259 HV, the maximum tensile strength is 860 MPa, and the electrical conductivity is 76 IACS.

[0087] Example 5

[0088] A method for preparing an oriented Cu-Ag composite material, wherein the composite material is composed of the following components with the following mass content: Ag: 10%, Cr: 1.0%, Zr: 0.15%, and the balance being Cu.

[0089] The preparation method of the oriented Cu-Ag composite material includes the following steps:

[0090] ① Under the protection of argon atmosphere, the raw materials (pure metal Cu, pure metal Ag, Cu-Cr master alloy and Cu-Zr master alloy) are placed in the crucible of the directional solidification device. The inner cavity of the crucible is in the shape of a slab. The material is heated to complete melting using a high frequency induction furnace and held at 1300℃ for 10 minutes to obtain alloy liquid.

[0091] ②The alloy liquid was directionally solidified under the action of a constant magnetic field (magnetic induction intensity 0.8T), and the temperature gradient was set to 50K / cm and the pulling speed was 100μm / s to prepare Cu-Ag-Cr alloy slab ingots with Cu dendrites longitudinally oriented along the temperature gradient direction.

[0092] ③ Under nitrogen atmosphere protection, the Cu-Ag-Cr alloy slab ingot after directional solidification was subjected to solution heat treatment at 950℃ for 10h.

[0093] ④ The Cu-Ag-Cr alloy slab ingot after solution heat treatment is forged with 70% deformation to reduce the thickness of the alloy slab.

[0094] ⑤ Under nitrogen atmosphere protection, the forged Cu-Ag-Cr alloy slab ingot is oriented annealed using an oriented annealing device. The recrystallization is controlled to proceed along the longitudinal temperature gradient direction, so that the Ag nano-precipitates are oriented along the longitudinal direction. The oriented annealing system parameters are set to 600℃ and 100μm / s, so that the precipitates are oriented along the temperature gradient direction, consistent with the long grain arrangement direction of Cu.

[0095] ⑥ The alloy after directional annealing is subjected to multi-pass rolling processing, with a deformation of 90%;

[0096] ⑦ The rolled alloy was heat-treated at 300℃ for 4 hours to obtain an oriented Cu-Ag composite material, which further controlled the microstructure and optimized the alloy properties.

[0097] Example 5 shows a Cu-Ag alloy composite material with an oriented structure. In the composite material, Cu grains are long grains arranged in the longitudinal direction, Ag phase is a fibrous nanophase arranged in the longitudinal direction, and Cr phase is a dispersed particle distributed near the grain boundary. The Vickers hardness of this Cu-Ag alloy composite material is 271 HV, the maximum tensile strength is 995 MPa, and the electrical conductivity is 69.6 IACS.

[0098] Comparative Example 1

[0099] A Cu-Ag composite material, wherein the composite material is composed of the following components by mass content: Ag: 6%, with the balance being Cu.

[0100] The preparation method of the Cu-Ag composite material includes the following steps:

[0101] ① Under the protection of argon atmosphere, the raw materials (pure metal Cu, pure metal Ag) are heated to complete melting in a high frequency induction furnace and held at 1200℃ for 10 min to obtain alloy liquid;

[0102] ② The alloy liquid is directly poured into the mold to obtain Cu-Ag alloy slab ingots with a composition of Cu-6%Ag;

[0103] ③ Under the protection of argon atmosphere, Cu-Ag alloy ingots are subjected to solution heat treatment at 900℃ for 4 hours;

[0104] ④ The Cu-Ag alloy slab ingot after solution heat treatment is forged with a deformation of 50%.

[0105] ⑤ Under the protection of argon atmosphere, the forged Cu-Ag-Cr alloy slab ingot was subjected to annealing heat treatment; the annealing parameters were set to 450℃, the holding time was 2h, and the precipitated phases were randomly distributed.

[0106] ⑥ The annealed alloy is subjected to multi-pass rolling with a deformation of 95% to prepare Cu-Ag composite material.

[0107] ⑦ The rolled alloy was heat-treated at 240℃ for 2 hours to obtain Cu-Ag composite material.

[0108] The Cu-Ag alloy composite material prepared in Comparative Example 1 has Cu grains that are non-oriented ordinary grains and Ag phase that is a non-oriented randomly arranged precipitate. The Vickers hardness of the Cu-Ag alloy composite material is 180 HV, the maximum tensile strength is 665 MPa, and the electrical conductivity is 78 IACS.

[0109] For anyone skilled in the art, many possible variations and modifications can be made to the technical solutions of this invention, or equivalent embodiments can be modified based on the disclosed technical content, without departing from the scope of the technical solutions of this invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this invention without departing from the content of the technical solutions of this invention should still fall within the protection scope of the technical solutions of this invention.

Claims

1. A method for producing an oriented structure Cu-Ag composite material, characterized by, The composite material is composed of components with the following mass content: Ag: 2% to 10%, Cr: 0.1% to 1.0%, Zr: 0.05% to 0.15%, and the balance being Cu; the Cu grains in the composite material are long grains arranged in the longitudinal direction, the Ag phase is a fibrous nanophase arranged in the longitudinal direction, and the Cr phase is a dispersed particle distributed near the grain boundary. The preparation method of the oriented structure Cu-Ag composite material comprises the following steps: ① placing raw materials into a crucible of a directional solidification device under the protection of an inert atmosphere, heating to complete melting by using a high-frequency induction furnace, and keeping the temperature at 1100°C to 1300°C for 10 min to obtain an alloy liquid; ② directionally solidifying the alloy liquid under the action of a steady magnetic field to prepare a Cu-Ag-Cr alloy slab ingot with Cu dendrites oriented in the longitudinal direction of the temperature gradient; the magnetic induction intensity of the steady magnetic field is 0.1 to 1.0 T; the temperature gradient of the directional solidification is set to be 10 to 50 K / cm, and the pulling speed is 10 to 100 μm / s; ③ performing solid solution heat treatment on the Cu-Ag-Cr alloy slab ingot under the protection of an inert atmosphere; ④ performing forging deformation treatment on the Cu-Ag-Cr alloy slab ingot after the solid solution heat treatment; ⑤ performing directional annealing on the forged Cu-Ag-Cr alloy slab ingot by using a directional annealing device under the protection of an inert atmosphere, controlling the recrystallization to occur in the longitudinal direction of the temperature gradient, and making the Ag nanophase oriented and arranged in the longitudinal direction; the directional annealing temperature is 350°C to 600°C, and the pulling speed is 2 to 100 μm / s; ⑥ performing rolling processing on the alloy after the directional annealing; ⑦ performing heat treatment on the alloy after the rolling at 200°C to 300°C for 2 to 4 h to obtain the oriented structure Cu-Ag composite material.

2. The method for preparing an oriented Cu-Ag composite material according to claim 1, characterized in that, The raw materials in step ① are pure metal Cu, pure metal Ag, Cu-Cr intermediate alloy, and Cu-Zr intermediate alloy.

3. The method for preparing an oriented Cu-Ag composite material according to claim 1, characterized in that, The solid solution heat treatment temperature in step ③ is 780°C to 950°C, and the time is 2 to 10 h.

4. The method for preparing an oriented Cu-Ag composite material according to claim 1, characterized in that, The deformation amount of the forging treatment in step ④ is 30% to 70%.

5. The method for preparing an oriented Cu-Ag composite material according to claim 1, characterized in that, The deformation amount of the rolling processing in step ⑥ is 70% to 95%.

6. The method for preparing an oriented Cu-Ag composite material according to claim 1, characterized in that, The oriented structure Cu-Ag composite material is composed of components with the following mass content: Ag: 5% to 7%, Cr: 0.4% to 0.6%, Zr: 0.08% to 0.12%, and the balance being Cu.

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