Grain refining treatment method for high-conductivity copper alloy material
By employing lanthanum deoxidation and composite deformation processes, combined with drawing and torsion, the problems of conductivity and performance inhomogeneity during the fine grain formation of copper alloys were solved, enabling the preparation of copper alloy materials with high conductivity and high strength.
Patent Information
- Application Number
- CN202511491394.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-18
- Publication Date
- 2026-01-23
AI Technical Summary
Existing copper alloy grain refinement processes struggle to achieve effective grain refinement while maintaining excellent conductivity, resulting in performance inhomogeneity and reduced conductivity.
The process employs lanthanum deoxidation and composite deformation, including drawing and torsion, combined with common smelting, casting, hot extrusion molding and cold working processes. Lanthanum is used to form a well-dispersed La2O3 compound, which, in conjunction with drawing to provide axial plastic deformation and torsion to provide tangential stress, achieves uniform and refined grains.
While maintaining high conductivity (≥98.5% IACS) and tensile strength (≥350MPa), it achieves uniform grain refinement, improves the overall performance of the material, reduces production costs, and is suitable for industrial production.
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of processing of copper alloy materials, and particularly relates to a fine-grain processing method for high-conductivity copper alloy materials. BACKGROUND
[0002] Copper and copper alloys are widely used in the fields of electric wires and cables, electronic components, etc. due to their excellent electrical conductivity, and fine-grain processing is a key means to improve the mechanical properties such as strength and hardness of copper alloys.
[0003] Existing fine-grain processes mostly rely on single deformation (such as only drawing) or adding a large amount of alloying elements. The former easily leads to insufficient grain refinement and poor microstructure uniformity, and the latter significantly reduces the electrical conductivity of copper alloys, making it difficult to balance the performance requirements of "high conductivity" and "fine grain".
[0004] Therefore, how to provide a processing method for copper alloy materials to ensure excellent electrical conductivity while achieving effective fine-grain processing has become a technical problem to be solved. SUMMARY
[0005] The present application is to solve the above technical problems, and provides a fine-grain processing method for high-conductivity copper alloy materials. The technical purpose of the present application is to provide a fine-grain processing method for high-conductivity copper alloy materials, which realizes uniform and fine-grain refinement and improves the comprehensive performance of the material by optimizing the deoxidizing elements and the composite deformation process while ensuring high electrical conductivity of the copper alloy.
[0006] In order to achieve the above technical purpose, the technical solution adopted by the present application is as follows:
[0007] The present application first provides a fine-grain processing method for high-conductivity copper alloy materials, comprising the following steps:
[0008] (1) Selecting oxygen-free copper as a base material and performing surface pretreatment;
[0009] (2) Melting: melting the surface pretreated oxygen-free copper into a copper liquid at 1100-1200℃, adding lanthanum elements at 0.01-0.05% of the mass of the copper liquid, and pouring into a copper alloy ingot after holding for 15-20min and cooling to room temperature;
[0010] (3) Hot extrusion molding: placing the copper alloy ingot obtained in step (2) into an induction heating furnace, heating to 760℃±10℃, holding for 30min, and then performing water-sealed extrusion deformation processing;
[0011] (4) Pickling: pickling the extruded billet obtained in step (3) to remove surface oxides;
[0012] (5) the copper bar blank obtained in step (4) is subjected to multi-pass drawing, and the cumulative drawing deformation is 40%-50%, to obtain a pre-deformed copper bar; the pre-deformed copper bar is twisted at a speed of 10-15 revolutions / min, and the twisting mode is: 9 clockwise turns and 11 counterclockwise turns; the "drawing-twisting" is repeated in the above manner to obtain the high-conductivity copper alloy material.
[0013] Further, in step (1), the purity of the oxygen-free copper is ≥99.99%, and the surface pretreatment is to remove the surface oxide layer by polishing.
[0014] Further, in step (2), the melting and heat preservation processes are both carried out in a vacuum environment, and the copper alloy ingot is a bar blank with a diameter of φ=120 mm.
[0015] Further, in step (2), the content of the lanthanum element is La%≥99.9%.
[0016] Further, in step (3), the hot extrusion forming adopts reverse hot extrusion forming.
[0017] Further, in step (5), the total deformation of the drawing is 40%-50%.
[0018] Further, in step (5), a water-soluble lubricant is used for cooling during the drawing process, and the deformation of each pass of drawing is 8%-12%.
[0019] Further, in step (5), the "drawing-twisting" cycle is repeated 2-3 times.
[0020] Further, in step (5), the high-conductivity copper alloy material has the following properties: at room temperature, the average grain size range is 4-10 um, the conductivity is ≥98.5% IACS, and the tensile strength is ≥350 MPa.
[0021] The second object of the present application is to provide a high-conductivity copper alloy material obtained by the fine-grain processing method according to any one of the above.
[0022] The present application has the following advantages:
[0023] (1) The present application uses lanthanum element deoxidization, and compared with traditional deoxidizers (such as phosphorus), the La2O3 compound formed by lanthanum and oxygen has good dispersibility and does not reduce the conductivity of copper. The conductivity of the final copper alloy material at room temperature (20℃) is ≥98.5% IACS, the average grain size range is 4-10 um, and the tensile strength is ≥350 MPa.
[0024] (2) Through the "drawing + twisting" composite deformation process, drawing provides axial plastic deformation, and twisting provides tangential stress, both of which can break the internal coarse grains of the material, promote fine grain formation, and the uniformity of the average grain size is better than that of single drawing process, and the tensile strength of the material is improved by 25%-35%.
[0025] (3) The preparation process is simple: the preparation method of the application adopts common melting, casting, hot extrusion molding, cold working process and twisting process, the process steps are simple and easy to operate and control, without complex equipment and special process conditions, suitable for large-scale industrial production, can effectively reduce the production cost, and has wide application prospect. DETAILED DESCRIPTION
[0026] In order to make the purpose, technical scheme and advantages of the application more clear and obvious, the application is specifically described below in combination with examples, and it is necessary to point out that the following examples are only used to explain and illustrate the application, and do not limit the application. Some non-essential improvements and adjustments made by those skilled in the art based on the above invention content still belong to the protection scope of the application.
[0027] Example 1
[0028] A fine grain treatment method of a high-conductivity copper alloy material, comprising the following steps:
[0029] (1) Raw material preparation: selecting oxygen-free copper with a purity of ≥99.99% as a base material, and performing surface pretreatment.
[0030] (2) Melting and casting: placing the pretreated oxygen-free copper in a vacuum melting furnace, heating to 1160℃ to melt, adding 0.03% of lanthanum with a purity of 99.92% according to the mass of the copper liquid, stirring uniformly, and then holding for 20min, and casting into a copper bar blank, and cooling to room temperature.
[0031] (3) Hot extrusion molding: placing the obtained copper alloy ingot into an induction furnace, heating to 760℃, holding for 30min to make the grains uniform and refined, and then performing extrusion deformation processing; the extrusion deformation processing is performed on an 800 type horizontal extruder, and the equipment specification is 8.0MN. The extrusion adopts a reverse extrusion mode, the extrusion die adopts an inlaid ceramic, and the size of the extrusion die is: outer circle inner hole Extrusion temperature 760℃±10℃.
[0032] (4) Pickling: placing the obtained blank after extrusion in a 15% sulfuric acid tank for pickling to remove surface oxides.
[0033] (5) Drawing + twisting: the copper bar blank is drawn: 10% deformation per pass, water-soluble lubricant cooling, 45% cumulative deformation, a 15mm diameter pre-deformed copper bar is obtained; then the copper bar is twisted at a speed of 15 revolutions per minute, in a clockwise 9 turns and counterclockwise 11 turns manner. The "drawing-twisting" cycle is repeated 2 times, and finally a copper alloy material with a diameter of 8mm is obtained .
[0034] (6) The above treated rod is straightened, polished and cut to size.
[0035] The copper alloy material is tested to have an average grain size of 6μm, an electrical conductivity of 98.9% IACS, and a tensile strength of 360MPa at room temperature (20℃).
[0036] Example 2
[0037] A fine-grain processing method of a high-conductivity copper alloy material includes the following steps:
[0038] (1) Raw material preparation: oxygen-free copper with a purity of ≥99.99% is selected as the base material, and surface pretreatment is performed.
[0039] (2) Melting: the pretreated oxygen-free copper is placed in a vacuum melting furnace, heated to 1160℃ to melt, 0.01% of lanthanum with a purity of 99.9% is added according to the mass of the copper liquid, stirred uniformly, and then held for 15min, and cast into a copper bar blank, and cooled to room temperature.
[0040] (3) Hot extrusion forming: the obtained copper alloy ingot is placed in an induction furnace and heated to 760℃ for 30min to make the grains uniform and fine, and then extrusion deformation processing is performed; the extrusion deformation processing is performed on an 800-type horizontal extruder with a device specification of 8.0MN. The extrusion adopts a reverse extrusion mode, the extrusion die adopts an inlaid ceramic, and the size of the extrusion die is: outer circle inner hole Extrusion temperature 760℃±10℃.
[0041] (4) Pickling: the obtained blank after extrusion is placed in a 15% sulfuric acid tank for pickling to remove surface oxides.
[0042] (5) Drawing + twisting: the copper bar blank is drawn: 10% deformation per pass, water-soluble lubricant cooling, 40% cumulative deformation, a 12mm diameter pre-deformed copper bar is obtained; then the copper bar is twisted at a speed of 15 revolutions per minute, in a clockwise 9 turns and counterclockwise 11 turns manner; the "drawing-twisting" cycle is repeated 3 times, and finally a copper alloy material with a diameter of 8mm is obtained.
[0043] (6) The above drawn deformed rod is straightened, polished and cut to size.
[0044] The copper alloy material was tested to have an average grain size of 5.0 pm, an electrical conductivity of 99.2% IACS, and a tensile strength of 365 MPa at room temperature (20°C).
Claims
1. A method of fine-grain processing of a high-copper alloy material, characterized by, The method comprises the following steps: (1) selecting oxygen-free copper as a base material and performing surface pretreatment; (2) smelting: smelting the oxygen-free copper after surface pretreatment into copper liquid at 1100-1200°C, adding lanthanum element at 0.01-0.05% of the mass of the copper liquid, and pouring into a copper alloy ingot after 15-20 min of heat preservation and cooling to room temperature; (3) hot extrusion forming: placing the copper alloy ingot obtained in step (2) into an induction heating furnace, heating to 760°C±10°C, and performing water-sealed extrusion deformation processing after 30 min of heat preservation; (4) pickling: pickling the extruded billet obtained in step (3) to remove surface oxides; (5) performing multi-pass drawing on the copper rod billet obtained in step (4), with a cumulative drawing deformation of 40-50% to obtain a pre-deformed copper rod; twisting the pre-deformed copper rod at a speed of 10-15 r / min, with a clockwise twisting of 9 turns and a counterclockwise twisting of 11 turns; and repeating the "drawing-twisting" in the above manner to obtain a high-conductivity copper alloy material.
2. The method of claim 1, wherein, In step (1), the purity of the oxygen-free copper is ≥99.99%, and the surface pretreatment is to remove the surface oxide layer by grinding.
3. The fine-grain processing method of claim 1, wherein In step (2), the melting and heat preservation processes are performed in a vacuum environment, and the copper alloy ingot is a rod billet with a diameter of φ=120 mm.
4. The fine-grain processing method of claim 1, wherein In step (2), the content of the lanthanum element is La%≥99.9%.
5. The fine-grain processing method of claim 1, wherein In step (3), the hot extrusion forming is reverse hot extrusion forming.
6. The fine-grain processing method of claim 1, wherein In step (5), the total deformation of drawing is 40-50%.
7. The fine-grain processing method of claim 1, wherein In step (5), a water-soluble lubricant is used for cooling during drawing, and the deformation of each pass of drawing is 8-12%.
8. The fine-grain processing method of claim 1, wherein In step (5), the "drawing-twisting" cycle is repeated 2-3 times.
9. The fine-grain processing method of claim 1, wherein In step (5), the high-conductivity copper alloy material has the following properties: at room temperature, the average grain size is 4-10 μm, the electrical conductivity is ≥98.5% IACS, and the tensile strength is ≥350 MPa.
10. A high-conductivity copper alloy material obtained by the fine-grain processing method of any one of claims 1-9.