A copper bar and a method for manufacturing the same

Abstract

The application relates to the field of copper bars, and particularly discloses a copper bar and a preparation method thereof. The copper bar is prepared from the following raw materials in percentage by weight: copper: 98.98-99.18%, alloy elements: 0.82-1.02%; the alloy elements include Ag and C, the percentage by weight of Ag is greater than or equal to 0.33%, the percentage by weight of C is greater than or equal to 0.13% and less than or equal to 0.26%; the preparation method comprises the following steps: S1, melting the pretreated Cu, then heating, adding the alloy elements into the molten copper to prepare a uniform mixed solution; S2, pouring the uniform mixed solution into a casting cavity to cast and cool to obtain a cast ingot; S3, heating, extruding and cooling the remaining cast ingot in a nitrogen environment to obtain a copper bar; and S4, aging the copper bar. The copper bar has high conductivity, and is used in a detection instrument to reduce the detection error of the detection instrument.

Description

Technical Field

[0001] This application relates to the field of copper rods, and more specifically, to a copper rod and a method for preparing the same. Background Technology

[0002] Copper is a transition element. Pure copper is a soft metal with a reddish-orange metallic luster when freshly cut. In its elemental form, it is purplish-red. It has good ductility and high electrical conductivity, making copper rods a common material for cables and electronic components.

[0003] Copper rods can be made of pure copper or copper alloys. When made of pure copper, the rod has good electrical conductivity, but its strength is relatively poor, making it difficult to process. When made of copper alloys, the processing performance can be improved by appropriately selecting alloying elements, provided that it does not affect the use of the rod in cables and electronic components; that is, copper rods made of copper alloys still need to have good electrical conductivity.

[0004] A copper rod is disclosed in the related technology. This copper rod contains 0.5% sulfur, 0.25% selenium, 0.19% antimony, 0.006% niobium, and the remainder is copper. Testing shows that the tensile strength of the copper rod is 240 MPa and its electrical conductivity is 80% IACS.

[0005] The copper rod made from the above-mentioned doped alloy material has a conductivity of 80% IACS, which can be used to make conductive materials, but the conductivity needs to be further improved. Summary of the Invention

[0006] To further improve the conductivity of copper rods made by doping alloying elements, this application provides a copper rod and a method for preparing the same.

[0007] In a first aspect, this application provides a copper rod, which adopts the following technical solution: A copper rod is made from the following raw materials by weight percentage: Copper: 98.98-99.18% Alloying elements: 0.82-1.02% The alloying elements include Ag and C, wherein the weight percentage of Ag is greater than or equal to 0.33% and the weight percentage of C is greater than or equal to 0.13% and less than or equal to 0.26%.

[0008] By adopting the above technical solution, in order to maximize the conductivity of the copper rod doped with alloying elements, it is necessary to strictly control the contents of Ag and C. When the weight percentage of Ag is greater than or equal to 0.33% and the weight percentage of C is greater than or equal to 0.13% and less than or equal to 0.26%, the conductivity of the copper rod can reach above 90% IACS.

[0009] Preferably, the alloying elements further include Zn, Cr, and Zr, wherein the copper rod is made from the following raw materials in weight percentages: Cu: 98.98-99.18% Ag: 0.42-0.76% C: 0.16-0.20% Zn: 0.05-0.16% Cr: 0.08-0.12% Zr: Balance.

[0010] By adopting the above technical solution, when the copper rod is made from the above elements in the above proportion range, the conductivity of the copper rod is further increased.

[0011] Preferably, the copper rod is made from the following raw materials by weight percentage: Cu: 99.02% Ag: 0.56% C: 0.16% Zn: 0.05% Cr: 0.09% Zr: 0.12%.

[0012] By adopting the above technical solution, when the copper rod is made from the above elements in the above proportions, the conductivity and tensile strength of the copper rod are further improved, but the wear resistance is poor.

[0013] Preferably, the copper rod is made from the following raw materials by weight percentage: Cu: 99.10% Ag: 0.44% C: 0.18% Zn: 0.09% Cr: 0.10% Zr: 0.09%.

[0014] By adopting the above technical solution, when the copper rod is made from the above elements in the above proportions, the conductivity and wear resistance of the copper rod are further improved, but the tensile strength is poor.

[0015] Preferably, the copper rod is made from the following raw materials by weight percentage: Cu: 99.10% Ag: 0.44% C: 0.18% Zn: 0.13% Cr: 0.11% Zr: 0.04%.

[0016] By adopting the above technical solution, when the copper rod is made from the above elements in the above proportions, the conductivity, tensile strength and wear resistance of the copper rod are all improved.

[0017] Secondly, this application provides a method for preparing a copper rod, which adopts the following technical solution: A method for preparing a copper rod, based on any of the copper rods mentioned above, includes the following steps: S1. Melt the pretreated Cu in a nitrogen atmosphere, then heat it to 1600-1800℃, add the alloying elements to the molten copper in a nitrogen atmosphere, and after the alloying elements are completely melted, keep it at the temperature for 4-5 hours to obtain a homogeneous mixture. S2. Pour the homogeneous mixture into the mold cavity for casting, cool, and obtain an ingot; S3. The remaining ingot is heated, extruded, and cooled in a nitrogen atmosphere to obtain a copper rod; S4. Aging treatment is performed on the copper rod.

[0018] By adopting the above technical solution and preparing copper rods according to the above method, the copper rods obtained have lower residual stress, more stable structure, and higher tensile strength.

[0019] Preferably, before melting Cu and alloying elements, Cu and alloying elements are first ball-milled in a nitrogen atmosphere.

[0020] By adopting the above technical solution, Cu and alloying elements are ball-milled in a nitrogen environment before melting, which helps to further improve the tensile strength of the copper rod.

[0021] Preferably, in step S3, the edge material on each outer surface of the ingot is first removed by 2-4 mm, and then the remaining ingot is heated, extruded and cooled in a nitrogen environment to obtain a copper rod.

[0022] By adopting the above technical solution, when step S3 is processed frequently according to the above steps, the tensile strength of the obtained copper rod is further improved.

[0023] Preferably, in step S4, the aging treatment includes two stages of aging treatment. In the first stage, a tensile stress of 100-150 MPa is applied to the copper rod, the aging treatment temperature is 100-150℃, and the holding time is 2-4 hours. In the second stage, a tensile stress of 200-300 MPa is applied, the aging treatment temperature is 350-450℃, and the holding time is 2-4 hours.

[0024] By adopting the above technical solution and performing two-stage aging treatment on the copper rod according to the above method, the copper rod obtained has lower residual stress and better tensile strength.

[0025] Preferably, in step S4, the aging treatment includes three stages of aging treatment: in the first stage, a tensile stress of 100-150 MPa is applied to the copper rod, the aging treatment temperature is 100-150℃, and the holding time is 2-4 hours; in the second stage, a tensile stress of 200-300 MPa is applied, the aging treatment temperature is 350-450℃, and the holding time is 2-4 hours; in the third stage, a tensile stress of 100-150 MPa is applied to the copper rod, the aging treatment temperature is 100-150℃, and the holding time is 2-4 hours.

[0026] By adopting the above technical solution and performing two-stage aging treatment on the copper rod according to the above method, the residual stress of the copper rod is smaller and the tensile strength of the copper rod is further improved.

[0027] In summary, this application has the following beneficial effects: 1. Because this application strictly controls the content of Ag and C in the copper rod, when the weight percentage of Ag is greater than or equal to 0.33% and the weight percentage of C is greater than or equal to 0.13% and less than or equal to 0.26%, the conductivity of the copper rod can reach more than 90% IACS.

[0028] 2. When the copper rod is made of 99.02% Cu, 0.56% Ag, 0.15% C, 0.05% Zn, 0.09% Cr, and 0.12% Zr, the conductivity and tensile strength of the copper rod are further improved, but the wear resistance is poor.

[0029] 3. When the copper rod is made of 99.10% Cu, 0.44% Ag, 0.18% C, 0.09% Zn, 0.10% Cr, and 0.09% Zr, the conductivity and wear resistance of the copper rod are further improved, but the tensile strength is poor.

[0030] 4. When copper rods are made of 99.10% Cu, 0.44% Ag, 0.18% C, 0.13% Zn, 0.11% Cr, and 0.04% Zr, the conductivity, tensile strength, and wear resistance of the copper rods are all improved.

[0031] 5. When copper rods are prepared according to the method of this application, the residual stress of the copper rods is small, the structure of the copper rods is relatively stable, and the tensile strength is high. Detailed Implementation

[0032] The present application will be further described in detail below with reference to embodiments and comparative examples. Example

[0033] Example 1 A copper rod is made from the following raw materials by weight percentage: Cu: 99.18% Ag: 0.56% C: 0.26%; The method for preparing the copper rod in this embodiment includes the following steps: S1. Pretreated Cu is melted in a nitrogen atmosphere, and then heated to 1600℃. Alloying elements are added to the molten copper in a nitrogen atmosphere. After the alloying elements are completely melted, the mixture is kept at this temperature for 5 hours to obtain a homogeneous mixture. In this embodiment, the alloying elements are Ag and C. S2. Pour the homogeneous mixture into the mold cavity for casting, cool, and obtain an ingot; S3. The remaining ingot is heated, extruded, and cooled in a nitrogen atmosphere to obtain a copper rod; S4. Perform a two-stage aging treatment on the copper rod. In the first stage, apply a tensile stress of 100 MPa to the copper rod. The aging treatment temperature for the first stage is 100℃ and the holding time is 4 hours. In the second stage, apply a tensile stress of 300 MPa. The aging treatment temperature for the second stage is 450℃ and the holding time is 2 hours. Then cool down to complete the aging treatment.

[0034] Example 2 A copper rod is made from the following raw materials by weight percentage: Cu: 99.08% Ag: 0.72% C: 0.20%; The method for preparing the copper rod in this embodiment includes the following steps: S1. Pretreated Cu is melted in a nitrogen atmosphere, and then heated to 1700°C. Alloying elements are added to the molten copper in a nitrogen atmosphere. After the alloying elements are completely melted, the mixture is kept at this temperature for 4.5 hours to obtain a homogeneous mixture. In this embodiment, the alloying elements are Ag and C. S2. Pour the homogeneous mixture into the mold cavity for casting, cool, and obtain an ingot; S3. The remaining ingot is heated, extruded, and cooled in a nitrogen atmosphere to obtain a copper rod; S4. Perform a two-stage aging treatment on the copper rod. In the first stage, apply a tensile stress of 125 MPa to the copper rod. The aging treatment temperature for the first stage is 125℃ and the holding time is 3 hours. In the second stage, apply a tensile stress of 250 MPa. The aging treatment temperature for the second stage is 400℃ and the holding time is 3 hours.

[0035] Example 3 A copper rod is made from the following raw materials by weight percentage: Cu: 98.98% Ag: 0.89% C: 0.13%; The method for preparing the copper rod in this embodiment includes the following steps: S1. Pretreated Cu is melted in a nitrogen atmosphere, and then heated to 1800°C. Alloying elements are added to the copper in a nitrogen atmosphere. After the alloying elements are completely melted, the mixture is kept at this temperature for 4 hours to obtain a homogeneous mixture. In this embodiment, the alloying elements are Ag and C. S2. Pour the homogeneous mixture into the mold cavity for casting, cool, and obtain an ingot; S3. The remaining ingot is heated, extruded, and cooled in a nitrogen atmosphere to obtain a copper rod; S4. Perform two-stage aging treatment on the copper rod. In the first stage, apply a tensile stress of 150 MPa to the copper rod. The aging treatment temperature for the first stage is 150℃ and the holding time is 2 hours. In the second stage, apply a tensile stress of 200 MPa. The aging treatment temperature for the second stage is 350℃ and the holding time is 4 hours.

[0036] Example 4 A copper rod is made from the following raw materials by weight percentage: Cu: 99.18% Ag: 0.49% C: 0.16% Zn: 0.05% Cr: 0.08% Zr: 0.04%; In this embodiment, the preparation method of the copper rod is the same as in Embodiment 2, and the alloying elements are Ag, C, Zn, Cr and Zr.

[0037] Example 5 A copper rod is made from the following raw materials by weight percentage: Cu: 98.98% Ag: 0.42% C: 0.20% Zn: 0.16% Cr: 0.12% Zr: 0.12%; In this embodiment, the preparation method of the copper rod is the same as in Embodiment 2, and the alloying elements are Ag, C, Zn, Cr and Zr.

[0038] Example 6 A copper rod is made from the following raw materials by weight percentage: Cu: 99.02% Ag: 0.56% C: 0.16% Zn: 0.05% Cr: 0.09% Zr: 0.12%; In this embodiment, the preparation method of the copper rod is the same as in Embodiment 2, and the alloying elements are Ag, C, Zn, Cr and Zr.

[0039] Example 7 A copper rod is made from the following raw materials by weight percentage: Cu: 99.10% Ag: 0.44% C: 0.18% Zn: 0.09% Cr: 0.10% Zr: 0.09%; In this embodiment, the preparation method of the copper rod is the same as in Embodiment 2, and the alloying elements are Ag, C, Zn, Cr and Zr.

[0040] Example 8 A copper rod is made from the following raw materials by weight percentage: Cu: 99.10% Ag: 0.44% C: 0.18% Zn: 0.13% Cr: 0.11% Zr: 0.04%; In this embodiment, the preparation method of the copper rod is the same as in Embodiment 2, and the alloying elements are Ag, C, Zn, Cr and Zr.

[0041] Example 9 A copper rod, which differs from Example 8 in that: Before melting Cu and alloying elements, Cu and alloying elements were first ball-milled in a nitrogen atmosphere at a speed of 660 rad / min for 1 hour.

[0042] Example 10 A copper rod, which differs from Example 8 in that: In step S3, the edge material on each outer surface of the ingot is first removed by 3mm. Then, the remaining ingot is heated, extruded, and cooled in a nitrogen atmosphere to obtain a copper rod.

[0043] Example 11 A copper rod, which differs from Example 8 in that: The aging treatment also includes a third stage, in which a tensile stress of 125 MPa is applied to the copper rod. The aging treatment temperature in the first stage is 125℃, and the temperature is maintained for 3 hours.

[0044] Comparative Example Comparative Example 1 Copper rods in the background art.

[0045] Comparative Example 2 A copper rod is made from the following raw materials by weight percentage: Cu: 98.2% Ag: 1.56% C: 0.24%; In this embodiment, the preparation method of the copper rod is the same as in Example 2.

[0046] Comparative Example 3 A copper rod is made from the following raw materials by weight percentage: Cu: 99.35% Ag: 0.20% C: 0.45%; In this embodiment, the preparation method of the copper rod is the same as in Example 2.

[0047] Detection methods / test methods Conductivity: The conductivity was tested according to GB / T 32791-2016 "Eddy Current Test Method for Conductivity of Copper and Copper Alloys". Each sample was tested at least 3 times and the average value was recorded in Table 1 below.

[0048] Tensile strength: The test shall be conducted in accordance with GB / T 228.1-2010 "Metallic materials - Tensile testing - Part 1: Test at room temperature". Each sample shall be tested at least 3 times and the average value shall be recorded in Table 1 below.

[0049] Wear amount: The wear resistance of copper rods was tested using ML-100 abrasive wear test. Each sample was tested at least 3 times, and the average value was recorded in Table 1 below.

[0050] Table 1 Performance testing of copper rods in Examples 1-11 and Comparative Examples 1-3 Testing items Example 1 Example 2 Example 3 Example 4 Example 5 Conductivity / %IACS 92 93 92 99 101 Tensile strength / MPa 265 272 276 266 273 Wear amount / g 1.03 0.98 1.08 0.94 0.99 Testing items Example 6 Example 7 Example 8 Example 9 Example 10 Conductivity / %IACS 100 99 101 100 99 Tensile strength / MPa 334 236 318 420 347 Wear amount / g 1.01 0.58 0.49 0.52 0.56 Testing items Example 11 Comparative Example 1 Comparative Example 2 Comparative Example 3 Conductivity / %IACS 102 80 78 83 Tensile strength / MPa 373 216 245 219 Wear amount / g 0.54 0.92 1.19 1.23 As can be seen from Examples 1-10 and Comparative Example 1, and Table 1, the conductivity of the copper rods prepared in this application is higher than that of the copper rods in the prior art. When the copper rods prepared in this application are made into copper wires for conduction, the resistance of the copper wires is lower, which is beneficial to improving the accuracy of precision instrument detection.

[0051] As can be seen from Examples 1-3 and Comparative Examples 2-3 and Table 1, the copper rod can only have a high conductivity when the weight percentage of Ag is greater than or equal to 0.33% and the weight percentage of C is greater than or equal to 0.13% and less than or equal to 0.26%. This results in a lower resistance in the copper wire made from the copper rod, which is beneficial for improving the accuracy of precision instrument detection.

[0052] Combining Examples 1-3 and Examples 4-11 with Table 1, it can be seen that the conductivity of the copper rods obtained by adding Zn, Cr and Zr in Examples 4-11 all increased. This indicates that adding Zn, Cr and Zr to the copper rods is beneficial to reducing the resistance of the copper rods and improving the accuracy of precision instrument detection.

[0053] As can be seen from Examples 4-8 and Table 1, the difference between Examples 4-8 lies in the different weight percentages of each element in the copper rod. Specifically, when the copper rod is prepared according to the formulations in Examples 4 and 5, the conductivity of the obtained copper rod is higher than that of Examples 1-3, but the tensile strength and wear amount are not significantly different from those of Examples 1-3. When the copper rod is prepared according to the formulation in Example 6, the conductivity and tensile strength of the obtained copper rod are both higher than those of Examples 1-3, but the wear amount is not significantly different from that of Examples 1-3. When the copper rod is prepared according to the formulation in Example 7, the conductivity and wear resistance of the obtained copper rod are both higher than those of Examples 1-3, but the tensile strength is not significantly different from that of Examples 1-3. When the copper rod is prepared according to the formulation in Example 8, the conductivity, tensile strength, and wear resistance of the obtained copper rod are all higher than those of Examples 1-3.

[0054] As can be seen from Examples 8-11 and Table 1, the difference between Examples 8-11 lies in the different preparation methods of the copper rods. In Example 9, before melting Cu and alloying elements, Cu and alloying elements are first ball-milled in a nitrogen environment. This treatment is beneficial to further improve the tensile strength of the copper rod and extend its service life. In Example 10, in step S3, the edge material on each outer surface of the ingot is first removed by 3mm, and then heated, extruded, and cooled to obtain the copper rod. This treatment is also beneficial to further improve the tensile strength of the copper rod. In Example 11, the aging treatment of the copper rod is a three-stage aging treatment. After adding a first-stage aging treatment, the tensile strength of the copper rod is also improved.

[0055] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A copper bar characterized in that, Made from the following raw materials by weight percentage: Cu: 99.10%; Ag: 0.44%; C：0.18%； Zn: 0.13%; Cr：0.11%； Zr：0.04%； The copper rod is obtained by the following method: S1. Melt the pretreated Cu in a nitrogen atmosphere, then heat it to 1600-1800℃, add the alloying elements to the molten copper in a nitrogen atmosphere, and after the alloying elements are completely melted, keep it at the temperature for 4-5 hours to obtain a homogeneous mixture. S2. Pour the homogeneous mixture into the mold cavity for casting, cool, and obtain an ingot; S3. The remaining ingot is heated, extruded, and cooled in a nitrogen atmosphere to obtain a copper rod; S4. Perform two- or three-stage aging treatment on the copper rod; When the aging treatment is a two-stage aging treatment, the first stage applies a tensile stress of 100-150MPa to the copper rod, the first stage aging treatment temperature is 100-150℃, and the holding time is 2-4h; the second stage applies a tensile stress of 200-300MPa, the second stage aging treatment temperature is 350-450℃, and the holding time is 2-4h. When the aging treatment is a three-stage aging treatment, the first stage applies a tensile stress of 100-150 MPa to the copper rod, the first stage aging treatment temperature is 100-150℃, and the holding time is 2-4 hours; the second stage applies a tensile stress of 200-300 MPa, the second stage aging treatment temperature is 350-450℃, and the holding time is 2-4 hours; the third stage applies a tensile stress of 100-150 MPa to the copper rod, the first stage aging treatment temperature is 100-150℃, and the holding time is 2-4 hours.

2. A method of producing a copper bar based on the copper bar according to claim 1, characterized in that Includes the following steps: S1. Melt the pretreated Cu in a nitrogen atmosphere, then heat it to 1600-1800℃, add the alloying elements to the molten copper in a nitrogen atmosphere, and after the alloying elements are completely melted, keep it at the temperature for 4-5 hours to obtain a homogeneous mixture. S2. Pour the homogeneous mixture into the mold cavity for casting, cool, and obtain an ingot; S3. The remaining ingot is heated, extruded, and cooled in a nitrogen atmosphere to obtain a copper rod; S4. Perform two- or three-stage aging treatment on the copper rod; When the aging treatment is a two-stage aging treatment, the first stage applies a tensile stress of 100-150MPa to the copper rod, the first stage aging treatment temperature is 100-150℃, and the holding time is 2-4h; the second stage applies a tensile stress of 200-300MPa, the second stage aging treatment temperature is 350-450℃, and the holding time is 2-4h. When the aging treatment is a three-stage aging treatment, the first stage applies a tensile stress of 100-150 MPa to the copper rod, the first stage aging treatment temperature is 100-150℃, and the holding time is 2-4 hours; the second stage applies a tensile stress of 200-300 MPa, the second stage aging treatment temperature is 350-450℃, and the holding time is 2-4 hours; the third stage applies a tensile stress of 100-150 MPa to the copper rod, the first stage aging treatment temperature is 100-150℃, and the holding time is 2-4 hours.

3. The method of claim 2, wherein the copper rod is prepared by a process comprising the steps of: Before melting Cu and alloying elements, Cu and alloying elements are first ball-milled in a nitrogen atmosphere.

4. The method of claim 2, wherein the copper bar is prepared by the steps of: In step S3, the edge material on each outer surface of the ingot is first removed by 2-4 mm. Then, the remaining ingot is heated, extruded, and cooled in a nitrogen atmosphere to obtain a copper rod.