Manufacturing process of medium-diameter high-strength high-wear-resistance copper alloy rod

Abstract

The application discloses a manufacturing process of a medium-conductivity high-strength high-wear-resistance copper alloy rod, which comprises the following steps: S1, Cu, Ni, Co and Si are proportioned and weighed according to a certain proportion to obtain corresponding raw materials; S2, each raw material is added into a vacuum medium-frequency induction heating furnace to be smelted; S3, after smelting is completed, a cast ingot is obtained by casting; S4, the cast ingot is heated through the medium-frequency induction heating furnace, and after being heated, the cast ingot is extruded through forward hot extrusion to obtain an extruded rod; S5, the extruded rod is drawn on a rod drawing machine to obtain a rod; S6, the rod is subjected to aging heat treatment to obtain a treated rod; and S7, the treated rod is straightened on a copper alloy rod straightening machine, and then is sawn according to a multiple of the size of a customer part. The copper alloy rod has moderate conductivity, high hardness, high tensile strength and good wear resistance, and the service capability of the copper alloy rod is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of copper alloy manufacturing technology, specifically to a manufacturing process for a medium-conductivity, high-strength, and high-wear-resistant copper alloy rod. Background Technology

[0002] In recent years, copper alloy rods with high strength, high wear resistance, and good conductivity have been used more and more widely in connectors, which can not only improve the stability of connectors, but also extend their lifespan.

[0003] Meanwhile, copper alloy rods are also used as probe tips in the high-current testing probes of the battery formation and capacity cabinets for new energy vehicles. These copper alloy rods are required to have good conductivity, high hardness, and high wear resistance, which can improve the service life of the probes.

[0004] The materials used in existing high-strength, high-wear-resistant connectors and high-current probe head rods are mostly CuNiBe (C17510), which is widely used. However, CuNiBe (C17510) alloy has high production costs, and most importantly, beryllium is toxic. Even 1 milligram of beryllium per cubic meter of air can cause acute pneumonia—beryllium lung disease—in humans. Therefore, the production and application of beryllium requires careful processing to prevent environmental pollution and harm to human health. Consequently, the application of CuNiBe (C17510) material has been somewhat limited. The copper alloy rod with high conductivity, high hardness, high strength, and high wear resistance described in this invention can effectively replace CuNiBe (C17510) material in connectors and high-current probes, and is thus widely used.

[0005] Copper-nickel-cobalt-silicon (Cu-Ni-Co-Si) alloys are precipitation-hardening alloys. Ni(Co)₂Si compounds (θ or α₁ phases) are formed in Cu-Ni-Co-Si alloys, exhibiting a significant precipitation-hardening effect that improves the alloy's hardness and strength. Therefore, Cu-Ni-Co-Si alloys possess moderate conductivity, high strength, high hardness, and high wear resistance, meeting the requirements of connectors and high-current probe products. Summary of the Invention

[0006] To solve the above-mentioned technical problems, the present invention provides a manufacturing process for a medium-conductivity, high-strength, and high-wear-resistant copper alloy rod.

[0007] The technical solution of this invention is: a manufacturing process for a medium-conductivity, high-strength, and high-wear-resistant copper alloy rod, comprising the following steps:

[0008] S1, Ingredients

[0009] Weigh out the appropriate raw materials, including Cu, Ni, Co, and Si, in a certain proportion, and set them aside for later use.

[0010] S2, Smelting

[0011] Each raw material from step S1 is added to a vacuum medium-frequency induction heating furnace for melting, ensuring that the vacuum level is below 5 Pa during the melting process;

[0012] S3, Casting

[0013] After the melting in step S2 is completed, the ingot is cast to obtain a casting temperature of 1250℃-1400℃;

[0014] S4, Hot Extrusion

[0015] The ingot obtained in step S3 is heated in a medium frequency induction heating furnace at a temperature of 850℃-980℃. After reaching the temperature, it is extruded by forward hot extrusion. The extrusion die size is designed according to the product deformation ratio. After the rod material exits the extrusion die, it is quickly cooled in water. After cooling, the rod material is coiled into a coil by a coiler to obtain the extruded rod.

[0016] S5, Pulling

[0017] The extrusion bar prepared in step S4 is drawn on a bar drawing machine. The deformation amount in each drawing pass is 5-15%, and the cumulative deformation amount is 40%-70%, to obtain the bar.

[0018] S6, Aging Heat Treatment

[0019] The bar stock prepared in step S5 is subjected to aging heat treatment at a heating temperature of 450-520℃ for 3.5-5.5 hours to obtain the treated bar stock.

[0020] S7, Straightening, Sawing

[0021] The bar stock processed in step S6 is straightened on a copper alloy bar straightening machine to achieve a straightness of 1mm / m, and then sawn according to a multiple of the customer's part size.

[0022] Furthermore, the weight percentages of Cu, Ni, Co, and Si are as follows: Cu: balance, Ni: 1.5-3.0%, Co: 0.8-2.0%, Si: 0.4-1.2%.

[0023] Note: The Cu-Ni-Co-Si alloy prepared using the above ratio has moderate conductivity, high strength, high hardness and high wear resistance, which can meet the requirements of connectors and high current probe products.

[0024] Furthermore, the raw materials are added in the following ways: Cu is added by electrolytic copper plate, Ni is added by electrolytic nickel plate, Co is added by metallic cobalt block, and Si is added by elemental silicon.

[0025] Note: Using the above method of adding raw materials can ensure production costs while avoiding the introduction of excessive impurities, thereby ensuring that the mechanical properties of the copper alloy rod meet the expected requirements and manufacturing needs.

[0026] Furthermore, during smelting, the surface of the melt is protected with a covering agent, and all raw materials are added together to a vacuum medium-frequency induction heating furnace for smelting. The amount of the covering agent is 0.1-0.3% of the mass of the aluminum melt, and the covering agent, by mass percentage, includes: carbon black: 1%-10%, NaCl: 0.1%-1%, CaO: 5%-30%, MgO: 5%-30%, CaF2: 5%-10%, and the balance is vermiculite powder.

[0027] Note: By using the above-mentioned covering agent on the surface of the melt, it can play a role in heat preservation, adsorbing inclusions, and preventing oxidation, thereby protecting the molten metal and ensuring the performance of the obtained ingot.

[0028] Furthermore, the principle of the casting process is to start slowly, then speed up, and then slow down again.

[0029] Explanation: By using a casting method that starts slow, then speeds up, and then slows down again, the ingot can be fully fed back into the container by slowing down the casting speed in the later stages.

[0030] Furthermore, the method for designing the extrusion die size according to the product's deformation ratio is as follows: based on the designed deformation ratio, if the extrusion rod diameter is greater than 20mm, single-hole extrusion is used; if the extrusion rod diameter is less than 20mm, double-hole extrusion is used; the extrusion speed is 8-15mm / s, and the remaining 20-25mm of the ingot thickness is not extruded.

[0031] Note: The above method of designing the extrusion die size enables efficient hot extrusion of ingots, thereby improving production efficiency and obtaining extrusion bars that meet production requirements.

[0032] As one technical solution of the present invention, the method of aging heat treatment is as follows: first, the bar stock is loaded into the heat treatment furnace, then the heat treatment furnace is evacuated to ensure that the vacuum degree is lower than 5Pa. After evacuation, inert gas Ar is introduced for atmosphere protection. The amount of Ar introduced is such that the furnace chamber is slightly positively pressured. After Ar is introduced, heating begins at a temperature of 450-520℃ and is maintained for 3.5-5.5 hours. After the holding time is up, cooling begins. The bar stock is cooled to below 80℃ in the furnace and then removed from the furnace and air-cooled to room temperature to obtain the treated bar stock.

[0033] Note: The above-mentioned aging heat treatment method can meet the processing requirements of the bar stock, fully precipitate the precipitated elements inside the alloy, improve the tensile strength, yield strength and other mechanical properties of the material, and at the same time, eliminate or reduce internal stress, reduce brittleness and improve the service performance of copper alloy bars.

[0034] As another technical solution of the present invention, the method of aging heat treatment is as follows: First, the bar stock is loaded into the heat treatment furnace, the bar stock is connected to the positive electrode, the steel plate is connected to the negative electrode, and an insulating safety distance is maintained between the bar stock and the steel plate. Then, the heat treatment furnace is evacuated to ensure that the vacuum degree is lower than 5 Pa. After evacuation, inert gas Ar is introduced for atmosphere protection. The amount of Ar introduced is such that the furnace chamber is slightly positively pressured. After Ar is introduced, heating begins, and the formation of the GP zone is enhanced through the following three stages:

[0035] 1) First stage: Heating temperature 450-520℃, maintain for 1-2 hours, then continuously spray treatment liquid to cool the bar stock to 100-150℃;

[0036] 2) Second stage: Apply an electrostatic field to the bar stock intermittently. After cooling the bar stock to 100-150℃ in step 1), it is heated back to the rewarming point and held for 15 minutes. Then, apply an electrostatic field to the bar stock and continuously spray the treatment liquid to cool the bar stock to 80-120℃.

[0037] 3) In the third stage, the power of the electrostatic field is gradually increased by 1-10kV / cm / cycle, and the reheating point is gradually decreased by 30-60℃ / cycle as the power of the electrostatic field changes. Step 2) is repeated until the reheating point is less than or equal to the cooling temperature, at which point no reheating is required. Then the bar stock is cooled to room temperature with the furnace to obtain the processed bar stock with a large number of GP zones.

[0038] Explanation: By introducing an electrostatic field to assist in the aging heat treatment of copper alloy rods, the precipitation of precipitate elements inside the alloy can be significantly improved. Furthermore, by optimizing the electrostatic field, combined with the reheating point and multiple additions of the treatment solution, copper alloy rods with a large number of GP zones can be formed, further enhancing the performance of the copper alloy rods.

[0039] Furthermore, the power of the electrostatic field is 20-30 kV / cm, and the rewarming point is 280-320℃.

[0040] Note: The aging heat treatment method under the above electrostatic field and reheat point parameters can obtain a large number of GP region cores in the copper alloy rod, thereby ensuring that the treatment effect of the aging heat treatment method meets the expected requirements.

[0041] Furthermore, the treatment solution is a base solution prepared by deionized water, polyethylene glycol, and propylene glycol in a certain proportion, and contains 40-80 g / L zinc ferrous phosphate tetrahydrate, 30-50 g / L hydroxyethyl cellulose, and 1 g / L benzotriazole, wherein the mass ratio of deionized water, polyethylene glycol, and propylene glycol is 4:2:1; the temperature of the treatment solution is 30-40℃.

[0042] Explanation: By using the above-mentioned treatment solution, the rod material can be cooled to the preset temperature using a multi-gradient temperature method. At the same time, under the action of substances such as polyethylene glycol, propylene glycol, zinc ferrous phosphate tetrahydrate, and hydroxyethyl cellulose, and with the help of electrostatic field and other methods to strengthen the GP region in multiple stages, the performance of copper alloy rods can be improved.

[0043] The beneficial effects of this invention are:

[0044] (1) Due to the precipitation of Ni(Co)2Si phase, the copper alloy rod of the present invention has moderate conductivity, high hardness and tensile strength. Correspondingly, due to the high hardness, it has good wear resistance, electrical conductivity reaches 40% IACS, hardness reaches 240HB, and room temperature strength reaches 730Mpa.

[0045] (2) The copper alloy rod manufacturing process provided by the present invention is short and the production cost is greatly reduced, making it widely applicable. It can produce copper alloy rods with moderate conductivity, high hardness, high tensile strength and good wear resistance, which greatly improves the service capability of copper alloy rods and can meet the requirements of copper alloy materials for connectors and high current probes. Attached Figure Description

[0046] Figure 1 This is a flowchart illustrating the manufacturing process of the high-strength, high-wear-resistant copper alloy rod in this invention.

[0047] Figure 2 This is a metallographic photograph at 100x magnification of the high-strength, high-wear-resistant copper alloy rod in Embodiment 1 of the present invention.

[0048] Figure 3 This is a metallographic photograph at 100x magnification of the high-strength, high-wear-resistant copper alloy rod in Embodiment 6 of the present invention. Detailed Implementation

[0049] The present invention will now be described in more detail with reference to specific embodiments, so as to better demonstrate the advantages of the present invention.

[0050] Example 1

[0051] A manufacturing process for a medium-strength, high-wear-resistant copper alloy rod includes the following steps:

[0052] S1, Ingredients

[0053] Weigh out the corresponding raw materials of Cu, Ni, Co, and Si according to the following weight percentages: Cu: balance, Ni: 2.0%, Co: 1.0%, Si: 0.8%, and set aside for later use;

[0054] S2, Smelting

[0055] All the raw materials in step S1 are added together to a vacuum medium frequency induction heating furnace for melting. Cu is added by electrolytic copper plate, Ni is added by electrolytic nickel plate, Co is added by metallic cobalt block, and Si is added by elemental silicon. During melting, the surface of the melt is protected with a covering agent, and the vacuum degree is ensured to be 4 Pa ​​during the melting process.

[0056] The amount of the covering agent is 0.2% of the mass of the aluminum melt. The covering agent, by mass percentage, includes: carbon black: 8%, NaCl: 0.7%, CaO: 25%, MgO: 25%, CaF2: 7%, and the balance is vermiculite powder.

[0057] S3, Casting

[0058] After the melting in step S2 is completed, a Φ200mm ingot is obtained by casting. The casting should be slow at first, then fast, and then slow again. The casting temperature is 1350℃.

[0059] S4, Hot Extrusion

[0060] The ingot obtained in step S3 is heated in a medium-frequency induction heating furnace to a temperature of 850℃. After reaching the temperature, it is extruded by forward hot extrusion. The extrusion die is 21mm in diameter, and single-hole extrusion is used. The extrusion speed is 8mm / s. The remaining 20mm of the ingot thickness is not extruded. After the rod material exits the extrusion die, it is quickly immersed in water for cooling. After cooling, the rod material is coiled into a coil by a coiler to obtain the extruded rod.

[0061] S5, Pulling

[0062] The extrusion bar prepared in step S4 is cold drawn on a bar drawing machine. The diameter of the first drawing is 19.5 mm and the drawing deformation is 14%. The diameter of the second drawing is 18 mm and the drawing deformation is 14%. The diameter of the third drawing is 16.7 mm and the drawing deformation is 14%. The diameter of the fourth drawing is 15.5 mm and the drawing deformation is 14%. The diameter of the fifth drawing is 15 mm and the drawing deformation is 6.3%. The total deformation is 49%, and a bar is obtained.

[0063] S6, Aging Heat Treatment

[0064] The bar stock prepared in step S5 is subjected to aging heat treatment. First, the bar stock is loaded into the heat treatment furnace, and then the furnace is evacuated to ensure a vacuum degree of 4 Pa. After evacuation, inert gas Ar is introduced for atmosphere protection. The amount of Ar introduced is such that the furnace chamber is slightly positively pressured. After Ar is introduced, heating begins at 460℃ and is maintained for 3.5 hours. After the holding time is up, cooling begins. The bar stock is cooled in the furnace to below 80℃ and then removed from the furnace and air-cooled to room temperature to obtain the treated bar stock. Samples of the aging heat-treated bar stock are taken from each furnace to test the electrical conductivity and mechanical properties. Bar stock with electrical conductivity and mechanical properties that meet the expectations can be transferred to the next process. Bar stock with electrical conductivity lower than expected is returned to the furnace for aging heat treatment. Bar stock with electrical conductivity higher than expected and mechanical properties lower than expected is scrapped directly.

[0065] S7, Straightening, Sawing

[0066] The bar stock processed in step S6 is straightened on a copper alloy bar straightening machine to achieve a straightness of 1 mm / m, and then sawn into 1000 mm lengths.

[0067] Example 2

[0068] A manufacturing process for a medium-strength, high-wear-resistant copper alloy rod includes the following steps:

[0069] S1, Ingredients

[0070] Weigh out the corresponding raw materials of Cu, Ni, Co, and Si according to the following weight percentages: Cu: balance, Ni: 2.5%, Co: 1.5%, Si: 0.6%, and set aside for later use;

[0071] S2, Smelting

[0072] All the raw materials in step S1 are added together to a vacuum medium frequency induction heating furnace for melting. Cu is added by electrolytic copper plate, Ni is added by electrolytic nickel plate, Co is added by metallic cobalt block, and Si is added by elemental silicon. During melting, the surface of the melt is protected with a covering agent, and the vacuum degree is ensured to be 4 Pa ​​during the melting process.

[0073] S3, Casting

[0074] After the melting in step S2 is completed, a Φ200mm ingot is obtained by casting. The casting should be slow at first, then fast, and then slow again. The casting temperature is 1300℃.

[0075] S4, Hot Extrusion

[0076] The ingot obtained in step S3 is heated in a medium-frequency induction heating furnace to a temperature of 900℃. After reaching the temperature, it is extruded by forward hot extrusion. The extrusion die has a diameter of 19.4mm and adopts double-hole extrusion. The extrusion speed is 10mm / s. The remaining 22mm of the ingot thickness is not extruded. After the rod material exits the extrusion die, it is quickly immersed in water for cooling. After cooling, the rod material is coiled into a coil by a coiler to obtain the extruded rod.

[0077] S5, Pulling

[0078] The extrusion bar prepared in step S4 is cold drawn on a bar drawing machine. The diameter of the first drawing is 18 mm and the drawing deformation is 14%. The diameter of the second drawing is 16.7 mm and the drawing deformation is 14%. The diameter of the third drawing is 15.5 mm and the drawing deformation is 14%. The diameter of the fourth drawing is 15 mm and the drawing deformation is 6.3%. The total deformation is 40%, and a bar is obtained.

[0079] S6, Aging Heat Treatment

[0080] The bar stock prepared in step S5 is subjected to aging heat treatment. First, the bar stock is loaded into the heat treatment furnace, and then the heat treatment furnace is evacuated to ensure that the vacuum degree is below 5 Pa. After evacuation, inert gas Ar is introduced for atmosphere protection. The amount of Ar introduced is enough to create a slight positive pressure inside the furnace. After Ar is introduced, heating begins at 480℃ and is maintained for 4 hours. After the holding time is up, cooling begins. The bar stock is cooled to below 80℃ in the furnace and then removed from the furnace and air-cooled to room temperature to obtain the treated bar stock. Samples of the aging heat-treated bar stock are taken from each furnace to test the electrical conductivity and mechanical properties. Bar stock with electrical conductivity and mechanical properties that meet the expectations can be transferred to the next process. Bar stock with electrical conductivity lower than expected is returned to the furnace for aging heat treatment. Bar stock with electrical conductivity higher than expected and mechanical properties lower than expected is scrapped directly.

[0081] S7, Straightening, Sawing

[0082] The bar stock processed in step S6 is straightened on a copper alloy bar straightening machine to achieve a straightness of 1mm / m, and then sawn into 1500mm sections.

[0083] Example 3

[0084] A manufacturing process for a medium-strength, high-wear-resistant copper alloy rod includes the following steps:

[0085] S1, Ingredients

[0086] Weigh out the corresponding raw materials of Cu, Ni, Co, and Si according to the following weight percentages: Cu: balance, Ni: 2.8%, Co: 1.8%, Si: 1.2%, and set aside for later use;

[0087] S2, Smelting

[0088] All the raw materials in step S1 are added together to a vacuum medium frequency induction heating furnace for melting. Cu is added by electrolytic copper plate, Ni is added by electrolytic nickel plate, Co is added by metallic cobalt block, and Si is added by elemental silicon. During melting, the surface of the melt is protected with a covering agent, and the vacuum degree is ensured to be 4 Pa ​​during the melting process.

[0089] S3, Casting

[0090] After the melting in step S2 is completed, a Φ200mm ingot is obtained by casting. The casting should be slow at first, then fast, and then slow again. The casting temperature is 1400℃.

[0091] S4, Hot Extrusion

[0092] The ingot obtained in step S3 is heated in a medium-frequency induction heating furnace to a temperature of 950℃. After reaching the temperature, it is extruded by forward hot extrusion. The extrusion die is 27mm in diameter, and single-hole extrusion is used. The extrusion speed is 12mm / s. The remaining 25mm of the ingot thickness is not extruded. After the rod material exits the extrusion die, it is quickly immersed in water for cooling. After cooling, the rod material is coiled into a coil by a coiler to obtain the extruded rod.

[0093] S5, Pulling

[0094] The extrusion bar prepared in step S4 is cold drawn on a bar drawing machine. The diameter of the first drawing is 19.2 mm and the drawing deformation is 15%. The diameter of the second drawing is 17.7 mm and the drawing deformation is 15%. The diameter of the third drawing is 16.3 mm and the drawing deformation is 15%. The diameter of the fourth drawing is 15 mm and the drawing deformation is 8.5%. The total deformation is 70%, and a bar is obtained.

[0095] S6, Aging Heat Treatment

[0096] The bar stock prepared in step S5 is subjected to aging heat treatment. First, the bar stock is loaded into the heat treatment furnace, and then the furnace is evacuated to ensure a vacuum degree of 4 Pa. After evacuation, inert gas Ar is introduced for atmosphere protection. The amount of Ar introduced is such that the furnace chamber is slightly positively pressured. After Ar is introduced, heating begins at 520℃ and is maintained for 4.5 hours. After the holding time is up, cooling begins. The bar stock is cooled in the furnace to below 80℃ and then removed from the furnace and air-cooled to room temperature to obtain the treated bar stock. Samples of the aging heat-treated bar stock are taken from each furnace to test the electrical conductivity and mechanical properties. Bar stock with electrical conductivity and mechanical properties that meet the expectations can be transferred to the next process. Bar stock with electrical conductivity lower than expected is returned to the furnace for aging heat treatment. Bar stock with electrical conductivity higher than expected and mechanical properties lower than expected is directly scrapped.

[0097] S7, Straightening, Sawing

[0098] The bar stock processed in step S6 is straightened on a copper alloy bar straightening machine to achieve a straightness of 1 mm / m, and then sawn into 2000 mm lengths each.

[0099] To verify the performance of the copper alloy rods prepared in the above embodiments, the chemical composition, electrical properties, and mechanical properties of the copper alloy rods in each embodiment were tested. The results are shown in Tables 1 and 2 below:

[0100] Table 1 Results of Chemical Composition Detection

[0101]

[0102] Table 2 Electrical and Mechanical Properties

[0103] Example 1 42 252 785 Example 2 40.5 261 803 Example 3 40 269 811

[0104] As can be seen from Tables 1 and 2 above, copper alloy rods that meet production requirements can be prepared in all three examples. Among them, the copper alloy rod prepared in Example 3 has the best mechanical properties, while the copper alloy rod prepared in Example 1 has the best electrical properties.

[0105] Example 4

[0106] The difference between this embodiment and Embodiment 1 is that the amount of the covering agent is 0.1% of the mass of the aluminum melt. The covering agent, by mass percentage, includes: carbon black: 1%, NaCl: 0.1%, CaO: 5%, MgO: 5%, CaF2: 5%, and the balance is vermiculite powder.

[0107] Example 5

[0108] The difference between this embodiment and Embodiment 1 is that the amount of the covering agent is 0.3% of the mass of the aluminum melt, and the covering agent, by mass percentage, includes: carbon black: 10%, NaCl: 1%, CaO: 30%, MgO: 30%, CaF2: 10%, and the balance is vermiculite powder.

[0109] To verify the performance of the copper alloy rods prepared in the above embodiments, electrical and mechanical properties of the copper alloy rods in each embodiment were tested, and the results are shown in Table 3 below:

[0110] Table 3 Electrical and Mechanical Properties

[0111] Example 1 42 252 785 Example 4 41.7 246 779 Example 5 42.1 252 787

[0112] As can be seen from Table 3 above, the electrical and mechanical properties of the copper alloy rods prepared in Examples 4 and 5 are different. Among them, the electrical and mechanical properties of Example 5 are relatively the best. However, the performance difference between Example 1 and Example 5 is not significant. Therefore, the actual selection can be made based on the cost of each raw material.

[0113] Example 6

[0114] The difference between this embodiment and Embodiment 1 lies in the method of aging heat treatment. The aging heat treatment method in this embodiment is as follows:

[0115] First, the bar stock is loaded into the heat treatment furnace, with the bar stock connected to the positive electrode and the steel plate connected to the negative electrode, maintaining an insulating safety distance between the bar stock and the steel plate. Then, the heat treatment furnace is evacuated to ensure the vacuum level is below 5 Pa. After evacuation, inert gas Ar is introduced for atmosphere protection. The amount of Ar introduced is enough to create a slightly positive pressure inside the furnace. After Ar is introduced, heating begins, and the formation of the GP zone is enhanced through the following three stages:

[0116] 1) First stage: Heating temperature 460℃, maintained for 1.5h, followed by continuous spraying of treatment liquid to cool the bar stock to 120℃;

[0117] The treatment solution is a base solution prepared by deionized water, polyethylene glycol and propylene glycol in a certain proportion, and 67 g / L zinc ferrous phosphate tetrahydrate, 45 g / L hydroxyethyl cellulose and 1 g / L benzotriazole, wherein the mass ratio of deionized water, polyethylene glycol and propylene glycol is 4:2:1; the temperature of the treatment solution is 35°C.

[0118] 2) Second stage: Apply an electrostatic field intermittently to the bar stock. After cooling the bar stock to 120°C in step 1), it is kept at the rewarming point for 15 minutes. Then, an electrostatic field is applied to the bar stock and the treatment liquid is continuously sprayed to cool the bar stock to 110°C. The power of the electrostatic field is 25kV / cm, and the rewarming point is 310°C.

[0119] 3) In the third stage, the power of the electrostatic field is increased by 5kV / cm / cycle, and the rewarming point is decreased by 40℃ / cycle as the power of the electrostatic field changes. Step 2) is repeated. The first time, the power of the electrostatic field is 30kV / cm and the rewarming point is 270℃. The second time, the power of the electrostatic field is 35kV / cm and the rewarming point is 230℃. The third time, the power of the electrostatic field is 40kV / cm and the rewarming point is 190℃. The fourth time, the power of the electrostatic field is 45kV / cm and the rewarming point is 150℃. The fifth time, the power of the electrostatic field is 50kV / cm and the rewarming point is 110℃. Then, the material is cooled to room temperature in the furnace to obtain the processed bar stock with a large number of GP zones.

[0120] Example 7

[0121] The difference between this embodiment and embodiment 6 is that the formation of the GP region is enhanced through the following three stages:

[0122] 1) First stage: Heating temperature 450℃, maintain for 1 hour, then continuously spray treatment liquid to cool the bar stock to 100℃;

[0123] 2) Second stage: Apply an electrostatic field intermittently to the bar stock. After the bar stock is cooled to 100°C in step 1), it is kept at the rewarming point for 15 minutes. Then, an electrostatic field is applied to the bar stock and the treatment liquid is continuously sprayed to cool the bar stock to 80°C. The power of the electrostatic field is 20kV / cm, and the rewarming point is 280°C.

[0124] 3) In the third stage, the power of the electrostatic field is increased by 1 kV / cm per cycle, and the rewarming point is decreased by 30℃ per cycle as the power of the electrostatic field changes. Step 2) is repeated. The first time, the power of the electrostatic field is 21 kV / cm and the rewarming point is 250℃. The second time, the power of the electrostatic field is 22 kV / cm and the rewarming point is 220℃. The third time, the power of the electrostatic field is 23 kV / cm and the rewarming point is 190℃. The fourth time, the power of the electrostatic field is 24 kV / cm and the rewarming point is 160℃. The fifth time, the power of the electrostatic field is 25 kV / cm and the rewarming point is 130℃. The sixth time, the power of the electrostatic field is 26 kV / cm and the rewarming point is 100℃. The seventh time, the power of the electrostatic field is 27 kV / cm and the rewarming point is 70℃. Then, the material is cooled to room temperature in the furnace to obtain the processed bar stock with a large number of GP zones.

[0125] Example 8

[0126] The difference between this embodiment and embodiment 6 is that the formation of the GP region is enhanced through the following three stages:

[0127] 1) First stage: Heating temperature 520℃, maintain for 2 hours, then continuously spray treatment liquid to cool the bar stock to 150℃;

[0128] 2) Second stage: Apply an electrostatic field intermittently to the bar stock. After the bar stock is cooled to 100°C in step 1), it is heated back to the rewarming point and held for 15 minutes. Then, an electrostatic field is applied to the bar stock and the treatment liquid is continuously sprayed to cool the bar stock to 120°C. The power of the electrostatic field is 30kV / cm, and the rewarming point is 320°C.

[0129] 3) In the third stage, the power of the electrostatic field is increased by 10kV / cm / cycle, and the rewarming point is decreased by 60℃ / cycle as the power of the electrostatic field changes. Step 2) is repeated. The first time, the power of the electrostatic field is 40kV / cm and the rewarming point is 260℃. The second time, the power of the electrostatic field is 50kV / cm and the rewarming point is 200℃. The third time, the power of the electrostatic field is 60kV / cm and the rewarming point is 140℃. The fourth time, the power of the electrostatic field is 70kV / cm and the rewarming point is 80℃. Then, the material is cooled to room temperature in the furnace to obtain the treated bar stock with a large number of GP zones.

[0130] Example 9

[0131] The difference between this embodiment and Embodiment 6 is that the treatment solution is a base solution prepared by deionized water, polyethylene glycol, and propylene glycol in a certain proportion, and 40 g / L zinc ferrous phosphate tetrahydrate, 30 g / L hydroxyethyl cellulose, and 1 g / L benzotriazole, wherein the mass ratio of deionized water, polyethylene glycol, and propylene glycol is 4:2:1.

[0132] Example 10

[0133] The difference between this embodiment and Embodiment 6 is that the treatment solution is a base solution prepared by deionized water, polyethylene glycol, and propylene glycol in a certain proportion, and 80 g / L zinc ferrous phosphate tetrahydrate, 50 g / L hydroxyethyl cellulose, and 1 g / L benzotriazole, wherein the mass ratio of deionized water, polyethylene glycol, and propylene glycol is 4:2:1.

[0134] By observing the copper alloy rods of Examples 1 and 6, such as... Figure 2 , Figure 3 The metallographic images shown show that the copper alloy rod after aging heat treatment in Example 6 has finer grains and more grain interfaces. Therefore, the copper alloy rod prepared using Example 6 is relatively superior.

[0135] Meanwhile, to verify the performance of the copper alloy rods prepared in the above embodiments, electrical and mechanical properties tests were conducted on the copper alloy rods of each embodiment.

[0136] Meanwhile, a control group 1 was set up: based on Example 6, after the second stage of treatment, the furnace was directly cooled to room temperature without proceeding to the subsequent third stage.

[0137] Control 2: Based on Example 6, no zinc ferrous phosphate tetrahydrate or hydroxyethyl cellulose was added to the treatment solution;

[0138] The results are shown in Table 4 below:

[0139] Table 4 Electrical and Mechanical Properties

[0140] Example 1 42 252 785 Example 6 42.9 265 809 Example 7 42.8 263 806 Example 8 42.4 259 797 Example 9 42.7 263 804 Example 10 42.5 260 800 Comparison 1 42.1 254 789 Comparison 2 42.2 256 792

[0141] As can be seen from Table 4 above, Example 6 adopts a multi-stage strengthening GP formation method, which further improves the electrical and mechanical properties of the copper alloy rod compared with the aging heat treatment method of Example 1. Furthermore, by comparing the mechanical properties of the copper alloy rod of Example 3, it can be seen that after the treatment of Example 6, the copper alloy rod can maintain good electrical conductivity while having mechanical properties similar to those of the copper alloy rod of Example 3.

[0142] Examples 7-10 modified the process parameters and treatment solution of the aging heat treatment method. It can be seen that adjusting the power of the electrostatic field and the reheat point has a certain impact on the properties of the prepared copper alloy rod. Among them, the copper alloy rod of Example 6 has better electrical and mechanical properties.

[0143] Compared with Examples 1 and 2, the third stage of the aging heat treatment method and the treatment solution were modified respectively. It can be seen that without the third stage of treatment, although the overall process time was shortened, the improvement of its electrical and mechanical properties was not significant. This may be due to the small amount of contact between the treatment solution and the bar stock and the small number of temperature changes. After the addition of zinc ferrous phosphate tetrahydrate and hydroxyethyl cellulose to the treatment solution, the effect of the treatment solution decreased significantly. At the same time, the comparison between Examples 9 and 10 shows that the treatment solution composition of Example 6 is relatively optimal.

Claims

1. A manufacturing process for a medium-conductivity, high-strength, and high-wear-resistant copper alloy rod, characterized in that, Includes the following steps: S1, Ingredients Weigh out the appropriate raw materials, including Cu, Ni, Co, and Si, in a certain proportion, and set them aside for later use. S2, Smelting Each raw material from step S1 is added to a vacuum medium-frequency induction heating furnace for melting, ensuring that the vacuum level is below 5 Pa during the melting process; S3, Casting After the melting in step S2 is completed, the ingot is cast to obtain a casting temperature of 1250℃-1400℃. S4, Hot Extrusion The ingot obtained in step S3 is heated in a medium frequency induction heating furnace at a temperature of 850℃-980℃. After reaching the temperature, it is extruded by forward hot extrusion. The extrusion die size is designed according to the product deformation ratio. After the rod material exits the extrusion die, it is quickly cooled in water. After cooling, the rod material is coiled into a coil by a coiler to obtain the extruded rod. S5, Pulling The extrusion bar prepared in step S4 is drawn on a bar drawing machine. The deformation amount in each drawing pass is 5-15%, and the cumulative deformation amount is 40%-70%, to obtain the bar. S6, Aging Heat Treatment The bar stock prepared in step S5 is subjected to aging heat treatment at a heating temperature of 450-520℃ for 3.5-5.5 hours to obtain the treated bar stock. S7, Straightening, Sawing The bar stock processed in step S6 is straightened on a copper alloy bar straightening machine to achieve a straightness of 1mm / m, and then sawn according to a multiple of the customer's part size. The aging heat treatment method is as follows: First, the bar stock is loaded into the heat treatment furnace, the bar stock is connected to the positive electrode, and the steel plate is connected to the negative electrode, maintaining an insulating safety distance between the bar stock and the steel plate. Then, the heat treatment furnace is evacuated to ensure that the vacuum degree is below 5 Pa. After evacuation, inert gas Ar is introduced for atmosphere protection. The amount of Ar introduced is such that the furnace chamber is at a slightly positive pressure. After Ar is introduced, heating begins, and the formation of the GP zone is enhanced through the following three stages: 1) First stage: Heating temperature 450-520℃, maintain for 1-2 hours, then continuously spray treatment liquid to cool the bar stock to 100-150℃; 2) Second stage: Apply an electrostatic field intermittently to the bar stock. After cooling the bar stock to 100-150℃ in step 1), it is heated back to the rewarming point and held for 15 minutes. Then, apply an electrostatic field to the bar stock and continuously spray a treatment liquid at 30-40℃ to cool the bar stock to 80-120℃. 3) In the third stage, the intensity of the electrostatic field is gradually increased by 1-10kV / cm / cycle, and the reheating point is gradually decreased by 30-60℃ / cycle as the power of the electrostatic field changes. Step 2) is repeated until the reheating point is less than or equal to the cooling temperature. No reheating is required. Then the material is cooled to room temperature in the furnace to obtain the processed bar stock with a large number of GP zones. The treatment solution consists of a base solution prepared by mixing deionized water, polyethylene glycol, and propylene glycol in a certain proportion, as well as 40-80 g / L zinc ferrous phosphate tetrahydrate, 30-50 g / L hydroxyethyl cellulose, and 1 g / L benzotriazole, wherein the mass ratio of deionized water, polyethylene glycol, and propylene glycol is 4:2:1; the temperature of the treatment solution is 30-40℃.

2. The manufacturing process of a medium-conductivity, high-strength, and high-wear-resistant copper alloy rod as described in claim 1, characterized in that, The weight percentages of Cu, Ni, Co, and Si are as follows: Cu: balance, Ni: 1.5-3.0%, Co: 0.8-2.0%, Si: 0.4-1.2%.

3. The manufacturing process of a medium-conductivity, high-strength, and high-wear-resistant copper alloy rod as described in claim 1, characterized in that, The raw materials are added as follows: Cu is added by electrolytic copper plate, Ni is added by electrolytic nickel plate, Co is added by metallic cobalt block, and Si is added by elemental silicon.

4. The manufacturing process of a medium-conductivity, high-strength, and high-wear-resistant copper alloy rod as described in claim 1, characterized in that, During smelting, the surface of the melt is protected with a covering agent, and all raw materials are added together into a vacuum medium-frequency induction heating furnace for smelting.

5. The manufacturing process of a medium-conductivity, high-strength, and high-wear-resistant copper alloy rod as described in claim 1, characterized in that, The principle of casting is to start slowly, then speed up, and then slow down again.

6. The manufacturing process of a medium-conductivity, high-strength, and high-wear-resistant copper alloy rod as described in claim 1, characterized in that, The method for designing extrusion die size according to the product's deformation ratio is as follows: if the diameter of the extrusion rod is greater than 20mm, single-hole extrusion is used; if the diameter of the extrusion rod is less than 20mm, double-hole extrusion is used. The extrusion speed is 8-15mm / s, and the remaining 20-25mm of the ingot thickness is not extruded.

7. The manufacturing process of a medium-conductivity, high-strength, and high-wear-resistant copper alloy rod as described in claim 1, characterized in that, The strength of the electrostatic field is 20-30 kV / cm, and the rewarming point is 280-320℃.

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