A copper-rare earth intermediate alloy wire material and a method for preparing the same

Abstract

The application provides a copper-rare earth intermediate alloy wire material and a preparation method thereof, and relates to the technical field of copper alloy material processing, and comprises the following steps: step 1) taking first copper raw materials with a purity greater than 99.97% and rare earth particles with a purity greater than 99.9% as first raw materials to perform primary vacuum smelting and pouring to obtain alloy ingot I; step 2) removing the surface of the alloy ingot I to obtain a master alloy material; taking the master alloy material and second copper raw materials with a purity greater than 99.97% as second raw materials to perform secondary vacuum smelting and pouring to obtain alloy ingot II; the mass percentage of the rare earth in the second raw materials is 1%-8%; and step 3) preparing the alloy ingot II into a copper-rare earth intermediate alloy wire material. The application prepares a master alloy material first, and then dilutes the master alloy material to obtain a copper-rare earth intermediate alloy with uniform rare earth distribution, and then prepares the copper-rare earth intermediate alloy into a wire material, so that the copper-rare earth intermediate alloy can be used as a raw material for the preparation of a copper alloy, and the uniform distribution of the rare earth content in the prepared alloy is ensured.

Description

Technical Field

[0001] This invention relates to the field of copper alloy material processing technology, specifically to a copper-rare earth intermediate alloy wire material and its preparation method. Background Technology

[0002] Rare earth elements possess excellent properties for purifying and removing impurities from alloy materials, modifying their microstructure, and enhancing their performance, earning them the nickname "industrial MSG." In recent years, rare earth elements have been increasingly applied in the copper processing field, effectively purifying the melt, refining the microstructure, and regulating the properties of pure copper and copper alloys. This has garnered favor from scholars and manufacturing enterprises, demonstrating broad application prospects and development potential.

[0003] In existing technologies, pure rare earth elements or rare earth intermediate alloys are usually added to pure copper and copper alloys to obtain copper alloy billets.

[0004] However, the inventors discovered that: (1) if pure rare earth is added directly during the preparation of copper alloys, the rare earth is easily oxidized, resulting in waste, and the addition of rare earth causes severe corrosion to the furnace wall material of industrial production furnaces. (2) if rare earth master alloy is added during the preparation of copper alloys, although excessive oxidation can be avoided, the existing master alloys are often in the form of ingots or blocks. On the one hand, it is difficult to ensure the stability and accuracy of the amount added each time. On the other hand, the melting and diffusion of block rare earth master alloys after addition takes a certain amount of time, and the block size is not uniform, making it difficult to ensure uniform distribution in the melt. Usually, copper alloy billets are produced in the form of continuous casting. Uneven distribution of rare earth will lead to large differences in the microstructure and properties of the billet before and after casting (head and tail), resulting in scrap. Summary of the Invention

[0005] Therefore, the present invention provides a copper-rare earth intermediate alloy wire material and its preparation method. The main purpose is to prepare a copper-rare earth intermediate alloy wire material for use as a raw material in the preparation of copper alloys, ensuring the stability and accuracy of the addition amount, and improving the uniform distribution of rare earth in copper alloys.

[0006] To address the aforementioned problems, this invention provides a method for preparing copper-rare earth intermediate alloy wire material, comprising the following steps:

[0007] Step 1) Use a first copper raw material with a purity greater than 99.97% and rare earth particles with a purity greater than 99.9% as the first raw materials to perform a vacuum melting and casting process to obtain alloy ingot I;

[0008] Step 2) Remove the outer skin of the alloy ingot I to obtain the master alloy material; use the master alloy material and a second copper raw material with a purity greater than 99.97% as the second raw material for secondary vacuum melting and casting to obtain alloy ingot II; the mass ratio of rare earth in the second raw material is 1%-8%;

[0009] Step 3) Prepare the alloy ingot II into copper-rare earth intermediate alloy wire material.

[0010] Furthermore, in step 1), the first copper raw material is placed in a crucible in a vacuum furnace, and the rare earth particles are placed in a feeding frame. Then, a vacuum melting is performed. After the first copper raw material is completely melted, the rare earth particles are added to the crucible. After holding the temperature for 5-15 minutes, a casting is performed to obtain alloy ingot I.

[0011] Preferably, the first copper raw material is an electrolytic copper plate;

[0012] Preferably, the mass percentage of rare earth particles in the first raw material is 1%-50%;

[0013] Preferably, the temperature for a single vacuum melting process is 1180-1210℃;

[0014] Preferably, the vacuum degree in the vacuum furnace during a single casting is no greater than 5 Pa, the mold preheating temperature is 400-500℃, and the casting temperature is 1170-1190℃.

[0015] Furthermore, in step 2), the second raw material is placed in a vacuum furnace for secondary vacuum melting, and after the second raw material is melted, it is cast a second time to obtain alloy ingot II;

[0016] Preferably, the second copper raw material is an electrolytic copper plate;

[0017] Preferably, the temperature for secondary vacuum melting is 1170-1190℃;

[0018] Preferably, the vacuum degree in the vacuum furnace during the secondary casting is no greater than 5Pa, the mold preheating temperature is 350-450℃, and the casting temperature is 1170-1180℃.

[0019] Furthermore, step 3) includes:

[0020] Hot forging: The alloy ingot II is hot forged to obtain a forged rod; preferably, the diameter Φ of the forged rod is 50mm-55mm;

[0021] Solution treatment: The forging rod is subjected to solution treatment;

[0022] Hot rolling: The solution-treated forged rod is hot-rolled to obtain a hot-rolled rod blank; preferably, the diameter Φ of the hot-rolled rod blank is 6mm-8mm;

[0023] Drawing: The hot-rolled billet is drawn to obtain copper-rare earth intermediate alloy wire material.

[0024] Furthermore, in the hot forging step: the hot forging temperature is 800-850℃, and the final forging temperature is not lower than 650℃;

[0025] And / or, in the solution treatment step: the solution treatment temperature is 850-950℃, and the holding time is 1-3 hours;

[0026] And / or, the hot rolling temperature is 650-800℃.

[0027] Furthermore, in step 4), the hot-rolled billet is stripped and then drawn to obtain copper-rare earth intermediate alloy wire material with a diameter Φ of 0.5mm-4mm.

[0028] Preferably, the amount of skin peeled is 1%-5%.

[0029] Furthermore, the drawing method is multi-pass cold drawing;

[0030] Preferably, copper-rare earth intermediate alloy wire material with a diameter of 0.5mm is obtained by drawing 4-6 passes to Φ2.6mm, medium pass to 8-12 passes to Φ0.9mm, and small pass to 5-8 passes.

[0031] On the other hand, the present invention also provides a copper-rare earth intermediate alloy wire material, wherein the rare earth phase is distributed in a fibrous manner, and the diameter of the fiber is less than 5 μm, and the spacing between the fibers is 10-20 μm; preferably, the rare earth phase is uniformly distributed in the copper-rare earth intermediate alloy wire material.

[0032] Furthermore, the copper-rare earth intermediate alloy wire material is prepared using any of the methods described above.

[0033] In another aspect, the present invention also provides a method for continuous casting of copper alloy, wherein the copper alloy contains rare earth elements; wherein, when continuously casting the copper alloy, the raw material used to provide the rare earth elements is selected from the copper-rare earth intermediate alloy wire material described in any of the above-mentioned items.

[0034] Preferably, the rare earth absorption rate in the copper alloy is 60-90%;

[0035] Preferably, the rare earth element composition in the copper alloy is uniform and stable;

[0036] Preferably, the rare earth content in the copper alloy fluctuates within a range of no more than 5%.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. This invention provides a method for preparing copper-rare earth master alloy wire material. First, a master alloy material (alloy ingot I) is prepared, then diluted to obtain a master alloy with uniform rare earth content distribution (alloy ingot II). Then, through subsequent wire preparation processes (hot forging-hot rolling-cold drawing), a copper-rare earth master alloy wire material with uniform rare earth distribution is obtained. This copper-rare earth master alloy wire material is continuously added to the melt (pure copper or copper alloy), replacing the traditional method of adding master alloy ingots in block form. This allows the rare earth master alloy to dissolve quickly, uniformly, and stably into the copper alloy and solidify into a casting, thereby obtaining a copper alloy ingot with uniform and stable rare earth content distribution.

[0039] 2. This invention obtains a high-rare-earth content master alloy material through a first vacuum melting process. Rare-earth particles and electrolytic copper plates are placed in a vacuum furnace. The vacuum furnace isolates oxygen, preventing rare-earth from reacting with oxygen and wasting it. It also prevents pure rare-earth from reacting with the furnace wall material after reacting with oxygen, thus avoiding corrosion of the industrial production furnace by pure rare-earth during industrial production. The second process uses the master alloy as raw material and dilutes it with pure copper to obtain a low-rare-earth and uniform rare-earth intermediate alloy. During vacuum melting, the master alloy is better and more uniformly distributed in the melt. During solidification, the solid-liquid phase line range is reduced, supercooling is reduced, solidification temperature is lowered, and macro- and micro-segregation is mitigated. This results in a uniform rare-earth phase in the intermediate alloy ingot, with more uniform rare-earth element content throughout. Simultaneously, dilution with pure copper controls the rare-earth content in the intermediate alloy (alloy ingot II) within a reasonable range, preventing excessive rare-earth from increasing intermediate brittleness and causing cracking during hot forging and rolling, making it difficult to produce wire.

[0040] 3. This invention can deeply remove gas and impurities through secondary vacuum melting. Impurities and gases that could not be completely removed in the first melting can be further removed in the second vacuum melting. In particular, it is difficult to stably reduce gaseous elements such as hydrogen and oxygen in the alloy to below 10 ppm, thereby avoiding the secondary introduction of trace impurities due to the low purity of existing intermediate alloys, and avoiding affecting the purity of pure copper or copper alloy melt and the quality of the billet.

[0041] 4. During hot forging, rare earth elements may undergo local precipitation or agglomeration. This invention performs a solution treatment on the forging rod before hot rolling to ensure that the precipitated rare earth elements are fully dissolved into the copper matrix, thus avoiding excessive local rare earth element concentration that could affect hot rolling. The solubility of elements is directly related to temperature; the higher the temperature, the greater the solubility. However, excessively high temperatures can also cause overheating. Therefore, this invention rationally controls the temperature range for solution treatment. Attached Figure Description

[0042] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0043] Figure 1 This is a process flow diagram of the method for preparing copper-rare earth intermediate alloy wire material according to the present invention;

[0044] Figure 2 The image shows the metallographic structure of the intermetallic wire material prepared in Example 1 of this invention.

[0045] Figure 3 The image shows the metallographic structure of the intermetallic wire material prepared in Example 2 of this invention.

[0046] Figure 4 The image shows the metallographic structure of the intermetallic wire material prepared in Comparative Example 1 of this invention. Detailed Implementation

[0047] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0048] This invention provides a method for preparing copper-rare earth master alloy wire material. The preparation process is as follows: batching → primary vacuum melting → batching → secondary vacuum melting → hot forging → solution treatment → hot rolling → drawing. Figure 1 As shown.

[0049] Specifically, the following steps are included:

[0050] Step 1) Use a first copper raw material with a purity greater than 99.97% and rare earth particles with a purity greater than 99.9% as the first raw materials to perform a vacuum melting and casting process to obtain alloy ingot I;

[0051] Step 2) Remove the outer skin of the alloy ingot I to obtain the master alloy material; use the master alloy material and a second copper raw material with a purity greater than 99.97% as the second raw material for secondary vacuum melting and casting to obtain alloy ingot II; the mass ratio of rare earth in the second raw material is 1-8%;

[0052] Step 3) Prepare the alloy ingot II into copper-rare earth intermediate alloy wire material.

[0053] Based on the above method, the master alloy material (alloy ingot I) is first prepared by vacuum melting and casting, and then diluted to obtain an intermediate alloy with uniform rare earth content distribution (alloy ingot II). Then, through the subsequent wire preparation process (hot forging-hot rolling-cold drawing), a copper-rare earth intermediate alloy wire material with uniform rare earth distribution is obtained. This copper-rare earth intermediate alloy wire material is continuously added to the melt (pure copper or copper alloy), replacing the traditional method of adding intermediate alloy ingots in blocks, so as to obtain an alloy ingot with uniform and stable rare earth content.

[0054] During vacuum melting, the alloy can be better and more uniformly distributed in the melt. During solidification, the solid-liquid phase range is reduced, supercooling is decreased, solidification temperature is lowered, and macro- and micro-segregation is mitigated. This results in a more uniform rare earth phase and content of rare earth elements in the intermediate alloy ingot. Simultaneously, dilution with pure copper controls the rare earth content in the intermediate alloy (alloy ingot II) within a reasonable range, preventing excessive rare earth from increasing the alloy's brittleness and causing cracking during hot forging and rolling, making it difficult to produce wire. In practical applications, this invention is not limited to secondary vacuum melting; depending on the situation, pure copper can be added three, four, or more times for vacuum melting, as long as the rare earth mass percentage is 1%-8%.

[0055] In some embodiments, in step 1), the first copper raw material is placed in a crucible in a vacuum furnace, and rare earth particles are placed in a feeding frame. Then, a vacuum melting is performed. After the first copper raw material is completely melted, the rare earth particles are added to the crucible. After holding the temperature for 5-15 minutes, a casting is performed to obtain alloy ingot I. Rare earth should not be added too early or held for too long to prevent severe burn-off.

[0056] Preferably, the first copper raw material is an electrolytic copper plate; it can also be in block, rod, or granule form.

[0057] Preferably, the mass percentage of rare earth particles in the first raw material is 1%-50%;

[0058] Preferably, the temperature for a single vacuum melting process is 1180-1210℃;

[0059] Preferably, the vacuum degree in the vacuum furnace during a single casting is no greater than 5 Pa, the mold preheating temperature is 400-500℃, and the casting temperature is 1170-1190℃. A vacuum degree of no more than 5 Pa prevents oxygen and impurities from entering the vacuum furnace; mold preheating controls the cooling rate to prevent excessive cooling and thermal cracking; and the melting and casting temperatures are used to improve the fluidity of the molten metal and control grain growth.

[0060] In some embodiments, in step 2), the second raw material is placed in a vacuum furnace for secondary vacuum melting, and after the second raw material is melted, it is cast a second time to obtain alloy ingot II;

[0061] Preferably, the second copper raw material is an electrolytic copper plate;

[0062] Preferably, the temperature for secondary vacuum melting is 1170-1190℃;

[0063] Preferably, the vacuum degree in the vacuum furnace during the secondary casting is no greater than 5Pa, the mold preheating temperature is 350-450℃, and the casting temperature is 1170-1180℃.

[0064] The first vacuum melting process involved a copper-rare earth alloy system, requiring higher melting and casting temperatures and mold holding times. The second vacuum melting process, using a rare earth copper-copper alloy system, required lower melting and casting temperatures and mold holding times compared to the first process. This is primarily due to the different physical properties of the alloy systems. The second vacuum melting process allows for deeper degassing and impurity removal. Impurities and gases that were not completely removed in the first melting process can be further removed during the second process, resulting in a deeply purified alloy. This avoids the introduction of impurities during rare earth addition in practical applications, especially when rare earth and oxygen elements are present in the melt, which can easily react with the furnace wall materials. Deep deoxygenation prevents this reaction. Furthermore, the continuous and quantitative feeding using intermediate alloy wire avoids the waste and uneven composition caused by uncontrollable rare earth content during conventional processes.

[0065] In some implementations, step 3) includes:

[0066] Hot forging: The alloy ingot II is hot forged to obtain a forged rod; preferably, the diameter Φ of the forged rod is 50mm-55mm;

[0067] Solution treatment: The forging rod is subjected to solution treatment;

[0068] Hot rolling: The solution-treated forged rod is hot-rolled to obtain a hot-rolled rod blank; preferably, the diameter Φ of the hot-rolled rod blank is 6mm-8mm;

[0069] Drawing: The hot-rolled billet is drawn to obtain copper-rare earth intermediate alloy wire material.

[0070] Furthermore, in the hot forging step: the hot forging temperature is 800-850℃, and the final forging temperature is not lower than 650℃;

[0071] And / or, in the solution treatment step: the solution treatment temperature is 850-950℃, and the holding time is 1-3 hours;

[0072] And / or, the hot rolling temperature is 650-800℃ to prevent cracking during rolling. During hot forging, rare earth elements may undergo localized precipitation or agglomeration. This invention performs solution treatment on the forging rod before hot rolling to ensure that the precipitated rare earth elements are fully dissolved into the copper matrix, avoiding excessively high local levels of rare earth elements that could affect hot rolling. The solubility of elements is directly related to temperature; the higher the temperature, the greater the solubility. However, excessively high temperatures can also cause overheating. Therefore, this invention rationally controls the solution temperature range.

[0073] In some embodiments, in step 4), the hot-rolled billet is peeled and then drawn to obtain copper-rare earth master alloy wire material with a diameter Φ of 0.5mm-4mm. Preferably, the peeling amount is 1-5%, removing the oxide scale on the hot-rolled billet to prevent the oxide layer from being pressed into the matrix during subsequent drawing, which could cause cutting of the wire matrix and easily lead to breakage. The oxide layer entering the matrix leads to an increase in the oxygen content and other impurities in the matrix. In some embodiments, the drawing method is multi-pass cold drawing, and there is no specific requirement for the final drawn wire diameter, which can be adjusted according to the actual situation. For example, a copper-rare earth master alloy wire material with a diameter of Φ0.5mm can be obtained by drawing 4-6 times to Φ2.6mm, 8-12 times to Φ0.9mm, and 5-8 times.

[0074] On the other hand, the present invention also provides a copper-rare earth intermediate alloy wire material, wherein the rare earth is uniformly distributed in the copper-rare earth intermediate alloy wire material, and the rare earth content is tested at 3 randomly selected positions on the copper-rare earth intermediate alloy wire material, and the fluctuation range of rare earth content does not exceed 5%; the rare earth phase is uniformly distributed in a fibrous form, and the diameter of the fiber is less than 5 μm, and the spacing between the fibers is 10-20 μm.

[0075] In some embodiments, the copper-rare earth intermediate alloy wire material is prepared by any of the methods described above.

[0076] Furthermore, the present invention also provides a method for continuous casting of copper alloys, wherein the copper alloy contains rare earth elements; wherein, during the continuous casting of the copper alloy, the raw material used to provide the rare earth elements is selected from the copper-rare earth master alloy wire material described in any of the above-mentioned embodiments; other alloying elements are preferentially added during smelting, and after stabilization, the copper-rare earth master alloy wire is fed in, and continuous casting begins simultaneously, with the copper-rare earth master alloy being continuously fed into the copper alloy melt; the continuous feeding speed of the copper-rare earth master alloy wire is calculated based on the designed addition amount of rare earth in the copper alloy and the billet traction speed, wherein the rare earth burn-off rate is considered to be 10-40%;

[0077] Preferably, the rare earth absorption rate in the copper alloy is 60-90%. Generally speaking, when rare earth is added to the melt, it will react rapidly with oxygen and impurity elements, and even further react with the furnace material, causing corrosion of the furnace wall. All of these result in the waste of rare earth elements, and the absorption rate is low, generally 10-20%.

[0078] Preferably, the rare earth element composition in the copper alloy is uniform and stable;

[0079] Preferably, the rare earth content in the copper alloy fluctuates within a range of no more than 5%.

[0080] The present invention will be further described in detail below through specific embodiments:

[0081] Example 1

[0082] This embodiment provides a copper-rare earth intermediate alloy wire material, specifically including the following steps:

[0083] Step 1) Use a first high-purity electrolytic copper plate (purity 99.99%) and high-purity rare earth lanthanum particles (purity 99.95%) as the first raw materials for batching, wherein the rare earth mass percentage is 40%. Place the first high-purity electrolytic copper plate in a crucible in a vacuum furnace, place the rare earth lanthanum particles in a feeding frame, and then perform a vacuum melting. After the first high-purity electrolytic copper plate is completely melted, add the rare earth particles into the crucible, hold for 10 minutes, and then perform the first casting to obtain the master alloy ingot. During this process, ensure the vacuum degree in the furnace is 2 Pa, the melting temperature is 1185℃, and after holding, perform casting at 1175℃. The mold preheating temperature is 400℃ to obtain alloy ingot I.

[0084] Step 2) Remove the outer skin of alloy ingot I to obtain the master alloy material, and add a second high-purity electrolytic copper plate (99.99%) as the second raw material for batching, wherein the rare earth mass percentage is 8%. Place the second raw material in a vacuum furnace and perform a second vacuum melting in the vacuum furnace. After melting, perform a second casting in the vacuum furnace to obtain an intermediate alloy ingot. During this process, maintain the vacuum degree in the furnace at 2 Pa, the melting temperature at 1170℃, and after holding at 1170℃, cast at 350℃ to obtain alloy ingot II.

[0085] Step 3) Hot forging of alloy ingot II is performed at an initial forging temperature of 850℃ and a final forging temperature of 700℃ to obtain a forged rod with a diameter of 50mm. The hot-forged rod is then subjected to solution treatment at 900℃ for 3 hours. After solution treatment, the alloy rod is hot-rolled in multiple passes at an initial rolling temperature of 800℃ and a final rolling temperature of 650℃ to obtain a hot-rolled rod with a diameter of 8mm. The hot-rolled alloy rod is then peeled, with a peeling amount of 5%. Subsequently, it is drawn to 2.6mm in 6 passes and to 1.2mm in 8 passes.

[0086] In this embodiment, samples were taken from the head, middle, and tail sections of the copper-rare earth master alloy wire for chemical composition testing. The results are shown in Table 1. It can be seen that the rare earth La content at these three locations fluctuates within 3%, and the total amount of impurity elements is 20 ppm, while the total amount of gaseous elements is 5 ppm. The metallographic structure of the master alloy wire is as follows: Figure 2 As shown, the rare earth phase is fibrous, with a fiber diameter of approximately 4 μm and a fiber spacing of approximately 10 μm, exhibiting uniform distribution. The intermediate alloy wire prepared in this embodiment meets the requirements for high purity and high uniformity, satisfying the requirements for rare earth element addition in industrial production.

[0087] Example 2

[0088] This embodiment provides a copper-rare earth intermediate alloy wire material, specifically including the following steps:

[0089] Step 1) A first high-purity electrolytic copper plate (purity 99.99%) and high-purity rare earth lanthanum particles (purity 99.95%) are used as the first raw materials for batching, wherein the mass percentage of rare earth is 50%. The first high-purity electrolytic copper plate is placed in a crucible in a vacuum furnace, and the rare earth lanthanum particles are placed in a feeding frame. Then, a vacuum melting is carried out. After the first high-purity electrolytic copper plate is completely melted, the rare earth lanthanum particles are added to the crucible. After holding at the temperature for 10 minutes, the first casting is carried out to obtain the master alloy ingot. During this process, the vacuum degree in the furnace is maintained at 3 Pa, the melting temperature is 1190℃, and after holding at the temperature, the casting is carried out at 1180℃. The mold preheating temperature is 500℃ to obtain alloy ingot I.

[0090] Step 2) Remove the outer skin of alloy ingot I to obtain the master alloy material, and add a second high-purity electrolytic copper plate (99.99%) as the second raw material for batching, wherein the rare earth mass percentage is 3%. Place the second raw material in a vacuum furnace and perform a second vacuum melting in the vacuum furnace. After melting, perform a second casting in the vacuum furnace to obtain an intermediate alloy ingot. During this process, maintain the vacuum degree in the furnace at 3 Pa, the melting temperature at 1190℃, and after holding at the temperature, cast at 1180℃. The mold preheating temperature is 400℃ to obtain alloy ingot II.

[0091] Step 3) Hot forging of alloy ingot II is performed at an initial forging temperature of 850℃ and a final forging temperature of 750℃ to obtain a forged rod with a diameter of 50mm. The hot forged rod is then subjected to solution treatment at 900℃ for 3 hours. After solution treatment, the alloy rod is hot rolled in multiple passes at an initial rolling temperature of 800℃ and a final rolling temperature of 700℃ to obtain a hot-rolled rod with a diameter of 8mm. The hot-rolled alloy rod is then peeled, with a peeling amount of 5%. Subsequently, it is drawn in 6 passes to a diameter of 2.6mm and in 8 passes to a diameter of 1.2mm.

[0092] In this embodiment, samples were taken from the head, middle, and tail sections of the copper-rare earth master alloy wire for chemical composition testing. The results are shown in Table 1. It can be seen that the rare earth La content at these three locations fluctuates within 2%, and the total amount of impurity elements is 24 ppm, while the total amount of gaseous elements is 6 ppm. The metallographic structure of the master alloy wire is as follows: Figure 3 As shown, the rare earth phase is fibrous, with a fiber diameter of approximately 5 μm and a fiber spacing of 5 μm, exhibiting uniform distribution. The intermediate alloy wire prepared in this embodiment meets the requirements for high purity and high uniformity, satisfying the requirements for rare earth element addition in industrial production.

[0093] Example 3

[0094] This embodiment provides a method for continuous casting of copper alloys, specifically including the following steps:

[0095] Step 1) Use a first high-purity electrolytic copper plate (purity 99.99%) and high-purity rare earth lanthanum particles (purity 99.95%) as the first raw materials for batching, wherein the rare earth mass percentage is 40%. Place the first high-purity electrolytic copper plate in a crucible in a vacuum furnace, place the rare earth lanthanum particles in a feeding frame, and then perform a vacuum melting. After the first high-purity electrolytic copper plate is completely melted, add the rare earth particles into the crucible, hold for 10 minutes, and then perform the first casting to obtain the master alloy ingot. During this process, ensure the vacuum degree in the furnace is 2 Pa, the melting temperature is 1185℃, and after holding, perform casting at 1175℃. The mold preheating temperature is 400℃ to obtain alloy ingot I.

[0096] Step 2) Remove the outer skin of alloy ingot I to obtain the master alloy material, and add a second high-purity electrolytic copper plate (99.99%) as the second raw material for batching, wherein the rare earth mass percentage is 8%. Place the second raw material in a vacuum furnace and perform a second vacuum melting in the vacuum furnace. After melting, perform a second casting in the vacuum furnace to obtain an intermediate alloy ingot. During this process, maintain the vacuum degree in the furnace at 2 Pa, the melting temperature at 1170℃, and after holding at 1170℃, cast at 350℃ to obtain alloy ingot II.

[0097] Step 3) Hot forging of alloy ingot II is performed at an initial forging temperature of 850℃ and a final forging temperature of 700℃ to obtain a forged rod with a diameter of 50mm. The hot-forged rod is then subjected to solution treatment at 900℃ for 3 hours. After solution treatment, the alloy rod is hot-rolled in multiple passes at an initial rolling temperature of 800℃ and a final rolling temperature of 650℃ to obtain a hot-rolled rod with a diameter of 8mm. The hot-rolled alloy rod is then peeled, with a peeling amount of 5%. Subsequently, it is drawn to 2.6mm in 6 passes and to 1.2mm in 8 passes.

[0098] Step 4) Using the copper-rare earth intermediate alloy wire as the raw material for rare earth elements, in the horizontal continuous casting copper alloy production process, after adding other alloying elements, keep it at a temperature of not less than 1200℃ for 10 minutes, and then feed the copper-rare earth intermediate alloy wire into the casting furnace, and start the continuous casting traction program at the same time to ensure that the mass percentage of rare earth lanthanum in the unit copper alloy melt flow rate is 200 ppm.

[0099] In the continuously cast copper alloy billet obtained in this embodiment, the content of rare earth lanthanum was tested at three random locations. The results are shown in Table 2. It can be seen that the content of rare earth element lanthanum at the three locations fluctuates within 5%, and the average rare earth lanthanum content is 185 ppm. Compared with the addition of 200 ppm, the absorption rate is 92.5%.

[0100] Comparative Example 1

[0101] This comparative example provides a copper-rare earth intermediate alloy wire material, which specifically includes the following steps:

[0102] Step 1) A first high-purity electrolytic copper plate (purity 99.99%) and high-purity rare earth lanthanum particles (purity 99.95%) are used as the first raw materials for batching, wherein the rare earth mass percentage is 8%. The first high-purity electrolytic copper plate is placed in a crucible in a vacuum furnace, and the rare earth lanthanum particles are placed in a feeding frame. Then, a vacuum melting is carried out. After the first high-purity electrolytic copper plate is completely melted, the rare earth lanthanum particles are added to the crucible. After holding for 10 minutes, the first casting is carried out to obtain the master alloy ingot. During this process, the vacuum degree in the furnace is maintained at 3 Pa, the melting temperature is 1190℃, and after holding, the casting is carried out at 1180℃. The mold preheating temperature is 500℃ to obtain alloy ingot I.

[0103] Step 2) Hot forging of alloy ingot I is performed at an initial forging temperature of 850℃ and a final forging temperature of 750℃ to obtain a Φ50mm forged rod; the hot forged rod is then subjected to solution treatment at 950℃ for 3 hours; the solution-treated alloy rod is then subjected to multi-pass hot rolling forming at an initial rolling temperature of 800℃ and a final rolling temperature of 700℃ to obtain a Φ8mm hot-rolled rod.

[0104] Step 3) The hot-rolled alloy rod is peeled off, with a peeling amount of 5%; then it is drawn in 6 passes to Φ2.6mm and in 8 passes to Φ1.2mm.

[0105] This comparative example did not involve master alloy preparation, secondary vacuum melting, or dilution treatment. Chemical composition tests were performed on samples taken from the head, middle, and tail sections of the obtained copper-rare earth master alloy wire. The results are shown in Table 1. It can be seen that the rare earth La content at these three locations fluctuates by more than 10%, with a total impurity element content of 80 ppm and a total gaseous element content of 20 ppm. The metallographic structure of the master alloy wire is as follows: Figure 4As shown, the rare earth phase has an irregular shape and the fibers are of uneven thickness.

[0106] Table 1. Chemical composition analysis results of copper-rare earth master alloys

[0107]

[0108] Comparative Example 2

[0109] This comparative example provides a copper-rare earth intermediate alloy wire material, which specifically includes the following steps:

[0110] Step 1) A first high-purity electrolytic copper plate (purity 99.99%) and high-purity rare earth lanthanum particles (purity 99.95%) are used as the first raw materials for batching, wherein the rare earth mass percentage is 50%. The first high-purity electrolytic copper plate is placed in a crucible in a vacuum furnace, and the rare earth lanthanum particles are placed in a feeding frame. Then, the first vacuum melting is carried out. After the first high-purity electrolytic copper plate is completely melted, the rare earth lanthanum particles are added to the crucible. After holding at the temperature for 10 minutes, the first casting is carried out to obtain the master alloy ingot. During this process, the vacuum degree in the furnace is maintained at 3 Pa, the melting temperature is 1190℃, and after holding at the temperature, the casting is carried out at 1180℃. The mold preheating temperature is 500℃ to obtain alloy ingot I.

[0111] Step 2) Remove the outer skin of alloy ingot I to obtain the master alloy material, and add a second high-purity electrolytic copper plate (99.99%) as the second raw material for batching, wherein the rare earth mass percentage is 10%. Place the second raw material in a vacuum furnace and perform a second vacuum melting in the vacuum furnace. After melting, perform a second casting in the vacuum furnace to obtain an intermediate alloy ingot. During this process, ensure the vacuum degree in the furnace is 3Pa, the melting temperature is 1190℃, and after holding at the temperature, cast at 1180℃. The mold preheating temperature is 400℃ to obtain alloy ingot II.

[0112] Step 3) Hot forging of alloy ingot II was performed at an initial forging temperature of 850℃ and a final forging temperature of 750℃ to obtain a Φ50mm forged rod. The hot forged rod was then subjected to solution treatment at 900℃ for 3 hours. After solution treatment, the alloy rod was subjected to multi-pass hot rolling at an initial rolling temperature of 800℃ and a final rolling temperature of 700℃. Severe cracking occurred during hot forging, and the alloy forged rod could not be obtained.

[0113] The copper-rare earth master alloy prepared in this comparative example has an excessively high rare earth content, which increases the alloy's brittleness, makes it difficult to hot forge and form, and makes it impossible to obtain the required master alloy wire.

[0114] Comparative Example 3

[0115] This comparative example provides a method for preparing a continuously cast copper alloy, the steps of which are as follows:

[0116] Using pure rare earth lanthanum as raw material, in the horizontal continuous casting copper alloy production process, after adding other alloying elements, the mixture is kept at a temperature of not less than 1200℃ for 10 minutes, and then rare earth lanthanum is added to the casting furnace. At the same time, the continuous casting traction program is started to ensure that the mass percentage of rare earth lanthanum in the unit copper alloy melt flow rate is 200 ppm.

[0117] In the continuously cast copper alloy billet obtained in this comparative example, the content of rare earth lanthanum was tested at three random locations. The results are shown in Table 2. It can be seen that the content of rare earth element lanthanum at the three locations fluctuates greatly and is low. Most of it was burned off and failed to achieve a reasonable addition effect.

[0118] Comparative Example 4

[0119] This comparative example provides a method for preparing a continuously cast copper alloy, the steps of which are as follows:

[0120] Using the bulk material obtained after crushing copper-lanthanum master alloy ingots as rare earth raw material, in the horizontal continuous casting copper alloy production process, after adding other alloying elements, the mixture is kept at a temperature of not less than 1200℃ for 10 minutes, and then the copper-lanthanum master alloy bulk material is added to the casting furnace, and the continuous casting traction program is started at the same time to ensure that the mass percentage of rare earth lanthanum in the unit copper alloy melt flow rate is 200 ppm.

[0121] In the continuously cast copper alloy billet obtained in this comparative example, the content of rare earth lanthanum was tested at three random locations. The results are shown in Table 2. It can be seen that the content of rare earth element lanthanum at the three locations fluctuates greatly, with an average rare earth content of 35 ppm. Compared with an addition of 200 ppm, the absorption rate is 17.5%.

[0122] Table 2. Results of rare earth chemical composition analysis at random locations in continuously cast copper alloy billets.

[0123]

[0124] In summary, the preparation of copper-rare earth intermediate alloy wire material according to the method of this application, and the use of this copper-rare earth intermediate alloy wire material as a raw material for continuous casting of copper alloy, can result in a uniform and stable distribution of rare earth elements in the copper alloy ingot, and improve the absorption rate of rare earth elements in the copper alloy.

[0125] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0126] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A method for preparing a copper-rare earth intermediate alloy wire material, characterized in that, Includes the following steps: Step 1) Use a first copper raw material with a purity greater than 99.97% and rare earth particles with a purity greater than 99.9% as the first raw materials to perform a vacuum melting and casting process to obtain alloy ingot I; Step 2) Remove the outer skin of the alloy ingot I to obtain the master alloy material; use the master alloy material and a second copper raw material with a purity greater than 99.97% as the second raw material for secondary vacuum melting and casting to dilute the rare earth in the master alloy material and obtain alloy ingot II; the mass percentage of rare earth in the second raw material is 1%-8%; Step 3) Prepare the alloy ingot II into copper-rare earth intermediate alloy wire material.

2. The method for preparing copper-rare earth intermediate alloy wire material according to claim 1, characterized in that, In step 1), the first copper raw material is placed in a crucible in a vacuum furnace, and rare earth particles are placed in a feeding frame. Then, a vacuum melting is performed. After the first copper raw material is completely melted, the rare earth particles are added to the crucible. After holding the temperature for 5-15 minutes, a casting is performed to obtain alloy ingot I. The first copper raw material is an electrolytic copper plate; the mass percentage of rare earth particles in the first raw material is 1%-50%.

3. The method for preparing copper-rare earth intermediate alloy wire material according to claim 2, characterized in that, The temperature of a single vacuum melting is 1180-1210℃; the vacuum degree in the vacuum furnace during a single casting is no more than 5Pa, the mold preheating temperature is 400-500℃, and the casting temperature is 1170-1190℃.

4. The method for preparing copper-rare earth intermediate alloy wire material according to claim 1, characterized in that, In step 2), the second raw material is placed in a vacuum furnace for secondary vacuum melting. After the second raw material is melted, it is cast a second time to obtain alloy ingot II. The second copper raw material is an electrolytic copper plate.

5. The method for preparing copper-rare earth intermediate alloy wire material according to claim 4, characterized in that, The temperature for secondary vacuum melting is 1170-1190℃; the vacuum degree in the vacuum furnace during secondary casting is no more than 5Pa, the mold preheating temperature is 350-450℃, and the casting temperature is 1170-1180℃.

6. The method for preparing copper-rare earth intermediate alloy wire material according to claim 1, characterized in that, Step 3) includes: Hot forging: The alloy ingot II is hot forged to obtain a forged rod; the diameter Φ of the forged rod is 50mm-55mm; Solution treatment: The forging rod is subjected to solution treatment; Hot rolling: The solution-treated forged rod is hot-rolled to obtain a hot-rolled rod blank; the diameter Φ of the hot-rolled rod blank is 6mm-8mm; Drawing: The hot-rolled billet is drawn to obtain copper-rare earth intermediate alloy wire material.

7. The method for preparing copper-rare earth intermediate alloy wire material according to claim 6, characterized in that, In the hot forging step: the hot forging temperature is 800-850℃, and the final forging temperature is not lower than 650℃; And / or, in the solution treatment step: the solution treatment temperature is 850-950℃, and the holding time is 1-3 hours; And / or, the hot rolling temperature is 650-800℃.

8. The method for preparing copper-rare earth intermediate alloy wire material according to claim 6 or 7, characterized in that, After peeling the hot-rolled billet, it is drawn to obtain copper-rare earth intermediate alloy wire material with a diameter Φ of 0.5mm-4mm; wherein the peeling amount is 1%-5%.

9. The method for preparing copper-rare earth intermediate alloy wire material according to claim 8, characterized in that, The drawing method is multi-pass cold drawing; specifically, the large drawing is performed in 4-6 passes to obtain a copper-rare earth intermediate alloy wire material with a diameter of Φ2.6mm, and the medium drawing is performed in 8 passes to obtain a copper-rare earth intermediate alloy wire material with a diameter of Φ1.2mm.

10. A copper-rare earth intermediate alloy wire material, characterized in that, The copper-rare earth intermediate alloy wire material is prepared by the method described in any one of claims 1 to 9; in the copper-rare earth intermediate alloy wire material: the rare earth phase is distributed in a fibrous manner, and the diameter of the fiber is less than 5 μm, and the spacing between the fibers is 10-20 μm; in the copper-rare earth intermediate alloy wire material, the rare earth phase is uniformly distributed.

11. A method for continuous casting of copper alloys, characterized in that, The copper alloy contains rare earth elements; wherein, when continuously casting the copper alloy, the raw material used to provide the rare earth elements is the copper-rare earth intermediate alloy wire material as described in claim 10. The rare earth absorption rate in the copper alloy is 60-90%; the rare earth element composition in the copper alloy is uniform and stable; and the fluctuation range of the rare earth content in the copper alloy does not exceed 5%.

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