A crack-resistant copper rare earth alloy and its preparation method

Abstract

The invention discloses a crack-resistant copper rare earth alloy and a preparation method thereof, belonging to the technical field of alloys. The key points of the technical solution are a crack-resistant copper rare earth alloy, which is composed of the following components in percentage by mass: 0.5-1.2% chromium, 0.2-0.5% titanium, 0.2-0.4% manganese, 0.8-1.5% antimony, 0.2-0.7% zirconium, 0.4-1.5% rare earth elements, and the balance being copper and unavoidable impurities. The rare earth elements are composed of cerium and yttrium in a weight ratio of (0.5-1):(0.2-0.5), thereby achieving the technical effect of solving the problem of cracking during copper rare earth alloy processing.

Description

Technical Field

[0001] This invention relates to the field of alloy technology, and in particular to a crack-resistant copper-rare earth alloy and its preparation method. Background Technology

[0002] Copper is an important non-ferrous metal material with excellent electrical and thermal conductivity, good corrosion resistance and excellent processing performance, and is widely used in power electronics, petrochemicals, machinery manufacturing, national defense, home appliances and construction industry. Copper rare earth alloy is a composite material containing rare earth elements, copper and other alloying elements. Due to its unique physical and chemical properties, this alloy has a wide range of applications in aerospace, automobile manufacturing, electronics industry, nuclear industry and metallurgy.

[0003] The role of rare earth elements in copper alloys is mainly to purify the melt through degassing, deoxidation, impurity removal, and slag formation, thereby improving the performance of copper alloys. However, during the preparation of copper alloys, rare earth elements preferentially combine with copper to form a brittle low-melting-point eutectic structure, which is enriched at the grain boundaries. Therefore, the hot working performance of copper alloys is poor, and cracking is also prone to occur during cold working. Summary of the Invention

[0004] To address the problem of cracking during the processing of copper-rare earth alloys, this invention provides a crack-resistant copper-rare earth alloy and its preparation method.

[0005] The first aspect of this invention is to provide a crack-resistant copper-rare earth alloy, which adopts the following technical solution:

[0006] A crack-resistant copper-rare earth alloy, wherein the copper-rare earth alloy is composed of the following components in mass percentage: 0.5-1.2% chromium, 0.2-0.5% titanium, 0.2-0.4% manganese, 0.8-1.5% antimony, 0.2-0.7% zirconium, 0.4-1.5% rare earth elements, with the balance being copper and unavoidable impurities, wherein the rare earth elements are composed of cerium and yttrium in a weight ratio of (0.5-1):(0.2-0.5).

[0007] Preferably, the weight ratio of cerium to yttrium is 0.8:0.3.

[0008] A second aspect of the present invention is to provide a method for preparing a crack-resistant copper-rare earth alloy, comprising the following steps:

[0009] S1. Melting: Melt the copper fully according to the mass percentage of the copper rare earth alloy components;

[0010] S2. After the copper melts, raise the smelting temperature to 1400-1500℃ and add titanium, manganese, antimony and zirconium. Then, continue to raise the temperature to 1500-1550℃ and add chromium to continue smelting to obtain a refined liquid.

[0011] S3. Under the condition of 1100-1150℃, after slag removal, continue refining at this temperature for 8-10 minutes, then turn off the power and let it stand for 12-15 minutes. Then add rare earth mixture and let the rare earth mixture enter the bottom of the refining liquid. Then stir evenly, raise the temperature to 1100℃ and keep it warm for casting.

[0012] Preferably, the heat preservation casting is performed by heating the casting furnace to 900-1000℃ and then starting to load the mold for casting, with a casting speed of 260-280 r / min and a pitch of 4-5 mm.

[0013] Preferably, the material after casting is introduced into the drawing process for segregation layer removal, the drawing amount is 0.8-1.4mm, and after drawing, it is straightened by a straightening machine to obtain an ingot.

[0014] Preferably, the copper-rare earth alloy material is obtained by sequentially homogenizing, hot rolling, cold rough rolling, intermediate annealing, cold finish rolling and aging treatment of the ingot.

[0015] Preferably, the homogenization treatment temperature is 920-950℃ for homogenization annealing and holding for 4-6 hours.

[0016] Preferably, the intermediate annealing conditions are annealing at 460±10℃ for 8-10 hours.

[0017] Preferably, the aging treatment is performed by holding the temperature at 520±10℃ for 6-10 hours.

[0018] Preferably, the average particle size of the rare earth mixture is 30-50 μm.

[0019] Excessive furnace temperature can cause severe ablation of rare earth elements, reducing their yield.

[0020] In summary, the present invention has the following beneficial effects:

[0021] 1. Rare earth elements can effectively refine alloy grains, and the generated second phase helps reduce the hot cracking tendency of the alloy. In this application, the combination of rare earth elements cerium and yttrium makes the microstructure of the alloy finer and more uniformly distributed, resulting in a larger number of intergranular bridges. A large number of bridges helps resist the stress generated when grains separate, thus improving the crack resistance of the alloy. However, when excessive cerium and yttrium are added, the microstructure of the alloy does not continue to be refined but instead coarsens. At the same time, the second phase at the grain boundaries increases significantly, and the intergranular triangular region becomes larger. It can be seen that excessive cerium and yttrium will segregate at the grain boundaries of the alloy and precipitate a large number of second phases. The precipitation of a large number of second phases can easily block the feeding channels generated by the alloy under stress, thus leading to a high hot cracking tendency of the alloy. Therefore, in this application, when the rare earth elements are composed of cerium and yttrium in a weight ratio of (0.5-1):(0.2-0.5), the crack resistance of copper rare earth alloys can be effectively improved.

[0022] 2. The combined use of chromium, titanium, manganese, antimony and zirconium in this application helps to improve the overall performance of copper rare earth alloys, refine the grain size of the alloy, improve the strength and toughness of copper rare earth alloys, and reduce the hot cracking tendency of copper rare earth alloys.

[0023] 2. In this application, limiting the particle size of the rare earth mixture to between 30-50 μm can effectively improve the absorption rate of rare earth, reduce the burn-off rate, and make the rare earth more evenly distributed in the alloy, thereby improving the crack resistance of the alloy. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the embodiments.

[0025] The first aspect of this invention is to provide a crack-resistant copper-rare earth alloy, which adopts the following technical solution:

[0026] A crack-resistant copper-rare earth alloy, wherein the copper-rare earth alloy is composed of the following components in mass percentage: 0.5-1.2% chromium, 0.2-0.5% titanium, 0.2-0.4% manganese, 0.8-1.5% antimony, 0.2-0.7% zirconium, 0.4-1.5% rare earth elements, with the balance being copper and unavoidable impurities, wherein the rare earth elements are composed of cerium and yttrium in a weight ratio of (0.5-1):(0.2-0.5).

[0027] Preferably, the weight ratio of cerium to yttrium is 0.8:0.3.

[0028] A second aspect of the present invention is to provide a method for preparing a crack-resistant copper-rare earth alloy, comprising the following steps:

[0029] S1. Melting: Melt the copper fully according to the mass percentage of the copper rare earth alloy components;

[0030] S2. After the copper melts, raise the smelting temperature to 1400-1500℃ and add titanium, manganese, antimony and zirconium. Then, continue to raise the temperature to 1500-1550℃ and add chromium to continue smelting to obtain a refined liquid.

[0031] S3. Under the condition of 1100-1150℃, after slag removal, continue refining at this temperature for 8-10 minutes, then turn off the power and let it stand for 12-15 minutes. Then add rare earth mixture and let the rare earth mixture enter the bottom of the refining liquid. Then stir evenly, raise the temperature to 1100℃ and keep it warm for casting.

[0032] Preferably, the heat preservation casting is performed by heating the casting furnace to 900-1000℃ and then starting to load the mold for casting, with a casting speed of 260-280 r / min and a pitch of 4-5 mm.

[0033] Preferably, the material after casting is introduced into the drawing process for segregation layer removal, the drawing amount is 0.8-1.4mm, and after drawing, it is straightened by a straightening machine to obtain an ingot.

[0034] Preferably, the copper-rare earth alloy material is obtained by sequentially homogenizing, hot rolling, cold rough rolling, intermediate annealing, cold finish rolling and aging treatment of the ingot.

[0035] Preferably, the homogenization treatment temperature is 920-950℃ for homogenization annealing and holding for 4-6 hours.

[0036] Preferably, the intermediate annealing conditions are annealing at 460±10℃ for 8-10 hours.

[0037] Preferably, the aging treatment is performed by holding the temperature at 520±10℃ for 6-10 hours.

[0038] Preferably, the average particle size of the rare earth mixture is 30-50 μm.

[0039] Example 1

[0040] A method for preparing a crack-resistant copper-rare earth alloy, wherein the copper-rare earth alloy is composed of the following components by mass percentage: 0.5% chromium, 0.2% titanium, 0.2% manganese, 0.8% antimony, 0.2% zirconium, 0.4% rare earth elements, with the balance being copper and unavoidable impurities, wherein the rare earth elements are composed of cerium and yttrium in a weight ratio of 0.5:0.2.

[0041] The preparation method includes the following steps:

[0042] S1. Melting: Melt the copper fully according to the mass percentage of the copper rare earth alloy components;

[0043] S2. After the copper melts, raise the melting temperature to 1400℃ and add titanium, manganese, antimony and zirconium. Then, continue to raise the temperature to 1500℃ and add chromium to continue melting to obtain a refined liquid.

[0044] S3. Under the condition of 1100℃, after slag removal, continue refining at this temperature for 8 minutes, then turn off the power and let it stand for 12 minutes. Then add rare earth mixture with an average particle size of 30μm and let the rare earth mixture enter the bottom of the refining liquid. Then stir evenly and heat to 1100℃ and introduce it into the casting furnace. After heating the casting furnace to 900℃, start loading the mold for casting. The casting speed is 260r / min and the pitch is adjusted to 4-5mm.

[0045] S4. The material after casting is introduced into the drawing process for segregation layer removal. The drawing amount is 0.8mm. After drawing, it is straightened with a straightening machine to obtain the ingot.

[0046] S5. After homogenizing and annealing the ingot obtained in step S4 at 920℃ for 4 hours, hot-roll it to 14mm at 700℃, then cold-roll it to 0.8mm thick, intermediately anneal it at 460±10℃ for 8 hours, cold-roll it to 0.3mm thick, and then age it at 520±10℃ for 6 hours to obtain the copper rare earth alloy material.

[0047] Example 2

[0048] A method for preparing a crack-resistant copper-rare earth alloy, wherein the copper-rare earth alloy is composed of the following components by mass percentage: 0.5% chromium, 0.2% titanium, 0.2% manganese, 0.8% antimony, 0.2% zirconium, 0.4% rare earth elements, with the balance being copper and unavoidable impurities, wherein the rare earth elements are composed of cerium and yttrium in a weight ratio of 0.5:0.2.

[0049] The preparation method includes the following steps:

[0050] S1. Melting: Melt the copper fully according to the mass percentage of the copper rare earth alloy components;

[0051] S2. After the copper melts, raise the melting temperature to 1450℃ and add titanium, manganese, antimony and zirconium. Then, continue to raise the temperature to 1500℃ and add chromium to continue melting to obtain a refined liquid.

[0052] S3. At a temperature of 1120℃, after slag removal, continue refining at this temperature for 8 minutes, then turn off the power and let it stand for 15 minutes. Then add rare earth mixture with an average particle size of 30μm and let the rare earth mixture enter the bottom of the refining liquid. Then stir evenly and heat to 1100℃ before introducing it into the casting furnace. After heating the casting furnace to 950℃, start loading the mold for casting. The casting speed is 270r / min and the pitch is adjusted to 4-5mm.

[0053] S4. The material after casting is introduced into the drawing process for segregation layer removal. The drawing amount is 1.1mm. After drawing, it is straightened with a straightening machine to obtain the ingot.

[0054] S5. After homogenizing and annealing the ingot obtained in step S4 at 940℃ for 5 hours, hot-roll it to 14mm at 800℃, then cold-roll it to 1.0mm thick, intermediately anneal it at 460±10℃ for 9 hours, cold-roll it to 0.5mm thick, and then age it at 520±10℃ for 8 hours to obtain the copper rare earth alloy material.

[0055] Example 3

[0056] A method for preparing a crack-resistant copper-rare earth alloy, wherein the copper-rare earth alloy is composed of the following components by mass percentage: 0.5% chromium, 0.2% titanium, 0.2% manganese, 0.8% antimony, 0.2% zirconium, 0.4% rare earth elements, with the balance being copper and unavoidable impurities, wherein the rare earth elements are composed of cerium and yttrium in a weight ratio of 0.5:0.2.

[0057] The preparation method includes the following steps:

[0058] S1. Melting: Melt the copper fully according to the mass percentage of the copper rare earth alloy components;

[0059] S2. After the copper melts, raise the melting temperature to 1500℃ and add titanium, manganese, antimony and zirconium. Then, continue to raise the temperature to 1550℃ and add chromium to continue melting to obtain a refined liquid.

[0060] S3. At a temperature of 1150℃, after slag removal, continue refining at this temperature for 10 minutes, then turn off the power and let it stand for 15 minutes. Then add rare earth mixture with an average particle size of 30μm and let the rare earth mixture enter the bottom of the refining liquid. Then stir evenly and heat to 1100℃ before introducing it into the casting furnace. After heating the casting furnace to 1000℃, start loading the mold for casting. The casting speed is 280r / min and the pitch is adjusted to 4-5mm.

[0061] S4. The material after casting is introduced into the drawing process for segregation layer removal. The drawing amount is 1.4mm. After drawing, it is straightened with a straightening machine to obtain the ingot.

[0062] S5. After homogenizing and annealing the ingot obtained in step S4 at 950℃ for 6 hours, hot-roll it to 15mm at 920℃, then cold-roll it to 1.0mm thick, intermediately anneal it at 460±10℃ for 10 hours, cold-roll it to 0.5mm thick, and then age it at 520±10℃ for 10 hours to obtain copper rare earth alloy material.

[0063] Example 4

[0064] A method for preparing a crack-resistant copper-rare earth alloy, wherein the copper-rare earth alloy is composed of the following components by mass percentage: 0.9% chromium, 0.3% titanium, 0.3% manganese, 1.2% antimony, 0.5% zirconium, 1.0% rare earth elements, with the balance being copper and unavoidable impurities, wherein the rare earth elements are composed of cerium and yttrium in a weight ratio of 0.5:0.2.

[0065] The preparation method includes the following steps:

[0066] S1. Melting: Melt the copper fully according to the mass percentage of the copper rare earth alloy components;

[0067] S2. After the copper melts, raise the melting temperature to 1450℃ and add titanium, manganese, antimony and zirconium. Then, continue to raise the temperature to 1500℃ and add chromium to continue melting to obtain a refined liquid.

[0068] S3. At a temperature of 1120℃, after slag removal, continue refining at this temperature for 8 minutes, then turn off the power and let it stand for 15 minutes. Then add rare earth mixture with an average particle size of 30μm and let the rare earth mixture enter the bottom of the refining liquid. Then stir evenly and heat to 1100℃ before introducing it into the casting furnace. After heating the casting furnace to 950℃, start loading the mold for casting. The casting speed is 270r / min and the pitch is adjusted to 4-5mm.

[0069] S4. The material after casting is introduced into the drawing process for segregation layer removal. The drawing amount is 1.1mm. After drawing, it is straightened with a straightening machine to obtain the ingot.

[0070] S5. After homogenizing and annealing the ingot obtained in step S4 at 940℃ for 5 hours, hot-roll it to 14mm at 800℃, then cold-roll it to 1.0mm thick, intermediately anneal it at 460±10℃ for 9 hours, cold-roll it to 0.5mm thick, and then age it at 520±10℃ for 8 hours to obtain the copper rare earth alloy material.

[0071] Example 5

[0072] A method for preparing a crack-resistant copper-rare earth alloy, wherein the copper-rare earth alloy is composed of the following components by mass percentage: 1.2% chromium, 0.5% titanium, 0.4% manganese, 1.5% antimony, 0.7% zirconium, 1.5% rare earth elements, with the balance being copper and unavoidable impurities, wherein the rare earth elements are composed of cerium and yttrium in a weight ratio of 0.5:0.2.

[0073] The preparation method includes the following steps:

[0074] S1. Melting: Melt the copper fully according to the mass percentage of the copper rare earth alloy components;

[0075] S2. After the copper melts, raise the melting temperature to 1450℃ and add titanium, manganese, antimony and zirconium. Then, continue to raise the temperature to 1500℃ and add chromium to continue melting to obtain a refined liquid.

[0076] S3. At a temperature of 1120℃, after slag removal, continue refining at this temperature for 8 minutes, then turn off the power and let it stand for 15 minutes. Then add rare earth mixture with an average particle size of 30μm and let the rare earth mixture enter the bottom of the refining liquid. Then stir evenly and heat to 1100℃ before introducing it into the casting furnace. After heating the casting furnace to 950℃, start loading the mold for casting. The casting speed is 270r / min and the pitch is adjusted to 4-5mm.

[0077] S4. The material after casting is introduced into the drawing process for segregation layer removal. The drawing amount is 1.1mm. After drawing, it is straightened with a straightening machine to obtain the ingot.

[0078] S5. After homogenizing and annealing the ingot obtained in step S4 at 940℃ for 5 hours, hot-roll it to 14mm at 800℃, then cold-roll it to 1.0mm thick, intermediately anneal it at 460±10℃ for 9 hours, cold-roll it to 0.5mm thick, and then age it at 520±10℃ for 8 hours to obtain the copper rare earth alloy material.

[0079] Example 6

[0080] A method for preparing a crack-resistant copper-rare earth alloy differs from Example 4 in that the weight ratio of cerium to yttrium in the rare earth elements is 0.8:0.3, while the other elements are the same as in Example 4.

[0081] Example 7

[0082] A method for preparing a crack-resistant copper-rare earth alloy differs from Example 4 in that the weight ratio of cerium to yttrium in the rare earth elements is 1:0.5, while the other elements are the same as in Example 4.

[0083] Example 8

[0084] A method for preparing a crack-resistant copper-rare earth alloy differs from Example 6 in that the average particle size of the rare earth mixture is 40 μm, while the other aspects are the same as in Example 6.

[0085] Example 9

[0086] A method for preparing a crack-resistant copper-rare earth alloy differs from Example 6 in that the average particle size of the rare earth mixture is 50 μm, while the other aspects are the same as in Example 6.

[0087] Comparative Example 1

[0088] A method for preparing a crack-resistant copper-rare earth alloy differs from Example 2 in that the rare earth elements are composed of lanthanum and yttrium in a weight ratio of 0.5:0.2, while the other components are the same as in Example 2.

[0089] Comparative Example 2

[0090] A method for preparing a crack-resistant copper-rare earth alloy differs from Example 2 in that the rare earth elements are composed of praseodymium and yttrium in a weight ratio of 0.5:0.2, while the other components are the same as in Example 2.

[0091] Comparative Example 3

[0092] A method for preparing a crack-resistant copper-rare earth alloy differs from Example 2 in that only cerium is used as the rare earth element, while the others are the same as in Example 2.

[0093] Comparative Example 4

[0094] A method for preparing a crack-resistant copper-rare earth alloy differs from Example 2 in that only yttrium is used as the rare earth element, while the others are the same as in Example 2.

[0095] Comparative Example 5

[0096] A method for preparing a crack-resistant copper-rare earth alloy differs from Example 2 in that the copper-rare earth alloy does not contain antimony, while all other components are the same as in Example 2.

[0097] Performance testing

[0098] The copper-rare earth alloys obtained in the above embodiments and comparative examples were subjected to performance testing, and the test results are shown in Table 1.

[0099] Table 1. Test Results of Copper-Rare Earth Alloy Properties

[0100] project Tensile strength / MPa Elongation / % Yield strength / MPa Example 1 720 10.3 680 Example 2 724 10.8 685 Example 3 722 10.6 683 Example 4 733 11.4 692 Example 5 735 11.0 689 Example 6 736 11.6 693 Example 7 735 11.5 692 Example 8 737 11.7 694 Example 9 735 11.4 692 Comparative Example 1 720 9.3 667 Comparative Example 2 716 9.6 670 Comparative Example 3 706 7.8 654 Comparative Example 4 712 8.3 661 Comparative Example 5 718 9.8 673

[0101] As can be seen from Table 1:

[0102] The copper-rare earth alloys obtained in Examples 1-3 of this application all have tensile strengths of 720 MPa and above, elongation greater than 10%, and yield strength ≥ 680 MPa. This indicates that the copper-rare earth alloys obtained in this application have good tensile strength, yield strength, and elongation. High tensile strength indicates that the copper-rare earth alloy can withstand a large tensile force before fracture. Elongation reflects the plastic deformation capacity of the copper-rare earth alloy before fracture. The higher the elongation, the better the toughness of the copper-rare earth alloy and the correspondingly enhanced crack resistance. Therefore, the copper-rare earth alloys obtained in Examples 1-3 of this application have good crack resistance.

[0103] Compared with Example 2, when the proportion of each component in the copper-rare earth alloy is further increased, the tensile strength, elongation and yield strength of the copper-rare earth alloy obtained in Examples 4-5 are higher than those in Example 2. However, it can be seen from the test data in Example 5 that the elongation and yield strength of the copper-rare earth alloy obtained in Example 5 are lower than those in Example 4. It can be seen that when the mass proportion of each component in the copper-rare earth alloy is within the range of this application, it can effectively ensure that the rare earth alloy has good crack resistance.

[0104] Compared with Example 4, when the total amount of rare earth elements in the copper rare earth alloy remains unchanged, the tensile strength, elongation and yield strength of the copper rare earth alloy obtained in Example 7 are lower than those in Example 6 as the content of rare earth element cerium decreases. Therefore, when the ratio of rare earth elements cerium and yttrium is within the range defined in this application, the copper rare earth alloy can be effectively guaranteed to have good crack resistance.

[0105] Compared with Example 6, as the average particle size of the rare earth mixture increases, the tensile strength, elongation and yield strength of the copper rare earth alloys obtained in Examples 8-9 are not much different from those in Example 6. This indicates that when the average particle size of the rare earth mixture is within the range defined in this application, the absorption rate of rare earth elements can be effectively guaranteed and the burn-off rate can be reduced.

[0106] Compared with Example 2, when the rare earth elements are composed of lanthanum and yttrium, or praseodymium and yttrium, or when only cerium or yttrium is selected as the rare earth elements, the tensile strength, elongation and yield strength of the copper rare earth alloys obtained in Comparative Examples 1-4 are significantly reduced compared with Example 2. It can be seen that the combined use of rare earth elements cerium and yttrium in this application effectively improves the crack resistance of the rare earth alloys.

[0107] Compared with Example 2, when antimony was missing from the copper-rare earth alloy composition, the tensile strength, elongation and yield strength of the rare earth alloy obtained in Comparative Example 5 were reduced compared with Example 2. It can be seen that the addition of antimony to the copper-rare earth alloy can effectively ensure that the copper-rare earth alloy has good crack resistance.

[0108] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A crack-resistant copper-rare earth alloy, characterized in that: The copper-rare earth alloy is composed of the following components in mass percentage: 0.5-1.2% chromium, 0.2-0.5% titanium, 0.2-0.4% manganese, 0.8-1.5% antimony, 0.2-0.7% zirconium, 0.4-1.5% rare earth elements, with the balance being copper and unavoidable impurities. The rare earth elements are composed of cerium and yttrium in a weight ratio of (0.5-1):(0.2-0.5).

2. The crack-resistant copper-rare earth alloy according to claim 1, characterized in that: The weight ratio of cerium to yttrium is 0.8:0.

3.

3. A method for preparing a crack-resistant copper-rare earth alloy as described in claim 1 or 2, characterized in that, The steps include: S1. Melting: Melt the copper fully according to the mass percentage of the copper rare earth alloy components; S2. After the copper melts, raise the smelting temperature to 1400-1500℃ and add titanium, manganese, antimony and zirconium. Then, continue to raise the temperature to 1500-1550℃ and add chromium to continue smelting to obtain a refined liquid. S3. Under the condition of 1100-1150℃, after slag removal, continue refining at this temperature for 8-10 minutes, then turn off the power and let it stand for 12-15 minutes. Then add rare earth mixture and let the rare earth mixture enter the bottom of the refining liquid. Then stir evenly, raise the temperature to 1100℃ and keep it warm for casting.

4. The method for preparing a crack-resistant copper-rare earth alloy according to claim 3, characterized in that: The heat preservation casting process involves heating the casting furnace to 900-1000℃ and then starting to load the mold for casting, adjusting the pitch to 4-5mm.

5. The method for preparing a crack-resistant copper-rare earth alloy according to claim 4, characterized in that: The material after casting is introduced into the drawing process for segregation layer removal. The drawing amount is 0.8-1.4mm. After drawing, it is straightened using a straightening machine to obtain the ingot.

6. The method for preparing a crack-resistant copper-rare earth alloy according to claim 5, characterized in that: The copper-rare earth alloy material is obtained by sequentially homogenizing, hot rolling, cold rough rolling, intermediate annealing, cold finish rolling and aging treatment of the ingot.

7. The method for preparing a crack-resistant copper-rare earth alloy according to claim 6, characterized in that: The homogenization treatment temperature is 920-950℃, and the homogenization annealing is held for 4-6 hours.

8. The method for preparing a crack-resistant copper-rare earth alloy according to claim 6, characterized in that: The intermediate annealing conditions are annealing at 460±10℃ for 8-10 hours.

9. The method for preparing a crack-resistant copper-rare earth alloy according to claim 6, characterized in that: The aging treatment conditions are to keep the temperature at 520±10℃ for 6-10 hours.

10. The method for preparing a crack-resistant copper-rare earth alloy according to claim 3, characterized in that: The average particle size of the rare earth mixture is 30-50 μm.