High-performance copper-iron alloy material and preparation method thereof

Abstract

The application discloses a preparation method of high-performance copper-iron alloy material, which comprises the following steps: S1, raw material preparation; S2, powder mixing; S3, cold isostatic pressing; S4, vacuum sintering and degassing; S5, electric arc smelting; and S6, mechanical processing. The preparation method can solve the problems of uneven composition, easy segregation, pores, inclusions and the like in copper-iron alloy smelting, is beneficial to improving the performance of the copper-iron alloy material, and realizes high-purity, high-consistency, high-uniformity and low-cost manufacturing of the copper-iron alloy.

Description

Technical Field

[0001] This invention relates to the field of manufacturing products from metal powder, and specifically to a high-performance copper-iron alloy material and its preparation method. Background Technology

[0002] Copper-iron alloys combine the high electrical and thermal conductivity and good plasticity of copper with the high strength, wear resistance, and magnetic properties of iron. They also possess excellent electromagnetic wave shielding properties, making them promising for applications in electronic communications, rail transportation, marine vessels, aerospace, and defense industries. In recent years, they have attracted widespread attention from researchers. Currently, they are practically used in lead frames for large-scale integrated circuits, overhead conductors for high-speed electrified railway trains, electrical engineering switch bridges, resistance welding electrodes, 5G mobile phone heat sinks, shielding covers, large-size OLED backplane materials, large-size LED display heat sinks, electrical connectors, wireless charging circuit boards, and air conditioning condenser pipes, among others.

[0003] However, copper and iron have significantly different properties, with copper exhibiting a high positive enthalpy and belonging to metastable, immiscible alloys. As shown in the copper-iron alloy phase diagram, copper and iron phases do not undergo solid solution at room temperature, and even at high temperatures, immiscible liquid phases exist. Copper-iron alloys are often referred to as the "oil" and "water" of metallic materials. When preparing copper-iron alloys using traditional smelting methods, the molten metal undergoes a two-phase separation process during cooling and solidification, forming copper-rich and iron-rich regions. This results in compositional segregation, creating a layered structure and ultimately compromising performance. Therefore, preparing large-sized, uniformly composed, segregated copper-iron alloys with fine and evenly distributed iron particles is a significant technical challenge. Currently, CuFe alloys can be prepared using various methods, such as melt spinning and casting, powder metallurgy, mechanical alloying, rapid solidification, and in-situ deformation composite methods. CuFe alloys prepared by melting and casting present numerous challenges in both the melting and casting processes. For instance, when the alloy is melted, it forms two liquid phases, with the Fe phase separated on top of the Cu phase, making it extremely difficult to obtain a homogeneous material. Furthermore, due to its poor fluidity and significant volume shrinkage, and the need for melting in a non-metallic crucible, defects such as porosity and shrinkage inclusions are easily generated. Although secondary addition of CuFe master alloys during the melting process is possible, the process is complex, difficult to control, and often fails to achieve the desired results. To address the segregation problem, powder metallurgy is most commonly used, but because the strength and toughness of the resulting material are inferior to castings and forgings of similar composition, defects often appear during later deformation processes. Additionally, the high cost of die-casting makes it unsuitable for producing large products. Mechanical alloying and rapid solidification are the most frequently used techniques, but mechanical alloying is time-consuming, inefficient, and prone to impurities. Rapid solidification, due to the formation of a solid solution between Cu and Fe during cooling, results in residual Fe in the Cu matrix, which severely damages conductivity. When the Fe content in Cu is 0.05 wt%, the resistivity increases by 50%. The original microstructure of CuFe materials produced by the deformation in-situ composite method typically consists of a Cu matrix with uniformly distributed dendritic or granular Fe phases. After extensive deformation, the Fe phases transform into a fibrous structure. However, to improve the overall performance of CuFe alloys, deformation aging methods are often employed, a complex process currently still under research. Therefore, finding superior CuFe alloy preparation methods to achieve better properties remains a key focus of research in the CuFe alloy field and a crucial technical challenge for researchers to overcome. Summary of the Invention

[0004] To address the above problems, this invention provides a method for preparing high-performance copper-iron alloy materials.

[0005] The technical solution of this invention is: a method for preparing high-performance copper-iron alloy materials, comprising the following steps:

[0006] S1. Raw material preparation:

[0007] According to the weight percentage, Fe powder is 5-50%, and the balance is Cu powder. Weigh out Cu powder and Fe powder.

[0008] The Cu powder has a purity of ≥99.9%, a particle size of 10~150µm, and a loose packing density of 1.60~4.60g / cm³. 3 Electrolytic Cu powder with an oxygen content ≤500ppm;

[0009] The Fe powder has a purity of 99.5%~99.9%, a particle size of 20~100µm, and a loose packing density of 2.60~5.60g / cm³. 3 High-purity water atomized Fe powder with an oxygen content ≤300ppm;

[0010] S2, Powder Mixing:

[0011] The weighed Cu powder and Fe powder from step S1 are loaded into an automatic powder mixer. The mixing time is 1-8 hours. During the mixing process, a protective gas is introduced at a flow rate of 300 Nm³. 3 / h, pressure 0.15~0.5MPa; add process control agent accounting for 0.5~3% of the total mass fraction of Cu powder and Fe powder to obtain mixed powder;

[0012] S3, Cold Isostatic Pressing:

[0013] The mixed powder is cold isostatically pressed at a pressure of 100~500MPa and a holding time of 1~20min to obtain the pressed electrode rod.

[0014] S4. Vacuum sintering degassing:

[0015] The electrode rod obtained in step S3 is initially heated and dried in a vacuum drying oven at a temperature of 50~100℃. The dried electrode rod is then placed into a sintering mold and vacuum sintered for degassing, while simultaneously straightening it using a graphite V-groove mold. Sintering is then carried out from room temperature using a gradient heating method. After heating to 1080℃, the temperature is held for 1~5 hours. Finally, the temperature is lowered to 400℃ in the furnace, and then argon gas is introduced to cool it to 0~75℃ before it is removed from the furnace.

[0016] S5, Electric Arc Melting:

[0017] The electrode rod obtained in step S4 is melted in a vacuum consumable arc furnace for 1-2 hours, wherein the melting current is 1.0-6kA, the arc voltage is 8-30V, and the vacuum degree is controlled at 0.01-0.1mbar. Subsequently, the electrode rod is rapidly cooled to obtain an ingot by simultaneously using two cooling methods: system water cooling and 600mbar argon gas. The rapid cooling time is 20-100min, the cooling water flow rate in the furnace is 30-50L / min, the cooling water inlet temperature is 0-22℃, and the cooling water pressure is 2.0-3.0bar. The argon gas purging flow rate is 10-20L / min, and the pressure is 3.0-5.0bar.

[0018] S6. Machining: Roughly turn the outer diameter of the ingot obtained in step S5, saw the riser and the bottom plate to remove casting defects such as shrinkage cavities, and obtain the finished product.

[0019] Explanation: The above preparation method can solve problems such as uneven composition, segregation, porosity, and inclusions in copper-iron alloy smelting. By selecting electrolytic copper powder and high-purity water-atomized iron powder as raw materials, the powder is pressed to a high density, which best conforms to the principle of close packing. In addition, the pressed powder material has low gas content and few impurities. The use of argon gas flow can effectively remove oxygen, ensuring complete degassing in vacuum sintering, which is beneficial to the stability of the subsequent vacuum self-consuming arc melting process. The CuFe material prepared by vacuum melting has a uniform microstructure, a dispersed Fe phase, low gas content, good ingot appearance, and no obvious defects such as porosity and inclusions in the microstructure. The use of system water cooling plus simultaneous 600mba argon gas cooling can effectively refine the grains and achieve high-precision rapid cooling, so that the Fe phase can be effectively dispersed and the microstructure is fine and uniform, which is beneficial to improving the performance of copper-iron alloy materials and achieving high purity, high consistency, high uniformity, and low-cost manufacturing of copper-iron alloys.

[0020] Furthermore, in step S2, argon or helium is selected as the protective gas.

[0021] Note: Introducing a protective gas can prevent oxidation during powder mixing and avoid compromising the purity of the raw materials.

[0022] Furthermore, in step S3, the diameter of the electrode rod obtained after cold isostatic pressing is 67~71mm and the length is 600~810mm.

[0023] Furthermore, in step S4, the vacuum degree is controlled at 1~3 Pa during the sintering process, and the pressure is 0.1~0.8 MPa when inert argon gas is introduced for protection.

[0024] Note: By adjusting the pressure parameters mentioned above, sintering degassing can be promoted, effectively reducing the formation of porosity.

[0025] Further, in step S4, the gradient heating method is as follows: first, the temperature is increased from room temperature to 500°C at a heating rate of 5~8°C / min, then held at 500°C for 30min, and then increased to 1080°C at a heating rate of 10~12°C / min.

[0026] Note: The above heating method can utilize the melting characteristics of copper-iron alloys for sintering, resulting in better mixing of the two, a more uniform alloy structure, and improved overall alloy performance.

[0027] Further, in step S4, the furnace is cooled to 400°C at a cooling rate of 5~8°C / min, and then argon gas with a flow rate of 8~10L / min is introduced for further cooling. The initial temperature of the argon gas is 80~90°C. For every 20°C decrease in temperature inside the furnace, the temperature of the argon gas decreases by 7~9°C and the flow rate increases by 1~2m / s until cooling is complete.

[0028] Explanation: By setting the above cooling method and argon flow rate, the degassing effect is better during the sintering cooling process. If the argon flow rate and temperature drop too quickly, the degassing effect of the alloy may decrease. If the argon flow rate and temperature drop too slowly, the uniformity of the alloy structure may decrease. At the same time, ensuring complete degassing in vacuum sintering is beneficial to the stability of the subsequent vacuum self-consuming arc melting process.

[0029] Furthermore, in step S5, the temperature inside the vacuum consumable arc furnace is 0~30℃ and the humidity is 20~60%RH; the temperature of the argon gas introduced is 8~10℃ lower than the inlet temperature of the cooling water.

[0030] Note: By setting the above parameters, the influence of the environment on arc melting can be reduced, and the performance of the alloy can be prevented from deteriorating due to environmental factors.

[0031] Furthermore, the process control agent is stearic acid.

[0032] Note: The above process control agent can effectively prevent powder from sticking to the wall of the mixing tank.

[0033] Furthermore, the process control agent is composed of stearic acid powder, graphene powder, and polyaspartic acid in a ratio of 4g:2g:1ml.

[0034] Explanation: The process control agents described above can prevent adhesion while enhancing the mixing effect and uniformity of powders, resulting in better performance of the sintered product. Stearic acid can stabilize and lubricate the metal powder and protect its surface. Graphene, with its hexagonal honeycomb lattice structure, can provide a framework for the initial formation of the alloy during powder mixing and vacuum sintering, creating a synergistic effect with the metal powder. Subsequently, the graphene is removed through degassing, which can improve the various properties of the alloy. Polyaspartic acid has a dispersing effect on the metal and can effectively protect it. At the same time, its synergistic effect can be used as a carrier to allow stearic acid powder and graphene powder to fully exert their respective functions.

[0035] Furthermore, the preparation method of the process control agent is as follows:

[0036] S2-1. Stearic acid powder and graphene powder are mixed and stirred to form a mixture at a stirring speed of 100 r / min; then a current with a frequency of 10 kHz and a current density of 1 kA / m is applied to the mixture. 2 Positive and negative pulse currents;

[0037] S2-2. Add polyaspartic acid dropwise to the mixture at a rate of 5-8% of the mass of polyaspartic acid per min, and adjust the current density at 1 A / min·m. 2 The rate of addition is increased until polyaspartic acid is completely added; then it is dried at 60~120℃, then crushed and ground to a particle size of 0.1~20μm to obtain the process control agent.

[0038] Note: The process control agent obtained by the above preparation method has better performance. By adding positive and negative pulse current, the particle size of the mixed powder can be smaller and the performance can be better. At the same time, due to the excellent electrical properties of graphene, the overall effect of the process control agent can be improved. By adding polyaspartic acid, the mixing effect of the three can be better.

[0039] The beneficial effects of this invention are:

[0040] (1) The preparation method of the present invention can solve the problems of uneven composition, easy segregation, porosity and inclusions in copper-iron alloy smelting; by selecting electrolytic copper powder and high-purity water atomized iron powder as raw materials, the powder is pressed with high density, which best conforms to the principle of close packing; in addition, the powder material has low gas content and few impurities; the use of argon flow can effectively remove oxygen, ensure complete degassing in vacuum sintering, and is conducive to the stability of the subsequent vacuum self-consuming arc melting process. The CuFe material prepared by vacuum melting has a uniform metallographic structure, Fe phase is dispersed, gas content is low, the ingot has a good appearance, and there are no obvious defects of porosity and inclusions in the structure; the system water cooling + synchronous 600mba argon cooling method can effectively refine the grains and achieve high precision and rapid cooling, so that the Fe phase can be effectively dispersed and the metallographic structure is fine and uniform, which is conducive to improving the performance of copper-iron alloy materials and realizing high purity, high consistency, high uniformity and low cost manufacturing of copper-iron alloys.

[0041] (2) By setting the degassing and cooling method and the argon flow rate in the vacuum sintering process, the present invention achieves better degassing effect during the sintering cooling process. If the argon flow rate and temperature drop too quickly, the degassing effect of the alloy may decrease. If the argon flow rate and temperature drop too slowly, the uniformity of the alloy structure may decrease. At the same time, the vacuum sintering degassing is complete, which is beneficial to the stability of the subsequent vacuum self-consuming arc melting process.

[0042] (3) By using process control agents, this invention can prevent adhesion while enhancing the mixing effect and uniformity between powders, resulting in better performance of the sintered product. Stearic acid can stabilize and lubricate the metal powder and protect the surface of the metal powder. Graphene, due to its hexagonal honeycomb lattice structure, can provide a framework for the initial formation of the alloy during the alloy powder mixing process and vacuum sintering process, and produce a synergistic effect with the metal powder. Subsequently, it can be degassed through the degassing process, which can improve the various properties of the alloy. Polyaspartic acid has a dispersing effect on metals and can effectively protect metals. At the same time, its synergistic effect can be used as a carrier to allow stearic acid powder and graphene powder to fully play their respective roles.

[0043] (4) The process control agent prepared by the method of the present invention has better effect. By adding positive and negative pulse current, the particle size of the mixed powder can be smaller and the performance can be better. At the same time, due to the excellent electrical properties of graphene, the overall effect of the process control agent can be improved. By adding polyaspartic acid, the mixing effect of the three can be better. Attached Figure Description

[0044] Figure 1 This is a flowchart of the method of the present invention;

[0045] Figure 2These are comparative images of the ingot appearance of Comparative Example 1 and Example 1 of the present invention;

[0046] Figure 3 This is a 100x magnification metallographic image of Comparative Example 1 of the present invention after etching.

[0047] Figure 4 This is a 100x magnified metallographic image of Embodiment 1 of the present invention after etching;

[0048] Figure 5 This is a 100x magnification metallographic image of Embodiment 2 of the present invention after etching. 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 method for preparing a high-performance copper-iron alloy material includes the following steps:

[0052] S1. Raw material preparation:

[0053] According to the weight percentage, Fe powder is 5% and the balance is Cu powder. Weigh out Cu powder and Fe powder.

[0054] The Cu powder has a purity of 99.9%, a particle size of 10~150µm, and a bulk density of 2g / cm³. 3 Electrolytic Cu powder with an oxygen content of 200 ppm;

[0055] The Fe powder used has a purity of 99.8%, a particle size of 20~100µm, and a loose packing density of 3g / cm³. 3 High-purity water atomized Fe powder with an oxygen content of 200ppm;

[0056] The high-purity water-atomized Fe powder is produced by high-pressure water atomization of molten iron or ferroalloys. The technical parameters of the high-purity water-atomized Fe powder are shown in Table 1.

[0057] Table 1 Technical parameters of high-purity water atomized iron powder

[0058]

[0059] S2, Powder Mixing:

[0060] The weighed Cu powder and Fe powder from step S1 are loaded into an automatic powder mixer. The mixing time is 4 hours, and a protective gas is introduced during the mixing process at a flow rate of 300 Nm³. 3 / h, pressure 0.2MPa; add process control agent accounting for 1% of the total mass fraction of Cu powder and Fe powder to obtain mixed powder; argon is selected as protective gas; the process control agent is stearic acid;

[0061] S3. Cold isostatic pressing: The mixed powder is cold isostatically pressed at a pressure of 200 MPa for 10 min to obtain a pressed electrode rod; the diameter of the electrode rod obtained after cold isostatic pressing is 69 mm and the length is 700 mm.

[0062] S4. Vacuum sintering degassing:

[0063] The electrode rod obtained in step S3 was initially heated and dried in a vacuum drying oven at 70°C. The dried electrode rod was then placed into a sintering mold and vacuum sintered for degassing, while simultaneously straightening it using a graphite V-groove mold. Sintering was then carried out using a gradient heating method starting from room temperature, raising the temperature to 1080°C and holding it for 2 hours. Finally, the temperature was lowered to 400°C in the furnace, and then argon gas was introduced to cool it to 50°C before removing it from the furnace. During the sintering process, the vacuum degree was controlled at 2 Pa, and the pressure of inert argon gas protection was 0.5 MPa. The gradient heating method was: heating to 1080°C at a heating rate of 6°C / min.

[0064] S5, Electric Arc Melting:

[0065] The electrode rod obtained in step S4 was melted in a vacuum consumable arc furnace for 1.5 hours, with a melting current of 2kA, an arc voltage of 20V, and a vacuum level of 0.05mbar. Subsequently, the electrode rod was rapidly cooled to obtain an ingot using both system water cooling and 600mbar argon gas purging. The rapid cooling time was 50 minutes, the furnace cooling water flow rate was 35L / min, the cooling water inlet temperature was 15℃, and the cooling water pressure was 2.5bar. The argon gas purging flow rate was 15L / min, and the pressure was 4.0bar. In the arc melting environment of step S5, the temperature was 20℃, and the humidity was 40%RH. The temperature of the argon gas introduced was 9℃ lower than the cooling water inlet temperature.

[0066] S6. Machining: Roughly turn the outer diameter of the ingot obtained in step S5, saw the riser and the bottom plate to remove casting defects such as shrinkage cavities, and obtain the finished product.

[0067] Example 2

[0068] The difference between this embodiment and embodiment 1 is that the raw material composition in step S1 is different. By weight percentage, Fe powder is 45% and the remainder is Cu powder. Cu powder and Fe powder are weighed.

[0069] Example 3

[0070] The difference between this embodiment and embodiment 1 is that the raw material composition in step S1 is different. By weight percentage, Fe powder is 50% and the remainder is Cu powder. Cu powder and Fe powder are weighed.

[0071] Example 4

[0072] The difference between this embodiment and Embodiment 1 lies in the purity of the raw material components and the condition parameters in steps S1 and S2. In S1, the loose packing density of Cu powder is 1.60 g / cm³. 3 The oxygen content is 100 ppm; the loose density of the iron powder is 2.60 g / cm³. 3 The oxygen content is 300 ppm;

[0073] In step S2: The Cu powder and Fe powder weighed in step S1 are loaded into an automatic powder mixer. The mixing time is 1 hour. During the mixing process, a protective gas is introduced at a flow rate of 300 Nm³. 3 / h, pressure is 0.15MPa; add process control agent accounting for 0.5% of the total mass fraction of Cu powder and Fe powder to obtain mixed powder; helium is selected as protective gas; the process control agent is stearic acid.

[0074] Example 5

[0075] The difference between this embodiment and Embodiment 1 lies in the purity of the raw material components and the condition parameters in steps S1 and S2. In S1, the loose packing density of Cu powder is 4.60 g / cm³. 3 The oxygen content is 500 ppm; the loose density of the iron powder is 5.60 g / cm³. 3 The oxygen content is 300 ppm;

[0076] In step S2: The Cu powder and Fe powder weighed in step S1 are loaded into an automatic powder mixer. The mixing time is 8 hours. During the mixing process, a protective gas is introduced at a flow rate of 300 Nm³. 3 / h, pressure is 0.5MPa; add process control agent accounting for 3% of the total mass fraction of Cu powder and Fe powder to obtain mixed powder; select argon or helium as protective gas; the process control agent is stearic acid.

[0077] Example 6

[0078] The difference between this embodiment and embodiment 1 is that the cold isostatic pressing conditions in step S3 are different. The pressure is 500 MPa and the holding time is 1 min. The diameter of the electrode rod obtained after cold isostatic pressing is 67 mm and the length is 600 mm.

[0079] Example 7

[0080] The difference between this embodiment and embodiment 1 is that the cold isostatic pressing conditions in step S3 are different. The pressure is 100MPa and the holding time is 20min. The diameter of the electrode rod obtained after cold isostatic pressing is 71mm and the length is 810mm.

[0081] Example 8

[0082] The difference between this embodiment and Embodiment 1 lies in the different vacuum sintering degassing conditions in step S4. The electrode rod obtained in step S3 is initially heated and dried in a vacuum drying oven at a temperature of 50°C. The dried electrode rod is then placed into a sintering mold and subsequently vacuum sintered for degassing, while simultaneously straightening it using a graphite V-groove mold. Sintering is then carried out using a gradient heating method starting from room temperature, raising the temperature to 1080°C, holding it at that temperature for 5 hours, and finally cooling it to 400°C in the furnace. After cooling to 75°C, it is then removed from the furnace after being filled with argon gas. During the sintering process, the vacuum degree is controlled at 1 Pa, and the pressure is 0.8 MPa when inert argon gas is used for protection. The gradient heating method involves raising the temperature to 1080°C at a rate of 8°C / min.

[0083] Example 9

[0084] The difference between this embodiment and Embodiment 1 lies in the different vacuum sintering degassing conditions in step S4. The electrode rod obtained in step S3 is initially heated and dried in a vacuum drying oven at a temperature of 100°C. The dried electrode rod is then placed into a sintering mold and subsequently vacuum sintered for degassing, while simultaneously straightening it using a graphite V-groove mold. Sintering is then carried out using a gradient heating method starting from room temperature, raising the temperature to 1080°C, holding it at that temperature for 1 hour, and finally cooling it to 400°C in the furnace. After cooling to 0°C, it is then removed from the furnace after being filled with argon gas. During the sintering process, the vacuum degree is controlled at 3 Pa, and the pressure is 0.1 MPa when inert argon gas is used for protection. The gradient heating method involves raising the temperature to 1080°C at a rate of 5°C / min.

[0085] Example 10

[0086] The difference between this embodiment and Embodiment 1 lies in the different arc melting conditions in step S5. The electrode rod obtained in step S4 is melted in a vacuum consumable arc furnace for 2 hours, with a melting current of 1.0 kA, an arc voltage of 8 V, and a vacuum level of 0.01 mbar. Subsequently, the electrode rod is rapidly cooled to obtain an ingot by simultaneously using system water cooling and 600 mbar argon gas. The rapid cooling time is 20 minutes, the cooling water flow rate in the furnace is 30 L / min, the cooling water inlet temperature is 0°C, and the cooling water pressure is 2.0 bar. The argon gas purging flow rate is 10 L / min, and the pressure is 3.0 bar. In the arc melting environment of step S5, the temperature is 0°C, and the humidity is 20% RH. The temperature of the argon gas introduced is 8°C lower than the cooling water inlet temperature.

[0087] Example 11

[0088] The difference between this embodiment and Embodiment 1 lies in the different arc melting conditions in step S5. The electrode rod obtained in step S4 is melted in a vacuum consumable arc furnace for 1 hour, wherein the melting current is 6kA, the arc voltage is 30V, and the vacuum degree is controlled at 0.1mbar. Subsequently, the electrode rod is rapidly cooled to obtain an ingot by simultaneously using two cooling methods: system water cooling and argon gas charging at 600mbar. The rapid cooling time is 100min, the cooling water flow rate of the furnace is 50L / min, the cooling water inlet temperature is 22℃, and the cooling water pressure is 3.0bar. The argon gas purging flow rate is 20L / min, and the pressure is 5.0bar. In the arc melting environment of step S5, the temperature is 30℃, and the humidity is 60%RH. The temperature of the argon gas introduced is 10℃ lower than the cooling water inlet temperature.

[0089] Example 12

[0090] The difference between this embodiment and embodiment 1 is that in step S4, the gradient heating method is as follows: first, the temperature is increased from room temperature to 500°C at a heating rate of 6°C / min, then held at 500°C for 30 minutes, and then increased to 1080°C at a heating rate of 11°C / min.

[0091] Example 13

[0092] The difference between this embodiment and embodiment 12 is that in step S4, the gradient heating method is as follows: first, the temperature is increased from room temperature to 500°C at a heating rate of 8°C / min, then held at 500°C for 30 minutes, and then increased to 1080°C at a heating rate of 12°C / min.

[0093] Example 14

[0094] The difference between this embodiment and embodiment 12 is that in step S4, the gradient heating method is as follows: first, the temperature is increased from room temperature to 500°C at a heating rate of 5°C / min, then held at 500°C for 30 minutes, and then increased to 1080°C at a heating rate of 10°C / min.

[0095] Example 15

[0096] The difference between this embodiment and embodiment 12 is that in step S4, the furnace is cooled to 400°C at a cooling rate of 6°C / min, and then argon gas with a flow rate of 9L / min is introduced for further cooling. The initial temperature of the argon gas is 85°C. For every 20°C decrease in temperature inside the furnace, the temperature of the argon gas decreases by 8°C and the flow rate increases by 1.5L / min until cooling is complete.

[0097] Example 16

[0098] The difference between this embodiment and embodiment 15 is that in step S4, the furnace is cooled to 400°C at a cooling rate of 5°C / min, and then argon gas with a flow rate of 10L / min is introduced for further cooling. The initial temperature of the argon gas is 90°C. For every 20°C decrease in temperature inside the furnace, the temperature of the argon gas decreases by 9°C and the flow rate increases by 2L / min until cooling is complete.

[0099] Example 17

[0100] The difference between this embodiment and embodiment 15 is that in step S4, the furnace is cooled to 400°C at a cooling rate of 8°C / min, and then argon gas with a flow rate of 8L / min is introduced for further cooling. The initial temperature of the argon gas is 80°C. For every 20°C decrease in temperature inside the furnace, the temperature of the argon gas decreases by 7°C and the flow rate increases by 1L / min until cooling is complete.

[0101] Example 18

[0102] The difference between this embodiment and Embodiment 15 is that the process control agent is composed of stearic acid powder, graphene powder, and polyaspartic acid in a ratio of 4g:2g:1ml.

[0103] The preparation method of the process control agent is as follows: S2-1, Stearic acid powder and graphene powder are mixed and stirred to form a mixture at a stirring speed of 100 r / min; then, a current density of 1 kA / m is applied to the mixture at a frequency of 10 kHz. 2 Positive and negative pulse currents;

[0104] S2-2. Polyaspartic acid is added dropwise to the mixture at a rate of 6% / min (based on the mass of polyaspartic acid), and the current density is adjusted to 1 A / min·m. 2 The rate of addition is increased until polyaspartic acid is completely added; then it is dried at 80°C, crushed and ground to a particle size of 0.1~20μm to obtain the process control agent.

[0105] Example 19

[0106] The difference between this embodiment and Embodiment 18 is that, in S2-2, polyaspartic acid is added dropwise to the mixture at a rate of 5% / min by mass of polyaspartic acid, and the current density is adjusted to 1 A / min·m. 2 The rate of addition is increased until polyaspartic acid is completely added; then it is dried at 120°C.

[0107] Example 20

[0108] The difference between this embodiment and Embodiment 18 is that, in S2-2, polyaspartic acid is added dropwise to the mixture at a rate of 8% / min of the mass of polyaspartic acid, and the current density is adjusted to 1 A / min·m. 2The rate of addition is increased until polyaspartic acid is completely added; then it is dried at 60°C.

[0109] Experimental Example

[0110] I. Testing of CuFe alloy:

[0111] Comparative Example 1:

[0112] Using the same raw materials and parameters as in Example 1, a CuFe alloy was prepared by vacuum consumable arc melting in the prior art, with helium protection melting and system water cooling, as Comparative Example 1;

[0113] 1. Compare the appearance of the ingots obtained in Example 1 with those obtained in Comparative Example 1.

[0114] like Figure 2 As shown, the outer circle and riser of the ingot in Comparative Example 1 were severely oxidized and blackened; the outer circle and riser of the ingot in Example 1 showed the normal color of copper alloy material.

[0115] 2. The metallographic structures of the ingot surfaces obtained in Example 1 and Comparative Example 1 were analyzed and compared:

[0116] A mixed solution of H2O, HCl, and FeCl3 was prepared in a ratio of 100 mL: 50 mL: 5 g. The finished products of Example 1 and Comparative Example 1 were immersed and etched for 6 seconds and then removed. The second phase Fe dendrites were then visible as uniformly distributed on the matrix.

[0117] like Figure 3 As shown, the CuFe alloy in Comparative Example 1 exhibits severe Fe phase segregation and structural defects such as porosity and inclusions.

[0118] like Figure 4 , 5 As shown, in Example 1, the Fe phase in the CuFe alloy microstructure is uniformly and diffusely distributed, and no microstructural defects such as pores or inclusions are observed.

[0119] II. Tests were conducted on the CuFe alloys obtained in Examples 1-18: 1. The effect of different raw material components on the gas composition generated during the preparation of CuFe alloys was investigated; the gas content detection results are shown in Table 2.

[0120] Table 2. Effects of different raw material components on the gas content generated during CuFe alloy preparation.

[0121]

[0122] As shown in Table 2, compared with Examples 2 and 3, Example 1 has a lower gas content and a more preferred composition.

[0123] 2. Investigate the effects of different raw materials and mixing parameters on the properties of the obtained CuFe alloy;

[0124] Take a CuFe alloy and measure the Fe composition values ​​V1 and V2 at the top and bottom ends of the finished product, respectively. Then, use the percentage difference between the Fe composition values ​​(V1-V) + (V2-V) / V as the deviation value.

[0125] Example 1, Example 4 and Example 5 are compared, as shown in Table 3;

[0126] Table 3. Test results of CuFe alloys obtained under different raw materials and mixing parameters.

[0127]

[0128] By comparing Examples 1, 4 and 5 in Table 3, it can be found that Example 1 has a lower deviation value and a very low degree of segregation, resulting in a better uniformity of the CuFe alloy. At the same time, the porosity is low, indicating that the preparation method of Example 1 can avoid porosity inclusions to a certain extent. Therefore, the process parameters of Example 1 are more optimized.

[0129] 3. Investigate the effects of different cold isostatic pressing conditions on the properties of the obtained CuFe alloy;

[0130] Comparisons were made between Examples 1 and Examples 6-7, as shown in Table 4.

[0131] Table 4. Experimental results of CuFe alloy properties under different cold isostatic pressing conditions.

[0132]

[0133] By comparing Examples 1, 6, and 7 in Table 4, it can be concluded that the CuFe alloy prepared using Example 1 has superior performance.

[0134] 4. Investigate the effects of different vacuum sintering degassing conditions on the properties of the obtained CuFe alloy;

[0135] Examples 1, 8-9, and 12-17 were compared, as shown in Table 5.

[0136] Table 5. Experimental results of CuFe alloy properties under different vacuum sintering and degassing conditions.

[0137]

[0138] By comparing Examples 1 and 8-9 with Table 5, it can be concluded that the CuFe alloy obtained by using the vacuum sintering degassing conditions and parameters of Example 1 has better performance. By comparing Examples 1 and 12-14, it can be seen that the method and conditions and parameters set in Example 12 are better. By comparing Examples 12 and 15, it can be seen that the processing method of Example 15 is more preferred. By comparing Examples 15-17, it can be seen that the parameters of Example 15 are better.

[0139] 5. Investigate the effects of different electric arc melting conditions on the properties of the obtained CuFe alloy;

[0140] Comparisons were made between Examples 1 and Examples 10-11, as shown in Table 6.

[0141] Table 6. Experimental results of CuFe alloy properties under different arc melting conditions.

[0142]

[0143] By comparing Example 1, Example 10, and Example 11 in Table 6, it can be concluded that Example 1 has better performance.

[0144] 6. Investigate the effects of different process control agents on the properties of the obtained CuFe alloy;

[0145] Examples 18-20 were compared, as shown in Table 7;

[0146] Table 7 Experimental results of CuFe alloy properties affected by different process control agents

[0147]

[0148] By comparing Example 1 and Example 18 in Table 7, it can be concluded that the CuFe alloy obtained by using the process control agent used in Example 18 has better performance; by comparing Examples 18 to 20, it can be seen that the parameters of Example 18 are more preferred.

Claims

1. A method for preparing a high-performance copper-iron alloy material, characterized in that, Includes the following steps: S1. Raw material preparation: According to the weight percentage, Fe powder is 5-50%, and the balance is Cu powder. Weigh out Cu powder and Fe powder. The Cu powder has a purity of ≥99.9%, a particle size of 10~150µm, and a loose packing density of 1.60~4.60g / cm³. 3 Electrolytic Cu powder with an oxygen content ≤500ppm; The Fe powder has a purity of 99.5%~99.9%, a particle size of 20~100µm, and a bulk density of 2.60~5.60g / cm³. 3 High-purity water atomized Fe powder with an oxygen content ≤300ppm; S2, Powder Mixing: The Cu powder and Fe powder weighed in step S1 are loaded into an automatic powder mixer. The mixing time is 1-8 hours. During the mixing process, a protective gas is introduced at a flow rate of 300 Nm³. 3 / h, pressure 0.15~0.5MPa; add process control agent accounting for 0.5~3% of the total mass fraction of Cu powder and Fe powder to obtain mixed powder; The process control agent is composed of stearic acid powder, graphene powder, and polyaspartic acid in a ratio of 4g:2g:1ml; the preparation method of the process control agent is as follows: S2-1. Stearic acid powder and graphene powder are mixed and stirred to form a mixture at a stirring speed of 100 r / min; then a current with a frequency of 10 kHz and a current density of 1 kA / m is applied to the mixture. 2 Positive and negative pulse currents; S2-2. Add polyaspartic acid dropwise to the mixture at a rate of 5-8% of the mass of polyaspartic acid per min, and adjust the current density at 1 A / min·m. 2 The rate of addition is increased until polyaspartic acid is completely added; then it is dried at 60~120℃, then crushed and ground to a particle size of 0.1~20μm to obtain the process control agent; S3, Cold Isostatic Pressing: The mixed powder is cold isostatically pressed at a pressure of 100~500MPa and a holding time of 1~20min to obtain the pressed electrode rod. S4. Vacuum sintering degassing: The electrode rod obtained in step S3 is initially heated and dried in a vacuum drying oven at a temperature of 50~100℃. The dried electrode rod is then placed into a sintering mold and vacuum sintered for degassing, while simultaneously straightening it using a graphite V-groove mold. Sintering is then carried out from room temperature using a gradient heating method. After heating to 1080℃, the temperature is held for 1~5 hours. Finally, the temperature is lowered to 400℃ in the furnace, and then argon gas is introduced to cool it to 0~75℃ before it is removed from the furnace. S5, Electric Arc Melting: The electrode rod obtained in step S4 is melted in a vacuum consumable arc furnace for 1-2 hours, wherein the melting current is 1.0-6kA, the arc voltage is 8-30V, and the vacuum degree is controlled at 0.01-0.1mbar. Subsequently, the electrode rod is rapidly cooled to obtain an ingot by simultaneously using two cooling methods: system water cooling and 600mbar argon gas. The rapid cooling time is 20-100min, the cooling water flow rate in the furnace is 30-50L / min, the cooling water inlet temperature is 0-22℃, and the cooling water pressure is 2.0-3.0bar. The argon gas purging flow rate is 10-20L / min, and the pressure is 3.0-5.0bar. S6. Machining: Roughly turn the outer diameter of the ingot obtained in step S5, saw the riser and the bottom plate to remove casting defects such as shrinkage cavities, and obtain the finished product.

2. The method for preparing a high-performance copper-iron alloy material as described in claim 1, characterized in that, In step S2, argon or helium is selected as the protective gas.

3. The method for preparing a high-performance copper-iron alloy material as described in claim 1, characterized in that, In step S3, the diameter of the electrode rod obtained after cold isostatic pressing is 67~71mm and the length is 600~810mm.

4. The method for preparing a high-performance copper-iron alloy material as described in claim 1, characterized in that, In step S4, the vacuum level is controlled at 1~3 Pa during sintering, and the pressure is 0.1~0.8 MPa when argon gas is introduced for protection.

5. The method for preparing a high-performance copper-iron alloy material as described in claim 1, characterized in that, In step S4, the gradient heating method is as follows: first, the temperature is increased from room temperature to 500℃ at a heating rate of 5~8℃ / min, then held at 500℃ for 30min, and then increased to 1080℃ at a heating rate of 10~12℃ / min.

6. The method for preparing a high-performance copper-iron alloy material as described in claim 5, characterized in that, In step S4, the furnace is cooled to 400°C at a rate of 5-8°C / min. Then, argon gas with a flow rate of 8-10 L / min is introduced for further cooling. The initial temperature of the argon gas is 80-90°C. For every 20°C decrease in temperature inside the furnace, the temperature of the argon gas decreases by 7-9°C and the flow rate increases by 1-2 L / min until cooling is complete.

7. The method for preparing a high-performance copper-iron alloy material as described in claim 1, characterized in that, In step S5, the temperature inside the vacuum self-consuming arc melting furnace is 0~30℃ and the humidity is 20~60%RH; the temperature of the argon gas introduced is 8~10℃ lower than the inlet temperature of the cooling water.

8. The method for preparing a high-performance copper-iron alloy material as described in claim 1, characterized in that, The process control agent is stearic acid.

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