Method for preparing copper yttrium oxide spherical powder with coating structure
The preparation of copper yttrium oxide spherical powder through vacuum smelting, vacuum atomization, internal oxidation and high temperature reduction processes has solved the problem of uneven distribution of Y2O3 particles, achieved high conductivity and high elongation of ODS-Cu materials, and met the needs of large-scale production.
Patent Information
- Application Number
- CN202211412760.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-11-11
- Publication Date
- 2025-08-08
- Estimated Expiration
- 2042-11-11
AI Technical Summary
The prior art is difficult to achieve mass production of dispersed copper powders of evenly distributed Y2O3 particles, and the traditional methods cannot meet the excellent conductivity and mechanical properties of ODS-Cu bulk materials.
Vacuum smelting, vacuum air atomization, internal oxidation and high-temperature reduction processes are used to prepare copper yttrium oxide spherical powder with a coated structure. Through vacuum smelting, yttrium is uniformly distributed in copper, internal oxidation is formed into Y2O3 and reduced to Cu at high temperature, and ODS-Cu bulk material is formed by field-assisted sintering.
The prepared ODS-Cu powder has good spherical shape and excellent fluidity. The ODS-Cu bulk material has high elongation of more than 50% and high conductivity of 90% IACS under high hardness.
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Figure CN115889793B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of dispersed copper powder preparation, and in particular to a method for preparing copper yttrium oxide spherical powder with a coating structure. Background Art
[0002] Oxide dispersion-strengthened copper (ODS-Cu) is widely used as a heat dissipation material and electrical contact material due to its excellent mechanical properties and electrical conductivity. The uniform distribution of nanoparticles (NPs) in ODS-Cu leads to improved mechanical properties. In recent years, researchers have studied a variety of nanoparticles, such as Al2O3, Y2O3, and ZrO2. Y2O3 has been selected as one of the best candidates due to its high thermodynamic stability and low solubility in Cu. Preparation methods for DS-Cu include mechanical alloying, wet chemical methods, and internal oxidation methods.
[0003] Currently, the preparation of dispersed copper powder faces several challenges: (1) Traditional methods are not suitable for large-scale processing. Mechanical alloying and wet chemical methods are relatively simple and low-cost methods for producing dispersed powders, and their process parameters are easy to control, but neither method can meet the requirements of large-scale powder production. (2) The uniformity of Y2O3 particle distribution is a key factor affecting powder performance, and direct addition methods make it difficult to control the distribution of Y2O3. Summary of the Invention
[0004] In response to the problems raised in the background technology, the present invention studies and designs a method for preparing copper yttrium oxide spherical powder with a coating structure, the purpose of which is to provide a method for preparing copper yttrium oxide spherical powder in which the alloy powder is spherical and the yttrium is evenly distributed in the copper, and the ODS-Cu bulk material prepared from the alloy powder has excellent electrical conductivity and mechanical properties.
[0005] The technical solution of the present invention:
[0006] A method for preparing copper yttrium oxide spherical powder with a coating structure, characterized by comprising the following steps:
[0007] (1) Vacuum melting
[0008] Place yttrium with a higher melting point on the copper ingot and evacuate to 6×10 -3 Pa; arc melting, turning on electromagnetic stirring during the melting process to make yttrium evenly distributed in copper, and finally obtaining copper-yttrium alloy;
[0009] (2) Vacuum air atomization
[0010] The copper-yttrium alloy ingot was placed in a vacuum melting furnace of a gas atomization furnace and vacuumed to 6×10 -3Pa, under vacuum conditions, the molten metal is poured from the smelting furnace into a tundish crucible, and after insulation, it is introduced into a high-pressure gas atomizer, and finally collected by a cyclone separator and sieved to obtain atomized Cu-Y powder;
[0011] (3) Internal oxidation process
[0012] The Cu-Y powder obtained by the above atomization was placed in a ceramic sintering boat and placed in a muffle furnace for internal oxidation under air atmosphere. The temperature was kept for 2 hours to obtain Cu-Y2O3 powder. At this time, a small amount of copper oxide was generated in the powder.
[0013] (4) High temperature reduction
[0014] The powder after internal oxidation was placed in a ceramic sintering boat and placed in a tube furnace for reduction under a high-purity hydrogen atmosphere and kept warm for 2 hours to obtain pure spherical Cu-Y2O3 powder;
[0015] (5) Field-assisted sintering: Pure Cu-Y2O3 powder is added to a graphite mold, and the mold is placed in a spark plasma sintering chamber for pre-compaction. The furnace chamber is then vacuum-treated and sintered. After sintering, a Cu-Y2O3 composite material is obtained.
[0016] In the step (1), the arc striking current is about 100-120A, the melting temperature is set to 1300°C, the melting working current is 300A, the working voltage is 20V, each melting time is maintained at 5 minutes, and the melting is repeated 4 times.
[0017] The model of the gas atomization furnace in the step (ii) is TJQWH-50. To ensure that the copper-yttrium alloy is completely melted, the melting temperature is set to 1350-1450°C.
[0018] In the step (ii), the temperature of the tundish is 1150-1250° C., and the holding time is 7-9 minutes.
[0019] The atomization pressure in the step (2) is 3.5 MPa.
[0020] In step (2), the diameter of the flow guide tube is set to 5 mm to control the powder particle size.
[0021] In the step (3), the muffle furnace model is KSL-1200X, and the internal oxidation temperature is 100-200°C.
[0022] The tubular furnace model in the step (iv) is GSL-1700X, and the reduction temperature is 400-600°C.
[0023] The specific sintering process in step (5) is as follows: set the program to heat up to 600°C at a heating rate of 100°C / min and keep warm for 5 minutes, then heat up to 900°C and keep warm for 5 minutes, and then cool down to room temperature at a cooling rate of 100°C / min. The pre-pressure during sintering is 10 MPa and the maximum pressure is 50 MPa.
[0024] The beneficial effects of the present invention are as follows: the present invention prepares copper-yttrium alloy ingots into copper-yttrium alloy powder through vacuum melting and vacuum gas atomization. The alloy powder obtained by this process is spherical and the yttrium is evenly distributed in the copper; through the internal oxidation and reduction process, Y is oxidized into Y2O3, and then the excess CuO is reduced to Cu. The Y2O3 particles obtained by this process are fine and evenly distributed, and the ODS-Cu powder has good sphericity and excellent fluidity; the ODS-Cu bulk material prepared by using the powder maintains a high hardness of more than 130HV and also has a high elongation of more than 50% and a high conductivity of 90% IACS that other ODS-Cu materials do not have. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 This is a SEM image of the Cu-Y alloy powder obtained after vacuum gas atomization.
[0026] Figure 2 This is the SEM image of Cu-Y2O3 powder after internal oxidation and reduction.
[0027] Figure 3 This is the TEM image of the Cu-Y2O3 powder surface.
[0028] Figure 4 This is a TEM image of the interior of Cu-Y2O3 powder. DETAILED DESCRIPTION
[0029] The present invention will be further described below with reference to specific embodiments.
[0030] Example 1
[0031] The spherical copper yttrium oxide powder in this embodiment is produced by vacuum melting, vacuum gas atomization, low-temperature internal oxidation and high-temperature reduction.
[0032] The preparation method of the spherical copper yttrium oxide powder in this embodiment is as follows:
[0033] 1. Vacuum melting: Place yttrium with a higher melting point on the copper ingot and evacuate to 6×10 -3 Pa; arc melting, arc current 110A. The melting temperature is set to 1300℃, the melting working current is 300A, the working voltage is 20V, each melting time is kept at 5 minutes, and the melting is repeated 4 times. During the melting process, electromagnetic stirring is turned on to ensure that the yttrium is evenly distributed in the copper, and finally a copper-yttrium alloy is obtained.
[0034] 2. Vacuum gas atomization: Place the copper-yttrium alloy ingot in a vacuum melting furnace of a gas atomization furnace (TJQWH-50) and evacuate to 6×10 -3 Under vacuum conditions, the molten metal is poured from the melting furnace into a tundish crucible. After being held warm, it is then fed into a high-pressure gas atomizer, collected by a cyclone separator, and sieved to produce an atomized powder. To ensure complete melting of the copper-yttrium alloy, the melting temperature is set at 1350-1450°C; the tundish temperature is 1150°C, the holding time is 7 minutes, the atomization pressure is set at 3.5 MPa, and the diameter of the draft tube is 5 mm to control the powder particle size.
[0035] 3. Low-temperature internal oxidation process: The Cu-Y powder obtained by the above atomization is placed in a ceramic sintering boat and placed in a muffle furnace (KSL-1200X). Internal oxidation is carried out at 100°C in an air atmosphere and kept warm for 2 hours to obtain Cu-Y2O3 powder. At this time, a small amount of copper oxide is produced in the powder.
[0036] 4. High-temperature reduction: The powder after internal oxidation is placed in a ceramic sintering boat and placed in a tube furnace (GSL-1700X). It is reduced at 400°C in a high-purity hydrogen atmosphere and kept warm for 2 hours to obtain pure spherical Cu-Y2O3 powder.
[0037] 5. Field-Assisted Sintering: Pure Cu-Y2O3 powder is added to a graphite mold and pre-compacted in a spark plasma sintering chamber. The temperature is then raised to 600°C at a rate of 100°C / min and held for 5 minutes. The temperature is then raised to 900°C and held for 5 minutes. The temperature is then lowered to room temperature at a rate of 100°C / min. The pre-pressure during sintering is 10 MPa and the maximum pressure is 50 MPa. The furnace chamber is then vacuum-treated and sintered. After sintering, a Cu-Y2O3 composite material is obtained.
[0038] Example 2:
[0039] The spherical copper yttrium oxide powder in this embodiment is produced by vacuum melting, vacuum gas atomization, low-temperature internal oxidation and high-temperature reduction.
[0040] The preparation method of the spherical copper yttrium oxide powder in this embodiment is as follows:
[0041] 1. Vacuum melting: Place yttrium with a higher melting point on the copper ingot and evacuate to 6×10 -3 Pa; arc melting, arc current 110A. The melting temperature is set to 1300℃, the melting working current is 300A, the working voltage is 20V, each melting time is kept at 5 minutes, and the melting is repeated 4 times. During the melting process, electromagnetic stirring is turned on to ensure that the yttrium is evenly distributed in the copper, and finally a copper-yttrium alloy is obtained.
[0042] 2. Vacuum gas atomization: Place the copper-yttrium alloy ingot in a vacuum melting furnace of a gas atomization furnace (TJQWH-50) and evacuate to 6×10 -3 Under vacuum conditions, the molten metal is poured from the melting furnace into a tundish crucible. After being held warm, it is then fed into a high-pressure gas atomizer, collected by a cyclone separator, and sieved to produce an atomized powder. To ensure complete melting of the copper-yttrium alloy, the melting temperature is set at 1350-1450°C; the tundish temperature is 1200°C, the holding time is 8 minutes, the atomization pressure is set at 3.5 MPa, and the diameter of the draft tube is 5 mm to control the powder particle size.
[0043] 3. Internal oxidation process: The Cu-Y powder obtained by the above atomization is placed in a ceramic sintering boat and placed in a muffle furnace (KSL-1200X). Internal oxidation is carried out at 150°C in an air atmosphere and kept warm for 2 hours to obtain Cu-Y2O3 powder. At this time, a small amount of copper oxide is generated in the powder.
[0044] 4. High-temperature reduction: The powder after internal oxidation is placed in a ceramic sintering boat and placed in a tube furnace (GSL-1700X). It is reduced at 500°C in a high-purity hydrogen atmosphere and kept warm for 2 hours to obtain pure spherical Cu-Y2O3 powder.
[0045] 5. Field-Assisted Sintering: Pure Cu-Y2O3 powder is added to a graphite mold and pre-compacted in a spark plasma sintering chamber. The temperature is then raised to 600°C at a rate of 100°C / min and held for 5 minutes. The temperature is then raised to 900°C and held for 5 minutes. The temperature is then lowered to room temperature at a rate of 100°C / min. The pre-pressure during sintering is 10 MPa and the maximum pressure is 50 MPa. The furnace chamber is then vacuum-treated and sintered. After sintering, a Cu-Y2O3 composite material is obtained.
[0046] Example 3:
[0047] The spherical copper yttrium oxide powder in this embodiment is produced by vacuum melting, vacuum gas atomization, low-temperature internal oxidation and high-temperature reduction.
[0048] The preparation method of the spherical copper yttrium oxide powder in this embodiment is as follows:
[0049] 1. Vacuum melting: Place yttrium with a higher melting point on the copper ingot and evacuate to 6×10 -3 Pa; arc melting, arc current 110A. The melting temperature is set to 1300℃, the melting working current is 300A, the working voltage is 20V, each melting time is kept at 5 minutes, and the melting is repeated 4 times. During the melting process, electromagnetic stirring is turned on to ensure that the yttrium is evenly distributed in the copper, and finally a copper-yttrium alloy is obtained.
[0050] 2. Vacuum gas atomization: Place the copper-yttrium alloy ingot in a vacuum melting furnace of a gas atomization furnace (TJQWH-50) and evacuate to 6×10 -3 Under vacuum conditions, the molten metal is poured from the melting furnace into a tundish crucible. After being held warm, it is then fed into a high-pressure gas atomizer, collected by a cyclone separator, and sieved to produce an atomized powder. To ensure complete melting of the copper-yttrium alloy, the melting temperature is set at 1350-1450°C; the tundish temperature is 1250°C, the holding time is 9 minutes, the atomization pressure is set at 3.5 MPa, and the diameter of the draft tube is 5 mm to control the powder particle size.
[0051] 3. Internal oxidation process: The Cu-Y powder obtained by the above atomization is placed in a ceramic sintering boat and placed in a muffle furnace (KSL-1200X). Internal oxidation is carried out at 200°C in an air atmosphere and kept warm for 2 hours to obtain Cu-Y2O3 powder. At this time, a small amount of copper oxide is generated in the powder.
[0052] 4. High-temperature reduction: The powder after internal oxidation is placed in a ceramic sintering boat and placed in a tube furnace (GSL-1700X). It is reduced at 600°C in a high-purity hydrogen atmosphere and kept warm for 2 hours to obtain pure spherical Cu-Y2O3 powder.
[0053] 5. Field-Assisted Sintering: Pure Cu-Y2O3 powder is added to a graphite mold and pre-compacted in a spark plasma sintering chamber. The temperature is then raised to 600°C at a rate of 100°C / min and held for 5 minutes. The temperature is then raised to 900°C and held for 5 minutes. The temperature is then lowered to room temperature at a rate of 100°C / min. The pre-pressure during sintering is 10 MPa and the maximum pressure is 50 MPa. The furnace chamber is then vacuum-treated and sintered. After sintering, a Cu-Y2O3 composite material is obtained.
[0054] Depend on Figure 1 It can be seen that the Cu-Y alloy powder is spherical and has a somewhat rough surface.
[0055] Depend on Figure 2 It can be seen that the surface of the Cu-Y2O3 powder after internal oxidation and reduction is smooth and the sphericity is better.
[0056] Depend on Figure 3 It can be seen that small Y2O3 particles are attached to the surface of the powder.
[0057] Depend on Figure 4 It can be seen that the Y2O3 particles inside the powder are dispersed and small.
[0058] By the attached Figure 2It can be seen that the surface of the Cu-Y2O3 powder after internal oxidation and reduction is smooth, and its good sphericity can give the powder excellent flow properties. In addition, the small and uniform distribution of Y2O3 particles on the surface of the copper particles can ensure the dispersion of the Y2O3 phase during the sintering process.
[0059] The ODS-Cu bulk materials prepared using this powder maintain a high hardness of about 130HV and also have a high elongation of more than 50% and a high conductivity of 90% IACS that other ODS-Cu materials do not have.
[0060] Table 1. Properties of specimen blocks
[0061]
[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of the essential technical content of the present invention. The essential technical content of the present invention is broadly defined in the scope of the claims of the application. Any technical entity or method completed by others, if it is exactly the same as that defined in the scope of the claims of this application or is an equivalent variation, will be deemed to be included in the scope of the claims.
Claims
1. A method for preparing a copper yttrium oxide composite material, characterized in that: The steps include: (1) Vacuum melting Place yttrium with a higher melting point on the copper ingot and evacuate to 6×10 -3 Pa; arc melting, electromagnetic stirring is turned on during the melting process to make the yttrium evenly distributed in the copper, and finally a copper-yttrium alloy is obtained. The melting temperature is set to 1300 ° C, and the melting time is kept at 5 minutes each time. The melting is repeated 4 times; (2) Vacuum air atomization The copper-yttrium alloy ingot was placed in a vacuum melting furnace of a gas atomization furnace and vacuumed to 6×10 -3 Pa, under vacuum conditions, the molten metal is poured from the smelting furnace into a tundish crucible, and after insulation, it is introduced into a high-pressure gas atomizer, and finally collected by a cyclone separator and sieved to obtain atomized Cu-Y powder; (3) Internal oxidation process The Cu-Y powder obtained by the above atomization was placed in a ceramic sintering boat and placed in a muffle furnace for internal oxidation under air atmosphere. The temperature was kept for 2 hours to obtain Cu-Y2O3 powder. At this time, a small amount of copper oxide was generated in the powder. (4) High-temperature reduction The powder after internal oxidation is placed in a ceramic sintering boat and placed in a tube furnace for reduction under a high-purity hydrogen atmosphere. The temperature is kept for 2 hours to obtain pure spherical Cu-Y2O3 powder with a coating structure. (5) Field-assisted sintering: Pure Cu-Y2O3 powder is added to a graphite mold, and the mold is placed in a spark plasma sintering chamber for pre-compaction, and then the furnace chamber is vacuum-treated and sintered. After sintering, a Cu-Y2O3 composite material is obtained. The specific sintering process is as follows: set the program to heat up to 600℃ at a heating rate of 100℃ / min and keep warm for 5 minutes, then heat up to 900℃ and keep warm for 5 minutes, and then cool to room temperature at a cooling rate of 100℃ / min. The pre-pressure during sintering is 10 MPa and the maximum pressure is 50 MPa.
2. The method for preparing a copper-yttrium oxide composite material according to claim 1, wherein: In step (1), the arc striking current is 100-120 A, the melting working current is 300 A, and the working voltage is 20 V.
3. The method for preparing a copper-yttrium oxide composite material according to claim 1, wherein: The model of the gas atomization furnace in step (ii) is TJQWH-50. To ensure that the copper-yttrium alloy is completely melted, the melting temperature is set to 1350-1450°C.
4. The method for preparing a copper-yttrium oxide composite material according to claim 1, wherein: In step (2), the tundish temperature is 1150-1250°C, and the holding time is 7-9 minutes.
5. The method for preparing a copper-yttrium oxide composite material according to claim 1, wherein: The atomization pressure in the step (2) is 3.5 MPa.
6. The method for preparing a copper-yttrium oxide composite material according to claim 1, wherein: In step (2), the diameter of the flow guide tube is set to 5 mm to control the powder particle size.
7. The method for preparing a copper-yttrium oxide composite material according to claim 1, wherein: In the step (iii), the muffle furnace model is KSL-1200X, and the internal oxidation temperature is 100-200°C.
8. The method for preparing a copper-yttrium oxide composite material according to claim 1, wherein: In the step (iv), the tube furnace model is GSL-1700X, and the reduction temperature is 400-600°C.