Additive manufacturing method of winding part with high electric conductivity and heat conductivity and pure copper winding part

Abstract

The invention discloses an additive manufacturing method of a winding part with high electric conductivity and heat conductivity and a pure copper winding part, and relates to the technical field of additive manufacturing. The method comprises the following steps: establishing a three-dimensional digital model of a winding part; slicing and layering the model, designing a scanning path, and importing the scanning path into control software of electron beam printing equipment; the gun chamber and the forming chamber are vacuumized; preheating the substrate; pure copper powder with the preset thickness is laid on the substrate, and a powder bed is pre-sintered through discrete electron beams; melting a powder layer by using a focused electron beam according to layered scanning data to finish single-layer forming; the formed substrate is lowered by the thickness of one slice, and powder laying and forming operation is repeated until the whole winding part is printed; and naturally cooling to below 50 DEG C under a vacuum condition to obtain the pure copper winding part. The pure copper winding part prepared by the manufacturing method provided by the invention has good electrical conductivity and thermal conductivity, is easy to realize industrialization, and has certain theoretical research value and practical application value.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing, and in particular to an additive manufacturing method for a high-conductivity and heat-conductivity winding part and a pure copper winding part. Background Art

[0002] Windings are parts that are made by winding conductive materials around the motor chip in a certain way. They are composed of multiple coils or coil groups connected together. The main purpose of windings is to generate an electromagnetic field, thereby generating a driving force to rotate the rotor. Electrical conductivity and thermal conductivity have a direct impact on the performance and life of winding parts. Good electrical conductivity ensures that current can flow quickly through the coil, providing efficient power transmission; at the same time, good thermal conductivity helps to transfer the heat generated by induction heating more evenly, avoiding local overheating, thereby protecting the windings from damage and extending their service life.

[0003] Copper is widely used in motor winding manufacturing due to its excellent electrical and thermal conductivity, good chemical stability and corrosion resistance, and its ability to maintain good electrical properties during long-term use. It is currently the most commonly used motor winding material.

[0004] Electron beam selective melting is a powder bed melting additive manufacturing technology that uses a high-energy electron beam as a heat source. It is not restricted by the shape of the parts and can directly form various parts with complex shapes and fine sizes, which can effectively shorten the production cycle of complex parts. In addition, in the molding of highly reflective materials such as pure copper, electron beam selective melting technology has the advantages of high energy utilization, fast production efficiency, low molding stress, and vacuum pollution-free.

[0005] Traditional pure copper winding parts rely on forming methods such as turning, milling, drilling, grinding, and welding, with a long manufacturing cycle and high production cost. The resulting winding parts have low density, poor electrical and thermal conductivity, and short service life. Therefore, there is an urgent need to improve the production process of pure copper winding parts. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide an additive manufacturing method for high-conductivity and high-thermal-conductivity winding parts.

[0007] In order to solve the above problems, the present invention proposes the following technical solutions:

[0008] The present invention provides an additive manufacturing method for a high-conductivity and high-heat-conductivity winding part, comprising the following steps:

[0009] S1. Use 3D modeling software to establish a 3D digital model of the winding parts;

[0010] S2. Use the segmentation software to slice the model into layers and design the scanning path, and import it into the control software of the electron beam printing device;

[0011] S3, placing the pure copper powder and the substrate into the electron beam equipment to complete the leveling preparation, and evacuating the gun chamber and the molding chamber;

[0012] S4, preheating the substrate;

[0013] S5, laying a preset thickness of pure copper powder on the substrate, and pre-sintering the powder bed using a discrete electron beam;

[0014] S6, using a focused electron beam to melt the powder layer according to the layered scanning data to complete single-layer molding;

[0015] S7, lower the molding substrate by one slice thickness, repeat steps S5 to S6, and complete the molding layer by layer until the entire winding part is printed;

[0016] S8. Cool naturally to below 50°C under vacuum conditions to obtain pure copper winding parts.

[0017] Furthermore, in the step S5, the preset thickness is the same as the thickness of the single-layer slice, and the thickness of the single-layer slice is 30 to 80 μm.

[0018] Furthermore, in step S3, the vacuum degree of the molding chamber is ≤10-3Pa, and the vacuum degree of the gun chamber is ≤10-4Pa.

[0019] Furthermore, in step S4, the substrate is preheated at a temperature of 300-500°C.

[0020] Furthermore, in step S4, the scanning speed of the substrate preheating is 10-20 m / s.

[0021] Furthermore, in step S5, the pre-sintering current is 8-16 mA, the defocusing amount is 0.2-0.4 V, and the time is 6-12 s.

[0022] Furthermore, in step S6, the scanning current is 12-20 mA, the scanning speed is 2-4 m / s, and the scanning interval is 80-120 μm.

[0023] Furthermore, in step S2, the scanning path of the electron beam is designed to be a reciprocating unidirectional scanning, and the scanning direction is rotated 90° layer by layer without interfering with each other.

[0024] Furthermore, the step S8 also includes cleaning and recovering residual powder on the surface and gaps of winding parts using a powder recovery system.

[0025] Furthermore, the substrate is made of stainless steel.

[0026] On the other hand, the present invention also provides a pure copper winding part, which is prepared by the above preparation method, and the density of the obtained pure copper winding part is ≧99.5%.

[0027] Compared with the prior art, the technical effects achieved by the present invention include:

[0028] The invention provides an additive manufacturing method for highly conductive and thermally conductive winding parts, which adopts electron beam selective melting 3D printing technology, changes the traditional preparation process of winding parts, and directly completes the preparation of winding parts in one step, greatly shortening the manufacturing cycle and reducing production costs. In addition, pure copper powder has no reflection on the electron beam, and has high energy utilization; the vacuum environment of the chamber and the molding chamber minimizes the absorption of oxygen by the copper material, avoids defects such as oxidation and inclusions in the parts, and improves the density of the product; in addition, the invention provides optimization of the process parameters of electron beam selective melting, which can effectively improve the conductive and thermal conductivity of the winding parts and extend the service life.

[0029] The pure copper winding parts prepared by the manufacturing method provided by the present invention have good electrical conductivity and thermal conductivity, are easy to realize industrialization, and have certain theoretical research value and practical application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A flow chart of the additive manufacturing method for the high electrical and thermal conductive winding parts provided by the present invention;

[0031] Figure 2 This is a physical picture of a pure copper winding part manufactured by the additive manufacturing method for a high-conductivity and thermal-conductivity winding part according to Example 1 of the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0034] It should also be understood that the terms used in this description of the embodiments of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the embodiments of the present invention. As used in the description of the embodiments of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms of "a", "an" and "the" are intended to include plural forms.

[0035] See also Figure 1 , which is a flow chart of the additive manufacturing method of the high electrical and thermal conductivity winding parts provided by the present invention.

[0036] An embodiment of the present invention provides an additive manufacturing method for a high-conductivity and high-thermal-conductivity winding part, comprising the following steps:

[0037] S1. Use 3D modeling software to build a 3D digital model of the winding parts.

[0038] S2. Use the segmentation software to slice the model into layers and design the scanning path, which is then imported into the control software of the electron beam printing device.

[0039] In a specific embodiment, the scanning path of the electron beam is designed to be a reciprocating unidirectional scanning, and the scanning direction is rotated 90° layer by layer without interfering with each other.

[0040] In a specific embodiment, the thickness of a single-layer slice is designed to be 30-80 μm. For example, the thickness of a single-layer slice is 30 μm, 50 μm, 70 μm, or 80 μm.

[0041] S3. Place the pure copper powder and the substrate into the electron beam equipment to complete the leveling preparation, and evacuate the gun chamber and the molding chamber.

[0042] In a specific embodiment, the vacuum degree of the molding chamber is ≤10 -3 Pa, gun chamber vacuum ≤ 10 - 4 Pa, in order to reduce the impact of oxygen and tiny impurities in the air on the product.

[0043] In a specific embodiment, the pure copper powder is prepared by gas atomization method, with a particle size of 45 to 105 μm, and the material of the substrate is stainless steel.

[0044] S4. Preheat the substrate.

[0045] In a specific embodiment, the substrate is preheated by using an electron gun, the scanning speed is 10-20 m / s, and the substrate preheating temperature is 300-500°C.

[0046] S5, laying a preset thickness of pure copper powder on the substrate, and pre-sintering the powder bed using a discrete electron beam;

[0047] In a specific embodiment, the thickness of the powder on the substrate is the same as the thickness of a single-layer slice.

[0048] The pre-sintering current is 8 to 16 mA, the defocusing amount is 0.2 to 0.4 V, and the time is 6 to 12 s.

[0049] S6. Using a focused electron beam, the powder layer is melted according to the layered scanning data to complete the single-layer molding.

[0050] In a specific embodiment, the scanning current is 12-20 mA, the scanning speed is 2-4 m / s, and the scanning interval is 80-120 μm.

[0051] S7, lower the molding substrate by one slice thickness, repeat steps S5 to S6, and complete the molding layer by layer until the entire winding part is printed;

[0052] S8. Cool naturally to below 50°C under vacuum conditions to obtain pure copper winding parts.

[0053] In a specific embodiment, the method further includes utilizing a powder recovery system to clean and recover residual powder on the surface and gaps of winding parts.

[0054] The embodiment of the present invention further provides a pure copper winding part, which is prepared by the above preparation method. The obtained pure copper winding part has a density of ≧99.5% and a thermal conductivity of ≧395.0 W / (m·K) at room temperature.

[0055] The following is a specific example to illustrate the effect of this solution on improving the electrical and thermal conductivity of winding parts and extending the service life by optimizing the process parameters of electron beam selective melting.

[0056] Example 1

[0057] An additive manufacturing method for a high-conductivity and high-thermal-conductivity winding part comprises the following steps:

[0058] (1) Use 3D modeling software to build a 3D digital model of the winding parts.

[0059] (2) Use the segmentation software to cut the digital model into several slices with a thickness of 50 μm, design the scanning path, and then import it into the control software of the electron beam printing equipment.

[0060] (3) Place the pure copper powder and substrate into the electron beam equipment to complete the leveling preparation, close the molding chamber door, and evacuate the molding chamber to a vacuum degree of ≤10 -3 Pa, gun chamber vacuum ≤ 10 -4 Pa.

[0061] (4) The stainless steel substrate was preheated to 400°C using an electron beam. The preheating current was increased from 5 mA to 15 mA over time, and the scanning speed was 20 m / s.

[0062] (5) Pure copper powder with a thickness of 50 μm was laid on the substrate using a scraper, and the powder bed was pre-sintered for 8 s using a 14 mA discrete electron beam to keep the temperature of the powder bed at 400 °C.

[0063] (6) A focused electron beam is used to melt the powder layer according to the layered scanning data to complete the single-layer molding. The scanning current is 15 mA, the scanning speed is 3 m / s, and the scanning interval is 100 μm.

[0064] (7) Lower the molding substrate by one slice thickness, repeat steps (5) to (6), and complete the layer-by-layer molding until the entire winding part is printed.

[0065] (8) After naturally cooling to below 50°C under vacuum conditions and cleaning the residual copper powder using a powder recovery system, pure copper winding parts with high electrical and thermal conductivity can be obtained.

[0066] The pure copper winding parts manufactured in this embodiment are as follows Figure 2 As shown in the figure, it can be seen that the pure copper winding parts have a complete structure, clear edges, good quality, and no defects such as holes, cracks, and unfused parts.

[0067] Example 2

[0068] The additive manufacturing method for high-conductivity and high-thermal-conductivity winding parts provided in this embodiment is different from that in Embodiment 1 in that:

[0069] In step (2), the digital model is cut into a number of slices with a thickness of 30 μm using a segmentation software, and a scanning path is designed, which is then imported into the control software of the electron beam printing device.

[0070] In step (4), the stainless steel substrate is preheated to 500° C. using an electron beam, the preheating current is increased from 5 mA to 15 mA over time, and the scanning speed is 20 m / s.

[0071] In step (5), pure copper powder with a thickness of 30 μm is laid on the substrate using a scraper, and the powder bed is pre-sintered for 6 seconds using a discrete electron beam of 10 mA to keep the temperature of the powder bed at 500° C.

[0072] In step (6), a focused electron beam is used to melt the powder layer according to the layered scanning data to complete single-layer molding. The scanning current is 13 mA, the scanning speed is 3.5 m / s, and the scanning interval is 100 μm.

[0073] Except for the above steps and parameters, the remaining steps and parameters are the same as those in Example 1.

[0074] Example 3

[0075] The additive manufacturing method for high-conductivity and high-thermal-conductivity winding parts provided in this embodiment is different from that in Embodiment 1 in that:

[0076] In step (2), the digital model is cut into a number of slices with a thickness of 80 μm using a segmentation software, and a scanning path is designed, which is then imported into the control software of the electron beam printing device.

[0077] In step (4), the stainless steel substrate is preheated to 300° C. using an electron beam, the preheating current is increased from 5 mA to 15 mA over time, and the scanning speed is 20 m / s.

[0078] In step (5), pure copper powder with a thickness of 80 μm is laid on the substrate using a scraper, and the powder bed is pre-sintered for 10 seconds using a discrete electron beam of 18 mA to keep the temperature of the powder bed at 300° C.

[0079] In step (6), a focused electron beam is used to melt the powder layer according to the layered scanning data to complete single-layer molding. The scanning current is 17 mA, the scanning speed is 2.5 m / s, and the scanning interval is 100 μm.

[0080] Except for the above steps and parameters, the remaining steps and parameters are the same as those in Example 1.

[0081] The same pure copper winding parts were prepared by the method of Examples 1-3. The pure copper windings prepared in Examples 1-3 were tested for performance. The results are shown in Table 1.

[0082] Table 1 Performance results of pure copper winding parts obtained by the methods of Examples 1-3

[0083]

[0084] From the results in Table 1, it can be seen that the additive manufacturing method for high-conductivity and heat-conductivity winding parts provided by the present invention has good density and excellent conductivity and heat-conductivity within the limited process parameter range, which is conducive to extending the service life of the winding. The electron beam selective melting technology can produce pure copper winding parts with complex shapes and fine sizes.

[0085] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0086] The above is a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. An additive manufacturing method for high electrical and thermal conductive winding parts, characterized in that: The following steps are involved: S1. Use 3D modeling software to establish a 3D digital model of the winding parts; S2. Use the segmentation software to slice the model into layers and design the scanning path, and import it into the control software of the electron beam printing device; S3, placing the pure copper powder and the substrate into the electron beam equipment to complete the leveling preparation, and evacuating the gun chamber and the molding chamber; S4, preheating the substrate; S5, laying a preset thickness of pure copper powder on the substrate, and pre-sintering the powder bed using a discrete electron beam; S6, using a focused electron beam to melt the powder layer according to the layered scanning data to complete single-layer molding; S7, lower the substrate by one slice thickness, repeat steps S5 to S6, and complete the layer-by-layer molding until the entire winding part is printed; S8. Naturally cool to below 50°C under vacuum conditions to obtain pure copper winding parts.

2. The additive manufacturing method for high electrical and thermal conductive winding parts according to claim 1, characterized in that: In the step S5, the preset thickness is the same as the thickness of the single-layer slice, and the thickness of the single-layer slice is 30-80 μm.

3. The additive manufacturing method for high electrical and thermal conductive winding parts according to claim 1, characterized in that: In step S3, the vacuum degree of the molding chamber is ≤10 -3 Pa, gun chamber vacuum ≤ 10 -4 Pa.

4. The additive manufacturing method for high electrical and thermal conductive winding parts according to claim 1, characterized in that: In the step S4, the substrate is preheated at a temperature of 300-500°C.

5. The additive manufacturing method for high electrical and thermal conductive winding parts according to claim 1, characterized in that: In the step S5, the pre-sintering current is 8-16 mA, the defocusing amount is 0.2-0.4 V, and the time is 6-12 s.

6. The additive manufacturing method for high electrical and thermal conductive winding parts according to claim 1, characterized in that: In the step S6, the scanning current is 12-20 mA, the scanning speed is 2-4 m / s, and the scanning interval is 80-120 μm.

7. The additive manufacturing method for high electrical and thermal conductive winding parts according to claim 1, characterized in that: In step S2, the scanning path of the electron beam is designed to be a reciprocating unidirectional scanning, and the scanning direction is rotated 90 degrees layer by layer without interfering with each other.

8. The additive manufacturing method for high electrical and thermal conductive winding parts according to claim 1, characterized in that: The step S8 also includes using a powder recovery system to clean and recover residual powder on the surface and gaps of winding parts.

9. The additive manufacturing method for high electrical and thermal conductive winding parts according to claim 1, characterized in that: The substrate is made of stainless steel.

10. A pure copper winding part, characterized in that: The pure copper winding part is manufactured by the additive manufacturing method of the high-conductivity and heat-conductivity winding part according to any one of claims 1 to 9, and the density of the pure copper winding part is ≥ 99.5%.

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