A thin-walled helical antenna of copper alloy

Abstract

This invention relates to the field of thin-walled helical antenna technology, specifically to a high-precision small thin-walled helical antenna made of copper alloy and its application. The copper alloy thin-walled helical antenna is made of CuCrZr alloy and is fabricated by 3D printing. The raw material used in 3D printing is micro-oxidized CuCrZr alloy powder, which contains 0.5%~1.5% Cr, 0.05%~0.25% Zr, 0.02%~0.12% O by mass percentage, with the remainder being Cu. This invention achieves integrated fabrication of small, high-precision, thin-walled, complex structure antennas with high strength and excellent electrical and thermal conductivity. It solves the problem of difficulty in manufacturing thin-walled helical structures using traditional machining methods, as well as the challenges of low surface precision and poor metallurgical quality in copper alloy laser printing. The process is simple, low-cost, and produces high-quality prints, making it widely applicable to the production and manufacturing of copper alloys and high-precision thin-walled components.

Description

Technical Field

[0001] This invention relates to the field of thin-walled spiral antenna technology, specifically to a high-precision copper alloy miniature thin-walled spiral antenna and its applications. Background Technology

[0002] Antennas are devices that transmit and receive electromagnetic signals. As a key component of radio wave communication systems, they occupy an important position in spacecraft. Spacecraft operate in space regions at altitudes of hundreds to tens of thousands of kilometers above the Earth, and deep space probes have even wider orbital ranges. Therefore, spaceborne antennas are generally installed outside the spacecraft body and are directly affected by the space environment, placing high demands on their performance and reliability. Spaceborne antennas must meet the specific requirements for fulfilling their mission, namely, specific electrical performance, a reasonable structural form, and reasonable structural strength, and be able to operate normally in the harsh space environment. With the rapid development of commercial spaceflight, spaceborne antennas are evolving towards integration, miniaturization, high performance, and high reliability.

[0003] The quad-arm helical antenna, characterized by its wide bandwidth, small size, high gain, and applicability to multiple frequencies, is a high-performance communication antenna. With increasing demand for complex antenna structures, traditional manufacturing processes are gradually becoming insufficient. Additive manufacturing (AM) technology has brought new opportunities for the production of small, complex antenna structures. Copper alloys, with their high strength and high conductivity, are often used as the core material in antenna design. However, due to copper's excellent thermal conductivity and reflectivity, its absorption rate is low during laser melting, making it difficult for the laser to continuously melt copper powder. This leads to problems such as low forming efficiency, low dimensional accuracy, and difficulty in controlling metallurgical quality. Therefore, it is necessary to find a new 3D printing method to achieve high-precision manufacturing of small, thin-walled helical copper alloy structures. Summary of the Invention

[0004] To address the challenges of 3D printing manufacturing of copper alloy four-arm spiral antennas, this invention proposes for the first time a high-precision copper alloy miniature thin-walled spiral antenna prepared by 3D printing and its application. This effectively solves the requirements of satellite antenna products for miniaturization, thin-walled spiral structure, and high strength and high conductivity. The manufacturing process is simple and industrializable.

[0005] This invention discloses a thin-walled copper alloy helical antenna. The antenna is made of CuCrZr alloy and is fabricated by 3D printing. During 3D printing, the raw material used is micro-oxidized CuCrZr alloy powder, wherein the oxygen content in the micro-oxidized CuCrZr alloy powder is 0.02%~0.12% by mass, preferably 0.03%~0.08%, and more preferably 0.03%~0.06%. In this invention, controlling the oxygen content in the raw material powder is necessary to balance the powder laser absorption rate and the size and distribution of dispersed oxides in the alloy. If the oxygen content is too high, it will lead to poor powder melting effect and difficulty in obtaining nanoscale oxide phases in the alloy structure. If the oxygen content is too low, it will lead to low powder laser absorption rate, low forming density, and surface blackening.

[0006] The micro-oxidized CuCrZr alloy powder of the present invention comprises, by mass percentage: Cr 0.5%~1.5%, preferably 0.5%~1.0%, more preferably 0.5%~0.8%; Zr 0.05%~0.25%, preferably 0.10%~0.25%, more preferably 0.15%~0.25%; O 0.02%~0.12%, with the remainder being Cu.

[0007] This invention discloses a copper alloy thin-walled helical antenna, wherein the dimensional accuracy of the copper alloy thin-walled helical antenna is controlled within 0.05~0.1mm, and the surface roughness reaches Ra3.2~6.3μm. The technology developed by this invention can control the dimensional accuracy within ±0.1mm and the surface roughness within Ra6.3μm even for industrial applications.

[0008] The present invention discloses a copper alloy thin-walled helical antenna, wherein the length and width of the helical structure cross-section of the copper alloy thin-walled helical antenna are 1~2mm and 2~4mm respectively, the diameter of the central axis hole is 3~8mm, and the wall thickness of the central axis is 1~3mm.

[0009] This invention discloses a thin-walled copper alloy helical antenna, wherein the 3D printing process includes the following steps:

[0010] Step 1: Preparation of micro-oxidation powder

[0011] CuCrZr alloy powder was prepared using gas atomization powder preparation technology, and fine-particle powder was obtained by sieving. Then, micro-oxidation treatment was performed to obtain micro-oxidized powder for 3D printing.

[0012] Step 2: Preheating

[0013] The micro-oxidized powder is preheated to temperature A, and then placed in the powder hopper of the SLM printing equipment to preheat the printing substrate to temperature B.

[0014] Step 3: High-precision printing

[0015] A spiral contour scanning strategy is used for powder SLM printing, and in-situ laser remelting scanning is performed directly on the original printed structure to obtain high-precision printed parts.

[0016] Step 4: Time-sensitive processing

[0017] The printed parts are aged to obtain high-performance antenna products.

[0018] The present invention discloses a copper alloy thin-walled helical antenna. In step one, the fine-particle powder is a powder with a particle size of 5-35 mm.

[0019] The present invention discloses a copper alloy thin-walled spiral antenna. In step one, the micro-oxidation treatment involves placing fine-particle powder in a mixer for heating and mixing. The heating temperature is 50~400℃, preferably 150~350℃, and even more preferably 200~350℃, and the mixing time is 5~20min.

[0020] This invention discloses a thin-walled helical antenna made of copper alloy. In step two, the preheating treatment involves placing the powder raw material in a vacuum drying oven and heating it to temperature A. The preheating temperature of the printed substrate is B, where A = BC. A is 200~350℃, B is 250~400℃, and C is 20~50℃.

[0021] In step three of this invention, a thin-walled spiral antenna made of copper alloy is formed by scanning the spiral contour layer by layer from the outside to the inside of the contour using a curved scanning path.

[0022] In step three of this invention, the in-situ laser remelting scan is performed by performing a second laser scan on the solidified metal surface directly at the original printing location after the laser scan melts the powder.

[0023] This invention discloses a thin-walled helical antenna made of copper alloy. In step three, the SLM (Silicon-Laser Laminate) is used for forming. The printing parameters are: layer thickness 0.02~0.05mm, scanning speed 600~1000mm / s, scanning spacing 0.04~0.12mm, and laser power 320~420W. In industrial applications, the parameters for the second scan can be the same as those for the first scan.

[0024] In step four of this invention, the aging treatment is performed by holding the temperature at 400-600℃ for 0.5-2 hours and then cooling it with the furnace.

[0025] The copper alloy thin-walled helical antenna designed and manufactured in this invention has applications including its use as a communication antenna for satellite navigation.

[0026] Principles and advantages

[0027] This invention discloses a high-precision 3D printing manufacturing method for small thin-walled spiral antennas made of copper alloy. The process presents two main challenges: First, dimensional accuracy control. While existing SLM (Surface Mount Technology) components can generally achieve dimensional accuracy within 0.1~0.3 mm and surface roughness of Ra 6.3 μm, the high thermal conductivity and high coefficient of thermal expansion of copper alloys can easily lead to molten pool instability and localized stress concentration during SLM forming, resulting in defects such as porosity, deformation, and cracks, making dimensional accuracy difficult to control. Second, due to the low laser absorption rate, high laser reflectivity, and high thermal conductivity of CuCrZr alloys, problems such as large spatter, low forming density, and surface blackening are prone to occur in the SLM process, severely affecting metallurgical quality and making it difficult to guarantee the structural strength and electrical and thermal conductivity of the product.

[0028] This invention proposes a printing manufacturing method consisting of "fine powder - micro-oxidation treatment - preheating - spiral contour scanning - remelting printing - aging treatment". By ensuring the dimensional accuracy of the product through the preheating - spiral contour scanning - remelting printing process and achieving high strength and high conductivity through the design and synergistic optimization of the fine powder - micro-oxidation treatment - printing process scheme, high-precision and high-performance manufacturing of small thin-walled copper alloy spiral antennas can be achieved, meeting the needs of satellite-borne applications.

[0029] The specific principle is as follows: To achieve high-precision and high-performance manufacturing of small thin-walled helical antennas made of copper alloy, this invention improves printing accuracy by first preheating the printing platform and raw material powder to improve the fluidity of the metal powder and reduce defects such as spheroidization, warping, and cracking during powder melting and cooling, thereby improving dimensional accuracy. Using fine powder with a high powder bed density reduces powder sintering shrinkage and melt sinking, which is beneficial for controlling dimensional accuracy. The process of preheating-helical contour scanning-remelting printing is employed. On the one hand, the contour is scanned layer by layer from the outside in, resulting in a small temperature gradient and the absence of sharp corners in the spherical scanning, greatly reducing stress concentration and warping deformation of the formed part. On the other hand, preheating-remelting printing improves the thermal conductivity of the powder, enhances flow diffusion and wetting, avoids sintering voids and warping deformation, and improves forming quality. Remelting printing after printing repairs defects such as burrs and voids on the surface of the printed sample, while significantly improving surface smoothness, achieving a printing accuracy of less than 0.1 mm.

[0030] From the perspective of achieving high performance, the laser absorption rate of copper alloy powder is first improved by fine powder + pre-oxidation treatment to avoid defects such as unmelted powder, pores, and low density in SLM forming, thereby improving the metallurgical quality of the product. Then, the micro-oxidation-direct aging treatment causes the ZrO2 nanophase to precipitate in the printed alloy. The large number of nano-precipitated phases are dispersed in the alloy, which simultaneously improves the room temperature and high temperature mechanical properties of the alloy.

[0031] Compared with existing methods, the advantages of the present invention are:

[0032] 1) The present invention provides a high-precision copper alloy small thin-walled spiral antenna 3D printing manufacturing method, which solves the problem that small thin-walled spiral structures cannot be directly processed and manufactured by CNC. Its preparation process is based on ordinary laser printing technology, and the powder raw material is based on existing CuCrZr alloy powder. It has low cost, simple process, is suitable for industrialization, and meets the aerospace cost reduction and efficiency improvement requirements.

[0033] 2) The preheating-spiral contour scanning-remelting printing process of the present invention solves the problem of low printing accuracy of SLM. Through process coordination and optimization, high-precision manufacturing of small thin-walled spiral antennas of copper alloy is achieved, with dimensional accuracy reaching 0.05~0.1mm, breaking through the printing capability of existing products with an accuracy of 0.1~0.3mm. At the same time, the surface finish is high, meeting the application requirements of antenna products.

[0034] 3) The fine powder pre-oxidation printing-aging treatment method of the present invention ensures high-quality forming of copper alloy under high laser absorption rate. At the same time, through micro-oxidation control, oxide dispersion strengthening nanophase is generated in situ, realizing high-performance manufacturing of copper alloy products and meeting the requirements of antenna satellite mounting. Attached Figure Description

[0035] Figure 1 This is a small thin-walled copper alloy spiral antenna obtained in Embodiment 1 of the present invention.

[0036] Figure 2 This is a schematic diagram of the voltage standing wave ratio of the antenna obtained in Embodiment 1 of the present invention.

[0037] Figure 3 This is a schematic diagram of the axial ratio radiation pattern of the antenna obtained in Embodiment 1 of the present invention at 2200MHz.

[0038] Figure 4 This is a schematic diagram of the axial ratio radiation pattern of the antenna obtained in Embodiment 1 of the present invention at 2250MHz.

[0039] Figure 5 This is a schematic diagram of the axial ratio radiation pattern of the antenna obtained in Embodiment 1 of the present invention at 2300MHz.

[0040] Figure 6 This is the main polarization pattern of the antenna obtained in Embodiment 1 of the present invention at 2200MHz.

[0041] Figure 7 This is the cross-polarization pattern of the antenna obtained in Embodiment 1 of the present invention at 2200MHz.

[0042] Figure 8 This is the main polarization pattern of the antenna obtained in Embodiment 1 of the present invention at 2250MHz.

[0043] Figure 9This is the cross-polarization pattern of the antenna obtained in Embodiment 1 of the present invention at 2250MHz.

[0044] Figure 10 This is the main polarization pattern of the antenna obtained in Embodiment 1 of the present invention at 2300MHz.

[0045] Figure 11 This is the cross-polarization pattern of the antenna obtained in Embodiment 1 of the present invention at 2300MHz. Detailed Implementation

[0046] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0047] Example 1

[0048] The high-precision copper alloy miniature thin-walled spiral antenna 3D printing manufacturing method of this embodiment is carried out according to the following steps:

[0049] Step 1: Preparation of micro-oxidation powder

[0050] CuCrZr alloy powder (0.58wt%Cr, 0.21wt%Zr, and the remainder Cu) was prepared using gas atomization powder preparation technology. The powder was sieved to obtain a particle size of 5-35μm. Then, the powder was placed in a mixer for heating and mixing at 200℃ for 10min to obtain micro-oxidized powder for 3D printing (oxygen content of about 0.04%).

[0051] Step 2: Preheating

[0052] The micro-oxidized powder is preheated to 300°C and then placed in the powder hopper of the SLM printing equipment to preheat the printing substrate to 330°C.

[0053] Step 3: High-precision printing

[0054] A spiral contour scanning strategy is employed for powder SLM printing. After the laser scans the molten powder, a secondary laser scan is performed directly on the solidified metal surface at the original printing location, resulting in a high-precision printed part. The laser scans layer by layer from the outside in, parallel to the contour boundary, using a curved scanning path. Printing parameters are: layer thickness 0.03 mm, scanning speed 800 mm / s (scanning speed consistent in both prints), scanning spacing 0.08 mm (scanning spacing consistent in both prints), and laser power 340 W (power consistent in both prints).

[0055] Step 4: Time-sensitive processing

[0056] The printed parts are subjected to aging treatment, which involves holding them at 450℃ for 1 hour and then cooling them in the furnace to obtain a high-performance antenna product.

[0057] The copper alloy miniature thin-walled helical antenna product prepared by the above process is shown below. Figure 1 .

[0058] The obtained antenna products were tested, and the dimensional accuracy of the upper surface reached 0.05~0.08mm, while that of the lower surface and other parts was below 0.1mm, with a surface roughness of Ra3.2μm. The tensile performance test results of the furnace samples were as follows: tensile strength 632MPa, elongation after fracture 25.1%, exceeding the level of traditional manufacturing methods; tensile strength at 100℃ 516MPa, elongation after fracture 16.3%, and good temperature resistance. Within the operating frequency band (2200MHz~2300MHz), the antenna VSWR <1.3, antenna axial ratio <6dB within ±60° beamwidth, and gain >1.5dBi within ±60° beamwidth met the antenna design specifications (VSWR: ≤2.0, antenna gain: ≥2dBi@(normal), ≥1dBi@(±60° beamwidth)), demonstrating excellent electrical performance and meeting the application requirements of satellite antennas in the space environment.

[0059] Example 2

[0060] The high-precision copper alloy miniature thin-walled spiral antenna 3D printing manufacturing method of this embodiment is carried out according to the following steps:

[0061] Step 1: Preparation of micro-oxidation powder

[0062] CuCrZr alloy powder (0.66wt%Cr, 0.23wt%Zr, and the remainder Cu) was prepared using gas atomization powder preparation technology. The powder was sieved to obtain a particle size of 5-35μm. The powder was then placed in a mixer for heating and mixing at 200℃ for 10min to obtain micro-oxidation powder for 3D printing.

[0063] Step 2: Preheating

[0064] The micro-oxidized powder is preheated to 300°C and then placed in the powder hopper of the SLM printing equipment to preheat the printing substrate to 330°C.

[0065] Step 3: High-precision printing

[0066] A spiral contour scanning strategy is employed for powder SLM printing. After the laser scans the molten powder, a secondary laser scan is performed directly on the solidified metal surface at the original printing location to obtain a high-precision printed part. The laser scans layer by layer from the outside in, parallel to the contour boundary, using a curved scanning path. The initial printing parameters are: layer thickness 0.03 mm, scanning speed 800 mm / s, scanning spacing 0.08 mm, and laser power 340 W. The parameters for the second printing are: scanning speed 800 mm / s, scanning spacing 0.08 mm, and laser power 340 W.

[0067] Step 4: Time-sensitive processing

[0068] The printed parts are subjected to aging treatment, which involves holding them at 450℃ for 1 hour and then cooling them in the furnace to obtain a high-performance antenna product.

[0069] The copper alloy miniature thin-walled helical antenna product prepared by the above process is shown below. Figure 1 .

[0070] The obtained antenna products were tested, and the dimensional accuracy of the upper surface reached 0.05~0.08mm, while that of the lower surface and other parts was below 0.1mm, with a surface roughness of Ra3.2μm. The tensile performance test results of the furnace samples were as follows: tensile strength 654MPa, elongation after fracture 21.1%, exceeding the level of traditional manufacturing methods; tensile strength at 100℃ 577MPa, elongation after fracture 13.6%, and good temperature resistance. Within the operating frequency band (2200MHz~2300MHz), the antenna VSWR <1.4, antenna axial ratio <6dB within ±60° beamwidth, and gain >1.5dBi within ±60° beamwidth met the antenna design specifications (VSWR: ≤2.0, antenna gain: ≥2dBi@(normal), ≥1dBi@(±60° beamwidth)), demonstrating excellent electrical performance and meeting the requirements of satellite antenna space environment applications.

[0071] Example 3

[0072] The high-precision copper alloy miniature thin-walled spiral antenna 3D printing manufacturing method of this embodiment is carried out according to the following steps:

[0073] Step 1: Preparation of micro-oxidation powder

[0074] CuCrZr alloy powder (0.58wt%Cr, 0.21wt%Zr, and the remainder Cu) was prepared using gas atomization powder preparation technology. The powder was sieved to obtain a particle size of 5-35mm. The powder was then placed in a mixer for heating and mixing at 300℃ for 5min to obtain micro-oxidized powder for 3D printing (oxygen content of approximately 0.05wt%).

[0075] Step 2: Preheating

[0076] The micro-oxidized powder is preheated to 300°C and then placed in the powder hopper of the SLM printing equipment to preheat the printing substrate to 330°C.

[0077] Step 3: High-precision printing

[0078] A spiral contour scanning strategy is employed for powder SLM printing. After the laser scans the molten powder, a secondary laser scan is performed directly on the solidified metal surface at the original printing location to obtain a high-precision printed part. The laser scans layer by layer from the outside in, parallel to the contour boundary, using a curved scanning path. The initial printing parameters are: layer thickness 0.03 mm, scanning speed 800 mm / s, scanning spacing 0.08 mm, and laser power 340 W. The parameters for the second printing are: scanning speed 800 mm / s, scanning spacing 0.08 mm, and laser power 340 W.

[0079] Step 4: Time-sensitive processing

[0080] The printed parts are subjected to aging treatment, which involves holding them at 450℃ for 1 hour and then cooling them in the furnace to obtain a high-performance antenna product.

[0081] The copper alloy miniature thin-walled helical antenna product prepared by the above process is shown below. Figure 1 .

[0082] The obtained antenna products were tested, and the dimensional accuracy of the upper surface reached 0.05~0.08mm, while that of the lower surface and other parts was below 0.1mm, with a surface roughness of Ra3.2μm. The tensile performance test results of the furnace samples were as follows: tensile strength 648MPa, elongation after fracture 22.1%, exceeding the level of traditional manufacturing methods; tensile strength at 100℃ 534MPa, elongation after fracture 14.7%, and good temperature resistance. Within the operating frequency band (2200MHz~2300MHz), the antenna VSWR <1.3, antenna axial ratio <5dB within ±60° beamwidth, and gain >2.2dBi within ±60° beamwidth met the antenna design specifications (VSWR: ≤2.0, antenna gain: ≥2dBi@(normal), ≥1dBi@(±60° beamwidth)), demonstrating excellent electrical performance and meeting the requirements of satellite antenna space environment applications.

[0083] Example 4

[0084] The high-precision copper alloy miniature thin-walled spiral antenna 3D printing manufacturing method of this embodiment is carried out according to the following steps:

[0085] Step 1: Preparation of micro-oxidation powder

[0086] CuCrZr alloy powder (0.58wt%Cr, 0.21wt%Zr, and the remainder Cu) was prepared using gas atomization powder preparation technology. The powder was sieved to obtain a particle size of 5-35mm. The powder was then placed in a mixer for heating and mixing at 300℃ for 5min to obtain micro-oxidation powder for 3D printing.

[0087] Step 2: Preheating

[0088] The micro-oxidized powder is preheated to 350°C and then placed in the powder hopper of the SLM printing equipment to preheat the printing substrate to 400°C.

[0089] Step 3: High-precision printing

[0090] A spiral contour scanning strategy is employed for powder SLM printing. After the laser scans the molten powder, a secondary laser scan is performed directly on the solidified metal surface at the original printing location to obtain a high-precision printed part. The laser scans layer by layer from the outside in, parallel to the contour boundary, using a curved scanning path. The initial printing parameters are: layer thickness 0.02 mm, scanning speed 700 mm / s, scanning spacing 0.09 mm, and laser power 350 W. The parameters for the second printing are: scanning speed 700 mm / s, scanning spacing 0.09 mm, and laser power 350 W.

[0091] Step 4: Time-sensitive processing

[0092] The printed parts are subjected to aging treatment, which involves holding at 500℃ for 0.5 hours and then cooling in the furnace to obtain a high-performance antenna product.

[0093] The obtained antenna products were tested, and the overall dimensional accuracy was below 0.1 mm, with a surface roughness of Ra 3.2 μm. The tensile properties of the furnace samples were tested, and the results showed a tensile strength of 602 MPa and an elongation after fracture of 27.7%, which exceeded the level of traditional manufacturing methods. The tensile strength at 100℃ was 503 MPa, and the elongation after fracture was 17.9%, indicating good temperature resistance. The products also exhibited excellent electrical properties, which can meet the application requirements of satellite antennas in the space environment.

[0094] Comparative Example 1 (compared to Example 1)

[0095] The high-precision copper alloy miniature thin-walled spiral antenna 3D printing manufacturing method of this embodiment is carried out according to the following steps:

[0096] Step 1: Preparation of micro-oxidation powder

[0097] CuCrZr alloy powder was prepared using gas atomization powder preparation technology, and the powder with a particle size of 5-35 mm was obtained by sieving, thus obtaining powder for 3D printing.

[0098] Step 2: Preheating

[0099] The micro-oxidized powder is preheated to 300°C and then placed in the powder hopper of the SLM printing equipment to preheat the printing substrate to 330°C.

[0100] Step 3: High-precision printing

[0101] A spiral contour scanning strategy was employed for powder SLM printing to obtain high-precision printed parts. The laser scanned layer by layer from the outside in, parallel to the contour boundary, along a curved scanning path. The printing parameters were: layer thickness 0.03 mm, scanning speed 800 mm / s, scanning spacing 0.08 mm, and laser power 340 W.

[0102] Step 4: Time-sensitive processing

[0103] The printed parts are subjected to aging treatment, which involves holding them at 450℃ for 1 hour and then cooling them in the furnace to obtain a high-performance antenna product.

[0104] The obtained antenna products were tested. The dimensional accuracy of the upper surface was 0.1~0.3mm, and that of the lower surface and other parts was 0.1~0.5mm. The surface roughness was Ra6.4. The tensile performance test results of the furnace samples were as follows: tensile strength 512MPa, elongation after fracture 26.2%, exceeding the level of traditional manufacturing methods; tensile strength at 100℃ 412MPa, elongation after fracture 8.7%. Within the operating frequency band (2200MHz~2300MHz), the antenna standing wave ratio was <2.2, the antenna axial ratio within ±60° beamwidth was <6dB, and the gain within ±60° beamwidth was >0.8dBi, which did not meet the antenna design specifications (VSWR: ≤2.0, antenna gain: ≥2dBi@(normal), ≥1dBi@(±60° beamwidth)), and did not meet the requirements of satellite antenna applications.

[0105] Comparative Example 2

[0106] All other conditions are the same as in Example 1, except that:

[0107] Step one involves preparing CuCrZr alloy powder (0.58wt%Cr, 0.21wt%Zr, and the remainder Cu) using gas atomization powder preparation technology. The powder is then sieved to obtain a particle size of 5-35mm. The powder is then placed in a mixer for heating and mixing at a temperature of 450℃ for 25 minutes to obtain micro-oxidized powder for 3D printing (oxygen content of approximately 0.15wt%).

[0108] The performance of the resulting product is as follows: the antenna product has unmelted particles protruding on its surface, as well as internal pores and cracks. Its dimensional accuracy and surface roughness are poor, and it does not meet the basic surface quality requirements of the product.

[0109] Comparative Example 3

[0110] All other conditions are the same as in Example 1, except that:

[0111] Step one involves preparing CuCrZr alloy powder (0.58% Cr, 0.21% Zr, and the remainder Cu) using gas atomization powder preparation technology. The powder is then sieved to obtain a particle size of 5-35 mm. The powder is then placed in a mixer for heating and mixing at a temperature of 40°C for 5 minutes to obtain micro-oxidized powder for 3D printing (oxygen content of approximately 0.02 wt%).

[0112] The performance of the obtained product is as follows: The antenna product was tested, and the dimensional accuracy of the upper surface was 0.1~0.3mm, the lower surface and other parts were 0.1~0.5mm, and the surface roughness was Ra6.4. The tensile performance test results of the furnace-fired sample were: tensile strength 528MPa, elongation after fracture 25.5%, exceeding the level of traditional manufacturing methods; tensile strength at 100℃ 436MPa, elongation after fracture 8.1%. Within the operating frequency band (2200MHz~2300MHz), the antenna standing wave ratio was <2.2, the antenna axial ratio within ±60° beamwidth was <6dB, and the gain within ±60° beamwidth was >0.8dBi, failing to meet the antenna design specifications (VSWR: ≤2.0, antenna gain: ≥2dBi@(normal), ≥1dBi@(±60° beamwidth)), and not meeting the requirements for satellite antenna applications.

[0113] Comparative Example 4 (compared to Example 1)

[0114] All other conditions are the same as in Example 1, except that:

[0115] Step three involves SLM printing using a common parallel grating scanning strategy to obtain the printed part. The printing parameters are: layer thickness 0.03 mm, scanning speed 800 mm / s, scanning spacing 0.08 mm, and laser power 340 W.

[0116] The performance of the resulting product is as follows: the overall dimensional accuracy of the obtained antenna product is above 0.3mm, and the surface roughness is Ra10.2, which does not meet the requirement of satellite antenna dimensional accuracy index (<0.1mm).

[0117] Comparative Example 5 (compared to Example 2)

[0118] All other conditions are the same as in Example 1, except that:

[0119] No preheating treatment in step two.

[0120] The performance of the obtained product is as follows: the size of the obtained antenna product is measured, the size accuracy of the upper surface is 0.05~0.3mm, the size accuracy of the lower surface and other parts is 0.2~0.5mm, the surface roughness is Ra6.4, the size accuracy fluctuates greatly, and it does not meet the requirements of satellite antenna size accuracy index (<0.1mm).

Claims

1. A thin-walled helical antenna made of copper alloy, characterized in that: The copper alloy thin-walled helical antenna is made of CuCrZr alloy and is fabricated by 3D printing. The raw material used in 3D printing is micro-oxidized CuCrZr alloy powder, in which the oxygen content by mass is 0.02%~0.12%. The 3D printing includes the following steps: Step 1: Preparation of micro-oxidation powder CuCrZr alloy powder was prepared using gas atomization powder preparation technology, and fine-particle powder was obtained by sieving. Then, it was subjected to micro-oxidation treatment to obtain micro-oxidized powder for 3D printing. Step 2: Preheating The micro-oxidized powder is preheated at a temperature of A, and then placed in the powder hopper of the SLM printing equipment to preheat the printing substrate at a temperature of B; wherein A is 200~350℃ and B is 250~400℃. Step 3: High-precision printing A spiral contour scanning strategy is used for powder SLM printing, and in-situ laser remelting scanning is performed directly on the original printed structure to obtain high-precision printed parts. Step 4: Time-sensitive processing The printed parts are subjected to aging treatment to obtain high-performance antenna products; the aging treatment is carried out by holding at 400~600℃ for 0.5~2h and then cooling in the furnace. The dimensional accuracy of the copper alloy thin-walled helical antenna is controlled within 0.05~0.1mm, and the surface roughness reaches Ra3.2~6.3μm.

2. The copper alloy thin-walled helical antenna according to claim 1, characterized in that: In a copper alloy thin-walled helical antenna, the length and width of the helical structure cross-section are 1~2mm and 2~4mm respectively, the diameter of the central axis hole is 3~8mm, and the wall thickness of the central axis is 1~3mm.

3. The copper alloy thin-walled helical antenna according to claim 1, characterized in that: In step one, the fine-particle powder is a powder with a particle size of 5-35 μm; In step one, the micro-oxidation treatment involves placing fine-particle powder in a mixer and heating and mixing it in an oxygen-containing atmosphere at a temperature of 50~400℃ for a time of 5~20 minutes.

4. A copper alloy thin-walled helical antenna according to claim 1, characterized in that: In step two, the preheating treatment involves placing the powder raw material in a vacuum drying oven and heating it to temperature A, and preheating the printing substrate to temperature B, where A = BC; A is 200~350℃, B is 250~400℃, and C is 20~50℃.

5. A copper alloy thin-walled helical antenna according to claim 1, characterized in that: In step three, the spiral contour scanning strategy involves the laser scanning and shaping layer by layer from the outside to the inside of the contour boundary using a curved scanning path. In step three, the in-situ laser remelting scan is a second laser scan performed directly on the original printing location on the solidified metal surface after the laser scan melts the powder. The scanning parameters are the same as those of the first scan.

6. A copper alloy thin-walled helical antenna according to claim 1, characterized in that: In step three, the SLM printing process is carried out with the following printing parameters: layer thickness 0.02~0.05mm, scanning speed 600~1000mm / s, scanning spacing 0.04~0.12mm, and laser power 320~420W.

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