An ultra-high electromagnetic shielding performance alloy powder and a preparation method and application thereof

Abstract

The application relates to an alloy powder with super-high electromagnetic shielding performance and a preparation method and application thereof, and belongs to the technical field of laser additive manufacturing. According to mass fraction, the chemical component composition of the alloy powder comprises the following components: Fe: 50%-60%, Co: 20%-30%, Ni: 2%-10%, Cu: 1%-2%, Mo: 2%-5%, Si: 2%-5%, B: 1%-6%, Y: 0.1%-0.5%, La: 0.1%-0.5%, and Nd: 0.1%-0.5%. The obtained alloy shows excellent soft magnetic performance and electromagnetic shielding performance, is suitable for laser additive manufacturing of K-waveband key equipment parts in the field of 5G communication, and has important application prospects in the fields of electromagnetic shielding of high-end equipment key parts such as communication and aerospace.

Description

Technical Field

[0001] This invention relates to an alloy powder with ultra-high electromagnetic shielding performance, its preparation method and application, belonging to the field of laser additive manufacturing technology. Background Technology

[0002] With the rapid popularization and high-frequency development of 5G communication technology, key components of equipment in aerospace, medical equipment, industrial production, and military facilities are facing increasingly severe electromagnetic interference (EMI) challenges. Especially in the K-band (18.5-26.5 GHz) high-frequency environment, the integration of electronic devices is constantly increasing, making electromagnetic compatibility issues more prominent. Sensitive electronic equipment such as radar equipment, navigation systems, communication modules, and flight control computers are highly susceptible to signal distortion, performance degradation, or even complete failure due to external electromagnetic radiation intrusion. This not only affects the operational stability of equipment but may also lead to safety accidents and significant economic losses. Therefore, developing novel functional alloys and efficient surface preparation technologies with ultra-high electromagnetic shielding performance (>60 dB, i.e., shielding efficiency better than 99.9999%) has become a core requirement for solving the electromagnetic interference problem in the 5G era.

[0003] Laser additive manufacturing technology, with its advantages of high flexibility in alloy design, non-equilibrium microstructures (such as nanocrystals and intermetallic compounds) and excellent performance, and the ability to achieve precise surface strengthening of parts, has become the mainstream technology for preparing high-performance electromagnetic shielding alloys. Among them, Fe-Co based alloys have a natural advantage in the field of electromagnetic shielding due to their excellent soft magnetic properties of high permeability and low coercivity. By adjusting the ratio of Fe and Co elements, or introducing alloying elements such as B, Cu, and Si, key parameters such as resistivity and hysteresis loss can be further optimized, thereby improving electromagnetic shielding effectiveness. In addition, the addition of rare earth elements has been proven to refine alloy grains, suppress cracks and porosity defects, and form new rare earth magnetic phases, which have a positive effect on improving alloy formability and magnetic properties, providing an important direction for the performance upgrading of Fe-Co based alloys.

[0004] However, existing laser additive manufacturing techniques for Fe-Co-based electromagnetic shielding alloys still face numerous unresolved issues and shortcomings, making it difficult to meet the demands of 5G communication for high-performance, high-stability electromagnetic shielding materials. Firstly, the rapid heating and non-equilibrium solidification characteristics of laser additive manufacturing easily lead to defects such as cracks and pores within the Fe-Co-based alloy. Highly alloyed Fe-Co-Ni-based alloys are prone to compositional segregation and thermal stress concentration during solidification, which are difficult to effectively control using existing processes, resulting in generally low alloy density, directly affecting the stability of electromagnetic shielding performance and the service life of components. Secondly, the highest reported shielding effectiveness of FeCoSiMoNiBCu-based electromagnetic shielding alloys in the 18.5-26.5 GHz range is only 96 dB, and there are significant fluctuations in shielding effectiveness across the entire frequency range. Furthermore, their shielding mechanisms are primarily based on single losses (such as ohmic loss or hysteresis loss), lacking a multi-mechanism synergistic enhancement effect, making it difficult to cope with the complex and variable electromagnetic environment of 5G communication. Summary of the Invention

[0005] To address the technical problems of insufficient formability and reliability, and the difficulty in simultaneously achieving shielding effectiveness and stability, existing Fe-Co based electromagnetic shielding alloys for laser additive manufacturing present a high-performance electromagnetic shielding alloy powder, its preparation method, and its applications. This invention introduces Y, La, and Nd multi-element rare earth elements to generate nanoscale rare earth compound reinforcing phases in situ. Simultaneously, it optimizes laser additive manufacturing process parameters to control the alloy's microstructure, forming a heterogeneous structure with synergistic effects of conductive, magnetic, and reinforcing phases. Ultimately, this yields a FeCoNiCuMoSiBYLaNd alloy with no obvious cracks or porosity defects and exhibiting ultra-high electromagnetic shielding effectiveness in the 18.5-26.5 GHz range. This provides high-performance alloy materials and efficient preparation technology for electromagnetic protection of key components in the 5G communication field.

[0006] In a first aspect, the present invention provides an alloy powder with ultra-high electromagnetic shielding performance. The chemical composition of the alloy powder, by mass fraction, includes: Fe: 50%~60%, Co: 20%~30%, Ni: 2%~10%, Cu: 1%~2%, Mo: 2%~5%, Si: 2%~5%, B: 1%~6%, Y: 0.1%~0.5%, La: 0.1%~0.5%, and Nd: 0.1%~0.5%.

[0007] Preferably, the chemical composition of the alloy powder, by mass fraction, includes: Fe: 57%~58%, Co: 27%~28%, Ni: 3%~4%, B: 2%~3%, Cu: 1%~2%, Mo: 3%~5%, Si: 3%~4%, Y: 0.10%~0.25%, La: 0.10%~0.25%, Nd: 0.10%~0.15%.

[0008] Furthermore, the alloy powder is spherical with a sphericity ≥99%, a flowability of 17~20 s / 50 g, and a loose packing density of 4.0~4.5 g / cm³. 3 Hollow sphere ratio ≤2%, oxygen content ≤0.05%, particle size 15~150 μm.

[0009] Secondly, the present invention provides a method for preparing the above-mentioned ultra-high electromagnetic shielding performance alloy powder. The alloy powder is prepared by vacuum induction melting gas atomization method, specifically including a melting power of 58~65 kW, a melting temperature of 1350~1400 ℃, a vacuum degree of 0.48~0.52 Pa, and an argon atomization pressure of 2.0~3.0 MPa.

[0010] Thirdly, this invention provides a method for preparing a novel alloy material with ultra-high electromagnetic shielding performance using laser additive manufacturing, comprising the following steps:

[0011] (1) Sieving: The above alloy powder is sieved to select powder with a particle size of 50~150 μm for later use; (2) Substrate pretreatment: After grinding and polishing and ultrasonic cleaning, the additive manufacturing substrate is dried at 100~120 ℃ for 15~25 min and set aside. (3) Powder spreading and printing: The alloy powder obtained in step (1) is evenly spread on the surface of the substrate obtained in step (2) in a powder spreading manner. Under the protection of inert gas, a semiconductor laser is used for printing. After the first additive manufacturing layer cools to room temperature, the above powder spreading and printing steps are repeated to obtain a new type of laser additive manufacturing alloy material with ultra-high electromagnetic shielding performance of the required thickness.

[0012] Further, in step (2), Q235 steel is used as the additive manufacturing substrate with a size of 200 mm × 100 mm × 10 mm. It is first polished with 400#, 800# and 1200# sandpaper in stages until the surface is flat to remove oxide scale and mechanical defects. Then it is placed in anhydrous ethanol for ultrasonic cleaning for 10 min to remove oil and impurities. It is then placed in a drying oven and dried and heated at 40 ℃ for 20 min before use.

[0013] Furthermore, in step (3), the parameters of the semiconductor laser are: laser energy density of 145~191 J / mm². 2 The scanning spacing is 2~2.5 mm, the overlap rate is 30%~40%, and the spot size is 4×4 mm. 2 .

[0014] Furthermore, in step (3), the inert protective gas is argon with a purity ≥99.99% and an argon flow rate of 10~20 L / min.

[0015] Furthermore, in step (3), the thickness of each layer of powder is 0.4~0.5 mm.

[0016] Furthermore, in step (3), the number of repetitions can be adjusted and selected according to the required thickness of the actual alloy material.

[0017] Fourthly, the present invention provides a novel alloy material with ultra-high electromagnetic shielding performance obtained by the above method using laser additive manufacturing. The alloy material has a density of 99.5%~99.9%, a hardness of 700~877 HV, a saturation magnetization of 171.6~177.3 emu / g, a coercivity of 85~103 Oe, a remanent magnetization of 2.1~4.9 emu / g, and a shielding effectiveness of 70~120 dB in the frequency band of 18.5-26.5 GHz.

[0018] Furthermore, the microstructure of the alloy material mainly consists of α-Fe(BCC), Fe2B, and Co. 21 Mo2B6, Fe 11 The composition consists of Co5 and a small amount of rare earth phases, with corresponding volume fractions of 58-61 vol.%, 16-24 vol.%, 9-16 vol.%, 5-8 vol.%, and <2 vol.%, respectively. The rare earth phases include Fe. 17 Nd2、(Y 0.5 La 0.25 Nd 0.25 FeO3 and YFe 10 Mo2.

[0019] The alloy material described in this invention has a heterogeneous structure of "α-Fe dominant + boride network + rare earth compound reinforcement", which plays a role in multiphase synergy to enhance electromagnetic shielding.

[0020] The synergistic effect of the conductive-magnetic dual-network synergy, multiphase interface polarization and multiple reflection-absorption coupling mechanisms of the alloy material described in this invention depends on the linkage and regulation of multidimensional parameters such as phase content, grain size, Ms, Hc, and density in the alloy.

[0021] The beneficial effects of this invention are: 1. This invention addresses the ultra-high electromagnetic shielding requirements of the 18.5-26.5 GHz range in 5G communication by providing a novel FeCoNiCuMoSiBYLaNd alloy powder that meets the characteristics of laser non-equilibrium solidification and possesses both excellent formability and soft magnetic properties. The alloy material prepared from this powder not only exhibits good laser formability (density up to 99.9%, with no obvious cracks or pores), but also excellent soft magnetic properties and ultra-high electromagnetic shielding performance, achieving a maximum shielding effectiveness of 120 dB and an electromagnetic wave attenuation rate of 99.99%. Compared to the military electromagnetic shielding standard of ≥60 dB, its electromagnetic shielding effectiveness is twice that of the standard.

[0022] 2. During the laser additive manufacturing of FeCoNiCuMoSiBYLaNd alloy materials, Fe atoms with a size of 100-300 nm were generated in situ. 17 Nd2、(Y 0.5 La 0.25 Nd 0.25 FeO3, YFe 10 Mo2 rare earth compound phase, which forms a synergistic enhancement structure with α-Fe matrix and boride network, achieves efficient electromagnetic wave attenuation through mechanisms such as conductive-magnetic dual network synergy, multiphase interface polarization and multiple reflection-absorption coupling, providing a new approach for laser additive manufacturing of key components in the 5G communication field. Attached Figure Description

[0023] Figure 1 These are SEM images of the FeCoNiCuMoSiBYLaNd alloy powder obtained in Example 1 of this invention, wherein (a) is an SEM image of the alloy powder at a magnification of 50x and (b) is an SEM image of the alloy powder at a magnification of 100x.

[0024] Figure 2 This is a scanning energy dispersive spectroscopy (SED) result of the FeCoNiCuMoSiBYLaNd alloy powder obtained in Example 1 of this invention.

[0025] Figure 3 This is a particle size distribution diagram of the FeCoNiCuMoSiBYLaNd alloy powder obtained in Example 1 of the present invention.

[0026] Figure 4 This is the XRD pattern of the FeCoNiCuMoSiBYLaNd alloy powder obtained in Example 1 of the present invention.

[0027] Figure 5 The alloy material obtained in Example 2 of this invention (laser energy density of 145 J / mm²) 2 Metallographic images of the alloy, where (a) is a metallographic image of the uncorroded alloy and (b) is a metallographic image of the alloy after corrosion.

[0028] Figure 6 These are the density statistics of the alloy materials obtained in Examples 2-6 of this invention.

[0029] Figure 7 These are SEM images of the alloy material obtained in Example 2 of the present invention. The left image is an SEM image of the alloy material magnified at 5000x, and the right image is an SEM image of the alloy material magnified at 8000x.

[0030] Figure 8 These are the XRD patterns of the alloy materials obtained in Examples 2-6 of this invention.

[0031] Figure 9 These are EBSD images of the alloy material obtained in Example 2 of the present invention, wherein the left image is a crystal orientation imaging image of the alloy material, and the right image is a phase diagram of the alloy material.

[0032] Figure 10 This is a hardness curve of the alloy material obtained in Examples 2-6 of the present invention (the microhardness is measured in a direction perpendicular to the laser scanning direction, and is measured by making dots from the additive manufacturing layer into the matrix).

[0033] Figure 11 It is the hysteresis loop of the alloy material obtained in Examples 2-6 of this invention.

[0034] Figure 12 These are curves showing the overall electromagnetic wave shielding effectiveness of the alloy materials obtained in Examples 2-6 of this invention at electromagnetic wave frequencies of 18-26.5 GHz.

[0035] Figure 13 These are curves showing the electromagnetic wave absorption efficiency of the alloy materials obtained in Examples 2-6 of this invention at electromagnetic wave frequencies of 18-26.5 GHz.

[0036] Figure 14 These are curves showing the electromagnetic wave reflection efficiency of the alloy materials obtained in Examples 2-6 of this invention at electromagnetic wave frequencies of 18-26.5 GHz.

[0037] Figure 15 The alloy material obtained in Example 3 of this invention (laser energy density of 156 J / mm²) 2 Metallographic images of the alloy, where (a) is a metallographic image of the uncorroded alloy and (b) is a metallographic image of the alloy after corrosion.

[0038] Figure 16 These are SEM images of the alloy material obtained in Example 3 of the present invention. The left image is an SEM image of the alloy material magnified at 5000x, and the right image is an SEM image of the alloy material magnified at 8000x.

[0039] Figure 17These are EBSD images of the alloy material obtained in Example 3 of the present invention, wherein the left image is a crystal orientation imaging image of the alloy material, and the right image is a phase diagram of the alloy material.

[0040] Figure 18 The alloy material obtained in Example 4 of this invention (laser energy density of 168 J / mm²) 2 Metallographic images of the alloy, where (a) is a metallographic image of the uncorroded alloy and (b) is a metallographic image of the alloy after corrosion.

[0041] Figure 19 These are SEM images of the alloy material obtained in Example 4 of the present invention. The left image is a SEM image of the alloy material magnified at 5000x, and the right image is a SEM image of the alloy material magnified at 8000x.

[0042] Figure 20 The above are the scanning energy dispersive spectroscopy (EDS) results of the alloy material obtained in Example 4 of the present invention, wherein (a) is the scanning energy dispersive spectroscopy result of the alloy material and (b) is a partial magnified view.

[0043] Figure 21 This is the energy dispersive spectroscopy (EDS) result of the alloy material obtained in Example 4 of this invention under an electron probe microanalysis.

[0044] Figure 22 These are the scan images of the alloy material obtained in Example 4 of this invention in transmission electron microscopy (TEM) mode, where (a), (b), (d), (e), and (f) are the phase distribution and elemental distribution diagrams of the alloy, respectively, and (c) is the Fe distribution diagram. 11 Co5, Fe2B and Co 21 The diffraction pattern of Mo2B6, (g~i) is (Y 0.5 La 0.25 Nd 0.25 FeO3, YFe 10 Mo2 and Fe 17 Diffraction spots of Nd2.

[0045] Figure 23 These are EBSD images of the alloy material described in Embodiment 4 of the present invention, wherein the left image is a crystal orientation imaging image of the alloy material, and the right image is a phase diagram of the alloy material.

[0046] Figure 24 This is the DSC curve of the alloy material obtained in Example 4 of the present invention.

[0047] Figure 25 The alloy material obtained in Example 5 of this invention (laser energy density of 181 J / mm²) 2 Metallographic images of the alloy, where (a) is a metallographic image of the uncorroded alloy and (b) is a metallographic image of the alloy after corrosion.

[0048] Figure 26 These are SEM images of the alloy material obtained in Example 5 of the present invention. The left image is an SEM image of the alloy material magnified at 5000x, and the right image is an SEM image of the alloy material magnified at 8000x.

[0049] Figure 27 These are EBSD images of the alloy material obtained in Example 5 of the present invention, wherein the left image is a crystal orientation imaging image of the alloy material, and the right image is a phase diagram of the alloy material.

[0050] Figure 28 The alloy material obtained in Example 6 of this invention (laser energy density of 191 J / mm²) 2 Metallographic images of the alloy, where (a) is a metallographic image of the uncorroded alloy and (b) is a metallographic image of the alloy after corrosion.

[0051] Figure 29 These are SEM images of the alloy material obtained in Example 6 of the present invention. The left image is an SEM image of the alloy material magnified at 5000x, and the right image is an SEM image of the alloy material magnified at 8000x.

[0052] Figure 30 These are EBSD images of the alloy material obtained in Example 6 of the present invention, wherein the left image is a crystal orientation imaging image of the alloy material, and the right image is a phase diagram of the alloy material. Detailed Implementation

[0053] The following non-limiting embodiments are intended to enable those skilled in the art to more fully understand the invention, but do not limit the invention in any way.

[0054] Unless otherwise specified, the experimental methods described in the following examples are conventional methods; the reagents and materials described are commercially available unless otherwise specified.

[0055] Example 1 A method for preparing FeCoNiCuMoSiBYLaNd alloy powder by gas atomization includes the following steps: (1) Composition of alloy powder: Fe, Co, Ni, Cu, Mo, Si, B pure metal elemental powder and Y, La, Nd rare earth elemental powder are precisely proportioned and mixed. The specific composition by mass fraction is: Fe: 57.60%, Co: 27.20%, Ni: 3.65%, B: 2.53%, Cu: 1.08%, Mo: 4.21%, Si: 3.32%, Y: 0.17%, La: 0.13%, Nd: 0.11%; (2) Preparation of alloy powder: The proportioned mixed powder was added to a vacuum induction melting furnace, and alloy powder was prepared by vacuum induction melting gas atomization (VIGA). The melting power was 60 kW, the melting temperature was 1380 ℃, and the vacuum degree of the melting chamber was 5.0×10⁻⁶. -1 Pa, argon atomization pressure 2.5 MPa; the prepared alloy powder had a sphericity ≥99%, flowability 17 s / 50 g, and loose packing density 4.45 g / cm³. 3 With a hollow sphere ratio of 2% and an oxygen content of 0.035%, the powder meets the performance requirements of laser additive manufacturing processes. It is vacuum-sealed and stored for later use. A photograph of the alloy powder is shown below. Figure 1 As shown, the elemental distribution of the alloy powder is as follows: Figure 2 As shown, the particle size distribution and XRD pattern of the powder are as follows: Figure 3 and Figure 4 As shown, the alloy powder contains α-Fe, γ-Fe, Fe₂B, and Co. 21 Mo2B6 phase.

[0056] Example 2 A method for preparing a novel alloy material with ultra-high electromagnetic shielding performance using laser additive manufacturing includes the following steps: a. Equipment used: FL-Dlight02-3000 W semiconductor laser (spot size 4×4 mm) 2 ); b. Sieving: The alloy powder obtained in Example 1 is sieved to select powder with a particle size of 50~150 μm for later use; c. Substrate pretreatment: Q235 steel is used as the additive manufacturing substrate with dimensions of 200 mm × 100 mm × 10 mm. It is first polished with 400#, 800# and 1200# sandpaper in stages until the surface is smooth to remove oxide scale and mechanical defects. Then it is ultrasonically cleaned in anhydrous ethanol for 10 min to remove oil and impurities. It is then placed in a drying oven and dried at 40 ℃ for 20 min before use. d. Powder Spreading and Printing: The FeCoNiCuMoSiBYLaNd alloy powder obtained after sieving was uniformly spread onto the surface of the pretreated substrate using a powder spreading method. The powder spreading thickness (t) was 0.5 mm. Laser additive manufacturing was then used for printing. Laser additive manufacturing process parameters: laser energy density was 145 J / mm². 2(Corresponding to a laser power of 2900 W and a scanning speed of 5 mm / s), the scanning interval (d) is 2.4 mm, the overlap rate is 40%, the protective gas is high-purity argon (purity ≥99.99%), the argon flow rate is 15 L / min, and the first layer of additive manufacturing is completed under argon protection conditions; after the first layer of additive manufacturing is cooled to room temperature, the second to tenth layers are prepared according to the same powder thickness and process parameters, and finally a laser additive manufacturing Fe-Co based alloy material with a total thickness of about 5.0 mm is obtained. The whole process is filled with argon protective gas.

[0057] Performance testing of the laser additive manufacturing Fe-Co based alloy material obtained in Example 2: (1) Verification of the formability of Fe-Co based alloy samples manufactured by laser additive manufacturing. The results are shown in […]. Figure 5 and Figure 6 Laser additive manufacturing of Fe-Co based alloy samples at a laser energy density of 145 J / mm² 2 The metallographic morphology at that time showed that the structure was dense, without cracks, and only a small number of scattered micropores were present. Figure 5 The density, calculated using the area method, is approximately 99.5%. Figure 6 This indicates that it possesses good laser forming properties.

[0058] (2) Verify the generation of the electromagnetic shielding phase; the results are shown in […]. Figures 7-9 To analyze the microstructure of the alloy, the samples were etched using 25 mL hydrochloric acid + 5 g anhydrous CuSO4 + 25 mL anhydrous ethanol as etchants, followed by metallographic microscopy. The microstructure and phase composition were then identified using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that the laser additive manufacturing of the Fe-Co based alloy samples resulted in in-situ formation of a phase dominated by α-Fe(BCC) cores, with synergistic effects of Fe2B and Co. 21 Mo2B6, Fe 11 Co5. EBSD analysis showed that the volume fractions of each phase were 60 vol. % α-Fe, 24 vol. % Fe2B, and 9 vol. % Co. 21 Mo2B6, 6 vol. % Fe 11 Co5 ( Figure 9 XRD phase analysis results ( Figure 8 Consistent with SEM observations, this verifies the feasibility of in-situ generation of multi-component synergistic electromagnetic shielding phases in novel Fe-Co based alloys using laser additive manufacturing.

[0059] (3) The mechanical properties of the laser additively manufactured Fe-Co based alloy samples were verified, and the results are shown in […]. Figure 10The Vickers microhardness tester was used to measure the microhardness at multiple points on different locations on the sample surface under a load of 200 N and a holding time of 10 s. The results showed that the average hardness of the laser additively manufactured Fe-Co based alloy sample was 859 HV. Figure 10 It has a uniform hardness distribution and good mechanical strengthening properties.

[0060] (4) Verify the soft magnetic properties of the Fe-Co based alloy samples manufactured by laser additive manufacturing. The results are shown in […]. Figure 11 The soft magnetic properties of the sample were tested at room temperature using a vibrating sample magnetometer (VSM). The results showed that the sample's saturation magnetization was 171 emu / g and its coercivity was 10³ Oe. Figure 11 The soft magnetic properties of the alloy, characterized by low coercivity and high saturation magnetization, provide the core foundation for its excellent electromagnetic shielding performance.

[0061] (5) Verify the electromagnetic shielding performance of the laser additive manufacturing Fe-Co based alloy samples. The results are shown in […]. Figures 12-14 To test the electromagnetic shielding effectiveness in the 18.5-26.5 GHz range, a vector network analyzer was used to test the samples within this frequency range. The test parameters were room temperature and an unshielded environment. The shielding effectiveness, absorption effectiveness, and reflection effectiveness of the alloy were calculated through analysis of the test data. The results show that the highest electromagnetic shielding effectiveness of the samples in the 18.5-26.5 GHz range is 97 dB, the average electromagnetic shielding effectiveness is 84 dB, and the absorption effectiveness accounts for 83% (…). Figures 12-14 This achieves effective electromagnetic shielding and meets the requirements for the use of high-efficiency electromagnetic shielding equipment.

[0062] Example 3 A method for preparing a novel alloy material with ultra-high electromagnetic shielding performance using laser additive manufacturing includes the following steps: a. Equipment used: FL-Dlight02-3000 W semiconductor laser (spot size 4×4 mm) 2 ); b. Sieving: The alloy powder obtained in Example 1 is sieved to select powder with a particle size of 50~150 μm for later use; c. Substrate pretreatment: Q235 steel is used as the additive manufacturing substrate with dimensions of 200 mm × 100 mm × 10 mm. It is first polished with 400#, 800# and 1200# sandpaper in stages until the surface is smooth to remove oxide scale and mechanical defects. Then it is ultrasonically cleaned in anhydrous ethanol for 10 min to remove oil and impurities. It is then placed in a drying oven and dried at 40 ℃ for 20 min before use. d. Powder Spreading and Printing: The FeCoNiCuMoSiBYLaNd alloy powder obtained after sieving was uniformly spread onto the surface of the pretreated substrate using a powder spreading method. The powder spreading thickness (t) was 0.5 mm. Laser additive manufacturing was then used for printing. Laser additive manufacturing process parameters: laser energy density was 156 J / mm². 2 (Corresponding to a laser power of 2500 W and a scanning speed of 4 mm / s), the scanning spacing (d) is 2.4 mm, the overlap rate is 40%, the protective gas is high-purity argon (purity ≥99.99%), the argon flow rate is 15 L / min, and the first layer of additive manufacturing is completed under argon protection conditions; after the first layer of additive manufacturing is cooled to room temperature, the second to tenth layers are prepared according to the same powder thickness and process parameters, and finally a laser additive manufacturing Fe-Co based alloy material with a total thickness of about 5.0 mm is obtained. The whole process is filled with argon protective gas.

[0063] Performance testing of the laser additive manufacturing Fe-Co based alloy material obtained in Example 3: (1) Verification of the formability of Fe-Co based alloy samples manufactured by laser additive manufacturing. The results are shown in […]. Figure 6 and Figure 15 Laser additive manufacturing of Fe-Co based alloy samples at a laser energy density of 156 J / mm² 2 The metallographic morphology at that time showed that the structure was dense, without cracks, and only a small number of scattered micropores were present. Figure 15 The density, calculated using the area method, is approximately 99.9%. Figure 6 It possesses excellent laser forming properties; (2) Verify the generation of the electromagnetic shielding phase; the results are shown in […]. Figure 8 , Figure 16 and Figure 17 To analyze the microstructure of the alloy, the samples were etched using 25 mL hydrochloric acid + 5 g anhydrous CuSO4 + 25 mL anhydrous ethanol as etchants, followed by metallographic microscopy. The microstructure and phase composition were then identified using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that the laser additive manufacturing of the Fe-Co based alloy samples resulted in in-situ formation of a phase dominated by α-Fe(BCC) cores, with synergistic effects of Fe2B and Co. 21 Mo2B6, Fe 11 Co5. EBSD analysis showed that the volume fractions of each phase were 58 vol.% α-Fe, 20 vol.% Fe2B, and 16 vol.% Co. 21 Mo2B6, 5 vol. % Fe 11 Co5 ( Figure 17 XRD phase analysis results ( Figure 8 ) and SEM ( Figure 16 The observation results were consistent, verifying the feasibility of in-situ generation of multi-element synergistic electromagnetic shielding phases in novel Fe-Co based alloys using laser additive manufacturing.

[0064] (3) The mechanical properties of the laser additively manufactured Fe-Co based alloy samples were verified, and the results are shown in […]. Figure 10 The Vickers microhardness tester was used to measure the microhardness at multiple points on different locations on the sample surface under a load of 200 N and a holding time of 10 s. The results showed that the average hardness of the laser additively manufactured Fe-Co based alloy sample was 861 HV. Figure 10 It has a uniform hardness distribution and good mechanical strengthening properties.

[0065] (4) Verify the soft magnetic properties of the Fe-Co based alloy samples manufactured by laser additive manufacturing. The results are shown in […]. Figure 11 The soft magnetic properties of the sample were tested at room temperature using a vibrating sample magnetometer (VSM). The results showed that the sample's saturation magnetization was 172 emu / g and its coercivity was 86 Oe (…). Figure 11 The soft magnetic properties of the alloy, characterized by low coercivity and high saturation magnetization, provide the core foundation for its excellent electromagnetic shielding performance.

[0066] (5) Verify the electromagnetic shielding performance of the laser additive manufacturing Fe-Co based alloy samples. The results are shown in […]. Figures 12-14 To test the electromagnetic shielding effectiveness in the 18.5-26.5 GHz range, a vector network analyzer was used to test the samples within this frequency range. The test parameters were room temperature and an unshielded environment. The shielding effectiveness, absorption effectiveness, and reflection effectiveness of the alloy were calculated through analysis of the test data. The results show that the highest electromagnetic shielding effectiveness of the samples in the 18.5-26.5 GHz range is 115 dB, the average electromagnetic shielding effectiveness is 95 dB, and the absorption effectiveness accounts for 83% (…). Figures 12-14 This achieves effective electromagnetic shielding and meets the requirements for the use of high-efficiency electromagnetic shielding equipment.

[0067] Example 4 A method for preparing a novel alloy material with ultra-high electromagnetic shielding performance using laser additive manufacturing includes the following steps: a. Equipment used: FL-Dlight02-3000 W semiconductor laser (spot size 4×4 mm) 2 ); b. Sieving: The alloy powder obtained in step (2) above is sieved, and powder with a particle size of 50~150 μm is selected for later use; c. Substrate pretreatment: Q235 steel is used as the additive manufacturing substrate with dimensions of 200 mm × 100 mm × 10 mm. It is first polished with 400#, 800# and 1200# sandpaper in stages until the surface is smooth to remove oxide scale and mechanical defects. Then it is ultrasonically cleaned in anhydrous ethanol for 10 min to remove oil and impurities. It is then placed in a drying oven and dried at 40 ℃ for 20 min before use. d. Powder Spreading and Printing: The FeCoNiCuMoSiBYLaNd alloy powder prepared above was uniformly spread onto the surface of the pretreated substrate using a powder spreading method. The powder spreading thickness (t) was 0.5 mm. Laser additive manufacturing was then used for printing. Laser additive manufacturing process parameters: laser energy density was 168 J / mm². 2 (Corresponding to a laser power of 2700 W and a scanning speed of 4 mm / s), the scanning spacing (d) is 2.4 mm, the overlap rate is 40%, the protective gas is high-purity argon (purity ≥99.99%), the argon flow rate is 15 L / min, and the first layer of additive manufacturing is completed under argon protection conditions; after the first layer of additive manufacturing is cooled to room temperature, the second to tenth layers are prepared according to the same powder thickness and process parameters, and finally a laser additive manufacturing Fe-Co based alloy material with a total thickness of about 5.0 mm is obtained. The whole process is filled with argon protective gas.

[0068] Performance testing of the laser additive manufacturing Fe-Co based alloy material obtained in Example 4: (1) Verification of the formability of Fe-Co based alloy samples manufactured by laser additive manufacturing. The results are shown in […]. Figure 6 and Figure 18 The sample was tested at a laser energy density of 168 J / mm². 2 The metallographic morphology at that time showed that the structure was dense, without cracks, and only a small number of scattered micropores were present. Figure 18 The density, calculated using the area method, is approximately 99.9%. Figure 6 It has good laser forming properties.

[0069] (2) Verify the generation of the electromagnetic shielding phase; the results are shown in […]. Figure 8 and Figures 19-23To analyze the microstructure of the alloy, it was etched using 25 mL hydrochloric acid + 5 g anhydrous CuSO4 + 25 mL anhydrous ethanol as the etchant, and then observed under a metallographic microscope. Multi-scale fine characterization of the sample was performed using X-ray diffraction (XRD), scanning electron microscopy (SEM), electron probe microanalysis (EPMA), and transmission electron microscopy (TEM) to identify the microstructure and phase composition. The energy dispersive spectroscopy (EDS) and electron probe microanalysis (EPMA) results from SEM clearly showed that Fe, Co, Ni, and Si were uniformly distributed in the α-Fe (BCC) core phase. At the α-Fe grain boundaries, Mo and B elements exhibited network-like aggregation, while rare earth elements Y, La, and Nd were dispersed at the phase interfaces, playing a role in grain refinement and interface regulation, and showing aggregation at the α-Fe and network structures. Figures 19-21 TEM high-magnification morphology and selected area electron diffraction (SAED) results further confirmed the crystal structure of each phase. α-Fe is in lamellar form, Fe2B is distributed in fine lamellar form around α-Fe, and Co... 21 Mo2B6 grows in a clustered structure within the network, with rare earth phase Fe... 17 Nd2、(Y 0.5 La 0.25 Nd 0.25 FeO3, YFe 10 Mo2 is anchored at the grain boundaries in the form of nano-sized particles. Figure 22 XRD phase analysis results ( Figure 8 The results are consistent with the characterization results above, fully verifying the 168 J / mm 2 Under high laser energy density, the alloy can generate a multi-component, synergistic, and uniformly distributed electromagnetic shielding phase in situ. The results show that the laser additive manufacturing of Fe-Co based alloy samples generated in situ with an α-Fe (BCC) core phase as the main component, synergistically with Fe2B and Co phases. 21 Mo2B6, Fe 11 Co5. EBSD analysis showed that the volume fractions of each phase were 61 vol. % α-Fe, 17 vol. % Fe2B, and 14 vol. % Co. 21 Mo2B6, 7 vol. % Fe 11 Co5 ( Figure 23 This lays the microstructural foundation for superior performance and verifies the feasibility of in-situ generation of multi-component synergistic electromagnetic shielding phases in novel Fe-Co based alloys manufactured by laser additive manufacturing.

[0070] (3) Verify the phase transition process; the results are shown in […]. Figure 24 To analyze the phase transformation processes of each phase in the alloy, the phase transformation characteristics of the alloy were tested using differential scanning calorimetry (DSC), and DSC thermal analysis curves were obtained, such as... Figure 24As shown in the figure, during the heating and melting process, when the temperature reaches 850 °C, the endothermic peak indicates that α-Fe(M) of BCC has transformed into γ-Fe(M) of FCC in some alloys. Simultaneously, grain growth occurs, and elements such as Co, Ni, and Si, originally dissolved in α-Fe(M), rapidly dissolve into γ-Fe(M). When the temperature reaches 1000 °C, the endothermic peak corresponds to the solid-liquid transformation of γ-Fe(M) in the alloy. When the temperature rises to 1130 °C, multiple small peaks represent Fe2B and Co in the alloy. 21 The Mo₂B₆ phase melts into the liquid phase. During the cooling process, when the temperature drops from 1400 °C to 1175 °C, Co precipitates from the liquid phase. 21 When the temperature of the Mo2B6 and Fe2B phases drops to 1100 ℃~1050 ℃, a liquid-solid transformation of γ-Fe(M) precipitation occurs. When the temperature continues to drop to 544 ℃~599 ℃, the γ-Fe(M) of FCC in the alloy is transformed into α-Fe(M) of BCC.

[0071] (4) The mechanical properties of the laser additively manufactured Fe-Co based alloy samples were verified, and the results are shown in […]. Figure 10 The Vickers microhardness tester was used to measure the microhardness at multiple points on different locations on the sample surface under a load of 200 N and a holding time of 10 s. The results showed that the average hardness of the laser additively manufactured Fe-Co based alloy sample was 877 HV. Figure 10 It has a uniform hardness distribution and good mechanical strengthening properties.

[0072] (5) Verify the soft magnetic properties of the Fe-Co based alloy samples manufactured by laser additive manufacturing. The results are shown in […]. Figure 11 The soft magnetic properties of the sample were tested at room temperature using a vibrating sample magnetometer (VSM). The results showed that the sample's saturation magnetization was 177 emu / g and its coercivity was 77 Oe (…). Figure 11 The soft magnetic properties of the alloy, characterized by low coercivity and high saturation magnetization, provide the core foundation for its excellent electromagnetic shielding performance.

[0073] (6) Verify the electromagnetic shielding performance of the laser additive manufacturing Fe-Co based alloy samples. The results are shown in […]. Figures 12-14 To test the electromagnetic shielding effectiveness in the 18.5-26.5 GHz range, a vector network analyzer was used to test the samples within this frequency range. The test parameters were room temperature and an unshielded environment. The shielding effectiveness, absorption effectiveness, and reflection effectiveness of the alloy were calculated through analysis of the test data. The results show that the highest electromagnetic shielding effectiveness of the samples in the 18.5-26.5 GHz range is 120 dB, the average electromagnetic shielding effectiveness is 102 dB, and the absorption effectiveness accounts for 84% (…). Figures 12-14This achieves effective electromagnetic shielding and meets the requirements for the use of high-efficiency electromagnetic shielding equipment.

[0074] Example 5 A method for preparing a novel alloy material with ultra-high electromagnetic shielding performance using laser additive manufacturing includes the following steps: a. Equipment used: FL-Dlight02-3000 W semiconductor laser (spot size 4×4 mm) 2 ); b. Sieving: The alloy powder obtained in Example 1 is sieved to select powder with a particle size of 50~150 μm for later use; c. Substrate pretreatment: Q235 steel is used as the additive manufacturing substrate with dimensions of 200 mm × 100 mm × 10 mm. It is first polished with 400#, 800# and 1200# sandpaper in stages until the surface is smooth to remove oxide scale and mechanical defects. Then it is ultrasonically cleaned in anhydrous ethanol for 10 min to remove oil and impurities. It is then placed in a drying oven and dried at 40 ℃ for 20 min before use. d. Powder Spreading and Printing: The FeCoNiCuMoSiBYLaNd alloy powder obtained after sieving was uniformly spread onto the surface of the pretreated substrate using a powder spreading method. The powder spreading thickness (t) was 0.5 mm. Laser additive manufacturing was then used for printing. Laser additive manufacturing process parameters: laser energy density was 181 J / mm². 2 (Corresponding to a laser power of 2700 W and a scanning speed of 4 mm / s), the scanning spacing (d) is 2.4 mm, the overlap rate is 40%, the protective gas is high-purity argon (purity ≥99.99%), the argon flow rate is 15 L / min, and the first layer of additive manufacturing is completed under argon protection conditions; after the first layer of additive manufacturing is cooled to room temperature, the second to tenth layers are prepared according to the same powder thickness and process parameters, and finally a laser additive manufacturing Fe-Co based alloy material with a total thickness of about 5.0 mm is obtained. The whole process is filled with argon protective gas.

[0075] Performance testing of the laser additive manufacturing Fe-Co based alloy material obtained in Example 5: (1) Verification of the formability of Fe-Co based alloy samples manufactured by laser additive manufacturing. The results are shown in […]. Figure 6 and Figure 25 Laser additive manufacturing of Fe-Co based alloy samples at a laser energy density of 181 J / mm² 2 The metallographic morphology at that time showed that the structure was dense, without cracks, and only a small number of scattered micropores were present. Figure 25 The density, calculated using the area method, is approximately 99.9%. Figure 6 It has good laser forming properties.

[0076] (2) Verify the generation of the electromagnetic shielding phase; the results are shown in […]. Figure 8 , Figure 26 and Figure 27 To analyze the microstructure of the alloy, the samples were etched using 25 mL hydrochloric acid + 5 g anhydrous CuSO4 + 25 mL anhydrous ethanol as etchants, followed by metallographic microscopy. The microstructure and phase composition were then identified using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that the laser additive manufacturing of the Fe-Co based alloy samples resulted in in-situ formation of a phase dominated by α-Fe(BCC) cores, with synergistic effects of Fe2B and Co. 21 Mo2B6, Fe 11 Co5 ( Figure 8 EBSD analysis showed that the volume fractions of each phase were 61 vol. % α-Fe, 16 vol. % Fe2B, and 15 vol. % Co. 21 Mo2B6, 7 vol. % Fe 11 Co5 ( Figure 27 XRD phase analysis results ( Figure 8 ) and SEM ( Figure 26 The observation results were consistent, verifying the feasibility of in-situ generation of multi-element synergistic electromagnetic shielding phases in novel Fe-Co based alloys using laser additive manufacturing.

[0077] (3) The mechanical properties of the laser additively manufactured Fe-Co based alloy samples were verified, and the results are shown in […]. Figure 10 The Vickers microhardness tester was used to measure the microhardness at multiple points on different locations on the sample surface under a load of 200 N and a holding time of 10 s. The results showed that the average hardness of the laser additively manufactured Fe-Co based alloy sample was 871 HV. Figure 10 It has a uniform hardness distribution and good mechanical strengthening properties.

[0078] (4) Verify the soft magnetic properties of the Fe-Co based alloy samples manufactured by laser additive manufacturing. The results are shown in […]. Figure 11 The soft magnetic properties of the sample were tested at room temperature using a vibrating sample magnetometer (VSM). The results showed that the sample's saturation magnetization was 177 emu / g and its coercivity was 79 Oe (…). Figure 11 The soft magnetic properties of the alloy, characterized by low coercivity and high saturation magnetization, provide the core foundation for its excellent electromagnetic shielding performance.

[0079] (5) Verify the electromagnetic shielding performance of the laser additive manufacturing Fe-Co based alloy samples. The results are shown in […]. Figures 12-14To test the electromagnetic shielding effectiveness in the 18.5-26.5 GHz range, a vector network analyzer was used to test the samples within this frequency range. The test parameters were room temperature and an unshielded environment. The shielding effectiveness, absorption effectiveness, and reflection effectiveness of the alloy were calculated through analysis of the test data. The results show that the highest electromagnetic shielding effectiveness of the samples in the 18.5-26.5 GHz range is 111 dB, the average electromagnetic shielding effectiveness is 90 dB, and the absorption effectiveness accounts for 80% (…). Figures 12-14 This achieves effective electromagnetic shielding and meets the requirements for the use of high-efficiency electromagnetic shielding equipment.

[0080] Example 6 A method for preparing a novel alloy material with ultra-high electromagnetic shielding performance using laser additive manufacturing includes the following steps: a. Equipment used: FL-Dlight02-3000 W semiconductor laser (spot size 4×4 mm) 2 ); b. Sieving: The alloy powder obtained in Example 1 is sieved to select powder with a particle size of 50~150 μm for later use; c. Substrate pretreatment: Q235 steel is used as the additive manufacturing substrate with dimensions of 200 mm × 100 mm × 10 mm. It is first polished with 400#, 800# and 1200# sandpaper in stages until the surface is smooth to remove oxide scale and mechanical defects. Then it is ultrasonically cleaned in anhydrous ethanol for 10 min to remove oil and impurities. It is then placed in a drying oven and dried at 40 ℃ for 20 min before use. d. Powder Spreading and Printing: The FeCoNiCuMoSiBYLaNd alloy powder prepared above was uniformly spread onto the surface of the pretreated substrate using a powder spreading method. The powder spreading thickness (t) was 0.5 mm. Laser additive manufacturing was then used for printing. Laser additive manufacturing process parameters: laser energy density was 191 J / mm². 2 (Corresponding to a laser power of 2300 W and a scanning speed of 3 mm / s), the scanning spacing (d) is 2.4 mm, the overlap rate is 40%, the protective gas is high-purity argon (purity ≥99.99%), the argon flow rate is 15 L / min, and the first layer of additive manufacturing is completed under argon protection conditions; after the first layer of additive manufacturing is cooled to room temperature, the second to tenth layers are prepared according to the same powder thickness and process parameters, and finally a laser additive manufacturing Fe-Co based alloy material with a total thickness of about 5.0 mm is obtained. The whole process is filled with argon protective gas.

[0081] Performance testing of the laser additive manufacturing Fe-Co based alloy material obtained in Example 6: (1) Verification of the formability of Fe-Co based alloy samples manufactured by laser additive manufacturing. The results are shown in […]. Figure 6and Figure 28 Laser additive manufacturing of Fe-Co based alloy samples at a laser energy density of 191 J / mm² 2 The metallographic morphology at that time showed that the structure was dense, without cracks, and only a small number of scattered micropores were present. Figure 28 The density, calculated using the area method, is approximately 99.9%. Figure 6 It has good laser forming properties.

[0082] (2) Verify the generation of the electromagnetic shielding phase; the results are shown in […]. Figure 8 , Figure 29 and Figure 30 To analyze the microstructure of the alloy, the samples were etched using 25 mL hydrochloric acid + 5 g anhydrous CuSO4 + 25 mL anhydrous ethanol as etchants, followed by metallographic microscopy. The microstructure and phase composition were then identified using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that the laser additive manufacturing of the Fe-Co based alloy samples resulted in in-situ formation of a phase dominated by α-Fe(BCC) cores, with synergistic effects of Fe2B and Co. 21 Mo2B6, Fe 11 Co5. EBSD analysis showed that the volume fractions of each phase were 58 vol.% α-Fe, 19 vol.% Fe2B, and 15 vol.% Co. 21 Mo2B6, 7 vol. % Fe 11 Co5 ( Figure 30 XRD phase analysis results ( Figure 8 ) and SEM ( Figure 29 The observation results were consistent, verifying the feasibility of in-situ generation of multi-element synergistic electromagnetic shielding phases in novel Fe-Co based alloys using laser additive manufacturing.

[0083] (3) The mechanical properties of the laser additively manufactured Fe-Co based alloy samples were verified, and the results are shown in […]. Figure 10 The Vickers microhardness tester was used to measure the microhardness at multiple points on different locations on the sample surface under a load of 200 N and a holding time of 10 s. The results showed that the average hardness of the laser additively manufactured Fe-Co based alloy sample was 853 HV. Figure 10 It has a uniform hardness distribution and good mechanical strengthening properties.

[0084] (4) Verify the soft magnetic properties of the Fe-Co based alloy samples manufactured by laser additive manufacturing. The results are shown in […]. Figure 11 The soft magnetic properties of the sample were tested at room temperature using a vibrating sample magnetometer (VSM). The results showed that the sample's saturation magnetization was 172 emu / g and its coercivity was 92 Oe (…). Figure 11The soft magnetic properties of the alloy, characterized by low coercivity and high saturation magnetization, provide the core foundation for its excellent electromagnetic shielding performance.

[0085] (5) Verify the electromagnetic shielding performance of the laser additive manufacturing Fe-Co based alloy samples. The results are shown in […]. Figures 12-14 To test the electromagnetic shielding effectiveness in the 18.5-26.5 GHz range, a vector network analyzer was used to test the samples within this frequency range. The test parameters were room temperature and an unshielded environment. The shielding effectiveness, absorption effectiveness, and reflection effectiveness of the alloy were calculated through analysis of the test data. The results show that the highest electromagnetic shielding effectiveness of the samples in the 18.5-26.5 GHz range is 101 dB, the average electromagnetic shielding effectiveness is 87 dB, and the absorption effectiveness accounts for 84% (…). Figures 12-14 This achieves effective electromagnetic shielding and meets the requirements for the use of high-efficiency electromagnetic shielding equipment.

Claims

1. An alloy powder with ultra-high electromagnetic shielding performance, characterized in that: The chemical composition of the alloy powder, by mass fraction, includes: Fe: 50%~60%, Co: 20%~30%, Ni: 2%~10%, Cu: 1%~2%, Mo: 2%~5%, Si: 2%~5%, B: 1%~6%, Y: 0.1%~0.5%, La: 0.1%~0.5%, and Nd: 0.1%~0.5%.

2. The ultra-high electromagnetic shielding performance alloy powder according to claim 1, characterized in that: The chemical composition of the alloy powder, by mass fraction, includes: Fe: 57%~58%, Co: 27%~28%, Ni: 3%~4%, B: 2%~3%, Cu: 1%~2%, Mo: 3%~5%, Si: 3%~4%, Y: 0.10%~0.25%, La: 0.10%~0.25%, and Nd: 0.10%~0.15%.

3. The ultra-high electromagnetic shielding performance alloy powder according to claim 1, characterized in that: The alloy powder is spherical with a sphericity ≥99%, a flowability of 17~20 s / 50 g, and a loose packing density of 4.0~4.5 g / cm³. 3 Hollow sphere ratio ≤2%, oxygen content ≤0.05%, particle size 15~150 μm.

4. The method for preparing ultra-high electromagnetic shielding performance alloy powder according to any one of claims 1 to 3, characterized in that: The alloy powder is prepared by vacuum induction melting gas atomization method, specifically including melting power of 58~65 kW, melting temperature of 1350~1400 ℃, vacuum degree of 0.48~0.52 Pa, and argon atomization pressure of 2.0~3.0 MPa.

5. A method for preparing a novel alloy material with ultra-high electromagnetic shielding performance using laser additive manufacturing, characterized in that: Includes the following steps: (1) Sieving: The alloy powder according to any one of claims 1 to 3 is sieved to select powder with a particle size of 50 to 150 μm for later use; (2) Substrate pretreatment: After grinding and polishing and ultrasonic cleaning, the additive manufacturing substrate is dried at 100~120 ℃ for 15~25 min and then set aside. (3) Powder spreading and printing: The alloy powder obtained in step (1) is evenly spread on the surface of the substrate obtained in step (2) in a powder spreading manner. Under the protection of inert gas, a semiconductor laser is used for printing. After the first additive manufacturing layer cools to room temperature, the above powder spreading and printing steps are repeated to obtain a new type of laser additive manufacturing alloy material with ultra-high electromagnetic shielding performance of the required thickness.

6. The preparation method according to claim 5, characterized in that: In step (3), the parameters of the semiconductor laser are: laser energy density of 145~191 J / mm². 2 The scanning spacing is 2~2.5 mm, the overlap rate is 30%~40%, and the spot size is 4×4 mm. 2 .

7. The preparation method according to claim 5, characterized in that: In step (3), the inert protective gas is argon with a purity ≥99.99% and an argon flow rate of 10~20 L / min.

8. The preparation method according to claim 5, characterized in that: In step (3), the thickness of each layer of powder is 0.4~0.5 mm.

9. A novel alloy material with ultra-high electromagnetic shielding performance prepared by laser additive manufacturing according to any one of claims 5 to 8, characterized in that: The alloy material has a density of 99.5%~99.9%, a hardness of 700~877 HV, a saturation magnetization of 171.6~177.3 emu / g, a coercivity of 85~103 Oe, a remanent magnetization of 2.1~4.9 emu / g, and a shielding effectiveness of 70~120 dB in the frequency band of 18.5-26.5 GHz.

10. The novel alloy material with ultra-high electromagnetic shielding performance for laser additive manufacturing according to claim 9, characterized in that: The microstructure of the alloy material mainly consists of α-Fe(BCC), Fe2B, and Co. 21 Mo2B6, Fe 11 The composition consists of Co5 and a small amount of rare earth phases, with corresponding volume fractions of 58-61 vol.%, 16-24 vol.%, 9-16 vol.%, 5-8 vol.%, and <2 vol.%, respectively. The rare earth phases include Fe. 17 Nd2、(Y 0.5 La 0.25 Nd 0.25 FeO3 and YFe 10 Mo2.

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