Nickel-iron-molybdenum alloy electromagnetic absorption ink for 3D printing and preparation method of nickel-iron-molybdenum alloy electromagnetic absorption ink

Abstract

The invention relates to nickel-iron-molybdenum alloy electromagnetic absorption ink for 3D printing and a preparation method of the nickel-iron-molybdenum alloy electromagnetic absorption ink, and belongs to the field of ink processing. The nickel-iron-molybdenum alloy electromagnetic absorption ink is prepared from the following raw materials in parts by mass: 7 to 15 parts of a nickel-iron-molybdenum alloy electromagnetic absorbent, 45 to 60 parts of organic silicon modified polyurethane acrylate, 15 to 25 parts of hyperbranched polyacrylate resin, 10 to 15 parts of acryloylmorpholine, 2.5 to 5 parts of a photoinitiator, 0.8 to 2.5 parts of a defoaming agent, 1 to 3 parts of a dispersing agent and 2 to 4.5 parts of a surfactant. According to the nickel-iron-molybdenum alloy electromagnetic absorption ink for ultraviolet curing 3D printing, the electromagnetic wave absorption capacity of a material is greatly improved, and the ink has a wide absorption frequency band. The cured material has high wear resistance, stable physical and chemical properties at high temperature, and is not easy to deform, and can be applied to rapid manufacturing of high-precision electromagnetic absorbers with different shapes in military and civil fields.

Description

Technical Field

[0001] The present invention relates to the field of ink processing, and in particular, to a nickel-iron-molybdenum alloy electromagnetic absorption ink for 3D printing and a preparation method thereof, and more particularly, to a nickel-iron-molybdenum alloy electromagnetic absorption ink suitable for ultraviolet light-curing 3D printing and a preparation method thereof. Background Art

[0002] With the development of modern science and technology, electromagnetic radiation has become an inevitable pollution source, and its impact on human production and life is increasing day by day. Military and civilian electronic instruments are becoming more and more miniaturized, and higher requirements are put forward for the precision of equipment, the stability of instruments, the security of data, etc. The interference of electromagnetic radiation on electronic instruments will affect the normal operation of space exploration equipment, military machines, scientific equipment, surveillance cameras, etc. Electromagnetic radiation may also pose a threat to human health. For example, long-term exposure to electromagnetic radiation will increase the risk of cancer, heart disease, skin diseases and many other diseases. Electromagnetic absorption materials are materials that can convert the incident harmful electromagnetic wave energy into other forms of energy and dissipate it, and are rarely reflected back.

[0003] Polymer-based electromagnetic absorption materials have the advantages of high flexibility, good corrosion resistance, low cost, good processability, etc., and can better meet the requirements of fields such as aerospace and electronic communication, showing great advantages in the field of electromagnetic absorption materials. At present, when preparing polymer-based electromagnetic absorbers by 3D printing, mainly fused deposition modeling (FDM) type 3D printers are used, and the printing accuracy of this type of printer is not high (generally the accuracy is 500 μm). UV light-curing molding (DLP, SLA type) is one of the 3D printing methods with the highest accuracy (generally the accuracy is 10 μm). It cures and forms through the chain polymerization reaction of monomers and prepolymers in the resin triggered by ultraviolet light. By selecting UV light-curing resin as the matrix material and filling electromagnetic absorption agents to prepare electromagnetic absorption ink, and using UV light-curing 3D printing for printing, various complex-shaped and high-precision electromagnetic absorbers can be quickly designed and printed, expanding the application range of electromagnetic absorption materials.

[0004] At present, polymer-based electromagnetic absorbers are mainly formed through molds and calendering. The process is complex, the production cycle is long, and the accuracy is poor. 3D printing technology, also known as 3D rapid prototyping technology, is an additive manufacturing technology. First, the model structure is designed using 3D modeling software in a computer, and then a 3D object with a complex structure is quickly manufactured through precise 3D stacking and forming. In some literature, a fused deposition modeling (FDM) type 3D printer is used to prepare electromagnetic absorption materials, but the printing accuracy of this printer is not high (generally with an accuracy of 500 μm). The added electromagnetic absorbers are mainly carbon materials (electric loss materials) and magnetic metal oxide materials (magnetic loss materials). The electromagnetic wave absorption width is relatively narrow, the mechanical strength of the materials is poor, they are not wear-resistant, easy to break, and prone to deformation at high temperatures. Summary of the Invention

[0005] In view of this, in order to solve the above-mentioned many technical problems, the present invention provides a nickel-iron-molybdenum alloy electromagnetic absorption ink suitable for ultraviolet light-curing 3D printing and a preparation method thereof.

[0006] The first object of the present invention is to provide a nickel-iron-molybdenum alloy electromagnetic absorption ink suitable for ultraviolet light-curing 3D printing. By using organosilicon-modified polyurethane acrylate, hyperbranched polyacrylate resin, and acryloylmorpholine in combination, the resins in the formula have good mutual compatibility, no delamination phenomenon, and enhance the wetting effect on the nickel-iron-molybdenum alloy. At the same time, it has good stability, fluidity, and rapid curing and forming performance. When added to a light-curing 3D printer, the ink can meet the printing requirements. After curing and forming, it has good dimensional stability, high mechanical strength, stable physical and chemical properties under high-temperature conditions, is not easy to deform, has very strong electromagnetic absorption ability, and a relatively wide absorption band. It can be applied to the rapid manufacturing of electromagnetic absorbers with various shapes and high precision in military and civilian fields.

[0007] The second object of the present invention is to provide a preparation method for the above-mentioned nickel-iron-molybdenum alloy electromagnetic absorption ink suitable for ultraviolet light-curing 3D printing. The preparation method has the advantages of being able to completely retain the effective components of the raw materials, and is simple and easy to operate, with the front and back steps being closely connected and the operating conditions being mild.

[0008] In order to achieve the above objects of the present invention, the following technical solutions are adopted:

[0009] A nickel-iron-molybdenum alloy electromagnetic absorption ink for 3D printing is mainly prepared from the following raw materials: by mass, 7-15 parts of nickel-iron-molybdenum alloy electromagnetic absorber, 45-60 parts of organosilicon-modified polyurethane acrylate, 15-25 parts of hyperbranched polyacrylate resin, 10-15 parts of acryloylmorpholine, 2.5-5 parts of photoinitiator, 0.8-2.5 parts of defoamer, 1-3 parts of dispersant, and 2-4.5 parts of surfactant.

[0010] In order to further optimize the raw material formula, the amounts of raw materials are as follows: 8.5 - 10 parts of nickel-iron-molybdenum alloy electromagnetic absorber, 50.5 - 53 parts of organosilicon-modified polyurethane acrylate, 17.5 - 19 parts of hyperbranched polyacrylate resin, 11 - 12.5 parts of acryloylmorpholine, 3.5 - 4 parts of photoinitiator, 1 - 1.5 parts of defoamer, 1.5 - 2 parts of dispersant, and 3 - 3.5 parts of surfactant.

[0011] In addition, the amounts of raw materials can also be: 8 - 13 parts of nickel-iron-molybdenum alloy electromagnetic absorber, 49 - 58 parts of organosilicon-modified polyurethane acrylate, 17 - 22 parts of hyperbranched polyacrylate resin, 11 - 13.5 parts of acryloylmorpholine, 3.5 - 4.5 parts of photoinitiator, 1.2 - 1.8 parts of defoamer, 2 - 2.8 parts of dispersant, and 2.5 - 3.8 parts of surfactant.

[0012] More preferably, 10.2 - 11.5 parts of nickel-iron-molybdenum alloy electromagnetic absorber, 52.5 - 55.5 parts of organosilicon-modified polyurethane acrylate, 17.5 - 19 parts of hyperbranched polyacrylate resin, 12 - 13 parts of acryloylmorpholine, 3.9 - 4.2 parts of photoinitiator, 1.5 - 1.7 parts of defoamer, 2.4 - 2.7 parts of dispersant, and 2.8 - 3.3 parts of surfactant.

[0013] Among them, for the nickel-iron-molybdenum alloy electromagnetic absorber, by mass percentage, the content of nickel is 80 - 82%, the content of iron is 15 - 19%, and the content of molybdenum is 1 - 3%. The nickel-iron-molybdenum alloy electromagnetic absorber is in powder form, and the powder particle size ≤ 50 microns. The nickel-iron-molybdenum alloy electromagnetic absorber used has the characteristics of fine particles, strong electromagnetic loss ability, wide electromagnetic absorption frequency band, acid and alkali resistance, light and heat resistance, stable chemical properties, and good resin affinity. Nickel-iron-molybdenum alloy is a special soft magnetic alloy, which has good magnetic properties, small change in magnetic permeability and small change in saturation at high temperature, high corrosion resistance and excellent mechanical properties, good thermal stability, and certain electrical conductivity. Using nickel-iron-molybdenum alloy as an electromagnetic absorber and adding it to UV curable resin to prepare nickel-iron-molybdenum alloy electromagnetic absorption ink has a synergistic electromagnetic wave dissipation effect of magnetic loss and electrical loss, which can greatly improve the electromagnetic wave absorption ability of the material.

[0014] The organosilicon-modified polyurethane acrylate has 3 - 6 functional groups, a molecular weight of 15000 - 20000, an appearance of light yellow or colorless transparent viscous liquid, and a viscosity of 20 - 50 Pa·s.

[0015] The hyperbranched polyacrylate resin has a degree of branching of 0.5 - 0.9, a molecular weight of 1500 - 10000, an appearance of light yellow or colorless transparent viscous liquid, and a viscosity of 8 - 10 Pa·s.

[0016] Through modification treatment, the two resins have good wetting effects on electromagnetic absorbers, and at the same time have the characteristics of fast curing speed, strong wear resistance and high mechanical strength. They can meet the grinding performance and printing performance of inks, and the inks using organosilicon-modified polyurethane acrylate and hyperbranched polyacrylate resins can be printed on ultraviolet-curing 3D printers (DLP, SLA types), which can significantly improve the curing speed of the inks and the mechanical strength after curing.

[0017] Preferably, the photoinitiator is 2,4,6-trimethylbenzoyl diphenylphosphine oxide.

[0018] Preferably, the defoamer in the present invention is a polyether silicone copolymer defoamer, including BYK-810, TEGO 920, TEGO 843, TEGO 883 and / or TEGO 825. In this way, by reducing the surface tension of raw materials during the production of inks, the purpose of inhibiting the generation of foam can be achieved.

[0019] Preferably, the dispersant is a high molecular weight polymer solution, including BYK-163, BYK-9077, BYK-9151, BYK-111 and / or TEGO Dispers 670 wetting dispersant. The concentration of the active component contained is above 40wt%, which can reduce the time and energy required to complete the dispersion process, stabilize the dispersed nickel-iron-molybdenum alloy electromagnetic absorber, and can also modify the surface properties of the absorber particles and adjust the motility of the nickel-iron-molybdenum alloy electromagnetic absorber particles. It is found through experiments that the effect is better when the content of the active component is above 40wt%.

[0020] Preferably, the surfactant is a polysiloxane-polyether copolymer surfactant, including TEGOTwin4100, Dow HW 1000, Sangjing Chemical ST-333 and / or Sangjing Chemical COATOSIL 77, which can significantly reduce the surface tension and increase the wettability of the ink to the substrate.

[0021] It should be noted that from the amounts of each raw material, it can be seen that the addition amount of the silicone-modified polyurethane acrylate is relatively large. It is both the main raw material and the main substance providing the viscosity required for the ink. Therefore, its addition amount is relatively large. If the addition amount is too small, the dispersibility and performance required by the present invention may not be achieved. The hyperbranched polyacrylate resin plays a role in increasing the curing speed, and acryloylmorpholine plays a role in enhancing the mechanical strength after curing. It is mainly used in combination with the silicone-modified polyurethane acrylate, so the addition amount is relatively small. 2,4,6-Trimethylbenzoyl diphenylphosphine oxide is a free radical polymerization photoinitiator suitable for the ultraviolet light source of 3D printers (DLP, SLA types). The specific addition amounts of these raw materials were determined through a large amount of creative work by the inventor. Only when controlled within an appropriate range can the prepared nickel-iron-molybdenum alloy electromagnetic absorption ink for UV-curable 3D printing meet the required performance. If the addition amount of a certain raw material is too large or too small, it will affect the mechanical properties of the final ink. In addition, although various additives are common raw materials in this field and are also added correspondingly in other 3D printing ink formulations, their amounts have been adjusted accordingly to adapt to the specific raw material system of the present invention. It is necessary to strictly follow the scheme of the present invention for operation and batching, and do not randomly change the batching amounts.

[0022] The ink of the present invention can be used on a photo-curable 3D printer with a printing accuracy of 10 μm and can print various complex-shaped and high-precision microwave absorbers. The main raw materials in this ink are aliphatic polyurethane acrylate, hyperbranched polyacrylate resin, and acryloylmorpholine. Among them, the hyperbranched polyacrylate resin can provide the high mechanical strength required for the ink, and the aliphatic polyurethane acrylate can provide the high toughness required for the ink. The nickel-iron-molybdenum alloy, as an electromagnetic absorber, is added to the UV-curable resin to prepare the nickel-iron-molybdenum alloy electromagnetic absorption ink, which has a synergistic electromagnetic wave dissipation effect of magnetic loss and electrical loss, can greatly improve the electromagnetic wave absorption ability of the material, and the material has relatively high wear resistance, stable physical and chemical properties under high-temperature conditions, and is not easily deformed.

[0023] The nickel-iron-molybdenum alloy electromagnetic absorption ink for UV-curable 3D printing of the present invention is only applicable to UV-curable 3D printers (DLP, SLA types) and is not applicable to other types of 3D printers, which has specificity. For example, laser etching type and fused deposition modeling 3D printers are not applicable to the ink of the present invention. When the inventor carried out specific practices, reasonable batching was specifically carried out for UV-curable 3D printers, and the performance of its ink is also more suitable for the electromagnetic absorption field. Since the performance index requirements and standards of UV-curable 3D printing inks in other industries are different, when formulating the raw materials of the ink, the types and amounts of the formulations definitely need to be adjusted accordingly.

[0024] In addition to providing an electromagnetic absorption ink of nickel-iron-molybdenum alloy for UV-curable 3D printing, the present invention also provides a preparation method of the 3D printing ink, which includes the following steps: mixing all raw materials, first performing mechanical stirring, after mixing evenly, performing grinding and dispersion, passing quality inspection, filtering and packaging to obtain the ink. Among them, the nickel-iron-molybdenum alloy mainly plays the role of electromagnetic absorption in the ink. The organosilicon-modified polyurethane acrylate is one of the main components in the ink, which plays the role of dispersing the nickel-iron-molybdenum alloy absorbent and enables the ink to have UV-curing characteristics during printing, forming a polymer matrix with a certain mechanical strength after drying, which plays a protective role for the nickel-iron-molybdenum alloy absorbent. The hyperbranched polyacrylate resin and acryloylmorpholine have a synergistic effect, which can improve the mechanical strength, curing speed and stability of the ink, etc. The dispersant is a surfactant, which can reduce the interfacial tension between liquid and solid, enhance the wettability of the absorbent, improve the mixing and stirring efficiency. The dispersant adsorbs on the surface of the absorbent to form a charge effect or steric hindrance effect, preventing the nickel-iron-molybdenum alloy from flocculating and settling, and keeping the ink in a stable state. Since the ink is extremely easy to generate bubbles during stirring and grinding, affecting the efficiency and effect of grinding, an antifoaming agent should be added to the ink system. During 3D printing, it is required that the ink has a good leveling effect to ensure the smooth surface and precision requirements of the printed structure, so a surfactant needs to be added to reduce the surface tension of the ink system.

[0025] Among them, the mixing rate of all raw materials by mechanical stirring is controlled between 260-350 rpm, and the stirring time is controlled between 25-50 min.

[0026] Preferably, a sand mill is used during the grinding process. The working pressure of the diaphragm pump of the sand mill is between 0.28-0.45 MPa, and it is ground repeatedly for 2-5 times to make the particle size of the ink product more uniform and the flatness better.

[0027] In addition, the ink of the present invention has good printing applicability, and the particle size of the grinding is controlled below 9.7 μm, preferably between 5.4-9.5 μm.

[0028] The preparation method of the nickel-iron-molybdenum alloy electromagnetic absorption ink in the embodiment of the present invention has the advantages of being able to completely retain the effective components of the raw materials, and having the advantages of simple method, easy to operate, tight connection between front and back steps, mild operating conditions, etc. The inventor also finally adopted a better preparation route through repeated experiments.

[0029] The present invention does not generate any waste residue during the whole operation process, is green and environmentally friendly, and the operation process is relatively simple and easy to industrialize. The above preparation method is only a better one among many preparation methods, and does not represent the only preparation method. As long as the ink preparation method with the effect of the present invention is prepared by using the raw materials of the present invention, it is within the protection scope of the present invention.

[0030] In addition, the present invention also provides an application of a nickel-iron-molybdenum alloy electromagnetic absorption ink for 3D printing in ultraviolet light-curing 3D printing. This ink can be used in UV light-curing DLP-type and SLA-type 3D printers. The DLP 3D printer includes Creality LD-003, and the SLA 3D printer includes Formlabs form3+.

[0031] The ink of the present invention has good printing quality, strong electromagnetic loss ability, wide electromagnetic absorption frequency band, high mechanical strength, good surface flatness, low volume shrinkage rate, fast curing speed, and high forming accuracy. The ink of the present invention can be printed using a UV light-curing (DLP, SLA type) 3D printer to quickly manufacture electromagnetic absorbers with various shapes and high precision.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] (1) In the formula of the ink of the present invention, a nickel-iron-molybdenum alloy is used as an electromagnetic absorber. The nickel-iron-molybdenum alloy is a special soft magnetic alloy. It has good magnetic properties, small changes in magnetic permeability and saturation at high temperatures, high corrosion resistance, excellent mechanical properties, good thermal stability, and certain electrical conductivity. The electromagnetic absorption ink prepared using this absorber can play a synergistic electromagnetic wave dissipation effect of magnetic loss and electrical loss, can greatly improve the electromagnetic wave absorption ability of the material, and has a relatively wide absorption frequency band. The cured material has high wear resistance, stable physical and chemical properties and is not easily deformed under high temperature conditions, and can be used for the rapid manufacture of electromagnetic absorbers with various shapes and high precision in military and civilian fields.

[0034] (2) The ultraviolet light-curing 3D printing nickel-iron-molybdenum alloy electromagnetic absorption ink of the present invention is suitable for printing using a UV light-curing (DLP, SLA type) 3D printer. The production process of this ink is simple, it has good leveling property, high mechanical strength, good surface flatness, low volume shrinkage rate, fast curing speed, and high forming accuracy after curing. General metal alloy 3D printing inks are most likely to have problems such as slow curing speed, poor dispersibility, poor stability, and easy sedimentation, and cannot meet the requirements of printing machines. However, the present invention has well solved this technical problem through reasonable combination and ratio of raw materials.

[0035] (3) The preparation method of the ultraviolet light-curing 3D printing nickel-iron-molybdenum alloy electromagnetic absorption ink of the present invention has the advantages of being able to completely retain the effective components of the raw materials, and also has the advantages of simple method, easy operation, tight connection between front and back steps, and mild operation conditions. The inventor finally adopted a relatively optimal preparation route through repeated experiments. Description of the Drawings

[0036] Figure 1Schematic diagram of the mechanical property test sample and electromagnetic parameter test sample for 3D printing

[0037] Figure 2 Coaxial method sample size of the electromagnetic parameter test sample Specific implementation mode

[0038] The following will describe the implementation scheme of the present invention in detail in combination with embodiments. However, those skilled in the art will understand that the following embodiments are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. For those not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. For the reagents or instruments not specified for the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0039] The electromagnetic absorption ink of nickel-iron-molybdenum alloy applicable to ultraviolet light-curing 3D printing of the present invention is mainly prepared from the following raw materials: by mass, 7-15 parts of nickel-iron-molybdenum alloy electromagnetic absorber, 45-60 parts of organosilicon-modified polyurethane acrylate, 15-25 parts of hyperbranched polyacrylate resin, 10-15 parts of acryloylmorpholine, 2.5-5 parts of photoinitiator 2,4,6-trimethylbenzoyl diphenylphosphine oxide, 0.8-2.5 parts of defoaming agent, 1-3 parts of dispersant, and 2-4.5 parts of surfactant. The preparation method includes: mixing all raw materials evenly, grinding and dispersing, and then passing quality inspection, filtering and packaging to obtain the product.

[0040] The raw materials used in the following examples: Nickel-iron-molybdenum alloy electromagnetic absorber: the content of nickel is 80-82 wt.%, the content of iron is 15-19 wt.%, the content of molybdenum is 1-3 wt.%, the powder particle size ≤ 50 microns, Shanghai Alloy Powder Science Research Center; Organosilicon-modified polyurethane acrylate: Shanghai Yinchang YC 5016; Hyperbranched polyacrylate resin: Shanghai Yinchang YC2509S; Photoinitiator: 2,4,6-trimethylbenzoyl diphenylphosphine oxide; Defoaming agent: TEGO 843; Dispersant: TEGO Dispers670; Surfactant: TEGO Twin4100.

[0041] Example 1

[0042] The preparation method of the electromagnetic absorption ink of nickel-iron-molybdenum alloy applicable to ultraviolet light-curing 3D printing is as follows:

[0043] 1) Weigh each raw material according to the following quality: 12 kg of nickel-iron-molybdenum alloy electromagnetic absorber, 52 kg of organosilicon-modified polyurethane acrylate, 16.5 kg of hyperbranched polyacrylate resin, 11.5 kg of acryloylmorpholine, 2.6 kg of photoinitiator 2,4,6-trimethylbenzoyl diphenylphosphine oxide, 1.6 kg of defoaming agent, 1.3 kg of dispersant, and 2.5 kg of surfactant;

[0044] 2) Weigh the above components and pour them into a stirring device. Stir at a speed of 290 rpm for 46 minutes using a mechanical stirrer, then grind and disperse with a sand mill. The working pressure of the diaphragm pump is 0.4 MPa, and grind repeatedly for 3 - 4 times until the particle size is below 8.4 μm. If the particle size does not meet the standard, continue grinding. Finally, test the various indicators and properties of the ink. After passing the test, filter and package to obtain the finished product.

[0045] Example 2

[0046] The preparation method of nickel - iron - molybdenum alloy electromagnetic absorption ink applicable to ultraviolet - curable 3D printing is as follows:

[0047] 1) Weigh each raw material according to the following mass: 7.5 kg of nickel - iron - molybdenum alloy electromagnetic absorber, 53.5 kg of organosilicon - modified polyurethane acrylate, 20.5 kg of hyperbranched polyacrylate resin, 10.3 kg of acryloylmorpholine, 3.2 kg of photo - initiator 2,4,6 - trimethylbenzoyl diphenylphosphine oxide, 1 kg of defoamer, 1.6 kg of dispersant, 2.4 kg of surfactant;

[0048] 2) Weigh the above components and pour them into a stirring device. Stir at a speed of 310 rpm for 28 minutes using a mechanical stirrer, then grind and disperse with a sand mill. The working pressure of the diaphragm pump is 0.42 MPa, and grind repeatedly for 2 - 4 times until the particle size is below 9.1 μm. If the particle size does not meet the standard, continue grinding. Finally, test the various indicators and properties of the ink. After passing the test, filter and package to obtain the finished product.

[0049] Example 3

[0050] The preparation method of nickel - iron - molybdenum alloy electromagnetic absorption ink applicable to ultraviolet - curable 3D printing is as follows:

[0051] 1) Weigh each raw material according to the following mass: 11 kg of nickel - iron - molybdenum alloy electromagnetic absorber, 48.8 kg of organosilicon - modified polyurethane acrylate, 19.5 kg of hyperbranched polyacrylate resin, 10.6 kg of acryloylmorpholine, 3.2 kg of photo - initiator 2,4,6 - trimethylbenzoyl diphenylphosphine oxide, 1.3 kg of defoamer, 2.1 kg of dispersant, 3.5 kg of surfactant;

[0052] 2) Weigh the above components and pour them into a stirring device. Stir at a speed of 270 rpm for 43 minutes using a mechanical stirrer, then grind and disperse with a sand mill. The working pressure of the diaphragm pump is 0.36 MPa, and grind repeatedly for 3 - 4 times until the particle size is between 6.5 - 8.5 μm. If the particle size does not meet the standard, continue grinding. Finally, test the various indicators and properties of the ink. After passing the test, filter and package to obtain the finished product.

[0053] Example 4

[0054] The preparation method of nickel-iron-molybdenum alloy electromagnetic absorption ink applicable to ultraviolet light-curing 3D printing is as follows:

[0055] 1) Weigh each raw material according to the following mass: 8.6 kg of nickel-iron-molybdenum alloy electromagnetic absorber, 48.4 kg of organosilicon-modified polyurethane acrylate, 20 kg of hyperbranched polyacrylate resin, 13.2 kg of acryloylmorpholine, 4.1 kg of photoinitiator 2,4,6-trimethylbenzoyl diphenylphosphine oxide, 1.7 kg of defoamer, 2.2 kg of dispersant, and 4 kg of surfactant;

[0056] 2) Pour the above components into a stirring device after weighing, stir at a speed of 310 rpm by a mechanical stirrer for 25 min, then grind and disperse with a sand mill. The working pressure of the diaphragm pump is 0.38 MPa, and grind repeatedly for 2 - 3 times until the particle size is below 7.6 μm. If the particle size does not meet the standard, continue to grind. Finally, detect the various indexes and properties of the ink. After passing the test, filter and package to obtain the finished product.

[0057] Example 5

[0058] The preparation method of nickel-iron-molybdenum alloy electromagnetic absorption ink applicable to ultraviolet light-curing 3D printing is as follows:

[0059] 1) Weigh each raw material according to the following mass: 14 kg of nickel-iron-molybdenum alloy electromagnetic absorber, 49.4 kg of organosilicon-modified polyurethane acrylate, 18 kg of hyperbranched polyacrylate resin, 10.3 kg of acryloylmorpholine, 2.7 kg of photoinitiator 2,4,6-trimethylbenzoyl diphenylphosphine oxide, 1.6 kg of defoamer, 1.8 kg of dispersant, and 2.2 kg of surfactant;

[0060] 2) Pour the above components into a stirring device after weighing, stir at a speed of 340 rpm by a mechanical stirrer for 28 min, then grind and disperse with a sand mill. The working pressure of the diaphragm pump is 0.43 MPa, and grind repeatedly for 2 - 4 times until the particle size is between 6.2 - 8.7 μm. If the particle size does not meet the standard, continue to grind. Finally, detect the various indexes and properties of the ink. After passing the test, filter and package to obtain the finished product.

[0061] Example 6

[0062] The preparation method of nickel-iron-molybdenum alloy electromagnetic absorption ink applicable to ultraviolet light-curing 3D printing is as follows:

[0063] 1) Weigh each raw material according to the following mass: 7.3 kg of nickel-iron-molybdenum alloy electromagnetic absorber, 57.6 kg of organosilicon-modified polyurethane acrylate, 16.8 kg of hyperbranched polyacrylate resin, 10.7 kg of acryloylmorpholine, 2.5 kg of photoinitiator 2,4,6-trimethylbenzoyl diphenylphosphine oxide, 1.2 kg of defoamer, 1.4 kg of dispersant, and 2.6 kg of surfactant;

[0064] 2) Weigh the above components and pour them into a stirring device. Stir at a speed of 330 rpm for 29 minutes with a mechanical stirrer, and then grind and disperse with a sand mill. The working pressure of the diaphragm pump is 0.31 MPa, and grind repeatedly for 3 - 4 times until the particle size is between 6.1 - 9.2 μm. If the particle size does not meet the standard, continue grinding. Finally, detect the various indicators and performance of the ink. After passing the standard, filter and package to obtain the finished product.

[0065] Performance test:

[0066] Take the nickel - iron - molybdenum alloy electromagnetic absorption ink produced in Examples 1 - 6, which is applicable to ultraviolet - curable 3D printing, for printing performance detection. Use an ultraviolet - curable 3D printer (Creative 3D LD - 003 3D printer) to print electromagnetic absorption materials. As Figure 1 shown, the samples for 3D printing mechanical property test and electromagnetic parameter test are presented. Both the samples for 3D printing mechanical property test and electromagnetic parameter test include real part and imaginary part, and test the mechanical properties and electromagnetic properties.

[0067] 1. Particle size μm: Refer to GB / T 1724 - 2019 Detection of Grinding Fineness of Printing Ink.

[0068] 2. Young's modulus MPa, tensile fracture length %, tensile stress MPa: Refer to GBT1040.2 - 2022 Determination of Tensile Properties of Plastics.

[0069] 3. Surface tension mN / m: Test at 25 °C using a surface tension meter.

[0070] 4. Conductivity, permeability, electromagnetic loss (dB): Use a vector network analyzer (VNA, N5234APAN - L, Agilent, USA) to analyze the electromagnetic parameters of the material, and the test frequency range is 2 - 18 GHz.

[0071] The electromagnetic performance test of the sample is carried out on a vector network analyzer. The coaxial test fixture is connected to the two ports of the vector microwave network analyzer through two coaxial cables. Calibrate the system before measurement, and then carefully place the sample in the fixture, and test the electromagnetic parameters through the vector network analyzer.

[0072] For coaxial samples, as Figure 1 shown is the structural schematic diagram of the coaxial sample of the specimen. As Figure 2 shown are the dimensions of the coaxial - method sample. Its dimensions are: inner diameter is 3.04 mm, outer diameter is 7 mm, and thickness is 2 mm.

[0073] The specific process of sample preparation is as follows:

[0074] (1) Calculate and weigh the UV-curable microwave absorption material to be tested according to the pre-determined ratio;

[0075] (2) Pour the UV-curable microwave absorption material into the mold;

[0076] (3) Perform photocuring on the UV-curable microwave absorption material in the mold;

[0077] (4) After complete curing, use a blade and fine sandpaper to level the surface of the sample to achieve the appropriate size.

[0078] Further analyze the electromagnetic wave absorption performance of the composite material using the measured electromagnetic parameters, and study the relationship between the loss value RL of the electromagnetic wave reflection absorbed by a single-layer flat plate of the same thickness and the frequency. Based on the electromagnetic parameters, calculate the electromagnetic loss according to the absorption screen theory.

[0079] RL(dB) = 20log|(Z in - 1) / (Z in + 1)| (1)

[0080] Z in = Z0(μ γ / ε γ ) 1 / 2 tanh[j(2πfd / c)(μ γ ε γ ) 1 / 2 (2)

[0081] Among them, Z in and Z0 respectively represent the normalized input impedance of the wave-absorbing material and the input impedance of free space, while μ γ and ε γ respectively represent the relative permeability and permittivity of the material, d is the thickness of the absorption layer, c represents the speed of light, and f represents the free space frequency of the electromagnetic wave. As long as ε is large enough, the larger μ is, the better the absorption of electromagnetic waves. However, ε and μ are not simply the larger the better, and other influencing factors such as impedance and specific materials also need to be considered.

[0082] The specific test results are shown in Table 1 below:

[0083] Table 1 Test Results

[0084]

[0085]

[0086] As can be seen from the above table, the ink of the present invention has appropriate viscosity, uniform particle size, strong electromagnetic loss ability, wide electromagnetic absorption frequency band, high mechanical strength, good surface flatness, low volume shrinkage rate, fast curing speed, high forming accuracy, and good printing performance. Such effects are inseparable from the specific raw material formula adopted in the present invention.

[0087] The electromagnetic absorption ink of nickel-iron-molybdenum alloy for ultraviolet-curable 3D printing in the embodiment of the present invention uses nickel-iron-molybdenum alloy as an electromagnetic absorber, which can play a synergistic electromagnetic wave dissipation role of magnetic loss and electrical loss, greatly improving the electromagnetic wave absorption ability of the material and having a wide absorption frequency band. The aliphatic polyurethane acrylate, hyperbranched polyacrylate resin and acryloylmorpholine are compounded as the polymer matrix material. After curing, the material has high wear resistance, stable physical and chemical properties and is not easy to deform under high temperature conditions, and can be applied to the rapid manufacturing of electromagnetic absorbers with various shapes and high precision in military and civilian fields.

[0088] Although the present invention has been illustrated and described with reference to specific embodiments, it should be realized that many other changes and modifications can be made without departing from the spirit and scope of the present invention. Therefore, this means that all such changes and modifications that fall within the scope of the present invention are included in the appended claims.

Claims

1. A nickel-iron-molybdenum alloy electromagnetic absorption ink for 3D printing, characterized in that: It is prepared from the following raw materials: by mass, 7-15 parts of nickel-iron-molybdenum alloy electromagnetic absorber, 45-60 parts of organosilicon-modified polyurethane acrylate, 15-25 parts of hyperbranched polyacrylate resin, 10-15 parts of acryloylmorpholine, 2.5-5 parts of photoinitiator, 0.8-2.5 parts of defoamer, 1-3 parts of dispersant, and 2-4.5 parts of surfactant.

2. The electromagnetic absorption ink made of nickel-iron-molybdenum alloy for 3D printing according to claim 1, characterized in that: In the nickel-iron-molybdenum alloy electromagnetic absorber, the nickel content is 80-82 wt.%, the iron content is 15-19 wt.%, and the molybdenum content is 1-3 wt.%.

3. The electromagnetic absorption ink of nickel-iron-molybdenum alloy for 3D printing according to claim 2, characterized in that: The nickel-iron-molybdenum alloy electromagnetic absorber is in powder form, and the powder particle size is ≤50 microns.

4. The electromagnetic absorption ink of nickel-iron-molybdenum alloy for 3D printing according to claim 1, wherein: The organosilicon-modified polyurethane acrylate has 3-6 functional groups and a molecular weight of 15,000-20,000; the hyperbranched polyacrylate resin has a degree of branching of 0.5-0.9 and a molecular weight of 1500-10,000.

5. The electromagnetic absorption ink made of nickel-iron-molybdenum alloy for 3D printing according to claim 1, wherein: The photoinitiator is 2,4,6-trimethylbenzoyl diphenylphosphine oxide; the defoamer is a polyether silicone copolymer defoamer; the dispersant is TEGO Dispers 670 wetting dispersant; the surfactant is a polysiloxane-polyether copolymer surfactant.

6. The preparation method of the nickel-iron-molybdenum alloy electromagnetic absorption ink for 3D printing according to any one of claims 1-5 includes the following steps: mixing all raw materials, first performing mechanical stirring, after mixing evenly, performing grinding and dispersion, and passing quality inspection and then filtering and packaging.

7. The preparation method of the nickel-iron-molybdenum alloy electromagnetic absorption ink for 3D printing according to claim 6, wherein: The rate of the mechanical stirring is between 260-350 rpm, and the stirring time is between 25-50 min.

8. The preparation method of the nickel-iron-molybdenum alloy electromagnetic absorption ink for 3D printing according to claim 6, wherein: Grinding and dispersion are carried out using a sand mill. The working pressure of the diaphragm pump of the sand mill is 0.28-0.45 MPa, and it is ground repeatedly for 2-5 times to make the particle size of the ink finished product more uniform and the flatness better.

9. The preparation method of the nickel-iron-molybdenum alloy electromagnetic absorption ink for 3D printing according to claim 6, characterized in that: The particle size after grinding is below 9.7 μm.

10. The application of the nickel-iron-molybdenum alloy electromagnetic absorption ink for 3D printing according to any one of claims 1-5 in ultraviolet curable 3D printing.

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