An iron-based magnetic absorbent with corrosion warning and inhibition functions, and its preparation method and application

Abstract

The present invention discloses an iron-based magnetic absorber with corrosion warning and suppression functions, a preparation method, and an application, relating to the technical field of electromagnetic wave absorbing materials. The method includes adding an absorber, a silane coupling agent, and aqueous ammonia to a mixed solvent, mixing and reacting to obtain a dispersion of a silane coupling agent surface-treated absorber; adding 1,10-phenanthroline and / or a 1,10-phenanthroline derivative to the dispersion, stirring and mixing, and centrifugally drying to obtain a modified iron-based magnetic absorber. The present invention uses a silane coupling agent to treat the absorbent surface to enhance the resin-absorbent interface bonding force, and then deposits 1,10-phenanthroline and its derivatives on the absorbent surface by a chemical deposition method.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic absorbing materials, and in particular to an iron-based magnetic absorber with corrosion early warning and suppression functions, a preparation method and applications thereof. Background Art

[0002] The increasing need for modern equipment to conceal itself makes absorbing materials increasingly important. Absorbing materials absorb and dissipate incident electromagnetic waves, reducing the radar reflection area of ​​a target and effectively improving the survivability of equipment systems in specific environments. Iron-based magnetic absorbers, with their high magnetic permeability and high magnetic loss, are a commonly used type of electromagnetic absorber. However, ferromagnetic materials are susceptible to corrosion in environments with high humidity and salt content, which in turn reduces their absorbing performance. To ensure the long-term service of iron-based magnetic absorbers in extremely corrosive environments, they must be modified to be corrosion-resistant.

[0003] In real-world environments, corrosion often begins with tiny pitting. Furthermore, absorbers are often embedded in resin, making corrosion difficult to detect. By the time rust spots appear on the coating surface, the material's absorbing properties have already been severely compromised. To prevent the dangerous loss of absorbing properties, it is necessary to establish a warning and suppression mechanism that can detect and suppress corrosion in the absorbing coating at its earliest stages, facilitating subsequent repairs and minimizing the progression of corrosion.

[0004] 1,10-Phenanthroline is a commonly used metal complexing agent that can react with Fe 2+ The formation of an orange-red complex makes the occurrence of corrosion visible and provides a warning of corrosion. This complex can also adsorb onto metal surfaces to form a dense protective layer, repairing the barrier function of the coating and inhibiting further corrosion. Prior art has used self-healing mechanisms to enhance the corrosion resistance of carbonyl iron coatings, but no reports have yet reported on corrosion warning and suppression mechanisms. If this mechanism could be applied to iron-based magnetic absorbers, it could provide a more effective solution to their corrosion problems. Summary of the Invention

[0005] In view of the deficiencies in the above-mentioned background technology, the present invention mainly solves the problem in the prior art that the corrosion of iron-based magnetic absorbents is difficult to detect and inhibit in the early stage. The present invention provides an iron-based magnetic absorbent with corrosion warning and inhibition functions, as well as a preparation method and application. The method first uses a silane coupling agent to treat the absorbent surface to enhance the resin-absorbent interface bonding force, and then deposits 1,10-phenanthroline and its derivatives on the absorbent surface by chemical deposition. Once the absorbent corrodes, 1,10-phenanthroline and its derivatives will react with the Fe generated by the corrosion. 2+ Ions combine to form red complexes to warn of corrosion; at the same time, they adsorb on the corroded area to form a protective film to repair the corroded damaged area.

[0006] The first object of the present invention is to provide a method for preparing an iron-based magnetic absorbent having corrosion warning and inhibition functions, comprising the following steps:

[0007] Adding the absorbent, silane coupling agent and ammonia water into a mixed solvent, mixing and reacting, and obtaining a dispersion of the silane coupling agent surface-treated absorbent;

[0008] Adding 1,10-phenanthroline and / or 1,10-phenanthroline derivatives to the dispersion, stirring and mixing, and centrifugally drying to obtain a modified iron-based magnetic absorbent;

[0009] Wherein, the mixed solvent is prepared from water and anhydrous ethanol.

[0010] Preferably, the absorbent is one of carbonyl iron, iron-silicon-aluminum alloy, iron-silicon-chromium alloy, iron-silicon alloy, iron-aluminum-boron alloy or amorphous alloy, iron-boron-phosphorus alloy or amorphous alloy, iron-nickel alloy, iron-nickel-molybdenum alloy, iron-chromium-nickel alloy, iron-cobalt-chromium alloy, and iron-cobalt-nickel-chromium alloy; the absorbent is spherical or flaky in shape, with a particle size of 3-40 μm.

[0011] Preferably, the silane coupling agent is one or more of KH-550, KH-560, and KH-792.

[0012] Preferably, the mass ratio of the absorbent, the silane coupling agent and the ammonia solution is (50-80): (5-30): (0.5-4).

[0013] Preferably, the mass ratio of the 1,10-phenanthroline or 1,10-phenanthroline derivative to the absorbent is (5-10):(50-80).

[0014] Preferably, the 1,10-phenanthroline derivative is 1,10-phenanthroline-5-amine and / or 1,10-phenanthroline monohydrate.

[0015] Preferably, the mixing reaction comprises: stirring at 500-800 rpm and keeping warm at 60-80° C. for 3-6 hours;

[0016] The stirring and mixing is performed at 500-800 rpm for 1-3 hours; the centrifugal drying is performed at 8000-10000 rpm for 5-10 minutes, and then drying at 60-80° C. for 10-14 hours.

[0017] Preferably, the mass ratio of anhydrous ethanol to water is 1:1-8.

[0018] The second object of the present invention is to provide an iron-based magnetic absorbent with corrosion warning and inhibition functions.

[0019] The third object of the present invention is to provide an iron-based magnetic absorbent with corrosion warning and inhibition functions for use in electromagnetic absorption.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention provides an iron-based magnetic absorbent with corrosion warning and suppression functions, as well as a preparation method and application. The present invention addresses the problem that iron-based magnetic absorbents are prone to corrosion and difficult to detect, and provides a modified iron-based magnetic absorbent with corrosion warning and suppression functions. First, the silane coupling agent is hydrolyzed, condensed, and adsorbed on the surface of the absorbent. The functional group at the other end is bonded to the active hydroxyl group and amino group in the resin to enhance the interface interaction between the absorbent and the resin. Then, 1,10-phenanthroline and its derivatives are deposited on the surface of the absorbent by physical adsorption. 1,10-phenanthroline and its derivatives are bonded to Fe 2+ The resulting complex develops color to warn of corrosion. Simultaneously, the complex can adsorb onto the absorbent surface to form a protective film, repairing the corroded area and inhibiting the corrosion process, thereby achieving a corrosion warning-inhibition mechanism applicable to iron-based magnetic absorbents. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The actual color of the system of each embodiment and comparative example after immersion for 1 hour. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand and implement the technical solution of the present invention, the present invention is further described below with reference to specific embodiments, but the embodiments are not intended to limit the present invention.

[0024] The purpose of the present invention is to provide an iron-based magnetic absorbent with corrosion warning and suppression functions and a preparation method thereof to address the problem that corrosion of iron-based magnetic absorbents is difficult to detect and suppress in the early stages. The method first uses a silane coupling agent to treat the absorbent surface to enhance the resin-absorbent interface bonding strength, and then deposits 1,10-phenanthroline and its derivatives on the absorbent surface by chemical deposition. Once the absorbent corrodes, 1,10-phenanthroline and its derivatives will react with the Fe generated by the corrosion. 2+ Ions combine to form red complexes to warn of corrosion; at the same time, they adsorb on the corroded area to form a protective film to repair the corroded damaged area.

[0025] In order to achieve the above object, the first aspect of the present invention provides a method for preparing an iron-based magnetic absorbent having corrosion warning and inhibition functions, comprising the following steps:

[0026] Adding the absorbent, silane coupling agent and ammonia water into a mixed solvent, mixing and reacting, and obtaining a dispersion of the silane coupling agent surface-treated absorbent;

[0027] Adding 1,10-phenanthroline and / or 1,10-phenanthroline derivatives to the dispersion, stirring and mixing, and centrifugally drying to obtain a modified iron-based magnetic absorbent;

[0028] Wherein, the mixed solvent is prepared from water and anhydrous ethanol

[0029] The mass ratio of the anhydrous ethanol to water is 1:1-8.

[0030] The modified iron-based magnetic absorbent provided by the present invention is prepared by using an iron-based magnetic absorbent as a substrate, using a silane coupling agent for surface treatment and depositing 1,10-phenanthroline and its derivatives. 1,10-phenanthroline and its derivatives can react with Fe generated by the corrosion of the absorbent. 2+ The ions form a bright orange-red complex, thus warning of corrosion. They can also adsorb onto the surface of the absorbent to repair the corroded area. The addition of a silane coupling agent can enhance the surface activity of the absorbent and strengthen the bond between the absorbent and the resin.

[0031] The absorbent is one of carbonyl iron, iron-silicon-aluminum alloy, iron-silicon-chromium alloy, iron-silicon alloy, iron-aluminum-boron alloy or amorphous alloy, iron-boron-phosphorus alloy or amorphous alloy, iron-nickel alloy, iron-nickel-molybdenum alloy, iron-chromium-nickel alloy, iron-cobalt-chromium alloy, and iron-cobalt-nickel-chromium alloy; the absorbent is spherical or flaky in shape, with a particle size of 3-40 μm.

[0032] The silane coupling agent is one or more of KH-550, KH-560, and KH-792.

[0033] The mass ratio of the absorbent, the silane coupling agent and the ammonia water is (50-80): (5-30): (0.5-4).

[0034] The mass ratio of the 1,10-phenanthroline or 1,10-phenanthroline derivative to the absorbent is (5-10): (50-80).

[0035] The 1,10-phenanthroline derivative is 1,10-phenanthroline-5-amine and / or 1,10-phenanthroline monohydrate.

[0036] The mixing reaction comprises: stirring at 500-800 rpm and keeping warm at 60-80° C. for 3-6 hours;

[0037] The stirring and mixing is carried out at 500-800 rpm for 1-3 hours; the centrifugal drying is carried out at 8000-10000 rpm for 5-10 minutes, and then drying is carried out at 60-80° C. for 10-14 hours.

[0038] In one embodiment, a method for preparing an iron-based magnetic absorbent having corrosion warning and inhibition functions comprises the following steps:

[0039] Step 1: First, prepare 200-500 parts of a mixed solvent with deionized water and anhydrous ethanol by weight, add 50-80 parts of absorbent powder, then add 5-30 parts of a silane coupling agent and 0.5-4 parts of ammonia water, stir evenly, and heat in a water bath to obtain a dispersion of the absorbent surface treated with a silane coupling agent.

[0040] Step 2: Take 5-10 parts of 1,10-phenanthroline and its derivatives, add them to the dispersion, stir and mix them thoroughly, and centrifuge and dry them to obtain a modified carbonyl iron absorbent.

[0041] The mass ratio of deionized water to anhydrous ethanol in the mixed solvent described in step 1 is (2-8): (1-2).

[0042] The absorbent powder described in step 1 is one of carbonyl iron, iron-silicon-aluminum alloy, iron-silicon-chromium alloy, iron-silicon alloy, iron-aluminum-boron alloy or amorphous alloy, iron-boron-phosphorus alloy or amorphous alloy, iron-nickel alloy, iron-nickel-molybdenum alloy, iron-chromium-nickel alloy, iron-cobalt-chromium alloy, and iron-cobalt-nickel-chromium alloy, and is spherical or flaky in shape with a particle size of 3-40 μm.

[0043] The silane coupling agent described in step 1 is one or more of KH-550, KH-560, and KH-792. The function of the silane coupling agent is to enhance the active groups on the surface of the absorbent and strengthen the bonding with the resin.

[0044] The stirring rate in step 1 is 500-800 rpm; the water bath heating temperature is 60-80° C., and the heating time is 3-6 h.

[0045] The 1,10-phenanthroline and its derivatives described in step 2 are one or more of 1,10-phenanthroline, 1,10-phenanthroline-5-amine, and 1,10-phenanthroline-monohydrate. 1,10-phenanthroline and its derivatives can react with Fe 2+ Ion coordination provides early warning of corrosion.

[0046] The stirring parameters described in step 2 are 500-800 rpm for 1-3 hours; the centrifugation parameters are 8000-10000 rpm for 5-10 minutes; and the drying parameters are 60-80°C for 10-14 hours.

[0047] A second aspect of the present invention provides an iron-based magnetic absorbent having corrosion warning and inhibition functions.

[0048] A third aspect of the present invention provides an application of an iron-based magnetic absorbent having corrosion warning and suppression functions in electromagnetic absorption.

[0049] It should be noted that the experimental methods used in the present invention are all conventional methods unless otherwise specified; the reagents and materials used are all commercially available unless otherwise specified.

[0050] Example 1

[0051] Step 1: First, prepare 200 parts of a mixed solvent with a mass ratio of 5:1 with deionized water and anhydrous ethanol, add 50 parts of carbonyl iron powder, then add 5 parts of KH-550 coupling agent, 1 part of KH-560 coupling agent, and 1 part of ammonia water, stir evenly at 500 rpm, and heat in a water bath at 60°C for 3 hours to obtain a dispersion of the absorbent surface treated with a silane coupling agent.

[0052] Step 2: Take 5 parts of 1,10-phenanthroline and 1 part of 1,10-phenanthroline-5-amine, add them to the dispersion, stir and mix at 500 rpm for 1 hour, centrifuge at 8000 rpm for 10 minutes, and dry at 60°C for 12 hours to obtain a modified iron-based magnetic absorbent.

[0053] Example 2

[0054] Step 1: First, prepare 200-500 parts of a mixed solvent with a mass ratio of 5:1 with deionized water and anhydrous ethanol, add 60 parts of sendust powder, then add 5 parts of KH-550 coupling agent, 2 parts of KH-560 coupling agent, and 2 parts of ammonia water, stir evenly at 600 rpm, and heat in a water bath at 60°C for 4 hours to obtain a dispersion of the absorbent surface treated with a silane coupling agent.

[0055] Step 2: Take 5 parts of 1,10-phenanthroline and 2 parts of 1,10-phenanthroline-5-amine and add them to the dispersion, stir and mix at 800 rpm for 1 hour, centrifuge at 8000 rpm for 10 minutes, and dry at 80°C for 12 hours to obtain a modified iron-based magnetic absorbent.

[0056] Example 3

[0057] Step 1: First, prepare 300 parts of a mixed solvent with a mass ratio of 5:2 with deionized water and anhydrous ethanol, add 80 parts of iron-silicon-chromium alloy powder, then add 10 parts of KH-550 coupling agent, 1 part of KH-792 coupling agent, and 3 parts of ammonia water, stir evenly at 600 rpm, and heat in a water bath at 80°C for 3 hours to obtain a dispersion of the absorbent surface-treated with a silane coupling agent.

[0058] Step 2: Take 8 parts of 1,10-phenanthroline-5-amine and 1 part of 1,10-phenanthroline monohydrate, add them to the dispersion, stir and mix at 800 rpm for 1 hour, centrifuge at 10,000 rpm for 5 minutes, and dry at 80°C for 12 hours to obtain a modified iron-based magnetic absorbent.

[0059] Example 4

[0060] Step 1: First, prepare 200 parts of a mixed solvent with a mass ratio of 8:1 with deionized water and anhydrous ethanol, add 50 parts of iron-silicon alloy powder, then add 5 parts of KH-550 coupling agent, 1 part of KH-560 coupling agent, and 1 part of ammonia water, stir evenly at 500 rpm, and heat in a water bath at 60°C for 6 hours to obtain a dispersion of the absorbent surface-treated with a silane coupling agent.

[0061] Step 2: Take 5 parts of 1,10-phenanthroline and 2 parts of 1,10-phenanthroline-5-amine, add them to the dispersion, stir and mix at 800 rpm for 1 hour, centrifuge at 8000 rpm for 5 minutes, and dry at 80°C for 10 hours to obtain a modified iron-based magnetic absorbent.

[0062] Example 5

[0063] Step 1: First, prepare 300 parts of a mixed solvent with a mass ratio of 5:2 with deionized water and anhydrous ethanol, add 60 parts of iron-aluminum-boron alloy or amorphous alloy, then add 10 parts of KH-550 coupling agent, 1 part of KH-560 coupling agent, and 2 parts of ammonia water, stir evenly at 500 rpm, and heat in a water bath at 80°C for 3 hours to obtain a dispersion of the absorbent surface-treated with a silane coupling agent.

[0064] Step 2: Take 5 parts of 1,10-phenanthroline and 1 part of 1,10-phenanthroline monohydrate, add them to the dispersion, stir and mix at 500 rpm for 3 hours, centrifuge at 8000 rpm for 10 minutes, and dry at 80°C for 12 hours to obtain a modified iron-based magnetic absorbent.

[0065] Example 6

[0066] Step 1: First, prepare 500 parts of a mixed solvent with a mass ratio of 5:1 with deionized water and anhydrous ethanol, add 80 parts of iron-boron-phosphorus alloy or amorphous alloy, then add 20 parts of KH-550 coupling agent, 1 part of KH-560 coupling agent, and 4 parts of ammonia water, stir evenly at 800 rpm, and heat in a water bath at 80°C for 6 hours to obtain a dispersion of the absorbent surface-treated with a silane coupling agent.

[0067] Step 2: Take 9 parts of 1,10-phenanthroline and 1 part of 1,10-phenanthroline-5-amine, add them to the dispersion, stir and mix at 800 rpm for 3 hours, centrifuge at 10000 rpm for 5 minutes, and dry at 80°C for 14 hours to obtain a modified iron-based magnetic absorbent.

[0068] Example 7

[0069] Step 1: First, prepare 200 parts of a mixed solvent with a mass ratio of 5:1 with deionized water and anhydrous ethanol, add 50 parts of iron-nickel alloy powder, then add 5 parts of KH-550 coupling agent, 1 part of KH-792 coupling agent, and 1 part of ammonia water, stir evenly at 500 rpm, and heat in a water bath at 60°C for 3 hours to obtain a dispersion of the absorbent surface treated with a silane coupling agent.

[0070] Step 2: Take 5 parts of 1,10-phenanthroline and 1 part of 1,10-phenanthroline-5-amine, add them to the dispersion, stir and mix at 500 rpm for 2 hours, centrifuge at 8000 rpm for 5 minutes, and dry at 80°C for 10 hours to obtain a modified iron-based magnetic absorbent.

[0071] Example 8

[0072] Step 1: First, prepare 300 parts of a mixed solvent with a mass ratio of 5:1 with deionized water and anhydrous ethanol, add 60 parts of iron-nickel-molybdenum alloy powder, then add 10 parts of KH-550 coupling agent, 1 part of KH-560 coupling agent, and 2 parts of ammonia water, stir evenly at 800 rpm, and heat in a water bath at 80°C for 6 hours to obtain a dispersion of the absorbent surface treated with a silane coupling agent.

[0073] Step 2: Take 1 part of 1,10-phenanthroline and 5 parts of 1,10-phenanthroline-5-amine, add them to the dispersion, stir and mix at 800 rpm for 3 hours, centrifuge at 10000 rpm for 10 minutes, and dry at 80°C for 12 hours to obtain a modified iron-based magnetic absorbent.

[0074] Example 9

[0075] Step 1: First, prepare 300 parts of a mixed solvent with a mass ratio of 5:1 with deionized water and anhydrous ethanol, add 60 parts of iron-chromium-nickel alloy powder, then add 10 parts of KH-550 coupling agent, 1 part of KH-560 coupling agent, and 2 parts of ammonia water, stir evenly at 800 rpm, and heat in a water bath at 80°C for 3 hours to obtain a dispersion of the absorbent surface treated with a silane coupling agent.

[0076] Step 2: Take 5 parts of 1,10-phenanthroline and 1 part of 1,10-phenanthroline-5-amine, add them to the dispersion, stir and mix at 800 rpm for 3 hours, centrifuge at 8000 rpm for 10 minutes, and dry at 80°C for 12 hours to obtain a modified iron-based magnetic absorbent.

[0077] Example 10

[0078] Step 1: First, prepare 300 parts of a mixed solvent with a mass ratio of 5:1 with deionized water and anhydrous ethanol, add 60 parts of iron-cobalt-chromium alloy powder, then add 10 parts of KH-550 coupling agent, 1 part of KH-560 coupling agent, and 2 parts of ammonia water, stir evenly at 800 rpm, and heat in a water bath at 80°C for 6 hours to obtain a dispersion of the absorbent surface-treated with a silane coupling agent.

[0079] Step 2: Take 5 parts of 1,10-phenanthroline and 1 part of 1,10-phenanthroline-5-amine, add them to the dispersion, stir and mix at 800 rpm for 3 hours, centrifuge at 8000 rpm for 10 minutes, and dry at 80°C for 12 hours to obtain a modified iron-based magnetic absorbent.

[0080] Example 11

[0081] Step 1: First, prepare 300 parts of a mixed solvent with a mass ratio of 5:1 with deionized water and anhydrous ethanol, add 60 parts of iron-cobalt-nickel-chromium alloy powder, then add 10 parts of KH-550 coupling agent, 1 part of KH-560 coupling agent, and 2 parts of ammonia water, stir evenly at 800 rpm, and heat in a water bath at 80°C for 3 hours to obtain a dispersion of the absorbent surface-treated with a silane coupling agent.

[0082] Step 2: Take 5 parts of 1,10-phenanthroline and 1 part of 1,10-phenanthroline-5-amine, add them to the dispersion, stir and mix at 800 rpm for 3 hours, centrifuge at 10,000 rpm for 5 minutes, and dry at 80°C for 12 hours to obtain a modified iron-based magnetic absorbent.

[0083] Comparative Example 1

[0084] Step 1: First, prepare 300 parts of a mixed solvent with a mass ratio of 5:1 with deionized water and anhydrous ethanol, add 60 parts of iron-cobalt-nickel-chromium alloy powder, then add 10 parts of KH-550 coupling agent, 1 part of KH-560 coupling agent, and 2 parts of ammonia water, stir evenly at 800 rpm, heat in an 80°C water bath for 3 h, centrifuge at 10,000 rpm for 5 minutes, and dry at 80°C for 12 h to obtain a modified iron-based magnetic absorbent.

[0085] In order to illustrate the corrosion warning and inhibition capabilities of the modified iron-based magnetic absorbent provided by the present invention, the modified iron-based magnetic absorbent prepared in the embodiments and comparative examples was immersed in a 3.5 wt.% NaCl solution to test the Fe 2+ The changes in ion concentration and the color change of the system are observed. The specific results are shown in Table 1 and Figure 1 shown.

[0086] Table 1 Fe of each embodiment and comparative example at different times 2+ Concentration and system color

[0087]

[0088] As shown in Table 1, Fe 2+ The presence of ions proves that the samples have been corroded. Figure 1 It can be seen that each example can show obvious orange-red color in 1 hour, while the comparative example is colorless, which proves that the 1,10-phenanthroline contained in the modified iron-based magnetic absorbent can react with Fe 2+ The ions generate red complexes, thus giving an early warning at the beginning of corrosion. 2+ The ion concentration at 6 h and 12 h is much lower than that of the comparative example, indicating that the corrosion in the example is weaker. This shows that the generated complex can be adsorbed on the surface of the absorbent to form a protective film, so that the modified iron-based magnetic absorbent has corrosion inhibition function.

[0089] To illustrate the wave absorbing performance of the modified iron-based magnetic absorber, the modified iron-based magnetic absorber prepared in each embodiment and comparative example of the present invention was mixed with epoxy resin to prepare a coating, and the corresponding coating was prepared by spraying, as follows:

[0090] 70 parts of modified iron-based magnetic absorber, 20 parts of epoxy resin, and 10 parts of polyamide curing agent were dispersed in a stirring disperser at 3000 rpm for 15 minutes. Then, a certain amount of diluent was added to adjust the coating viscosity to 20-25 mPa·s, and stirring was continued at 3000 rpm for 15 minutes to obtain an absorbing coating.

[0091] The epoxy resin is a transparent viscous liquid.

[0092] The polyamide curing agent is a medium-viscosity brown liquid.

[0093] The diluent is prepared by mixing xylene and n-butanol in a mass ratio of 7:3, and both are colorless and transparent liquids.

[0094] Subsequently, an absorbing coating with a thickness of 1 mm was prepared by compressed air spraying. The specific method is as follows: pour the coating into a W-71 spray gun, adjust the spraying pressure to 0.5 MPa, the spraying distance to 15-20 cm, the spray gun moving speed to 30-40 cm / s, and spray evenly on the substrate surface in an S-shaped path; after each 0.1 mm coating is sprayed, the sample is dried at room temperature for 10-15 minutes, and then the sample is placed in an oven and kept at 80°C for 12 hours to solidify the coating sprayed on the substrate surface. Repeat this preparation process until the thickness of the obtained prefabricated layer reaches 1 mm.

[0095] In order to demonstrate the absorption capacity of the prepared absorbing coating for electromagnetic waves, the reflection loss of the absorbing coating was tested using the bow method according to the GJB 2038-94 standard. In order to verify the corrosion resistance of the absorbing coating, the absorbing coating was subjected to a 240-h neutral salt spray test according to the GJB150.11A-2009 standard, and then its absorbing performance was tested. The minimum reflection loss (RL min ) and the effective absorption bandwidth (E A ) as shown in Table 2.

[0096] Table 2 Minimum reflection loss and effective absorption bandwidth of each embodiment and comparative example

[0097]

[0098] From the data in Table 2, it can be seen that the RL of the ferromagnetic absorbing coating in each embodiment is min Value and E A After 240 hours of salt spray treatment, both showed a slight decrease in wear, while the coating loss in the comparative example decreased significantly. This demonstrates that the modified iron-based magnetic absorber prepared in the examples can repair damaged areas, thus endowing the ferromagnetic absorbing coating with excellent corrosion resistance. In summary, the ferromagnetic absorbing coating with corrosion warning and suppression functions prepared in the examples of the present invention effectively addresses corrosion issues and effectively enhances its performance in harsh environments.

[0099] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for preparing an iron-based magnetic absorbent with corrosion warning and inhibition functions, characterized in that: The following steps are involved: Adding the absorbent, silane coupling agent and ammonia water into a mixed solvent, mixing and reacting, and obtaining a dispersion of the silane coupling agent surface-treated absorbent; Adding 1,10-phenanthroline and / or 1,10-phenanthroline derivatives to the dispersion, stirring and mixing, and centrifugally drying to obtain a modified iron-based magnetic absorbent; Wherein, the mixed solvent is prepared by water and anhydrous ethanol; The mass ratio of the absorbent, silane coupling agent and ammonia water is (50-80): (5-30): (0.5-4); The mass ratio of the 1,10-phenanthroline or 1,10-phenanthroline derivative to the absorbent is (5-10): (50-80); The mixing reaction comprises: stirring at 500-800 rpm and keeping warm at 60-80° C. for 3-6 hours; The stirring and mixing is performed at 500-800 rpm for 1-3 hours; the centrifugal drying is performed at 8000-10000 rpm for 5-10 minutes, and then drying at 60-80° C. for 10-14 hours; The mass ratio of the anhydrous ethanol to water is 1:1-8.

2. The method for preparing the iron-based magnetic absorbent with corrosion warning and inhibition functions according to claim 1, characterized in that: The absorbent is one of carbonyl iron, iron-silicon-aluminum alloy, iron-silicon-chromium alloy, iron-silicon alloy, iron-aluminum-boron alloy or amorphous alloy, iron-boron-phosphorus alloy or amorphous alloy, iron-nickel alloy, iron-nickel-molybdenum alloy, iron-chromium-nickel alloy, iron-cobalt-chromium alloy, and iron-cobalt-nickel-chromium alloy; the absorbent is spherical or flaky, with a particle size of 3-40 μm.

3. The method for preparing the iron-based magnetic absorbent with corrosion warning and suppression functions according to claim 1, characterized in that: The silane coupling agent is one or more of KH-550, KH-560, and KH-792.

4. The method for preparing the iron-based magnetic absorbent with corrosion warning and inhibition functions according to claim 1, characterized in that: The 1,10-phenanthroline derivative is 1,10-phenanthroline-5-amine and / or 1,10-phenanthroline monohydrate.

5. An iron-based magnetic absorbent with corrosion warning and inhibition functions, obtained by the method according to any one of claims 1 to 4.

6. Use of the iron-based magnetic absorbent with corrosion warning and suppression functions as claimed in claim 5 in electromagnetic absorption.

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