CN115926516A - Magnetic composite absorbent suitable for thermal spraying, preparation method and application - Google Patents
Magnetic composite absorbent suitable for thermal spraying, preparation method and application Download PDFInfo
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Abstract
The invention discloses a magnetic composite absorbent suitable for thermal spraying and a preparation method thereof. The invention also discloses application of the magnetic composite absorbent suitable for thermal spraying, wherein the composite absorbent powder is used as a raw material, and an anti-electromagnetic interference coating or a wave-absorbing coating is prepared by adopting a thermal spraying process. The magnetic composite absorbent has excellent anti-electromagnetic interference performance and strong process applicability.
Description
Technical Field
The invention relates to a magnetic composite absorbent suitable for thermal spraying, a preparation method and application, and belongs to the technical field of electromagnetic interference resistance.
Background
Anti-electromagnetic interference technology is becoming more and more important in the status of modern military war; the magnetic material with high magnetic conductivity has obvious effect on inhibiting the electromagnetic wave interference of power signal circuits and circuits, and becomes an essential component in modern military electronic equipment and electronic instrument equipment. As one form of anti-electromagnetic interference material, a magnetic coating with a magnetic absorbent and organic resin as main components can be used for eliminating electromagnetic noise; taking a certain reported aircraft as an example, the non-metal shell of an engine of the aircraft needs to be subjected to anti-interference treatment, and an anti-interference coating is loaded on a relevant part by adopting a means. Most of anti-interference coating matrixes applied in China currently adopt organic resins such as epoxy resin, modified polyurethane and the like, and the defect that the resin is decomposed under a high-temperature environment to cause coating failure; therefore, the traditional magnetic coating material and the preparation technology can not meet the requirement of high-temperature anti-interference.
In the field of high-temperature coating preparation, functional coatings prepared by thermal spraying technology have been widely applied to the military field. The principle is that the powder material is heated to a micro-melting, semi-melting or melting state and then sprayed on the surface of a workpiece, the process has the advantages of high reliability, strong binding force and strong thermal shock resistance, and the magnetic coating prepared by adopting a thermal spraying tool can greatly improve the applicability of the magnetic coating in the field of electromagnetism resistance. At present, the report of using a magnetic coating for high temperature resistance and electromagnetic interference resistance is not seen, because the requirement on powder for thermal spraying is higher, if the magnetic powder is directly used for spraying, the magnetism of the magnetic powder is greatly reduced, and the loss capacity of the magnetic powder to electromagnetism is lost. The analysis of published relevant data shows that the existing magnetic material can not meet the requirement of thermal spraying, and the composition design and preparation of the magnetic material are required from the source.
Disclosure of Invention
The invention aims to overcome the defects, provides a magnetic composite absorbent suitable for thermal spraying, a preparation method and application, and solves the technical problem that the existing magnetic material cannot adapt to a thermal spraying process. The magnetic composite absorbent has excellent anti-electromagnetic interference performance and strong process applicability.
In order to achieve the above purpose, the invention provides the following technical scheme:
a magnetic composite absorbent suitable for thermal spraying is prepared from the following raw material components in parts by mass:
100 parts of a magnetic absorbent;
10-100 parts of ceramic powder;
0.5-15 parts of a binder;
the grain size of the magnetic absorbent is 100 nm-10 mu m, and the magnetic absorbent is more than one of Fe and alloy thereof, co and alloy thereof or Ni and alloy thereof;
the grain diameter of the ceramic powder is 100 nm-2 mu m, and the ceramic powder is SiO 2 、Al 2 O 3 More than one of anorthite or mullite;
the binder is more than one of polyethylene glycol, polyvinyl alcohol or phenolic resin.
Furthermore, the magnetic composite absorbent is spherical powder with the particle size of 20-120 mu m, wherein the magnetic absorbent is uniformly distributed in the ceramic phase.
A method of making a magnetic composite absorber suitable for thermal spraying, comprising:
s1, performing ball milling dispersion on a magnetic absorbent, ceramic powder deionized water and a dispersing agent to obtain a dispersion liquid;
s2, adding a binder into the dispersion liquid, and continuously performing ball milling to obtain mixed slurry;
s3, atomizing, drying and screening the mixed slurry in sequence;
s4, carrying out densification treatment on the particles obtained after screening to obtain the magnetic composite absorbent.
Further, in the step S1, when the magnetic absorbent, the ceramic powder deionized water and the dispersing agent are subjected to ball milling dispersion, adding zirconia ball milling beads of 1-3 cm, and carrying out ball milling for 18H-24H under the condition that the ball milling rotating speed is 1500 r/min-2000 r/min;
in step S2, the ball milling conditions are as follows: the ball milling speed is 1500 r/min-2000 r/min, and the ball milling time is 1H-4H.
Further, the magnetic absorbent, the ceramic powder deionized water, the dispersant and the binder are in parts by weight:
the grain size of the magnetic absorbent is 100 nm-10 mu m, and the magnetic absorbent is more than one of Fe and alloy thereof, co and alloy thereof or Ni and alloy thereof;
the grain diameter of the ceramic powder is 100 nm-2 mu m, and the ceramic powder is SiO 2 、Al 2 O 3 More than one of anorthite or mullite;
the dispersant is more than one of polycarboxylate type emulsion, sodium polyacrylate or ammonium citrate;
the binder is more than one of polyethylene glycol, polyvinyl alcohol or phenolic resin.
Further, in step S3, the particle size of the particles obtained by sieving is 20 to 120 μm.
Furthermore, the viscosity of the mixed slurry obtained in the step S2 is 6500-7200 MPa, the solid content is 60 +/-2 wt%, and the binder content is 8 +/-1 wt%.
Further, in step S3, the mixed slurry is atomized by an atomizer, wherein the feeding amount of the mixed slurry is 35 ± 2rpm, the rotation speed of the atomizer is 30 ± 5Hz, the inlet temperature of the atomizer is 290 ± 10 ℃, and the outlet temperature of the atomizer is 150 ± 10 ℃.
Further, in the step S4, the method for performing densification treatment on the sieved particles includes performing two-stage calcination on the sieved particles, wherein the first-stage calcination temperature is 650-700 ℃; the second stage of calcination is 1000-1100 ℃.
The application of the magnetic composite absorbent suitable for thermal spraying is to form the magnetic composite absorbent by a thermal spraying process to obtain an anti-electromagnetic interference coating or a wave-absorbing coating.
Compared with the prior art, the invention has at least one of the following beneficial effects:
(1) The invention creatively provides a magnetic composite absorbent, which selects nano-scale or micron-scale magnetic metal particles and low-dielectric ceramic powder to form composite powder, has excellent anti-electromagnetic interference performance, and is suitable for preparing an anti-electromagnetic interference coating by utilizing a thermal spraying process;
(2) According to the invention, the ceramic powder and the magnetic absorbent are compounded, so that on one hand, the ceramic phase can reduce the magnetic damage of the absorbent caused by high temperature; on the other hand, the preferred low dielectric ceramic can exert the attenuation of the magnetic powder to the electromagnetic wave to the maximum extent, and ensure the electromagnetic property of the composite powder absorbent;
(3) According to the preparation method of the magnetic composite absorbent, the ball milling dispersion process is adopted, so that the distribution uniformity of the magnetic absorbent in a ceramic phase can be effectively improved, and the protection effect of attenuation of the ceramic to electromagnetic waves of the magnetic absorbent in the thermal spraying process is improved;
(4) The preparation method of the magnetic composite absorbent adopts spray granulation and screens the particle size of the particles, is favorable for improving the sphericity and uniformity of the particle size of the product powder, lays a foundation for the stability of the magnetic composite absorbent, and simultaneously ensures that the composite particles have good fluidity so as to meet the requirements of a thermal spraying process;
(5) In the preparation method of the magnetic composite absorbent, densification treatment is adopted, so that the cohesive strength of the composite powder is improved, and the film formation of a thermal spraying process is facilitated.
(6) The preparation method of the magnetic composite absorbent has high production efficiency and strong reliability, and is suitable for preparing high-temperature anti-electromagnetic interference coatings by a thermal spraying process.
Drawings
FIG. 1 is an SEM photograph of a magnetic composite absorbent prepared in example 1 of the present invention; wherein, (a) is a low-magnification picture, (b) is a high-magnification picture, and (c) is a spectrogram;
FIG. 2 is a magnetic permeability curve of the magnetic composite absorbent prepared in example 2 of the present invention at 2-18 GHz.
Detailed Description
The features and advantages of the present invention will become more apparent and appreciated from the following detailed description of the invention.
The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.
In order to solve the defect that the existing magnetic absorbent can not meet the requirement of thermal spraying, the invention provides a magnetic composite absorbent suitable for thermal spraying and a preparation method thereof, the magnetic absorbent and ceramic powder are agglomerated and sintered into composite powder with the diameter of 20-120 mu m, and the magnetic composite absorbent has the characteristics of uniform component distribution and high cohesive strength; 50V% (magnetic absorbent/ceramic phase) in the range of 2-18 GHz of the magnetic absorbent, the dielectric constant of the magnetic absorbent is 20-50, and the magnetic conductivity of the magnetic absorbent is 1-10; the molding of the magnetic composite powder can be satisfied by the processes of ball milling dispersion, spray granulation, densification treatment and the like, and the invention has the characteristic of strong practicability. In an optional embodiment, the magnetic composite absorbent is spherical composite structure powder, and the particle size of the spherical composite absorbent is 25-125 μm; the designed structure and the grain size of the magnetic composite absorbent ensure that the composite particles have good fluidity so as to meet the requirements of a thermal spraying process.
In an alternative embodiment, the magnetic absorbent in the magnetic composite absorbent is uniformly distributed in the ceramic phase; on one hand, the ceramic can separate the absorbent to realize the electric insulation of the magnetic absorbent, and on the other hand, the ceramic phase can reduce the magnetic damage of the magnetic absorbent caused by high temperature.
In an optional embodiment, the raw material components for preparing the magnetic composite absorbent comprise, by mass: 100 parts of a magnetic absorbent: 10-100 parts of ceramic powder: 0.5-15 parts of a binder;
in an alternative embodiment, the magnetic absorbent is nano-scale or micro-scale magnetic metal particles with the trade name of 97T01, MF55, NDA40, DFM and the like, and the components of the magnetic absorbent include but are not limited to Fe, co, ni and alloys thereof, and the powder diameter of the magnetic absorbent is 100 nm-10 μm; the magnetic absorbent has high electromagnetic loss characteristic, and can have stronger attenuation capability on electromagnetic waves when used as an anti-interference coating.
In an alternative embodiment, the ceramic powder is a low dielectric ceramic having a composition including, but not limited to, siO 2 、Al 2 O 3 Anorthite, mullite and the like, and the diameter of the powder is 100 nm-2 mu m; the ceramic has low dielectric characteristics, is only used as a disperse phase, and does not influence the electromagnetic loss effect of the absorbent.
In an alternative embodiment, the binder is one of polyethylene glycol, polyvinyl alcohol, phenolic resin and other organic resins;
in an optional embodiment, the magnetic composite absorbent has a dielectric constant of 20-50 and a magnetic permeability of 1-10 in a volume ratio of 50% in a range of 2-18 GHz; the 0.5 mm-2 mm coating prepared from the composite absorbent powder has excellent high temperature resistance and electromagnetic interference elimination functions.
In an alternative embodiment, a magnetic composite absorber suitable for thermal spraying and a method for preparing the same includes the steps of:
step (1), ball milling and dispersing: mixing a magnetic absorbent, ceramic powder, deionized water and a dispersing agent according to a certain proportion, putting the mixture into a nylon ball tank, adding zirconia balls of 1-3 cm for milling, and performing ball milling dispersion: .
In an alternative embodiment, the magnetic absorbent in step (1): ceramic powder: deionized water: the mass ratio of the dispersant is 100:10 to 200:0.5 to 5.
In an optional stepIn the embodiment, the magnetic absorbent is nano-scale or micro-scale magnetic metal particles, the components of the magnetic absorbent include but are not limited to Fe, co, ni and alloys thereof, and the diameter of the magnetic powder is 100 nm-10 μm; the ceramic powder is a low dielectric ceramic, the composition of which includes but is not limited to SiO 2 、Al 2 O 3 Anorthite, mullite and the like, and the diameter of the powder is 100 nm-2 mu m; the dispersant is one of polycarboxylate type emulsion, sodium polyacrylate, ammonium citrate, etc.
In an alternative embodiment, the ball milling process parameters in step (1) are as follows: ball milling speed: 1500 r/min-2000 r/min, ball milling time 18H-24H, and the selected parameters can ensure that all phases are fully mixed to obtain a slurry blank with uniform components.
Preparing slurry in step (2): and (2) adding a binder into the mixed solution obtained in the step (1), and continuing ball milling to obtain the magnetic absorbent mixed slurry.
In an optional embodiment, the mass part of the binder in the step (2) is 0.5-15 parts (by mass part of the magnetic absorbent is 100 parts), and the content can ensure the surface smoothness and the flowability of the subsequent composite powder; ensure the tight combination of single particles and the complete structure of the agglomerated powder.
In an alternative embodiment, the binder in step (2) is one of polyethylene glycol, polyvinyl alcohol, phenolic resin and other organic resins. The binder is used for wrapping the powder, has an important effect on the stability of slurry, and can influence the diameter of fog drops, the volatilization rate of a liquid phase, the strength of granules and the like in the spray granulation process.
In an alternative embodiment, the ball milling process parameters in step (2) are as follows: ball milling speed: 1500 r/min-2000 r/min, ball milling time 1H-4H, the process effectively disperses the adhesive, ensures the selected content to ensure the effective bonding increase among raw material particles; and basic guarantee is provided for obtaining stable slurry.
In an alternative embodiment, the mixed slurry obtained in step (2) is characterized by having a slurry viscosity of 6500-7200mpa × s; the solid content is 60 +/-2 wt%, the binder content is 8 +/-1 wt%, and the obtained slurry provides a raw material basis for preparing the spray granulation with good sphericity, high agglomeration and high powder yield.
Step (3) spray granulation; carrying out slurry atomization and spray particle drying and balling on the mixed slurry obtained in the step (2) to obtain a spherical composite absorbent; sieving to obtain particles with the particle size of 25-125 mu m between 120-625 molybdenum.
In an optional embodiment, the feeding amount of the slurry in the step (3) is 35 +/-2 rpm, and the parameters are set to ensure that the mist is fully evaporated and the formed composite powder particles are full.
In an alternative embodiment, when the slurry is atomized in the step (3), the rotation speed of the atomizer is 30 +/-5 Hz, and the acting force of the atomizing disc on the slurry can enable the liquid drops to have sufficient agglomeration effect under the action of centrifugal force, so that the sphericity of the particles is better.
In an alternative embodiment, the inlet temperature for spray granulation in step (3) is 290 ± 10 ℃ and the outlet temperature is 150 ± 10 ℃. The parameter setting ensures that the powder obtains better sphericity and higher density while the composite powder is dried, so that the composite powder is suitable for the post-treatment of the powder.
And (4) densification treatment: and (4) carrying out vacuum calcination on the product obtained in the step (3) to obtain the composite powder with high cohesive strength.
In an alternative embodiment, the calcination of step (4) is divided into 2 stages: the calcination temperature of the first stage is 650-700 ℃; the second stage of calcination is 1000-1100 ℃; and calcining at constant temperature for 1-2H. After post-treatment, the surface of the single powder is smooth, and the interior of the particles has higher bonding strength.
The invention combines the ceramic powder and the magnetic absorbent, on one hand, the ceramic phase can reduce the magnetic damage of the magnetic absorbent caused by the high temperature of thermal spraying, on the other hand, the optimized low dielectric ceramic can furthest play the attenuation of the magnetic powder to electromagnetic waves, and the composite powder is utilized to prepare the coating, thereby solving the problem of high-temperature electromagnetic interference and being also used for preparing a high-temperature wave-absorbing coating.
The composite powder prepared by the invention can be directly used for thermal spraying, a high-temperature-resistant anti-interference or wave-absorbing coating is obtained by controlling spraying parameters, the coating shows the characteristic of broadband wave absorption at different thicknesses, the excellent electromagnetic parameters of the composite powder are reflected, and the composite powder can be formed into the coating by a thermal spraying process.
Example (b):
the raw materials used in the following were all commercially available products.
Example 1
The embodiment provides a composite absorbent suitable for thermal spraying, and the preparation method comprises the following steps:
(1) Ball milling and dispersing: magnetic absorbent (brand 97T 01) with the grain diameter of 1-10 mu m and the grain diameter of 500 nm-1 mu m SiO 2 The mass ratio of deionized water to sodium polyacrylate is 100:50, mixing and putting the mixture into a nylon ball tank, adding zirconia balls of 1-3 cm into the nylon ball tank for ball milling and dispersion, and controlling the ball milling speed: 2000r/min, and ball milling time of 24H.
(2) Preparing slurry: and (2) adding a binder polyvinyl alcohol into the mixed solution obtained in the step (1), controlling the mass ratio to be 8% (the binder accounts for the total mass of the absorbent, the ceramic powder and the binder), and performing ball milling for 2H at 1800r/min to obtain the magnetic absorbent mixed slurry. The slurry viscosity of the obtained mixed slurry is 6600MPa S; solid content 60wt%, binder content 8wt%
(3) Spray granulation: carrying out slurry atomization and spray particle drying and balling on the mixed slurry obtained in the step (2) to obtain a spherical composite absorbent, wherein the rotating speed of a spray disc is controlled to be 40Hz, the feeding amount is controlled to be 35rpm, and the inlet temperature and the outlet temperature are respectively set to be 280 ℃ and 160 ℃; sieving the obtained composite powder, and taking particles with the particle size of 25-125 mu m between 120-625 molybdenum.
(4) Densification treatment: vacuum calcining the obtained product in the step (3), wherein the calcining temperature in the first stage is 700 ℃, and 2H; the second stage of calcination is 1100 ℃ and 1H; obtaining the composite powder with high cohesive strength.
The prepared powder has good sphericity and high agglomeration degree, the absorbent is dispersed in a ceramic phase, an SEM picture is shown in figure 1, the particle size of the magnetic composite absorbent is 40-100 mu m, the magnetic composite absorbent has a dielectric constant of 37.6 and a magnetic permeability of 1.85 in a volume ratio of 50% within a range of 2-18 GHz.
The magnetic composite absorbent obtained in the embodiment can be directly used for a thermal spraying process, and can be used for preparing an anti-electromagnetic interference or high-temperature-resistant wave-absorbing coating by controlling the spraying power. When the thickness of the coating is 1mm, the coating has broadband wave-absorbing effect at 8-18 GHz; the composite powder used for spraying has excellent magnetic loss capability.
Example 2
The embodiment provides a magnetic composite powder suitable for thermal spraying, and the preparation method comprises the following steps:
(1) Ball milling and dispersing: magnetic absorbent (grade DFM) with particle size of 2-10 μm and Al with particle size of 1-2 μm 2 O 3 The mass ratio of the deionized water to the polycarboxylate type emulsion is 100:50, mixing and putting the mixture into a nylon ball tank, adding zirconia balls of 1-3 cm into the nylon ball tank for ball milling and dispersion, and controlling the ball milling speed: 1600r/min, and the ball milling time is 20H.
(2) Preparing slurry: adding a binder polyethylene glycol into the mixed solution obtained in the step (1), controlling the mass ratio to be 13wt% (the binder accounts for the total mass of the absorbent, the ceramic powder and the binder), and performing ball milling for 1H at 1600r/min to obtain the magnetic absorbent mixed slurry. The viscosity of the obtained mixed slurry is 7000MPa S; solid content 60. + -. 2wt%, binder content 13wt%
(3) Spray granulation: carrying out slurry atomization and spray particle drying and balling on the mixed slurry obtained in the step (2) to obtain a spherical composite absorbent, wherein the rotating speed of a spray disc is controlled to be 35Hz, the feeding amount is controlled to be 35rpm, and the inlet and outlet temperatures are respectively set to be 290 ℃ and 150 ℃; sieving the obtained composite powder, and taking particles with the particle size of 20-120 mu m between 120-625 molybdenum.
(4) Densification treatment; vacuum calcining the product obtained in the step (3), wherein the calcining temperature in the first stage is 650 ℃, and the calcining temperature is 2H; the second stage of calcination is at 1000 ℃ and 1H; obtaining the composite powder with high cohesive strength.
The particle diameter of the magnetic composite absorbent obtained in the embodiment is 20-120 μm, the 50% volume ratio in the range of 2-18 GHz and the magnetic permeability is 1.5-6.5, the test curve is shown in FIG. 2, wherein u 'represents the real part of the magnetic permeability, and u' represents the imaginary part of the magnetic permeability.
The magnetic composite absorbent obtained in the embodiment can be directly used for a thermal spraying process, and can be used for preparing a high-temperature-resistant electromagnetic interference-resistant coating or a wave-absorbing coating by controlling the spraying power, wherein the coating has the characteristic of broadband absorption at 2mm and 8-18 GH z, and the coating mainly adopts a magnetic loss mechanism, so that the composite powder used for spraying has excellent magnetic performance.
Comparative example 1:
other conditions were the same as in example 1 except that SiO alone was used 2 The ceramic powder is replaced by high-dielectric and high-melting-point ceramic such as zirconia, although the absorbent can be uniformly distributed in the ceramic phase, the coating prepared by thermally spraying the powder obtained in the comparative example cannot absorb and attenuate electromagnetic waves; the reason is that the high dielectric ceramic is not conducive to the transmission of electromagnetic waves, and further, the excellent loss characteristics of the absorber itself are exerted; when the high-melting-point ceramic is sprayed, the absorbent is melted due to the overhigh melting point, and the self-loss characteristic is lost.
Comparative example 2:
the other conditions were the same as in example 1, but without calcination, and the test results of this comparative example were: although the composite powder can be subjected to thermal spraying and can also be formed into a film, the coating does not have the capability of losing electromagnetic waves; the reason is that the composite powder which is not calcined has low strength, and is easy to collapse, break and the like in the spraying process, the ceramic powder can not protect the internal absorbent during spraying due to the collapsed and broken powder, so that the absorbent directly faces to a high-temperature environment, and the magnetism of the absorbent is greatly increased due to the high temperature; in addition, after the ceramic phase is crushed, the ceramic phase can not prevent the internal absorbent from contacting with oxygen, so that the absorbent is oxidized to generate another substance, and the electromagnetic property of the absorbent is changed; both of the above reasons result in the formation of a coating having no electromagnetic wave attenuation ability.
The invention has been described in detail with reference to specific embodiments and illustrative examples, but the description is not intended to be construed in a limiting sense. Those skilled in the art will appreciate that various equivalent substitutions, modifications or improvements may be made to the embodiments and implementations of the invention without departing from the spirit and scope of the invention, and are within the scope of the invention. The scope of the invention is defined by the appended claims.
Those skilled in the art will appreciate that those matters not described in detail in the present specification are not particularly limited to the specific examples described herein.
Claims (10)
1. The magnetic composite absorbent suitable for thermal spraying is characterized by being prepared from the following raw materials in parts by mass:
100 parts of a magnetic absorbent;
10-100 parts of ceramic powder;
0.5-15 parts of a binder;
the grain size of the magnetic absorbent is 100 nm-10 mu m, and the magnetic absorbent is more than one of Fe and alloy thereof, co and alloy thereof or Ni and alloy thereof;
the grain diameter of the ceramic powder is 100 nm-2 mu m, and the ceramic powder is SiO 2 、Al 2 O 3 More than one of anorthite or mullite;
the binder is more than one of polyethylene glycol, polyvinyl alcohol or phenolic resin.
2. The magnetic composite absorbent suitable for thermal spraying according to claim 1, wherein the magnetic composite absorbent is spherical powder with a particle size of 20 μm to 120 μm, and the magnetic absorbent is uniformly distributed in the ceramic phase.
3. A method for preparing a magnetic composite absorbent suitable for thermal spraying, comprising:
s1, performing ball milling dispersion on a magnetic absorbent, ceramic powder deionized water and a dispersing agent to obtain a dispersion liquid;
s2, adding a binder into the dispersion liquid, and continuously performing ball milling to obtain mixed slurry;
s3, atomizing, drying and screening the mixed slurry in sequence;
s4, carrying out densification treatment on the particles obtained after screening to obtain the magnetic composite absorbent.
4. The preparation method of the magnetic composite absorbent suitable for thermal spraying according to claim 3, wherein in the step S1, when the magnetic absorbent, the ceramic powder deionized water and the dispersing agent are subjected to ball milling dispersion, zirconia balls of 1-3 cm are added for ball milling, and 18H-24H is ball milled at a ball milling rotation speed of 1500 r/min-2000 r/min;
in step S2, the ball milling conditions are as follows: the ball milling speed is 1500 r/min-2000 r/min, and the ball milling time is 1H-4H.
5. The preparation method of the magnetic composite absorbent suitable for thermal spraying according to claim 3, wherein the magnetic absorbent, the ceramic powder deionized water, the dispersant and the binder are prepared from the following components in parts by weight:
the grain size of the magnetic absorbent is 100 nm-10 mu m, and the magnetic absorbent is more than one of Fe and alloy thereof, co and alloy thereof or Ni and alloy thereof;
the grain diameter of the ceramic powder is 100 nm-2 mu m, and the ceramic powder is SiO 2 、Al 2 O 3 More than one of anorthite or mullite;
the dispersant is more than one of polycarboxylate type emulsion, sodium polyacrylate or ammonium citrate;
the binder is more than one of polyethylene glycol, polyvinyl alcohol or phenolic resin.
6. The method of claim 3, wherein in step S3, the particle size of the sieved particles is 20 μm to 120 μm.
7. The method for preparing a magnetic composite absorbent suitable for thermal spraying according to claim 3, wherein the viscosity of the mixed slurry obtained in step S2 is 6500-7200 MPa S, the solid content is 60 +/-2 wt%, and the binder content is 8 +/-1 wt%.
8. The method for preparing a magnetic composite absorbent suitable for thermal spraying according to claim 3, wherein in step S3, the mixed slurry is atomized by an atomizer, the feeding amount of the mixed slurry during atomization is 35 +/-2 rpm, the rotation speed of the atomizer is 30 +/-5 Hz, the inlet temperature of the atomizer is 290 +/-10 ℃, and the outlet temperature of the atomizer is 150 +/-10 ℃.
9. The method for preparing the magnetic composite absorbent suitable for thermal spraying according to claim 3, wherein in the step S4, the particles obtained after screening are densified by two-stage calcination, wherein the first-stage calcination temperature is 650-700 ℃; the second stage of calcination is 1000-1100 ℃.
10. The application of the magnetic composite absorbent suitable for thermal spraying is characterized in that the magnetic composite absorbent of claim 1 or 2 is formed by a thermal spraying process to obtain an anti-electromagnetic interference coating or a wave-absorbing coating.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101003086A (en) * | 2006-11-27 | 2007-07-25 | 北京矿冶研究总院 | Cr (chromium)3C2-NiCr composite powder preparation technology |
| CN102758164A (en) * | 2011-04-25 | 2012-10-31 | 中国农业机械化科学研究院 | Temperature-resistant thermal-spray radar absorbing coating and preparation method of spraying powder thereof |
| CN110883337A (en) * | 2019-12-04 | 2020-03-17 | 电子科技大学 | Spray granulation Fe-Al2O3Preparation method of spraying composite powder |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101003086A (en) * | 2006-11-27 | 2007-07-25 | 北京矿冶研究总院 | Cr (chromium)3C2-NiCr composite powder preparation technology |
| CN102758164A (en) * | 2011-04-25 | 2012-10-31 | 中国农业机械化科学研究院 | Temperature-resistant thermal-spray radar absorbing coating and preparation method of spraying powder thereof |
| CN110883337A (en) * | 2019-12-04 | 2020-03-17 | 电子科技大学 | Spray granulation Fe-Al2O3Preparation method of spraying composite powder |
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