A kind of take foamed aluminium as the ferrite composite wave-suction material of matrix
Technical field
The present invention relates to a kind of composite wave-suction material, being specifically related to a kind of take foamed aluminium as the ferrite composite wave-suction material of matrix.
Background technology
Along with computer, substation, wireless communication station and sensor new and high technology universal, absorbing material has entered the stage be widely used.In the routine work and life of people, the electromagnetic radiation that some electronic and electrical equipments universal brings and interference problem day by day serious, the problem caused by electromagenetic wave radiation pursues the concern causing the public today gradually of high-quality life people.
Absorbing material can be divided into interfere type and the large class of absorption-type two by principle of work, and wherein absorption-type absorbing material can be divided into again magnetic loss type and dielectric loss type two kinds.Magnetic loss type absorbing material principal feature has higher magnetic loss tangent angle, utilize magnetic hysteresis loss, domain wall resonance and the magnetic polarization mechanism such as natural resonance, aftereffect loss decay electromagnetic wave absorption, mainly comprise ferrite powder, carbonyl iron dust, super-fine metal powder, nano-phase material etc.Dielectric loss type absorbing material principal feature has higher electrical loss tangent angle, rely on the electronic polarization of medium, ionic polarization, molecular polarization or interfacial polarization decay electromagnetic wave absorption, mainly comprise conductive carbon black, silicon carbide, metallic staple, conducting polymer etc.
At present, for absorbing material, simple magnetic loss type or dielectric loss type can not meet the needs of practical application, and it is weak mostly to there is wave-sucking performance when being used alone these materials, inhale the deficiencies such as ripple frequency band is narrow, quality weight, non-refractory and mechanical property are poor.In order to practical requirement, on the basis of traditional absorbing material, the limitation of original material will be broken through, positive development of new wave absorbing agent, explore the composite wave absorption material integrating magnetic loss and electrical loss, and meet the requirement of electromagnetic interference material " thin, light, wide, strong ".
Variation hole is the light multifunction that the ultra-light porous metal of feature achieve structured material, and because it has lightweight, high specific strength, high-energy absorption, the features such as sound, heat, electromagnetic shielding and multi-functional compatibility thereof, are just becoming one of current study hotspot.
Foamed aluminium is a kind of new function material, and it is the similar foamed ultralight metallic substance of numerous bubbles of being scattered here and there in metallic aluminium matrix, and general porosity is 40% ~ 98%.
The foamed aluminium preparation technology of current most commercial value is foam melt method, can production large size and have the closed-cell aluminum foam of regular pore space structure.But up to the present, rarely have the report of large gauge closed-cell foam aluminum products commercial applications.Problems existing is mainly manifested in: (1) traditional technology mostly adopts TiH
2deng as whipping agent and calcium metal as tackifier, TiH
2the fast feature of class whipping agent decomposition rate makes this method operational condition harsh, and yield rate is low; (2) expensive TiH
2the use of class whipping agent and calcium metal, also further increases the manufacturing cost of closed-cell aluminum foam.Therefore, alternative TiH is developed
2the type material of class whipping agent is significant.
Patent CN102002300B discloses a kind of preparation method of foam aluminium alloy wave-absorbing material, the method comprises the surface preparation of foam aluminium alloy matrix, the preparation of antiradar coatings and spraying, wherein polyaniline is wave absorbing agent, and the rare earth element of doping further increases the absorbing property of polyaniline.Meanwhile, the vesicular structure of foamed aluminium, makes hertzian wave multiple reflections, scattering and interference, increases its power loss.
Summary of the invention
The object of the invention is to a kind of take foamed aluminium as the ferrite composite wave-suction material of matrix.
The technical scheme realizing the object of the invention is: a kind of take foamed aluminium as the ferrite composite wave-suction material of matrix, by mass percentage, by whipping agent 5% ~ 15%, ferrite 20% ~ 50%, aluminium powder 25% ~ 40%, aluminum oxide powder 10% ~ 25%.
Whipping agent of the present invention, represents by mass percentage, is made up of rhombspar 32% ~ 52%, calcium carbonate 25% ~ 35%, calcium sulfate 5% ~ 10%, carbon dust 10% ~ 18% and silica flour 5% ~ 10%.
Ferrite of the present invention is nickel-zinc ferrite, and particle diameter is 3 ~ 5 μm.
The component of nickel-zinc ferrite of the present invention and the weight ratio of content are: Fe
2o
340 ~ 60%, NiO10 ~ 30%, ZnO20 ~ 40%, all the other are additive.
Additive of the present invention is BaO or Bi
2o
3.
Of the present invention take foamed aluminium as the ferrite composite wave-suction material of matrix, and this absorbing material is obtained by following steps:
1) batch mixing: example is by whipping agent, deionized water and dispersion agent in mass ratio, obtains powder with vibromill mixing after 0.5 ~ 3 hour;
2) sand milling: above-mentioned powder is put into sand mill, adds ferrite, aluminium powder, aluminum oxide powder simultaneously, and sand milling obtains slurry in 0.5 ~ 3 hour;
3) shaping: the slurry after above-mentioned sand milling to be carried out shapingly obtain green compact;
4) foam: after green compact drying, at 600 ~ 800 DEG C of constant temperature, insulation 5 ~ 10min, in atmosphere naturally cooling, obtain foamed aluminium/ferrite composite wave-suction material.
Further, in step 1), the mass percent of described whipping agent, deionized water and dispersion agent is 1:(10 ~ 50): (0.2 ~ 0.5).
Further, described whipping agent, represents by mass percentage, is made up of rhombspar 32% ~ 52%, calcium carbonate 25% ~ 35%, calcium sulfate 5% ~ 10%, carbon dust 10% ~ 18% and silica flour 5% ~ 10%.
Further, described dispersion agent is polyvinyl alcohol or methylcellulose gum.
Further, step 2) in, the mass percent of described ferrite, aluminium powder and aluminum oxide powder is 1:(0.5 ~ 2): (0.2 ~ 1.25), described ferrite and the mass percent of whipping agent are (2 ~ 10): 1.
Compared with prior art, the advantage had is in the present invention: 1) whipping agent of the present invention can solve TiH
2expensive, that operational condition is harsh problem is there is as whipping agent.2) whipping agent of the present invention regulates porosity and the pore size distribution of foamed aluminium by feed change proportioning, thus regulates the absorbing property of foamed aluminium/ferrite composite material.3) rhombspar in the present invention, decomposable asymmetric choice net goes out a large amount of gas, and the carbon dust selected, silica flour, as conditioning agent, not only regulate the foam performance of whipping agent, and enhance the heat resistance of foamed aluminium.4) foamed aluminium/ferrite composite material of the present invention, can meet the requirement of " thin, light, wide, strong ".
Embodiment
Below in conjunction with embodiment, the present invention is described further, but the invention is not restricted to these embodiments.
embodiment 1
1) batch mixing: take 100 grams of whipping agents (composition: rhombspar 32 grams, 35 grams, calcium carbonate, 10 grams, calcium sulfate, carbon dust 13 grams, silica flour 10 grams), 1 kilogram of deionized water and 20 grams of polyvinyl alcohol, obtain powder after mixing 0.5 hour with vibromill;
2) sand milling: above-mentioned powder is put into sand mill, adds 200 grams of nickel-zinc ferrite (composition Fe simultaneously
2o
380 grams, NiO20 gram, ZnO80 gram, BaO20 gram, particle diameter is 3 μm), 100 grams of aluminium powders, 40 grams of aluminum oxide powders, sand milling 0.5 hour slurry;
3) shaping: the slurry after above-mentioned sand milling to be carried out shapingly obtain green compact;
4) foam: after green compact drying, at 600 DEG C of constant temperature, insulation 5min, in atmosphere naturally cooling, obtain foamed aluminium/ferrite composite wave-suction material.
embodiment 2
1) batch mixing: take 100 grams of whipping agents (composition: rhombspar 52 grams, 25 grams, calcium carbonate, 5 grams, calcium sulfate, carbon dust 10 grams, silica flour 8 grams), 5 kilograms of deionized waters and 50 grams of polyvinyl alcohol, obtain powder after mixing 0.5 hour with vibromill;
2) sand milling: above-mentioned powder is put into sand mill, adds 1 kilogram of nickel-zinc ferrite (composition Fe simultaneously
2o
3600 grams, Ni100 gram, ZnO200 gram, BaO100 gram, particle diameter is 5 μm), 2 kilograms of aluminium powders, 1.25 kg of alumina powder, sand milling 3 hours slurry;
3) shaping: the slurry after above-mentioned sand milling to be carried out shapingly obtain green compact;
4) foam: after green compact drying, at 800 DEG C of constant temperature, insulation 10min, in atmosphere naturally cooling, obtain foamed aluminium/ferrite composite wave-suction material.
embodiment 3
1) batch mixing: take 100 grams of whipping agents (composition: rhombspar 40 grams, 30 grams, calcium carbonate, 6 grams, calcium sulfate, carbon dust 18 grams, silica flour 6 grams), 3 kilograms of deionized waters and 30 grams of methylcellulose gum, obtain powder after mixing 0.5 hour with vibromill;
2) sand milling: above-mentioned powder is put into sand mill, adds 500 grams of nickel-zinc ferrite (composition Fe simultaneously
2o
3225 grams, NiO150 gram, ZnO100 gram, BaO25 gram, particle diameter is 3 μm), 700 grams of aluminium powders, 300 grams of aluminum oxide powders, sand milling 2 hours slurry;
3) shaping: the slurry after above-mentioned sand milling to be carried out shapingly obtain green compact;
4) foam: after green compact drying, at 650 DEG C of constant temperature, insulation 5min, in atmosphere naturally cooling, obtain foamed aluminium/ferrite composite wave-suction material.
The present invention is not limited to above embodiment; the illustrative embodiments that embodiment 1 ~ 3 is only used to principle of the present invention is described and adopts; but for those skilled in the art; do not departing under real situation of the present invention; can make various modification and improvement, these modification and improvement are also considered as protection scope of the present invention.