34results about How to "Good microwave absorption characteristics" patented technology

The invention relates to a method for improving the strength of plastic rapid prototyping parts and equipment for producing special wire rods. The method is characterized in that the method includes the steps of: preparing plastic wire rods with graphene microchips on the surface, making rapid prototyping parts, microwave treatment, heat preservation and cool down. Its equipment includes frame, plastic extruder, cooling tank, ultrasonic disperser, traction wheel set and winder. Its advantages are: the manufactured plastic rapid prototyping parts have high strength and good strength along the layer direction, and can keep the original size and shape of the workpiece unchanged. This method is easy to operate, low in cost and good in effect. moldings.

A multiferroic wave-absorbing material and a preparation method thereof, the material belongs to a class of Aurivillius phase bismuth-layered perovskite oxides, and its chemical formula is Bi 5‑x R x Fe 1‑y Ni y Ti 3 o 15 ,in x 0.5≤ x ≤0.75, y 0.3≤ y ≤0.5; in the chemical formula, R is one of the rare earth elements Nd and Sm; the present invention also includes the preparation method of the multiferroic wave-absorbing material. The material of the invention has excellent magnetic properties, good reflection loss characteristics in the 8-18GHz microwave frequency band, high absorption strength and wide absorption frequency band. The preparation method is simple to operate, the process conditions are easy to control and has broad application prospects.

The invention provides a HoFeB / Fe 3 o 4 The composite wave-absorbing material and its preparation method are applicable to the field of wave-absorbing materials, and the preparation method comprises, respectively using Ho, Fe and B with a purity ≥ 99.95% as raw materials, repeatedly melting them into an ingot with uniform composition in an argon atmosphere, Vacuumize and seal in quartz glass for homogenization annealing at 800°C, then quench with ice-water mixture, and then perform mechanical crushing and high-energy ball milling. The powder after high-energy ball milling was mixed with ferroferric oxide in an agate mortar according to the relative molecular mass percentage to obtain HoFeB / Fe 3 o 4 composite material. The composite wave-absorbing material of the invention has good microwave absorption effect in the microwave frequency range of 2-18 GHz, wide absorption frequency point, simple preparation process, strong oxidation resistance and the like. It can be applied to the preparation of microwave absorbing products that require wide absorbing frequency band, good absorbing performance and strong oxidation resistance.

The invention discloses a single-phase multiferroic microwave absorbing material NdBi6Ti3 (Fe1-xCox) 3O21(x=0.25-0.3) and a preparation method thereof. Because of the symbiotic structure of layered perovskite and the chemical modification of neodymium, the microwave absorbing material exhibits excellent multiferrous properties due to the interaction between ferrite octahedron and cobalt-oxygen octahedron. Based on these physical characteristics, the material exhibits good microwave absorbing property in the microwave range of 2-18GHz, has high absorption intensity and wide absorption band, andis far superior to the microwave absorption performance of the partial carbon / ferrite composite material; and the preparation method has the advantages of simple operation, short experiment period, favorable for large-scale production and wide application prospect.

The invention discloses a LaNiCo magnetic wave-absorbing material and a preparation method thereof. The method comprises the following steps: 1) batching; 2) smelting; 3) heat treatment; 4) ball milling to obtain the LaNiCo magnetic wave-absorbing material. This magnetic absorbing material has the characteristics of wide absorption frequency band, high absorbing efficiency, good thermal stability, good corrosion resistance and good oxidation resistance in the 2GHz‑18GHz microwave band. The advantage of this method is that the process is simple and the operability is strong.

The invention discloses a magnetic hollow micro-nano material, a preparation method and application thereof, and belongs to the technical field of nano-materials. The invention discloses that the magnetic hollow micro-nano material prepared by a one-step liquid-phase reduction-oxidation method not only has a novel structure and formation mechanism, but also can regulate the concentration of Cu and Ni by changing the reaction temperature, time, stirring speed, gas flow, and reactant concentration. Content and composition, morphology and structure of magnetic hollow micro-nano materials, in which the diameter of micro-nanotubes is 0.1-2 μm, the length is 2-12 μm, and the wall thickness is 10-140 nm; the diameter of micro-nanospheres is 0.2-5 μm, and the wall thickness is 10~180nm. Because of the good dispersion and uniformity of the magnetic hollow micro-nano material and good microwave absorption characteristics, it is widely used in the fields of microwave absorption and shielding, electrocatalysis, lithium-ion batteries, and surface-enhanced Raman spectroscopy. In addition, the preparation method disclosed in the present invention is simple to operate, environmentally friendly, has good potential for industrial application, and is suitable for market promotion and application.

A kind of sheet ceramic wave-absorbing material and preparation method thereof, the chemical formula of this wave-absorbing material is Ba 12‑x R x Fe 28 Ti 15 o 84 ,in x is 2≤ x ≤4; R in the chemical formula is a rare earth element La or Nd; the absorbing material is a type of layered oxide with a monoclinic crystal structure, and the space group is C 2 / m ; The monoclinic crystal structure is randomly arranged flaky or plate-like grains, with a diameter of 2 to 7 µ m, thickness 1~2 µ m; the present invention also includes the preparation method of the wave-absorbing material, including the following steps: (1) preparation of sol; (2) preparation of primary powder; (3) preparation of wave-absorbing material; The sheet / plate microstructure features and is modified by magnetic element doping, showing excellent electromagnetic loss characteristics and good microwave impedance matching characteristics; the material shows good microwave absorption characteristics in the microwave range of 2~18GHz, the best The frequency bandwidth with return loss values ​​below ‑17dB and return loss below ‑10dB is greater than 4.0GHz.

The rare earth ReCrO3 magnetic wave-absorbing material and its preparation method of the present invention are prepared by mixing Re2O3 and Cr2O3 powders with a molecular ratio of 1:1 with a purity of ≥99.50%, and grinding them in an agate bowl mill for half an hour to mix Evenly, after mixing evenly, the powder is pressed into flakes, and the flakes are sintered at 1500°C for 24 hours under the protection of vacuum or argon, and then cooled with the furnace. The invention has the advantages of simple preparation process, good microwave absorption characteristics in the 2-18 GHz microwave band, wide absorption frequency band, good oxidation resistance and good temperature stability, and does not contain strategic metal elements such as Co and Ni, and has the characteristics of low price and the like. . It is more suitable for preparing microwave absorbing products with high microwave absorption efficiency, low material density, good non-oxidation and corrosion resistance, and good thermal stability.

The invention relates to a preparation method for a microwave absorption diatom ooze coating material and an application. The method comprises the following steps: mixing diatom ooze dry powder, a microwave absorbent and a dispersant according to a mass ratio of 1:1.5:(18-25), performing soaking for 10-20min, and performing electric stirring for 30-60min to obtain the microwave absorption diatom ooze coating material; and the microwave absorbent is a carbon magnetic heterostructural micro nano fiber. According to the microwave absorption diatom ooze coating material prepared from the method, when the microwave absorption diatom ooze coating material is applied, a concrete construction method comprises the following steps: scraping bottom-layer putty on cleaned wall surfaces, grinding wall surfaces until the wall surfaces are smooth, dispersing the microwave absorption diatom ooze coating material to building wall surfaces uniformly by 2-3 times, making diatom ooze patterns or performing coloring or making a press polishing layer at the treated building wall surfaces, and performing maintenance for 1-2 days to obtain the finished product. The microwave absorption diatom ooze coating material is an ideal green and environmentally-friendly building and decorative material, has excellent microwave absorbing characteristics, beautifies and decorates environments, and can avoid electromagnetic pollution and information leakage; and the microwave absorption diatom ooze coating material can be used at wall surfaces of buildings such as electromagnetic shielding darkrooms, residential power distribution rooms, military meeting rooms and secret rooms, television towers, broadcasting rooms, radars, and satellite communication launching pads.