32results about How to "Improve thermal compatibility" patented technology

The invention discloses a solid oxide fuel cell gradient porosity anode and a solid oxide fuel cell. The solid oxide fuel cell gradient porosity anode comprises an anode function layer, an anode transition layer and an anode support layer which are connected in sequence from top to bottom. The opening porosity of the anode transition layer is greater than or equal to the opening porosity of the anode function layer. The opening porosity of the anode transition layer is smaller than or equal to the opening porosity of the anode support layer. The opening porosity of the anode function layer, the opening porosity of the anode transition layer and the opening porosity of the anode support layer are in gradient gradual decrease along a horizontal direction, or the opening porosity of the anodefunction layer, the opening porosity of the anode transition layer and the opening porosity of the anode support layer are in gradient gradual increase. The anode is characterized by relatively low activation polarization, concentration polarization and ohm polarization loss. The fuel cell is characterized by high output electrical property and high intensity.

The invention relates to a carbon fiber reinforced carbon-hafnium-tantalum-carbon solid solution composite material and a preparation method thereof. The preparation method includes preparing a pyrolytic carbon interface layer on a carbon fiber preform by chemical vapor infiltration, preparing a C matrix by using a pyrolysis method or a precursor impregnation cracking method, and then preparing a C matrix by impregnating a hafnium-tantalum carbon ceramic precursor. Ta x HfC transition matrix, and finally Ta x HfC matrix. C prepared by the present invention f / C‑Ta x HfC composites contain uniformly distributed C‑Ta x HfC transition matrix, can increase the first C matrix and anti-oxidation Ta x The thermal matching of HfC matrix enhances the mechanical properties of composite materials; the C prepared by the present invention f / C‑Ta x Ta in HfC composites x The high content of HfC can significantly enhance the oxidation resistance of the composite.

The invention relates to a high-temperature-resistant high-strength aluminum oxide fiber enhanced composite material and a preparation method thereof. The preparation method comprises the following steps of: by taking a two-dimensional cloth paving layer and 2.5D woven or orthogonally three-dimensional woven continuous aluminum oxide fiber preform as an enhancer, preparing a matrix through a double nano composite impregnation liquid where silicon dioxide and aluminum oxide are uniformly mixed; and finally obtaining the aluminum oxide fiber enhanced composite material through the process of vacuum pressure impregnation, micro-positive pressure medium and low temperature pre-curing, micro-positive pressure curing and atmosphere temperature programming sub-sectional thermal treatment, wherein the mass ratio of silicon dioxide to aluminum oxide in the composite material is (19:1)-(12:8), and the volume content of the aluminum oxide fibers is 30-60%. The prepared composite material has a high-temperature-resistant property and a high-temperature mechanical property, and is high in compactness; the room temperature tensile strength of the material reaches 310+ / -30MPa, the tensile strength at 1100 DEG C reaches 135+ / -20MPa, and the tensile strength at 1200 DEG C reaches 90+ / -10MPa; and compared with a similar quartz fiber enhanced silicon dioxide oxide / oxide composite material, the performance is improved by 4-5 times.

The invention relates to a method for preparing a ceramic protective layer on a C / SiC composite material and the prepared ceramic protective layer. The method is as follows: a ZrC-SiC transition layer is prepared on the surface of the C / SiC composite material through an impregnation-curing-pyrolysis process, and the impregnating solution is zirconium-silicon containing zirconium and silicon with a weight ratio of (1-8):1 An integrated ceramic precursor solution; a ZrC oxidation-resistant coating is obtained on the basis of the ZrC-SiC transition layer by a brushing process; a SiC sealing layer is deposited on the surface of the ZrC oxidation-resistant coating obtained by chemical vapor deposition , thus making a ceramic protective layer on the C / SiC composite. The ceramic protective layer prepared by the present invention can have excellent oxidation resistance at a temperature above 2000°C, and also has a high bonding force with the substrate. with broadly application foreground.

The invention relates to an anti-oxidation coating for a C / ZrC-SiC composite material and a preparation method thereof. The anti-oxidation coating consists of HfC‑HfB sequentially formed alternately on the C / ZrC‑SiC composite 2 coating and SiC coating. The preparation method includes brushing the ceramic slurry containing Hf powder, B powder, ethanol and phenolic resin on the surface of the C / ZrC-SiC composite material, forming HfC-HfB after cracking 2 coating, and then depositing a SiC coating; repeating the above steps (N-2) / 2 times, thereby forming an anti-oxidation coating on the surface of the C / ZrC-SiC composite material. The method of the invention has simple process and low preparation cost, and solves the problem of HfC-HfB 2 , the uniform distribution of SiC and the combination with the matrix significantly improve the ablation resistance and oxidation resistance of the C / ZrC-SiC composite material, and further increase the service temperature of the C / ZrC-SiC composite material.

The invention discloses a graphene film frequency selective surface, the surface comprises a substrate and a graphene film layer arranged on the substrate, the substrate is a fiber reinforced resin composite material; the graphene film layer is graphite with periodic openings ene films or periodically arranged graphene film patches. The frequency selective surface technology of the graphene film of the invention is simple to implement, has good compatibility with the fiber reinforced resin composite material substrate, has small weight gain and corrosion resistance, and can be widely used in devices such as composite material radomes or filters.

The invention discloses an intermediate temperature solid oxide fuel battery composite cathode and a preparation method thereof, and belongs to the field of chemical power solid oxide fuel battery materials. The invention solves the problem that the conventional cathode materials are not suitable for working under the condition of intermediate temperature. The composite cathode material is composed of Ca2Fe1.4Co0.6O5 and a solid dielectric which is Ce0.8Gd0.2O1.95 or Ce0.8Sm0.2O1.95. The method comprises the following steps of: 1, mixing the Ca2Fe1.4Co0.6O5 and the solid dielectric, adding terpilenol and uniformly mixing the three materials to obtain a mixed material; 2, coating the mixed material on the surface of the dielectric, and placing the dielectric in an oven for drying; and 3, sintering the dielectric to obtain the intermediate temperature solid oxide fuel battery composite cathode material on the surface of the dielectric. The cathode has the advantages of high electro-catalytic activity and low polarization resistance in the temperature range of 500 to 700 DEG C.

The invention relates to the technical field of high-temperature infrared stealth materials, and specifically discloses an anti-oxidation / infrared stealth coating on the surface of a fiber-reinforced ceramic matrix composite material with a temperature resistance of 1650°C. The infrared stealth coating has a layered structure, which consists of A ceramic inner layer, a ceramic middle layer, a ceramic outer layer and a low infrared emissivity functional layer, the ceramic inner layer is a mullite layer, the ceramic middle layer is a rare earth silicate layer, and the ceramic outer layer is an 8YSZ layer , the low infrared emissivity functional layer is based on Pt as the conductive phase, Bi 2 o 3 coating for the binder phase. The invention also provides a preparation method for the anti-oxidation / infrared stealth coating on the surface of the fiber-reinforced ceramic matrix composite material with a temperature resistance of 1650°C. The infrared stealth coating of the invention improves the oxidation resistance and high temperature stability of the composite material, can significantly reduce the infrared radiation intensity of the base material, and has excellent oxidation resistance and infrared stealth function.

The invention relates to a ceramic protection layer for C / ZrC-SiC composite material and a preparation method thereof. The ceramic protective layer comprises (TiZrHfTa)C formed sequentially on the C / ZrC-SiC composite material. x ‑SiC transition layer, (TiZrHfTa)C x Anti-oxidation coating and SiC sealing layer. The method is: preparing (TiZrHfTa)C by PIP process x ‑SiC transition layer; (TiZrHfTa)C prepared on the basis of said transition layer by brushing process x An anti-oxidation coating; a SiC sealing layer is prepared on the basis of the anti-oxidation coating by a chemical vapor deposition process to obtain a ceramic protective layer. The ceramic protective layer prepared by the invention can have excellent oxidation resistance at a temperature above 2500° C., and also has a high bonding force with the substrate, and has broad application prospects on structural parts such as terminals and engines of new hypersonic aircraft.

The invention discloses a fabrication method for a cover body of a superhigh temperature ceramic matrix composite material ablation head antenna cover. The method comprises the following steps of weaving an ablation head flat plate fabric by a carbon fiber three-phase orthogonal mode to obtain an ablation head woven fabric; immersing and compounding to obtain C / SiC-ZrC composite ceramic ablation head rough blank, and carrying out profiling weaving on the cover body fabric by a needling mode to obtain a cover body woven fabric; mechanically processing the cover body woven fabric to required product sizes to obtain an ablation head and the cover body; and connecting and forming the ablation head and the cover body by nuts, thereby obtaining the cover body of the ablation head antenna cover. According to the method, the C / SiC-ZrC composite material and a C / SiC-HfC composite material which have excellent temperature resistance reaching 2,000 DEG C and ablation resistance are used; and through optimal design on a prefabricated element of the ablation head and control on volume content of annular fibers, zero expansion of the ablation head composite material in an annular direction can be achieved, and thus, the obtained cover body of the antenna cover can be applied to intermediate and remote land attack cruise missiles with high mach (greater than 10Ma), long endurance (greater than 1,000 seconds) and high accuracy.

The invention discloses a low thermal expansion cathode material for a solid oxide fuel cell. The low thermal expansion cathode material is prepared from barium, strontium, cobalt, iron and manganese, wherein Mn partially replaces Co in a Ba0.5Sr0.5Co0.8Fe0.2O3-delta-based cathode material; replacement is carried out in a position B of a perovskite structure; the content of manganese in a cathode is not greater than 15%, and the proportion of Co and Mn in a chemical formula is (0.8-x):x; and a cathode composition is expressed as Ba0.5Sr0.5Co0.8-xFe0.2MnxO3-delta, wherein x is greater than 0 and less than 0.3. The cathode material releases lattice oxygen at a slower speed, oxygen vacancy concentration in lattices is controlled, and thermal expansion changes slowly along with rise of the temperature, so that the thermal matching performance of the cathode and an electrolyte is improved; further the electrical property of the cathode is not weakened; and the preparation method is simple, uses simple equipment, is low-cost, has high repeatability, and is easy for industrial production.

The invention discloses a preparation method of a mullite whisker in-situ toughened chromium phosphate aluminum wave-transmitting material. The method is characterized by the following steps of: dissolving a phosphorus-containing compound into absolute ethyl alcohol or water, adding an aluminum-containing compound and a chromium-containing compound at the temperature of 50-100 DEG C while stirring for reacting, and adding ammonia water, citric acid or methanol for reacting to obtain a chromium phosphate aluminum precursor; putting the chromium phosphate aluminum precursor, the aluminum-containing compound, a silicon-containing compound, aluminum fluoride and water or alcohol into a ball milling device for performing ball milling to obtain a mixture; and drying the mixture, grinding, sieving, performing press forming on the minus sieve, i.e., sintering precursor powder, and calcining in an enclosed container at the temperature of 1,200-1,500 DEG C for 1-24 hours to obtain the mullite whisker in-situ toughened chromium phosphate aluminum wave-transmitting material. The method has the advantages of in-situ growth of mullite whiskers, uniform distribution of the whiskers, dense substrate sintering, good toughening effect, high performance of the wave-transmitting material, applicability of the wave-transmitting material to antenna covers of flying vehicles, radar antenna covers and the like.

The invention discloses a carbon nanotube film frequency selective surface, a preparation method thereof and a radome. The surface includes a substrate and a carbon nanotube thin film layer arranged on the substrate, the substrate is a fiber-reinforced resin composite material; the carbon nanotube thin film layer is a carbon nanotube thin film with periodic openings. The frequency selective surface technology of the carbon nanotube thin film of the invention is simple to implement, has good matching with the substrate of the fiber-reinforced resin composite material, has small weight gain, and is corrosion-resistant, and can be widely used in devices such as composite material radomes or filters.

The invention discloses a metallurgical bonding glass-sealed diode structure and a production method thereof. The metallurgical bonding glass-sealed diode structure comprises an electrode A, an electrode B, a chip and a glass tube, wherein the electrode A, the electrode B and the chip are arranged in the glass tube; electrical connection is achieved through diffusion welding between the chip and the electrode A and the electrode B; transition layer materials for diffusion welding are an upper surface metallization layer and a lower surface metallization layer of the chip respectively; and diffusion welding between the chip and the electrode A and the electrode B and sealing of the glass tube are synchronously finished to form a whole. The method comprises component assembling and sintering steps. The metallurgical bonding is achieved between the electrodes and the chip in a high-temperature process; the metallurgical bonding glass-sealed diode structure has the advantages of good heat dissipation performance, high current impact resistance and the like; the working range can be -55 DEG C to 175 DEG C; and the shortages that a metallurgical bonding glass-sealed diode product produced by the prior art is low in positive surge current resistance, reverse transient power resistance and the like are overcome.

The invention discloses a heat protection device, comprising: an upper panel, a bottom panel, an upper corrugated board layer composed of a plurality of upper corrugated boards arranged in sequence, and a lower corrugated board layer composed of a plurality of lower corrugated boards arranged in sequence layer; the upper corrugated board layer is set above the lower corrugated board layer, and the upper corrugated board layer and the lower corrugated board layer are arranged alternately; the lower end of the upper corrugated board and the upper end of the lower corrugated board are connected through heat insulation and load-bearing cooperative bolt connection structure ; Heat insulation and load-bearing collaborative bolt connection structure includes: connecting bolts, upper heat insulation gasket, middle heat insulation gasket, lower heat insulation gasket, connecting nut; the gap between the upper panel and the lower end of the upper corrugated plate is filled with resistant High temperature heat insulation material; the gap between the bottom panel and the upper end of the lower corrugated plate is filled with medium temperature heat insulation material. By using the thermal protection device of the present invention, the problem of thermal short circuit of the connecting structure and thermal mismatch of the hot and cold structures in the thermal protection device can be solved.