5results about How to "Rapid densification" patented technology

The application provides a UN-U3Si2 composite pellet sintering method based on spark plasma sintering, which comprises the following steps: crushing and ball-milling U3Si2 ingots to obtain U3Si2 powder; preparing UN powder; respectively weighing UN powder and U3Si2 powder in a set mass ratio in an inert gas glove box and uniformly mixing; pre-pressing the mixed powder into a graphite mold; taking out the graphite mold containing the UN-U3Si2 mixed powder from the glove box after pre-pressing; and densifying the UN-U3Si2 mixed powder through spark plasma sintering to prepare UN-U3Si2 two-phase composite fuel pellets. The UN-U3Si2 composite fuel pellets are rapidly densified through the spark plasma sintering process.

The application belongs to the technical field of carbon-based thermal protection composite materials, and discloses a kind of quick densification high tenacity carbon-based composite material and its preparation method, its preparation steps include: 1) after mixing uniformly benzoxazine resin, solvent and ceramic precursor, heating, first impregnation liquid is prepared;2) first impregnation liquid is brushed on carbon fiber cloth, and naturally air-dried, to obtain pretreated carbon fiber cloth;3) after mixing uniformly benzoxazine resin, solvent, ceramic precursor and ceramic particles, second impregnation liquid is prepared;4) second impregnation liquid is brushed on pretreated carbon fiber cloth, and dried, to obtain prepreg;5) after laminating and laying up prepreg, mould pressing is formed, to obtain blank;6) blank is heated and pyrolyzed under inert atmosphere, to obtain carbon-based composite material.The carbon-based composite material of the application can be formed and simultaneously quickly densified in only one cycle, almost realizes full densification, porosity is less than 1.5vol%, and has excellent mechanical properties and thermal protection performance.

The application provides a gradient wave-transparent heat shield forming method, comprising the following steps: S1, preparing a preform of a heat shield; S2, configuring ceramic slurry; S3, fusing the ceramic slurry into the preform of the heat shield to form a green body of the heat shield; S4, placing the green body of the heat shield into the ceramic slurry to densify the green body of the heat shield; and S5, sealing a large port of the green body of the heat shield and performing solution infiltration on the green body of the heat shield by using polytetrafluoroethylene to form the heat shield. The heat shield prepared by the method not only has the functions of bearing and transmitting waves, but also has excellent heat insulation and heat protection functions.

The invention discloses a carbon ceramic closing resistor for a high-voltage circuit breaker and a preparation method of the carbon ceramic closing resistor, and belongs to the technical field of power elements. The problems of poor resistor compactness, non-uniform performance, insufficient mechanical property and the like caused by high pressing and sintering difficulty, process instability and high and non-uniform resistor porosity of the carbon ceramic resistor are solved. The preparation process of the resistor comprises the following steps: by taking aluminum oxide and quartz as ceramic phases, presintered kaolin, mullite and potassium feldspar as clay phases and carbon black or graphite as conductive phases, pre-coating the ceramic phases with the clay phases, carrying out vacuum calcination on pre-coated powder, mixing the pre-coated powder with the secondarily added clay phases and the conductive phases, carrying out spray granulation, pressing a green body, sintering and spraying. And obtaining the carbon ceramic closing resistor. According to the invention, the kaolin is pre-sintered, and the clay phase is pre-coated with the ceramic phase, so that the subsequent blank pressing uniformity and density are increased, the structural defects of the carbon ceramic resistor are reduced, and in combination with the spark plasma sintering technology, the batch rapid production of the resistor can be realized.

This invention discloses a method for preparing highly spherical zirconia microspheres based on a controllable emulsion template method. Using a water-in-oil emulsion as a template, a composite emulsifier of Span-80 and Tween-80 is employed at a mass ratio of 2:1-4:1, a total concentration of 2-3%, and an oil-to-water volume ratio of 3:1-5:1. Uniform and stable emulsion droplets are formed under a stirring intensity of 800-1500 rpm. The emulsion is then cured at a constant temperature of 50-65℃ for 1-3 hours to allow the gel network to form slowly, preventing microsphere shrinkage and cracking. Finally, a three-stage stepped sintering process is used: increasing the temperature at 1-3℃ / min to 300-400℃ and holding for 1-2 hours; increasing the temperature at 2-5℃ / min to 700-800℃ and holding for 1-2 hours; and increasing the temperature at 3-8℃ / min to 1350-1400℃ and holding for 15-30 minutes to inhibit abnormal grain growth and achieve sufficient densification. Through the coordinated control of emulsification, curing and sintering, the prepared zirconia microspheres have excellent sphericity, particle size uniformity, density and mechanical properties, and the process parameters can be adjusted over a wide range, showing good prospects for industrial application.