8results 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 invention discloses a manufacturing method of a lead-tin-copper alloy-steel bimetal plate. The manufacturing method comprises the following steps that lead-tin-copper alloy powder is flatly laid on a steel plate; placing the steel plate on which the powder is laid in a mesh belt sintering furnace, raising two ends by using cushion blocks, and carrying out primary sintering; rolling the primary sintered plate, and then carrying out secondary sintering on the primary rolled plate; and the secondarily sintered plate is rolled and then leveled, and a finished plate is obtained. The cushion blocks are adopted in the mesh belt sintering furnace to block up a steel plate, so that fluctuation of a temperature field is accelerated, the temperature field is promoted to keep high uniformity, and the quality of a sintered plate is improved; according to the method, the primary sintering temperature and the secondary sintering temperature are controlled, so that the lead loss is reduced, the quality of a sintered product is ensured, and the sintering efficiency is improved. According to the manufactured lead-tin-copper alloy-steel bimetallic plate copper alloy, the particle size of lead is reduced, distribution is uniform, and the frictional wear performance is improved.

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.

The invention relates to the technical field of engineering ceramic materials, in particular to a method for preparing zirconium oxide toughened aluminum oxide ZTA ceramic through a low-temperature sintering method. The method comprises the following steps: preparing a ZTA ceramic sintering aid and a ZTA ceramic dry pressing material, molding the dry pressing material, drying, and sintering at 1200-1300 DEG C. The sintering aid is prepared from boric acid, sodium carbonate, potassium carbonate, calcium fluoride, bismuth trioxide, ammonium dihydrogen phosphate, antimony trioxide, silicon dioxide and other raw materials according to a certain proportion. The ZTA ceramic can be compactly sintered at 1250-1300 DEG C, the principal crystalline phase in the sintered ZTA ceramic is the same as the principal crystalline phase of the traditional ZTA ceramic which is not added with the sintering aid after high-temperature sintering, the principal crystalline phases are alpha-Al2O3 phase, tetragonal phase zirconia (t-ZrO2) phase and monoclinic phase zirconia (m-ZrO2) phase, and no other impurity phase is generated. After the ZTA ceramic prepared by the process disclosed by the invention is sintered at 1250 DEG C, the density of the ZTA ceramic reaches 97.8%, and the bending strength of the ZTA ceramic is 478 MPa.

The invention relates to the technical field of aluminum-based composite materials, in particular to a phase change energy storage-heat conduction synergistic aluminum-based composite material and a preparation method of the phase change energy storage-heat conduction synergistic aluminum-based composite material. 8-20 parts of a phase change energy storage material; 2-5 parts of a heat conduction reinforcing agent; 0.5 to 2 parts of a carbon nano tube; 0.2 to 1 part of an interface coupling agent; the carbon nanotubes and the aluminum nitride powder are introduced as heat-conducting fillers, so that a multi-stage heat-conducting network with the scale from nanometer to micrometer is constructed. The carbon nano tube forms a nano-scale heat conduction channel by virtue of the high length-diameter ratio and excellent axial heat conduction performance of the carbon nano tube. And the micron-sized aluminum nitride powder fills gaps among the carbon nanotubes, so that the continuity and the effectiveness of the heat-conducting network are further improved. According to the multi-scale structural design, the overall heat-conducting property of the composite material is remarkably improved, and meanwhile, the mechanical property of the material is accidentally enhanced.

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.