8results about How to "Promote densification" patented technology

This invention discloses a method for preparing silicon carbide fibers with an in-situ boron nitride coating. The method involves melt spinning a metal-doped polycarbosilane precursor to obtain doped polycarbosilane precursor fibers. These precursor fibers are then subjected to a non-melting treatment in an oxidizing atmosphere to obtain non-melting fibers. The non-melting fibers are then subjected to inorganic pyrolysis to obtain inorganic fibers. These inorganic fibers are then densified and sintered to obtain boron-containing SiC fibers. Finally, the boron-containing SiC fibers are subjected to high-temperature treatment in a nitrogen atmosphere to obtain silicon carbide fibers with an in-situ boron nitride coating. This invention provides a simple preparation method, resulting in an in-situ self-grown BN coating with high crystallinity, good stability, and excellent uniformity. The coating is tightly bonded to the SiC fibers, is low-cost, and can be mass-produced. Furthermore, it significantly improves the fiber's temperature resistance and high-temperature creep resistance, allowing the fiber to serve for extended periods at higher temperatures.

The invention discloses a zirconia ceramic matrix with high thermal shock resistance as well as a preparation method and application thereof. The zirconia ceramic matrix comprises a matrix and a coating layer a; the matrix comprises the following components: 90-98 wt% of zirconium oxide; 1.5 to 8 wt.% of a stabilizing agent; % of a grain boundary regulating agent; the stabilizing agent is prepared from the following components in percentage by weight: 2.0 to 4.0 percent of Sc2O3, 0.5 to 1.5 percent of Yb2O3 and 0.3 to 1.0 percent of Er2O3; the grain boundary regulating agent is a composition of a boron source and an aluminum source; in the coating layer a, the molar ratio of zirconium to aluminum is (2-3): 1; and the component 1 is polyvinyl alcohol or polyvinylpyrrolidone. The fracture toughness, bending strength and thermal shock resistance of the ceramic matrix are effectively improved, and the overall mechanical property is remarkably improved. When the material bears thermal shock, the thermal shock resistance of the material is improved, and the application scene of the zirconia ceramic material is expanded.

The application discloses high-strength low-thermal-conductivity refractory castable and a preparation method thereof, and belongs to the technical field of refractory materials. The high-strength low-thermal-conductivity refractory castable comprises the following raw materials in parts by weight: refractory aggregate 50-75 parts, matrix fine powder 10-30 parts, binding agent 5-10 parts, dispersing agent 0.5-1 part, water reducing agent 0.3-0.5 part, and deionized water 5-10 parts. The high-strength low-thermal-conductivity refractory castable prepared by the application has low thermal conductivity and good compressive strength.

This invention discloses a samarium-based rare-earth permanent magnet bulk material, its preparation method, and its application. (The last part, "ThMn," appears to be an incomplete sentence or fragment and is left untranslated.) 12 A uniform metallic T coating is formed on the surface of the magnetic powder. The composite magnetic powder is then oriented, pressed into blocks, and heat-treated to create a double-layered non-magnetic shell around the grains. This shell hinders domain movement, effectively improving the material's coercivity. Furthermore, compared to doping or melting, the coating process requires less T and allows for more precise control, preventing excessive T from entering the crystal lattice and negatively impacting the material's intrinsic magnetic properties, thus significantly improving the coercivity of ThMn. 12 Density and overall performance of rare earth permanent magnets.

This invention provides a high-pressure compacted sodium iron pyrophosphate cathode material, its preparation method, and its application. The preparation method of the high-pressure compacted sodium iron pyrophosphate cathode material includes: weighing sodium, iron, and phosphorus sources according to the stoichiometric ratio of sodium iron pyrophosphate, adding carbon source and solvent, and mixing and grinding to obtain a precursor slurry; spray drying the precursor slurry to obtain precursor powder; compacting and granulating the precursor powder under a pressure of 10 MPa to 80 MPa to obtain denser precursor particles; and finally sintering at 500℃ to 650℃ for 6 to 15 hours under an inert atmosphere. This invention effectively eliminates internal cavities and interparticle gaps in the precursor through compaction and granulation, and controls the pressure within the range of 10 MPa to 80 MPa. The subsequent sintering process improves the density of the cathode material while controlling the impurity phase content to below 1 wt% and maintaining good electrochemical performance.

This invention discloses a tungsten-titanium cemented carbide and its manufacturing method, relating to the field of cemented carbide materials technology. Through specific raw material ratios and preparation processes, this invention achieves excellent properties such as a Rockwell hardness ≥81 HRA and fracture toughness ≥10 MPa・m¹ / ². This high hardness and good fracture toughness enable the alloy to exhibit better wear resistance and impact resistance when preparing various cemented carbide products, thereby extending the service life of the finished products and improving production efficiency. Simultaneously, its preparation method, through precise batching, wet grinding, drying granulation, molding, and low-pressure sintering steps, ensures the uniformity of the alloy composition and the compactness of the structure. In particular, the introduction of argon gas to pressurize to 1 MPa~6 MPa during low-pressure sintering effectively promotes densification during the sintering process, further enhancing the overall performance of the alloy. This optimized preparation process not only improves production efficiency but also reduces production costs, providing strong support for industrial production.

The application discloses a kind of nanometer silicon-based powder material surface modification material and preparation method and application, structure includes from inside to outside nanometer silicon, first silicon oxide layer, second silicon oxide layer, carbon coating layer or oxide coating layer, wherein the size of nanometer silicon is 30-200nm;Wherein the thickness of first silicon oxide layer is 2-4nm, oxygen content is 2-6wt%;Wherein the thickness of second silicon oxide layer is 1-3nm, oxygen content is 1-4wt%;Wherein the carbon content in carbon coating layer is 1-5wt%, the content of oxide in oxide coating layer is 0.1-1wt%.The application utilizes the diffusion and flow characteristics of supercritical carbon dioxide, modifies nanometer silicon-based material, can control superfine powder material surface structure by this modification method, and can realize nanometer silicon-based material surface uniform coating, improve the utilization ability of nanometer silicon-based material.

The application discloses a kind of fire-retardant lignin-based formaldehyde-free adhesive and preparation method thereof, belong to adhesive preparation technical field, for solving in prior art, adhesive bonding strength and flame retardant performance need to be further improved technical problem;The present application is with lignin as main body, sequentially through triazine, phosphonate and nitrogenization modification, introduce nitrogen, phosphorus and polar group, prepare fire-retardant glue precursor, then combine catechol polyol and boric acid reaction generated borate polyol, and the hybrid prepolymer obtained by the action of amino POSS sol and glycerol carbonate, synergistic curing under the action of initiator, construct dense stable crosslinking network, the system has the environmental protection of lignin and the stability of organic-inorganic hybrid material, give adhesive high strength, excellent water resistance and flame retardant performance, and formaldehyde release is zero, suitable for green environmental protection field application.