42results about How to "Large diameter-to-thickness ratio" patented technology

The present invention relates to a silicon carbide base composite material reflector with honeycomb sandwich structure. It is characterized by that after the upper cover plate, sandwich layer with honeycomb structure and lower cover plate are bonded, then they are undergone the processes of siliconing and sintering treatment so as to obtain the invented reflector whole body with the characteristics of light weight, high rigidity and good workability, etc. Besides, said invention also provides its preparation method and concrete steps.

The invention provides a method for producing one-dimensional nanometer flake zinc powder by directly electrolyzing strong alkaline solution, relating to the production technology of flake zinc powder. The method is characterized by firstly preparing zinc-containing strong alkaline solution, wherein the solution contains 1-100g/L of Zn, 10-200g/L of OH<->, 5-70mg/L of additive A and 10-110mg/L ofadditive B; secondly taking a stainless steel plate as an anode and a magnesium plate as a cathode to electrolyze the solution for 1-180min under the following conditions: the distance between the two plates is 0.5-5cm; the current density is 100-2500A/m2; and the solution temperature is 10-100 DEG C, then stopping electrolysis, rapidly taking out the electrodeposit and washing the electrodepositwith water until the pH value of the water is lower than 8; and finally, rapidly vacuum-drying the washed electrodeposit, thus obtaining the one-dimensional nanometer flake zinc powder, wherein the electrolysis waste liquor is returned to be used for preparing the zinc-containing strong alkaline solution. The method has the following advantages and effects: the produced zinc powder has high activity, is flaky and is 10-100nm thick; the method is low in production cost and energy consumption, is simple to operate and is convenient for mass production; and the defects of high cost, high energy consumption, low capacity, difficulty in controlling quality and the like in the traditional production methods are thoroughly overcome.

The invention discloses a coal-series hard kaolinite stripping method. The method comprises the following steps of: crushing the coal-series hard kaolinite, mixing the crushed coal-series hard kaolinite with water and an intercalator to obtain intercalated compound pulp, striping the intercalated compound pulp by using medium spheres of three types grain sizes, and performing filtration washing and spray-drying to obtain the finished product. By the method, the hexagonal sheet-shaped crystal form of the kaolinite is kept relatively complete, and the content of hexagonal sheet-shaped kaolinite crystals is 30 to 60 percent.

The invention discloses a method for preparing superfine flaky zinc-containing alloy and an application of the superfine flaky zinc-containing alloy. Spherical atomized zinc-containing alloy powder, aball milling solvent, a grinding aid, a ball milling medium and a dispersant are added to ball milling tank in proportion, and the materials are subjected to wet ball milling under heating and temperature control conditions; and obtained ball-milled slurry is subjected to filtration, ultrasonic cleaning, rinsing and drying in sequence, and flaky zinc-containing alloy powder is obtained, wherein the flake diameter range of the powder is 8-20 micron, the radius-to-thickness ratio is (30-50):1, and the apparent density is 0.85 g/cm<3>-0.95 g/cm<3>. The prepared superfine flaky zinc-containing alloy powder has high flaky degree, high radius-to-thickness ratio, high covering power, smooth surface, low oxidation degree and good particle size distribution, and can be applicable to the productionfields of waterborne Dacromet coatings, inorganic waterborne zinc-rich aluminum paint and waterborne heavy anti-corrosion coatings with different specification requirements after treatment and classified screening.

The invention discloses special paint for a granary wall body and a preparation method thereof. The paint is prepared by taking polyurethane, hollow glass microsphere, blast furnace slag, titanium white powder, bamboo charcoal, vermiculite powder, perfluorohexyl ethanol, acetyl tributyl citrate, polyethylene wax, organic silicon, a de-foaming agent, a thickening agent, a flame retardant and a dispersant as raw materials; the paint has very high low temperature resisting performance, high moisture-proof performance and very high waterproof performance; the mechanical strength and adhesion forceof a paint film are enhanced and cracks are prevented; the paint is used for preventing ultraviolet rays and water from penetrating through the paint film and the service life of the paint film is prolonged; the paint has the advantages of heat insulation and heat preservation, and high moisture-proof performance, insect-proof performance and fireproof performance.

The invention relates to the technical field of composite materials, in particular to a polytetrafluoroethylene friction material with a high elastic modulus and a preparation method and application thereof. The provided polytetrafluoroethylene friction material with the high elastic modulus is prepared from, by mass, 55-70 parts of polytetrafluoroethylene, 15-35 parts of mica, 5-15 parts of glassfibers, 5-15 parts of nano alumina and 1-5 parts of graphite. The polytetrafluoroethylene friction material prepared from the raw materials in proportion has the advantages of great wear resistance,stable friction coefficient and the like on the basis of the high elastic modulus, and can meet the requirements of ultrasonic motors for friction materials.

The invention relates to the technical field of chemical industry, in particular to a preparation method of waterborne rainbow aluminum paste. The preparation method comprises the following steps: step one, coating a PET thin film with certain thickness with a layer of waterborne release coating of which the thickness of a dry film is not smaller than 1mu m; step two, plating a film coating with alayer of aluminum with the purity of 99.99 percent by using a PVD method, thus forming an aluminum-plated film, wherein the film thickness is seen in the description; step three, carrying out surfacecarving on the aluminum-plated film by laser engraving or molding, endowing the surface of a flat aluminum-plating layer with a micro-structure to obtain an aluminum layer which can generate interference and diffraction to light. According to the preparation method of the waterborne rainbow aluminum paste, disclosed by the invention, a waterborne aluminum pigment with rainbow effects selects a high-purity aluminum wire as a raw material; the high-purity aluminum wire is subjected to vapor deposition on the PET thin film by adopting a vacuum evaporation method; the high-purity aluminum wire isendowed with great diameter-thickness ratio and excellent rainbow effects by mould pressing, and is subjected to waterborne surface treatment at later stage to obtain a product. The waterborne rainbow aluminum paste is subjected to surface waterborne treatment based on oily rainbow aluminum paste; meanwhile, the rainbow effects of the waterborne rainbow aluminum paste are not affected.

The invention belongs to the technical field of composite materials, and discloses a nanoparticle reinforced metal-based composite material and a preparation method thereof. The method comprises the steps that firstly, surface modification and pre-dispersion are carried out on nanoparticles, so that the nanoparticles are in a relatively dispersed state before ball milling; low-speed ball milling in the initial stage of ball milling is carried out, and materials are fully mixed evenly; in the middle stage of ball milling, metal powder flaking and nanoparticle embedding mechanisms are combined, the work hardening phenomenon of flaky metal powder is reduced and eliminated through stress relief annealing, and the problems that nanoparticles are disembedded on the surface of the flaky metal powder and the load is small are solved; and finally, the rotating speed is reduced, the flaky powder with the large radius-thickness ratio is mechanically crushed through grinding balls, and then fine-scale-shaped nanoparticle reinforced metal-based composite powder is obtained through pressing, sintering and densification treatment. Through the steps of surface modification, pre-dispersion treatment, stress relief annealing added in the ball milling process and the like, the problem of work hardening of the metal powder is effectively solved, nanoparticles are dispersed more uniformly, and the loading capacity is higher.

The invention relates to a preparation method of a self-orientation Z-type hexaferrite substrate and belongs to the technical field of magnetic materials. The method includes: using a hydrothermal method to acquire precursor powder using M phase as the main crystal phase, wherein the M-phase precursor is large in diameter-thickness ratio, even in particle size distribution, free of agglomeration and the like, is a quite ideal texturing growth template and does not need an extra grain template. The Z-type hexaferrite substrate obtained by the method has a self-orientation feature, the orientation of the Z-type hexaferrite substrate does not need a complex casting process and an additional magnetic field, the specific saturation magnetization of the obtained Z-type hexaferrite substrate canreach 51.3emu/g after self-orientation, and the orientation degree of the Z-type hexaferrite substrate in the (001) direction is increased to 66.2%.

The invention provides a preparation method of flaky alpha aluminum oxide, which comprises the following steps: (1) weighing molten salt and an aluminum source, putting the molten salt and the aluminum source into a container, adding deionized water for dissolving, ultrasonically dispersing uniformly, and drying to obtain a mixture; (2) putting the mixture dried in the step (1) into a mortar, adding aluminum fluoride, and uniformly grinding; and (3) putting the powder in the step (2) into a crucible, putting the crucible into a heating furnace, heating to 750-900 DEG C, keeping the temperature for 0.5-5 hours, taking out a solid matter, grinding, and carrying out ultrasonic washing to obtain the flaky alpha aluminum oxide. The preparation method of the flaky alpha alumina is low in preparation temperature and short in reaction time, and the production cost is greatly reduced. The invention also provides the flaky alpha aluminum oxide prepared by the preparation method of the flaky alpha aluminum oxide, the average radial size of the flaky alpha aluminum oxide is 4-5 microns, the thickness is 150-250 nm, and the radius-thickness ratio is 16-25.

The invention relates to the technical field of composite materials and in particular relates to a high heat conduction insulating polytetrafluoroethylene friction material as well as a preparation method and application thereof. The high heat conduction insulating polytetrafluoroethylene friction material provided by the invention comprises the following preparation raw materials in parts by mass: 50-80 parts of polytetrafluoroethylene, 5-20 parts of polyimide, 5-20 parts of mica, 5-15 parts of nanometer aluminum oxide and 1-10 parts of nano aluminum nitride. The polytetrafluoroethylene friction material prepared from the raw materials in a ratio has the characteristics of being stable in wearing resistance, stable in friction coefficient, and the like on the basis of high heat conductionand high insulation properties, and requirements of ultrasonic motors on friction materials can be met.