36results about How to "Control thermal conductivity" patented technology

The present invention relates to a porcelain granule used as a conductive concrete aggregate and a preparation method thereof. The porcelain granule used as a conductive concrete aggregate is characterized in that: the porcelain granule is prepared by burning clay, iron powder and Fe2O3; the weight percentage of each material is as follows: 77 to 94 percent of clay, 3 to 10 percent of iron powder, 3 to 5 percent of coke dust, as well as 0 to 8 percent of Fe2O3; the sum of the weight percentage of each material is 100 percent. The preparation method for the porcelain granule used as a conductive concrete aggregate is characterized by comprising the following steps: 1) preprocessing the materials: the clay selected from soil is dried to have a water content being equal to or less than 5 percent, after being cracked, the clay is grinded to the powder the grain diameter of which is equal to or less than 0.1mm; then the coke sold in the market is cracked, and grinded into the powder the grain diameter of which is equal to or less than 0.1mm to obtain the coke dust; 2) selecting the materials; 3) shaping a blank: water is added for stirring, and the stirred materials are prepared into the ball-shaped grain blanks the grain diameters of which are between 5mm and 15mm by a pan-pelletizer; and 4) baking the porcelain granule to obtain the porcelain granule used as a conductive concrete aggregate. The porcelain granule used in the concrete as the aggregate can enhance the conductive performance of the concrete.

The invention discloses a preparation method of a thermoelectric power generation material, which relates to a preparation method of a thermoelectric material. The invention aims to solve the problems of high thermal conductivity, low electrical conductivity and low thermoelectric conversion efficiency of existing bismuth telluride thermoelectric power generation materials. Methods: 1. weighing; 2. ball milling; 3. heat treatment; 4. hot pressing sintering. The invention is used for the preparation of thermoelectric power generation materials.

The invention relates to a graphite-silicone rubber composite material and a preparation method thereof. The preparation method comprises the following steps: selecting graphite paper as a matrix; performing ultrasonic oscillation on the substrate in alkaline oil removal water at 55-75 DEG C, and cleaning the substrate in distilled water; preparing a KH-550 solution with the mass fraction concentration of 5-20% by using absolute ethyl alcohol or acetone as a solvent; soaking the cleaned graphite paper in a prepared KH-550 solution, and then taking out and drying the graphite paper; placing a layer of spread graphite paper; spraying a layer of methyl vinyl silicone rubber with uniform thickness on the upper surface of the graphite paper by using a spraying machine; placing a layer of spread graphite paper on the upper surface of the methyl vinyl silicone rubber; repeating the steps; applying continuous constant pressure to completely cure the material after preset time; and shearing the graphite paper along a direction perpendicular to the spreading direction to obtain the formed graphite-silicone rubber composite material. According to the method, the graphite-silicone rubber composite material with uniform thickness and high bonding strength can be obtained.

The invention discloses a brake friction plate with a high stable friction coefficient. The brake friction plate material comprises copper-based metallurgical powder and is prepared from, by weight, 10.0-10.5% of graphite, 0.6-1.0% Cr, 18.5-20.3% of Fe 4.3-5.8% of Sn, 1.5-2.5% of TiO2, 1-2% of SiO2 and the balance Cu. The invention discloses a preparation method of the brake friction plate with the high stable friction coefficient, the copper-based metallurgical powder used for preparing the brake friction plate is mixed in proportion and then subjected to cold pressing, the pressure intensityis 560 MPa, the compression speed is 170 mm / min, the powder is formed at 560 MPa and then kept at 3 min, sintering is conducted under the dissociated ammonia shielding gas condition, the sintering temperature is 1,120 DEG C, and the sintering time is 40 min.

The invention provides a preparation method of graphite foam. The method comprises the following steps that graphite nanosheets are used as raw materials; a small number of macromolecular bonding agents are added; through template forming, the graphite foam is formed after the drying. The preparation method provided by the invention is simple and convenient, and can be used for forming graphite foam in various shapes; in addition, the prepared graphite foam has the controllable density and uniform pores. The prepared graphite foam also has the advantages of high pressure-resistant intensity, low resistance, oil absorbability, high heat conductivity and the like, can be widely applied to the fields of heat radiators, heat conduction pads, electromagnetic shielding materials and the like, and has wide application prospects.

A method for sintering an aluminum nitride ceramic substrate. During the sintering process of the substrate, an inert gas is used to replace the atmosphere in the hearth of a graphite sintering furnace. The sintering method of the present invention adopts a controllable nitrogen protection atmosphere and periodically replaces the atmosphere in the furnace , adjust the furnace pressure of the graphite sintering furnace and the atmosphere of chemical substances in the furnace, discharge the impurity atmosphere, control the thermal conductivity of the aluminum nitride ceramic substrate and improve the flatness of the substrate. The thermal conductivity of the substrate produced by the method of the invention can be stably controlled above 170W / m·K, and the pass rate of the flatness of the substrate is above 95%.

The invention belongs to the technical field of polymer materials, and discloses a thermally-conductive polybutylene succinate ionomer and a preparation method and application thereof. The preparationmethod comprises the following steps that under an inert atmosphere, succinic acid and butanediol are mixed, stirred and heated for a reaction, a catalyst is added, during vacuuming, the temperatureis increased to 200-220 DEG C for a reaction of 0.5-2.5 hours, and a polybutylene succinate prepolymer is obtained; then the temperature is decreased to 135-155 DEG C, an ionic monomer is added, and vacuuming is conducted for a reaction of 1.5-3.5 hours; finally, nitrogen is introduced, a chain extender is added for a reaction, and after the reaction is completed, cooling is conducted to room temperature to obtain the thermally-conductive polybutylene succinate ionomer. The thermally-conductive polybutylene succinate ionomer is subjected to hot pressing treatment to prepare a sheet-shaped sample strip, then stretching treatment is conducted, and the anisotropic thermally-conductive polybutylene succinate ionomer is prepared.

The invention discloses a method for preparing a silicon nitride / silicon oxide composite crucible, relates to a method for preparing a composite crucible, and aims at solving the technical problems that the existing crucible of which the heat conductivity at the bottom is higher than that of the lateral wall is high in production cost and low in production success rate. The method for preparing the silicon nitride / silicon oxide composite crucible disclosed by the invention comprises the following steps: pulping, casting, degerming and sintering at a high temperature. By adopting the silicon nitride / silicon oxide composite crucible disclosed by the invention, the heating efficiency and the cooling efficiency can be improved, and the directional solidification effect of silicon melt is greatly improved. Thus, the growth quality of the silicon crystal is improved, and the cost of photovoltaic power generation of the crystal can be reduced. The method is mainly applied to directional solidification growth of polycrystalline silicon.

The invention belongs to the technical field of refractory materials and mainly relates to a lightweight thermal-insulting material containing silicon oxide micro powder. The lightweight thermal-insulting material containing the silicon oxide micro powder, provided by the invention, consists of a solid raw material and a liquid raw material; the total mass percentage of the solid raw material is 100 percent, and the solid raw material specifically consists of 1-85 percent by weight of silicon oxide micro powder, 0-80 percent by weight of gas phase white carbon black, 5-25 percent by weight of refractory fibers, 2-20 percent by weight of a foaming agent and 0.1-10 percent by weight of acid; the liquid raw material consists of a silica sol and water and occupies 40-300 percent of the total mass percentage of the solid raw material; the silica sol is an industrial-grade silica sol, and the content of silicon oxide is 28-30 percent. The lightweight thermal-insulting material provided by the invention has the benefits that the purpose of controlling the material thermal conductivity is achieved; the service life of equipment is prolonged.