33results about How to "Improve longitudinal thermal conductivity" patented technology

The invention discloses graphene heat radiation paint. The graphene heat radiation paint comprises the following ingredients, by weight, 40-80 parts of high-molecular resin, 5-15 parts of graphene, 1-8 parts of one-dimensional nanomaterials, 1-8 parts of heat conduction metal powder, 0.5-5 parts of dispersing agents, 0.5-5 parts of antifoaming agents and 100-200 parts of inert solvent. The heat conduction metal powder is at least one selected from silver powder, copper powder and aluminum powder and the granularity is 1-20 micrometers. The above paint has good heat radiation and heat conduction functions. The invention also discloses a preparation method for the graphene heat radiation paint. The preparation method mainly comprises processes of stirring, grinding and reblending. Operation is simple, and the cost is low. The graphene heat radiation paint is mainly applied in heat radiation of daily electronic products and also can be applied in spaceflight electronic devices with high requirements because of good heat conduction and heat radiation functions.

The invention discloses graphene radiating material and a preparation method thereof. The graphene radiating material comprises agent A and agent B mixed well at a mass ratio of 1:1, the agent A comprises the following components, by weight: 40-60% of fluorocarbon resin, 30-50% of a mixed solvent, 5-15% of graphene, 0.5-1.5% of a leveling agent, and a 0.5-1.5% of a dispersant; the agent B comprises a mixed solvent and a curing agent at a mass ratio of 10:1. The prepared coating has the advantages such as high thermal conductivity coefficient, high thermal radiation coefficient, god radiating effect, acid and alkali tolerance, salt spray tolerance, impact resistance and high matrix adhesion, and the radiating material is widely applicable and usable.

The invention provides a preparation method for a graphene based heat-conducting interface material. The preparation method comprises the following steps: A) mixing a graphene material, vinyl silicone rubber, hexagonal boron nitride, flake graphite, hydroxy-terminated silicone oil, vinyl silicone oil and a first silane coupling agent, and carrying out stirring so as to obtain a rubber material, wherein the graphene material is one or more selected from the group consisting of graphene, graphene/silica composite powder and a graphene/silica composite sheet material; and B) subjecting the rubber material to pull-pressing, rolling and cutting so as to obtain the graphene based heat-conducting interface material.

The invention relates to a preparation method of directionally assembled graphene. The preparation method comprises the following steps: mixing a graphene oxide aqueous solution and a water-soluble metal salt, slowly cooling until water molecules are crystallized into ice, carrying out a freeze drying treatment to obtain directionally assembled graphene oxide, and reducing to obtain directionallyassembled graphene loaded with metal nano particles. The directionally assembled graphene has a three-dimensional layered structure in which layers are arranged in parallel, an interlayer gap exists between the layers, and metal nano particles are riveted in the three-dimensional layered structure of the directionally assembled graphene. The invention also relates to directionally assembled graphene prepared by the above method. The invention further relates to a graphene-carbon nano tube composite heat-conducting film prepared from the directionally assembled graphene and a preparation methodthereof. The composite heat-conducting film has the advantages of low cost, high graphene phase selectivity, ultrahigh heat conduction coefficient, ultrahigh flexibility, controllable product thickness and the like, and the maximal vertical heat conduction coefficient can reach about 100W/(m.K).

The invention provides a graphite sheet and metal layer composed thermally conductive sheet and its composing method. According to one embodiment of the invention, through a PVD aluminum deposition layer, the composition of a graphite sheet and other metal layers becomes possible so as to solve the difficulty with increasing the thickness of graphite sheet and thermally-conductive sheet and the problem of low thermal conductivity in the thickness direction. Based on these ideas, the invention aims to improve the overall heat capacity of the thermally conductive sheet and the comprehensive thermal conductivity in the thickness direction. The thermally conductive sheet of the invention can replace the product structure characterized by the adhesion of adhesive layers among multiple graphite sheet layers or between a graphite sheet and metal. Based on the prior art, the present invention combines the PVD aluminum plating technique and the metal hot-press diffusion method. Compared with the pure use of CVD or liquid plating method, the method of the invention is more efficient to obtain a composite metal layer with the same thickness. In addition, the once hard-to-obtain composite thickness and composite structure in the prior art can be more likely to be achieved. The composing method resolves the problem of how to accumulate composite metal layers with designated thicknesses and avoids the inherent defects of CVD and the liquid plating method.

The invention discloses a preparation method of a high-thermal-conductivity graphite aerogel-based composite thermal interface material, and relates to a thermal interface material. The preparation method comprises the following steps of: adding ascorbic acid into deionized water, and stirring to obtain a uniform ascorbic acid solution; stirring, adding a GO aqueous solution, transferring the obtained mixed solution into a reaction kettle lining, sealing the reaction kettle lining, putting the reaction kettle lining into a stainless steel shell, and reacting in a blast drying oven; transferring a reaction product from the reaction kettle lining into other containers, and repeatedly cleaning the reaction product with deionized water and ethanol; freezing a cleaned sample, and then transferring the frozen sample into a freeze dryer for drying; putting the sample into a mold, compressing the sample by using a certain pressure, and then pouring a prepared polymer solution into the mold; drying the sample in a vacuum drying oven; and demolding the dried sample from the mold to obtain the high-thermal-conductivity graphite aerogel-based composite thermal interface material. The composite thermal interface material is high in longitudinal heat conductivity, good in mechanical property, capable of achieving self-supporting and easy to store, and the bottleneck problem of heat dissipation of electronic products is expected to be solved.

The invention relates to the field of aluminum alloy preparation, and discloses a preparation method of a directionally distributed prestressed carbon fiber reinforced aluminum matrix composite. The preparation method of the directionally distributed prestressed carbon fiber reinforced aluminum matrix composite comprises the following steps of (1) applying pretension to carbon fibers arranged in the same direction, and fixing with a mold to obtain directionally arranged carbon fibers; (2) pouring an aqueous solution of a surfactant into the mold, fully infiltrating, and drying to obtain the carbon fibers coated with the surfactant; and (3) pouring molten aluminum into the mold, carrying out ultrasonic oscillation, and then cooling to obtain the carbon fiber reinforced aluminum matrix composite. According to the preparation method provided by the invention, the carbon fibers are coated with the surfactant, so that the compatibility between the carbon fibers and an aluminum matrix can beeffectively improved, and the mechanical property and the heat-conducting property of the composite are improved.

The invention relates to composite powder which comprises graphene and silicon dioxide microspheres, the graphene and the silicon dioxide microspheres are combined together through chemical bonds, the average transverse size of the graphene is 5-30 [mu] m, and the particle size of the silicon dioxide microspheres is 0.5-20 [mu] m. The invention also relates to a preparation method of the composite powder and an application of the composite powder in a heat dissipation coating, and the application comprises the following steps: providing a heat dissipation coating through the composite powder, and then enabling the heat dissipation coating to form the heat dissipation coating. According to the composite powder and the silicon dioxide microspheres, the heat resistance of the coating can be improved, agglomeration of the graphene can be hindered, the dispersity of the graphene in the coating can be improved, the orientation distribution of the graphene in the coating can be changed, the orientation proportion in the direction perpendicular to a substrate is increased, and the heat resistance of the coating is improved. Therefore, the coating has excellent transverse and longitudinal heat-conducting properties at the same time.

The invention discloses a nano interlayer graphene heat dissipation coating and a preparation method and application thereof, and relates to the field of heat dissipation materials. According to the invention, the zero-dimensional spherical nano-filler and the one-dimensional linear nano-filler are arranged between the layers of the graphene material in an intercalation manner so that the defectsthat the graphene is easy to agglomerate and is difficult to disperse uniformly in polymer resin are greatly improved. Moreover, the prepared nano interlayer graphene composite material (graphene material-one-dimensional nanowire-zero-dimensional nanosphere compound) has the advantages that the longitudinal heat conductivity of graphene is greatly improved; meanwhile, no matter how the graphene material-one-dimensional nanowire-zero-dimensional nanosphere compound is distributed in the resin matrix, a three-dimensional heat conduction channel can be effectively established; therefore, the temperature of the heat source can be transmitted to the superficial surface and the surface of the coating more quickly, heat can be dissipated more quickly in an infrared radiation mode, and the main purpose of reducing the temperature of the heating core more quickly is achieved.

The invention discloses a three-dimensional heat-conducting and wave-absorbing reinforced composite film and a preparation method thereof. The three-dimensional heat-conducting and wave-absorbing reinforced composite film comprises a graphene oxide/MXene film, a plurality of through holes penetrating through the upper surface and the lower surface of the graphene oxide/MXene film are formed in the graphene oxide/MXene film, and graphene-coated nano-diamond particles are arranged in the through holes in a penetrating mode. The preparation method comprises the following steps: S1, mixing the graphene-coated nano diamond particles, the silane coupling agent and the solvent, and ultrasonically dispersing uniformly; s2, performing laser array punching on the graphene oxide/MXene film; and S3, pouring a solution containing the graphene-coated nano diamond particles into the through holes, and drying. The three-dimensional heat-conducting and wave-absorbing reinforced composite film not only has an ultrahigh heat conductivity coefficient in the transverse direction, but also has a relatively high heat conductivity coefficient in the longitudinal direction, and also has good wave-absorbing performance and good mechanical strength.

The invention discloses a graphite aluminum high-thermal-conductivity module with low longitudinal thermal resistance, which comprises a box body and a plurality of upper bosses arranged on the upper surface of the box body, a high-thermal-conductivity interlayer is embedded in the box body, locking strips are arranged on two sides of the box body, and the back side surfaces of the locking strips of the box body are external heat exchange surfaces of the box body. The module is characterized in that the high-heat-conduction interlayer is not fully paved in the box body, and the external heat exchange surfaces on the two sides are not fully paved with high-heat-conduction structures. According to the graphite aluminum high-thermal-conductivity module, the structure of an existing graphite aluminum high-thermal-conductivity module is improved, longitudinal thermal resistance is reduced, the longitudinal thermal conductivity of the graphite aluminum high-thermal-conductivity module is improved, and the overall thermal conductivity of the graphite aluminum high-thermal-conductivity module is enhanced.

The invention belongs to the technical field of micro thermophotovoltaic systems and particularly relates to a micro device, namely a micro combustor which can convert chemical energy of fuel combustion into electric energy, in particular to a micro combustor with heat pipes embedded in the wall face. The structure of the micro combustor is improved based on the micro-scale premixed combustion technology and the micro heat pipe technology, a series of micro heat pipes are additionally arranged in the wall face of the combustor, and the temperature uniformity of the wall face and the overall performance of the micro combustor are improved.

The invention relates to a radiation heat dissipating coating and a preparation method thereof. The radiation heat dissipating coating is composed of the following components in parts by mass: 100 parts of solvent, 2-20 parts of graphene crystallites, 48-200 parts of epoxy resin, 0.5-5 parts of dispersing agent, 0.5-5 parts of antifoaming agent, 2-20 parts of curing agent, and 2-10 parts of auxiliary agent, wherein the auxiliary agent is one or a mixture of two of diatomaceous earth and white carbon black. The heat dissipating coating provided by the invention has extremely excellent thermal conductivity, and the physical and chemical properties of a film formed by solidifying of the coating, such as hardness, adhesion, salt spray resistance, acid and alkali resistance and water resistance, are good, the heat conduction efficiency of electronic components can be significantly improved, and the market prospects are broad.