360 results about "Molybdenum disilicide" patented technology

A coating admixture, method of coating and substrates coated thereby, wherein the coating contains colloidal silica, colloidal alumina, or combinations thereof; a filler such as silicon dioxide, aluminum oxide, titanium dioxide, magnesium oxide, calcium oxide and boron oxide; and one or more emissivity agents such as silicon hexaboride, carbon tetraboride, silicon tetraboride, silicon carbide, molybdenum disilicide, tungsten disilicide, zirconium diboride, cupric chromite, or metallic oxides such as iron oxides, magnesium oxides, manganese oxides, chromium oxides, copper chromium oxides, cerium oxides, terbium oxides, and derivatives thereof. In a coating solution, an admixture of the coating contains water. A stabilizer such as bentonite, kaolin, magnesium alumina silicon clay, tabular alumina and stabilized zirconium oxide is also added.

This invention relates to a saw bit belonging to mechanical working field, which comprises metal base being alloy steel or carbon steel, with Phi8-Phi10mm radiating holes equispaced on its surface; Carcass including alumina, zircite, quartz, tungsten carbide, zirconium diboride, molybdenum disilicide; common abradant including brown fused alumina, carbofrax, green silicon carbide, cubic carbofrax, boron carbide; superhard abradant including diamond and cubic boron nitride. The produce process includes mixing carcass flour, working layered material batching-mixing process, welding layered material batching-mixing process, koldflo, thermal pressing-sintering formation, arc milling, welding, dressing and making edge. The invention has improved working efficiency, lowered product cost, and is suitable for cutting metal tube, plate such as this materials.

The present invention relates to novel lubricant additives for improving the tribological properties, novel lubricants containing these additives, processes for the preparation thereof and the use thereof. Lubricant comprises ceramic nanoparticles as additives comprising aluminum oxide, aluminum nitride, silicon dioxide, titanium dioxide, zirconium oxide, yttrium oxide, tungsten oxide, tantalum pentoxide, vanadium pentoxide, niobium pentoxide, cerium dioxide, boron carbide, aluminum titanate, boron nitride, molybdenum disilicide, silicon carbide, silicon nitride, titanium carbide, titanium nitride, zirconium diboride and/or clay minerals, and thermally stable carbonates and/or sulfates. The nanoparticles represent an ellipsoid with three semi-axes a, b and c, which are not equal to each other, or equal to each other. The ratio of a and b is 1-100, a and c is 1-1000, and b and c is 1:100.

A coating, method of coating and substrates coated thereby, wherein the coating contains an inorganic adhesive such as an alkali/alkaline earth metal silicate such as sodium silicate, potassium silicate, calcium silicate, and magnesium silicate; a filler such as a metal oxide for example silicon dioxide, aluminum oxide, titanium dioxide, magnesium oxide, calcium oxide and boron oxide; and one or more emissivity agents such as silicon hexaboride, carbon tetraboride, silicon tetraboride, silicon carbide, molybdenum disilicide, tungsten disilicide, zirconium diboride, cupric chromite, or metallic oxides such as iron oxides, magnesium oxides, manganese oxides, chromium oxides and copper chromium oxides, and derivatives thereof. In a coating solution, an admixture of the coating contains water. A stabilizer such as bentonite, kaolin, magnesium alumina silicon clay, tabular alumina and stabilized zirconium oxide may be added.

The invention relates to a carbon ceramic braking pad for a high-speed train and a preparation method of the carbon ceramic braking pad. The carbon ceramic braking pad is made of carbon ceramic composite material; the carbon ceramic composite material comprises the following components in percentage by mass: 16-30 percent of carbon fibers, 20-36 percent of pyrolytic carbon, 28-46 percent of silicon carbide, 6-12 percent of molybdenum disilicide and 2-6 percent of simple substance silicon; the density of the carbon ceramic composite material is 1.8-2.4g/cm<3>; the carbon fibers are uniformly distributed in the carbon ceramic composite material in a three-dimensional network structure. According to the invention, after the high-temperature heat treatment is performed on a carbon fiber felt with the density of 0.20-0.65g/cm<3>, the pyrolytic carbon is generated in the carbon fiber felt through the thermal-gradient chemical vapor deposition carburizing treatment, then the catalytic graphitization treatment, non-immersion type melting infiltration and assembly are performed, so that the carbon ceramic braking pad for the high-speed train is obtained.The carbon ceramic braking pad is simple in preparation technology, moderate in friction coefficient, good in abrasion performance, stable in braking and strong in environmental suitability and can meet braking requirements of the high-speed train with the speed of 200Km/h.

Tantalum-based ceramics are suitable for use in thermal protection systems. These composite structures have high efficiency surfaces (low catalytic efficiency and high emittance), thereby reducing heat flux to a spacecraft during planetary re-entry. These ceramics contain tantalum disilicide, molybdenum disilicide and borosilicate glass. The components are milled, along with a processing aid, then applied to a surface of a porous substrate, such as a fibrous silica or carbon substrate. Following application, the coating is then sintered on the substrate. The composite structure is substantially impervious to hot gas penetration and capable of surviving high heat fluxes at temperatures approaching 3000° F. and above.

The invention discloses a method for preparing a nanowire-toughened carbon/carbon composite material ceramic coating. The method aims to solve the technical problem that the ceramic coating prepared by a conventional method has poor denseness. The method adopts the following technical scheme that: the nanowire-toughened carborundum (SiC)-molybdenum disilicide (MoSi2)-chromium silicide (CrSi2) ceramic coating is prepared by chemical vapor deposition, the cracking trend of the coating is reduced, and the ceramic coating with a dense structure is prepared by means of the toughening effect of nanowires. The effective anti-oxidization time of the prepared ceramic coating in atmosphere at the temperature of 1,500 DEG C is improved to 140 and 155 hours from 50 hours in background technology.

The invention provides a molybdenum disulfide/porous carbon nanosphere composite material and a preparation method thereof and belongs to the technical field of composite materials. The diameter of the composite spheres of the molybdenum disulfide/porous carbon nanosphere composite material of a core-layer structure taking porous nitrogen doped carbon spheres as cores and molybdenum disulfide as shell layers is 500-600 nanometers. Molybdenum disulfide is uniformly coated to the surfaces of porous nitrogen doped carbon spheres and is pedal like. The composition is prepared by the following steps: dissolving porous polydopamine spheres in deionized water; then successively adding sodium molybdate, thiourea, anhydrous oxalic acid and anhydrous glucose; uniformly mixing and ultrasonically treating the solution; and then annealing the solution at a high temperature of 700-900 DEG C for 2-3 hour. The composite material prepared by the method for preparing a cathode material of a capacitor not only has a relatively high specific surface area, but also has a relatively high specific capacity and an excellent cyclic characteristic. The composite material is simple in preparation method andsuitable for industrial production.

The invention relates to a large casting-molding self-combined silicon carbide product. The method comprises the following steps: taking silicon carbon particulates and fine powder, silicon carbon powder, silica powder, silicon powder, carbon black, molybdenum disilicide micro powder, active magnesium oxide and a water reducer as powder; by taking ludox as a binding agent, molding by adopting a vibrating casting manner; sintering the molded green body under a protective atmosphere after conserving and baking, wherein the highest sintering temperature is 1300-1500 DEG C; sintering and cooling to room temperature along with a furnace, so as to prepare the self-combined silicon carbide product. The large and profile self-combined silicon carbide product can be prepared, and has the advantages that the size and the shape of the product are not limited, performance is excellent, and the like, and the prepared self-combined silicon carbide product can be applied to the fields such as a blast-furnace tuyere and a cooling wall tile in the iron and steel industry and an aluminum electrolytic cell in the non-ferrous industry.

The invention discloses a preparation method of a molybdenum disulfide thin film and the molybdenum disulfide thin film. A chemical vapor deposition method (CVD) is used for directly growing a large-area high-voltage low-defect molybdenum sulfide (MoS2) thin film on a silicon substrate plated with an oxide buffer layer, and rapid transferring of the MoS2 thin film can be creatively achieved.

The invention discloses a solvothermal preparation method of an in-situ molybdenum disulfide electrode. The preparation method comprises the following steps: dissolving molybdenum-containing salts (sodium molybdate, etc.) into an alcohol solution containing a sulfur source (thiourea, etc.), adding a substrate material, then filling the mixture into a hydrothermal kettle, carrying out solvothermal reactions for 6 to 24 hours at a temperature of 180 to 230 DEG C; taking out the substrate, and cleaning and drying the substrate. If people want to improve the crystallization property of molybdenum disulfide, the substrate can be annealed in an atmosphere of N2 for one hour at a temperature of 500 DEG C. The prepared in-situ molybdenum disulfide electrode has the advantages of high transparency and uniformity, and strong adhesion force on substrate. The dye-sensitized solar cell prepared from the provided in-situ molybdenum disulfide electrode has a higher photoelectric conversion efficiency, compared with the cells prepared from a conventional pyrolytic Pt electrode, and the result shows that the prepared molybdenum disulfide electrode has an extremely good electro-catalytic activity.

The invention relates to a solar selectively absorbing coating. A three-layer film structure is formed on a substrate from bottom to top, an infrared reflective layer, an absorbing layer and an antireflection layer are arranged on the substrate in turn; the first layer is the infrared reflective layer which is formed from metal copper layer prepared by magnetron sputtering, if a polished stainless steel substrate or a copper substrate is adopted, the substrate can be directly used as the infrared reflective layer; the second layer is the absorbing layer which is an alloy-ceramic composite layer which is formed by dispersing molybdenum disilicide particles in aluminium oxide ceramic medium according to a definite proportion through sputtering, the structure has two sub-layers with different thicknesses and MoSi2 volume percentages so as to form the interference and absorption effect; and the third layer is the Al2O3 antireflection layer which is prepared by magnetron sputtering of Al2O3 ceramic target or DC magnetron reactive sputtering of aluminum target. The coating has good medium-high temperature thermal stability, and when the air quality factor AM is 1.5, the absorption rate is 0.90-0.94, and the emissivity is 0.06-0.14. The solar selectively absorbing coating is suitable for the solar vacuum collector tube with medium-high work temperature (300-500 DEG C).

The invention relates to a method for preparing an ablation-resistant coating. The method comprises the following steps: mixing zirconium diboride and molybdenum disilicide or silicon carbide and yttrium oxide with the particle size of 1 to 3 microns, then, mixing the mixture with a binder so as to obtain a mixture, blending the mixture with deionized water, and then, carrying out ball milling, so as to obtain slurry; preparing spherical powder at the temperature of 110 DEG C to 130 DEG C; carrying out sintering for 1 to 2 hours at the temperature of 1,200 DEG C to 1,600 DEG C; carrying out sieving, so as to obtain zirconium diboride-molybdenum disilicide or silicon carbide-yttrium oxide powder for spraying; spraying a zirconium diboride-molybdenum disilicide or silicon carbide undercoat to the surface of a carbon/carbon composite material by a plasma spraying method, and then, spraying the zirconium diboride-molybdenum disilicide or silicon carbide-yttrium oxide powder to the undercoat by the same method, thereby preparing the ablation-resistant coating. The yttrium oxide modified zirconium diboride-molybdenum disilicide or silicon carbide coating prepared by the method can be used for remarkably improving the high-temperature ablation resistance of the carbon/carbon composite material.

The invention provides an experimental device and method for performing on-line monitoring on lump coal splitting decomposition. The experimental device is mainly formed by a molybdenum disilicide furnace, a protective gas supplying device, a flue gas analyzer, an electronic balance, a corundum crucible and a monitoring computer. The experimental device is simple, practical and capable of performing on-line monitoring on quality changes and a gas generation rule in the fast decomposition process when the lump coal instantly enters high temperature from normal temperature. The obtained monitoring data can provide important theoretical foundation and technical basis for research directions such as how to optimize a blending structure, reduce bed pressure damage or reduce fuel consumption in the COREX process. By means of the experimental device and method for performing on-line monitoring on the lump coal splitting decomposition, carbocoal products of a lump coal splitting decomposition experiment can be conveniently extracted and can be further used for carbocoal industrial analysis and elemental analysis after being subjected to dry quenching of coke, and detection to strength and changes of coal rock structures, particle sizes, porosity, shapes, functional group structures and the like. Therefore, the experimental device and method for performing on-line monitoring on the lump coal splitting decomposition have wide application prospects.

The invention relates to an experiment device for testing a softening and dropping point of a sinter. The device is composed of a large current transformer, a furnace body fixing column, a tray, a furnace body adjusting frame, a rotary column, a pressurized gas cylinder, a displacement sensor, a furnace top sealing furnace cover, a pressurized graphite compression strut, an anti-radiation graphite cover, a molybdenum disilicide heater, a graphite crucible, a high pure graphite sleeve, a sealed alundum tube, a pinhole camera, an air inlet channel fixing sleeve, a dropping crucible weighing device, a dropping crucible device, a furnace body chassis, furnace body castors, a heating furnace body, a cantilever beam, a sample temperature thermocouple, a alumina hollow ball member, a furnace temperature control thermocouple, a rotary column circular sleeve, a pressurized gas cylinder pipeline and a pressure transmitter. The large current transformer is adopted to supply power for the molybdenum disilicide heater; the pinhole camera is used to observe a dropping process of high temperature liquid slag iron; the dropping crucible weighing device is arranged; the crucible is assembled and disassembled in a manner of laterally opening the door; and the position of the heating furnace body is adjusted by the furnace body adjusting frame, so that the device is flexible, accurate and convenient for operations.

The invention relates to a composite high-temperature molybdenum disilicide-base material and a preparation method thereof. The method can prepare the composite high-temperature material under lower production cost, which has the highest room temperature toughness equivalent to that of high-temperature alloys, higher high temperature intensity, high temperature creep resistant performance and certain plastic processing performance; the substrate of the composite high-temperature material is a composite substrate composed of MoSi2 and Si3N4, wherein the average crystal grain size of the MoSi2 is smaller than 2 microns, and the average grain diameter of the Si3N4 particulates is smaller than 1 microns. The method adopts the following technical proposal: Mo2N powder or powder of Mo5Si3 or Mo3Si are used as initial powder to obtain composite powder Mo3Si-Mo5Si3-Si3N4 or Mo5Si3-MoSi2-Si3N4 after being processed by siliconization or nitridation-siliconization, the composite powder is further enhanced and mixed with materials such as Si powder, SiC powder and the like, and is pressing molded, and then a blank is sintered under the temperature of 1415 to 1550 DEG C, and finally the sintered blank is plastic deformed, thus obtaining a required dense article of the composite high-temperature material.

A preparation method of a C/C-SiC-MoSi2 ceramic-based composite material includes the following steps: 1) dispersing silicon carbide powder and molybdenum disilicide powder in isopropyl alcohol, and performing ultrasound vibration and stirring to obtain a suspension liquid A and a suspension liquid B: 2) increasing the density of a low-density carbon fiber stereo fabric in a manner of hydrothermal permeation of glucose, and placing the fabric in a suction filtration device having a glass sand core; 3) pouring the suspension liquid A and the suspension liquid B successively into a suction filtration flat-bottom funnel to enable the suspension liquids to pass the C/C composite material completely; 4) performing a homogeneous phase hydrothermal reaction until the density is 1.2-1.5 g/cm<3>; and 5) performing thermal treatment to obtain the C/C-SiC-MoSi2 ceramic-based composite material. The composite material is moderated in density, is compact in structure, and is excellent in interface binding between a C/C interface and a SiC interface, the SiC interface and a MoSi2 interface and the C/C interface and the MoSi2 interface. The raw materials are easy to obtain. The preparation method is simple in operation, is low in cost, is environment-friendly and is pollution-free.

The invention belongs to the field of preparation of heat insulating materials, and relates to a MoSi2-BSG coated zirconium oxide fiberboard integrated heat insulating material and a preparation method thereof. The preparation method comprises the following steps: preparing borosilicate glass by taking silicon dioxide and borax as raw materials; then preparing a MoSi2-BSG coating on the surface of a zirconium oxide fiberboard by taking molybdenum disilicide as a radiation agent, the borosilicate glass as a bonding agent, silicon hexaboride as a sintering aid and ethanol as a dispersant through a slurry immersion method, thereby finally obtaining the MoSi2-BSG coated zirconium oxide fiberboard integrated heat insulating material. The surface coating of the integrated heat insulating material infiltrates into a substrate material for 0.5-2mm, the emissivity is more than 0.8, and the temperature resistance at least can reach more than 1400 DEG C, so that the integrated heat insulating material has excellent heat insulating property, thermal shock resistance and bonding property.

The invention discloses a fiber-enhanced integrated material with high-temperature resistance property and high emissivity and a preparation method thereof. The preparation method comprises the following steps of using a carbon fiber felt as a framework support; filling the framework with a C-SiO2 (carbon-silicon dioxide) composite aerogel, so as to obtain the carbon fiber-enhanced C-SiO2 aerogel;coating a high-emissivity heat prevention coating layer to the surface of the carbon fiber-enhanced C-SiO2 aerogel; filling a C-SiO2 aerogel with high-temperature resistance property and low heat conductivity into the carbon fiber felt by a sol-gel method, a carbon dioxide super-critical drying technique and high-temperature heat treatment process, so as to form a heat isolation material with light weight, high-temperature resistance property and scouring resistance property; preparing a molybdenum disilicide-B2O3(boron oxide)-SiO2 glass coating layer at the surface of the heat isolation material by a slurry impregnating method and a quick heat treatment method, so as to form the fiber-enhanced integrated material with high-temperature resistance property and high emissivity. The fiber-enhanced integrated material has the advantages that the high temperature of 1500 DEG C can be resisted; the internal carbon fiber-enhanced C-SiO2 aerogel has lower heat conductivity of 0.035 to 0.045W.m<-1>.K<-1>; the emissivity of the surface heat protection coating layer at room temperature is greater than 0.85.

The invention relates to a method for preparing a C/C composite material nanometer silicon carbide-mullite-molybdenum disilicide composite external coating, which comprises the following steps of: adding mullite powder, nanometer silicon carbide powder and molybdenum disilicide powder into isopropanol and performing ultrasonic oscillation to obtain suspension A; adding an iodine simple substance into the suspension A and performing ultrasonic oscillation to obtain solution B; and pouring the solution B into a hydrothermal reaction kettle, clamping a C/C composite material sample with a SiC internal coating on a cathode clamp in the hydrothermal reaction kettle, performing hydrothermal electrophoresis reaction, naturally cooling to room temperature, taking the sample out and drying the sample to obtain the nanometer silicon carbide-mullite-molybdenum disilicide composite external coating. The reaction is finished in the hydrothermal reaction kettle at one time without subsequent heat treatment, wherein the nanometer silicon carbide powder can fill cracks, micropores and other defects in the coating; and the rodlike mullite whisker has good toughening effect so as to greatly improve the high-temperature oxidation protective capability of the composite coating.

The invention relates to a preparation method of a carbon/carbon composite material molybdenum disilicide external coating, which comprises the following steps: the ball-milled molybdenum disilicide powder and isopropanol are mixed in a supersonic generator and vibrated; suspending liquid A is obtained after magnetic stirring; iodine is added to the suspending liquid A and vibrated in the supersonic generator; solution B is obtained after magnetic stirring; the solution B is poured into a hydro-thermal reaction kettle; a carbon/carbon composite material sample with a SiC internal coating is clamped on a cathode clamp inside the hydro-thermal kettle; the hydro-thermal kettle is put in an oven; after the hydrothermal electrophoresis is finished, the sample is cooled to room temperature; and the sample is taken out and dried to obtain the final product, i.e., the carbon/carbon composite material with the protection of the molybdenum disilicide external coating and a carborundum internal coating. The adoption of the hydrothermal electrophoresis precipitation method can prepare the external coating with uniform thickness and without penetrating crackles and millipores. As the reaction is finished in the hydro-thermal kettle once without post heat treatment and carried out at low temperature, the base material is not damaged, the obtained molybdenum disilicide external coating has small internal stress and compact and uniform structure.

The invention discloses a high-temperature graphite carbon bush and a production method, wherein the high-temperature graphite carbon bush is suitable for carrying out heat treatment on a high-trademark cold rolling silicon steel sheet under the condition of high temperature (950-1,050 DEG C). The method comprises the following steps: mixing and kneading raw materials; molding; and dipping the raw materials by an antioxidant, wherein the raw materials comprise the following components in percentage by weight: 65-70 percent of powder with the grain diameter of 300-400 meshes and 30-35 percent of modified asphalt; the powder comprises the following components in percentage by weight: 99.5-99.8 percent of needle coke, 0.3-0.5 percent of titanium nitride and 0.2-0.3 percent of molybdenum disilicide; the modified asphalt is prepared by melting and dewatering high-temperature coal tar pitch and then adding phenolic resin to modify the coal tar pitch, and the weight ratio of the high-temperature coal tar pitch to the phenolic resin is 100:(3-5). The manufactured graphite carbon bush has the characteristics of high strength, wear resistance, good thermal shock resistance and good beading resistance and oxidation resistance; in addition, the working temperature can reach more than 1,050 DEG C.

The invention comprises an internal conducting layer, an internal resistance layer, an internal insulation layer, an external resistance layer, and an external conducting layer and an external insulation layer. The internal conducting layer sits in the center of the electric heating element; the internal resistance layer covers the internal conducting layer; the internal insulation layer covers the internal resistance layer; the external resistance layer covers the internal insulation layer; there is a through hole on the top of the internal insulation layer; the internal resistance layer is connected to the internal resistance layer by using the trough hole; the external conducting layer covers lower portion of the external resistance layer; the external insulation layer covers the external conducting layer; the material of each layer is made of ceramic material capable of containing silicon nitride and molybdenum disilicide.

The invention discloses electroplating liquid used for forming nickel molybdenum rare earth-molybdenum disilicide composite plating and a preparation method of the electroplating liquid. The per liter of the electroplating liquid used for forming the nickel molybdenum rare earth-molybdenum disilicide composite plating comprises the following components by mass: 10 to 400 g nickel salt, 10 to 800 g molybdenum polyoxometallate, 5 to 100 g complexing agent, 10 to 300 g chloride, 0.5 to 6 g rare earth, 5 to 60 g molybdenum disilicide, 0.01 to 0.9 g surfactant and water in balancing amount. The preparation method of the electroplating liquid comprises the following four steps: preparing a rare earth salt solution, pre-treating molybdenum disilicide particles, preparing nickel salt-molybdenum polyoxometallate-complexing agent-chloride-rare earth salt mixed liquor, and preparing the electroplating liquid of the nickel molybdenum rare earth-molybdenum disilicide composite plating, and the obtained electroplating liquid used for forming nickel molybdenum rare earth-molybdenum disilicide composite plating is used for performing electroplating on to-be-plated pieces to form the nickel molybdenum rare earth-molybdenum disilicide composite plating.