192results about How to "Reduce porosity" patented technology

The invention relates to a kind of benzoxazine colophony whose materials come from renewable resources, its composition and preparing method. This kind of benzoxazine colophony is prepared with phenols stemmed from the renewable resources, such as eugenol, guaiacol and cardanol, and diamine stemmed from the renewable resources such as decamethylene diamine, and cavaform or triformol or formaldehyde liquid. The relevant composition is prepared with this kind of benzoxazine colophony and other heat-convertibleresin. The benzoxazine and its composition can be used in many fields such as coatings, thermosetting plastics, matrix colophony of composite materials and so on.

The invention relates to a magnetic powder core material with stable magnetic permeability and low loss and a preparation method thereof. First modifying the surface of the iron powder; preparing iron/ferrite composite powder with core-shell structure by high-energy ball milling; mixing the composite powder with the modified powder and then filling the mixture into an alloy steel mold for normal temperature pressing to obtain iron/ferrite soft magnetic composite magnetic powder cores; then performing subsequent heating treatment on the magnetic powder cores. Compared with the prior art, the present invention utilizes a ball milling method to prepare iron/ferrite coated powder. The process is short in time, uniform in coating, and simple in operation. At the same time, the present inventionuses a ferrimagnetic ferrite as an insulating coating agent, which reduces the magnetic dilution phenomenon caused by a non-magnetic substance as a coating agent. The suitable heat treatment temperature avoids the reaction between iron and ferrite during heat treatment to form magnetic disadvantageous components, ensures high saturation magnetization of magnetic powder core, high magnetic permeability, reduces loss, and obtains magnetic permeability of soft magnetic composite magnetic powder core.

The invention provides a method for preparing a tungsten-containing alumina ceramic heating substrate, and relates to a method for preparing a ceramic heating element. The invention is capable of solving the problems of poor wettability on powder by a solvent (water), difficult defoaming on slurry, slow volatilization, long drying time, poor bonding force of ceramic and metal level after sintering during an aqueous tape-casting process. The method for preparing the tungsten-containing alumina ceramic heating substrate can substantially enhance the sintering qualification rate and production efficiency. The method comprises the following steps: preparing a premix compound and tungsten slurry, ball milling, tape-casting, screen printing, sintering and nickel plating.

The invention discloses a tapecasting temperature isostatic pressing composite molding preparation method of a metal soft magnetic composite material. The method comprises the following steps: (1) mixing a passivator and a solvent to obtain a passivating solution, and mixing, stirring and drying the passivating solution and magnetic metal powder to obtain passivated powder; (2) mixing the passivated powder, an organic solvent, a dispersing agent, an adhesive and a plasticizer according to a certain proportion, uniformly stirring, and filtering and de-foaming the mixture through a sieve to prepare slurry which is uniformly dispersed; (3) performing tape casting; (4) performing temperature isostatic pressing on a biscuit. According to the invention, solidification and isostatic pressing processes are simplified into a process, so that a metal soft magnetic composite film prepared by using the blade casting temperature isostatic composite molding method is high in resistivity and good in mechanical strength, and the density and the saturation flux density are greatly improved. By virtue of a more mature tape casting process and a temperature isostatic pressing process, the production process of the metal soft magnetic composite material is simplified, the cost is reduced, the performance is excellent, and the method has a wide application prospect in preparation of electronic devices such as film inductors.

The invention relates to a degradable nerve conduit with a highly-oriented tube-in-tube structure and a manufacturing method thereof. The degradable nerve conduit comprises an outer-layer tubular substrate and an inner small tube. The manufacturing method comprises the following steps of: (1) dissolving a degradable material into chloroform, adding a porogenic agent, uniformly stirring the solution, casting the solution into a mould, performing vacuum drying after the chloroform is volatilized, removing the mould and repeatedly flushing the casting with deionized water to obtain the outer-layer tubular substrate with a high void fraction after the porogenic agent is washed off; (2) dissolving the degradable material into an organic solvent to prepare spinning dope, injecting the spinning dope into an injector, performing electrostatic spinning under the action of a boost pump, and curling a fibrous membrane on the mould to form the small tube with a tubular structure; and (3) placing and fixing the small tube into a preserved tube arrangement cavity of the outer-layer tubular substrate, and performing sterilization to obtain the nerve conduit with the highly-oriented tube-in-tube structure. The product provided by the invention has high biocompatibility, low production cost and vast application prospect, and can be applied to the repair of a peripheral nervous system; and the preparation method is simple.

The present invention provides a method for coating an electrode material with a solid electrolyte, an obtained coating material, an electrode prepared by using the coating material, and an all-solid-state battery obtained by using the electrode. The solid electrolyte material mainly aims at halide electrolyte, and comprises LiaMXb, M is one or more of Al, Ga, In, Sc, Y, La, Ho, Sc and the like, Xis one or more of F, Cl and Br, a is more than or equal to 0 and less than or equal to 10, b is more than or equal to 1 and less than or equal to 13, and the X is represented as Li3InCl6, Li3YCl6, Li3YBr6, Li3HoCl6, Li3ScCl6 and the like, and can also be a mixture for coating a solid electrolyte and a conductive agent. According to the invention, the contact between the electrolyte and the electrode material can be significantly improved, the porosity of the pole piece is reduced, the ionic conductivity of the solid electrolyte is not changed after an alkane solvent treatment process, an all-solid-state battery assembled by the electrode material containing the coating layer is simple in process, and the battery can exert high capacity and good rate capability and has a commercial prospect.

The invention provides a preparation method of a fluorescent ceramic containing aluminum oxide matrix. The preparation method sequentially comprises the following steps: mixing aluminum oxide, fluorescent powder and a sintering additive and calcining to obtain fluorescent ceramic precursor powder; sintering the powder to obtain the fluorescent ceramic. The grain diameter of each component is selected to be a pre-set size and the fluorescent ceramic precursor powder is subjected to high-pressure treatment under the condition of 5MPa or above before a sintering process; the fluorescent ceramic precursor powder bears the high pressure of 30MPa to 200MPa in the sintering process and the sintering temperature is 1250 DEG C to 1550 DEG C; the sintering is carried out under an oxygen-free atmosphere. According to the preparation method provided by the invention, the aluminum oxide enters a liquid phase at relatively low temperature under the condition that the fluorescent powder has an unchanged crystal new look in a preparation process and the uniform and dense fluorescent ceramic with low porosity is obtained; the heat-conducting performance and luminous efficiency of the fluorescent ceramic are extremely improved.

A multifactor quantitative evaluation method for the 3D porosity in a geological period belongs to the technical field of diagenetic value simulation in a low-penetration compact reservoir. A planer grid well is selected, and well logging, logging, seismic and analysis and test data is collected and arranged; a 3D burial history and a thermal history under constraints of a sequence stratigraphic framework and deposition microfacies are established, 3D porosity evolution history models of mudstones, arkoses, quartz sandstones and rock-fragment sandstones are established on the basis of a target position, and porosity evolution histories of the different rock types in the target position are evaluated; on the basis of contribution of cementation and corrosion effects of the target position in a research region to the total porosity, porosity effect is corrected by decrease and increase, and a 3D porosity evolution process is evaluated; and a practically measured porosity of the grid well and the simulated porosity of a corresponding well point are analyzed by comparison, the precision requirement is met when the matching degree reaches 75%, and space-time distribution of the 3D porosity of the low-penetration compact reservoir in the geological period is evaluated.

The present invention is nanometer titania film and its preparation process, and belongs to low-dimensional nanometer material technology. In the electrochemical deposition process, nanometer titania powder, surfactant, anhydrous ethanol and metal salt as electrolyte are mixed and ultrasonic dispersed to obtain homogeneously dispersed stable suspension. By means of stainless steel or nickel sheet as anode, transparent conducting ITO glass or transparent conducting FTO polymer as depositing cathode, and constant voltage power source, nanometer titania film is deposited on the cathode substrate at room temperature. The deposited film is then heat treated at 400-550 deg.c or microwave treated for 1-3 hr. The process has easy control and low temperature, and the deposited nanometer titania film has flat surface, high porosity, great specific area and low cost. The present invention is suitable for industry production of dye sensitized solar cell film material.

A bearing having improved wear resistance has a bearing material of a copper-tin-bismuth alloy which may also include phosphorus which has excellent strength, due to the solid solution of copper, tin and phosphorus (when used), attached to a steel backing shell. The material also has good lubricity as a result of the presence of the bismuth which also promotes tin mobilization and formation of a layer of tin on the bearing surface upon use of the bearing. The addition of small amounts of relatively small hard particles in the copper-tin-matrix, particularly Fe₃P, MoSi₂ or a mixture thereof, provides a suitable hard surface artifact to improve the wear resistance of the bearing material. The bearing includes a sintered powder compact bearing material of a copper-tin-bismuth alloy powder and a metal compound powder which is bonded to a steel backing shell, wherein the metal compound powder has an average particle size of less than 10 μm.

The invention provides a preparation method and a using method of a carbon fiber compounded polyether sulfone resin sizing agent. A new carbon fiber sizing agent component for polyether sulfone resin is prepared for solving the problem that an epoxy sizing agent is not suitable for the carbon fiber compounded polyether sulfone material, and can effectively improve the interface bonding property of carbon fibers and polyether sulfone and improve the high temperature resistance of a composite material. A preparation method comprises the steps of processing polyether sulfone resin with a sulfonating agent to obtain a main component (sulfonic polyether sulfone) of the sizing agent; preparing a sizing solution and dipping the carbon fiber to obtain the sizing carbon fiber. The method can improve the interface bonding property of the carbon fiber compounded polyether sulfone resin and can fully achieve high specific strength of the carbon fiber and high temperature resistance of the polyether sulfone.

The invention belongs to the field of composite material production and preparation, and relates to a fiber reinforced thermoplastic resin unidirectional prepreg tape and a preparation method thereof. The prepreg tape is prepared from the following components, by weight: 30-70 parts of a thermoplastic resin, 30-70 parts of nature fibers, 0-1 part of a coupling agent, and 0-1 part of an emulsion. Compared with the prepreg tape in the prior art, the prepared nature fiber/thermoplastic resin unidirectional prepreg tape of the present invention has the following advantages and beneficial effects that: mechanical strength is high, the prepreg tape can be stored for a long time, the nature fibers are completely impregnated by the resin and are not exposed to the outside so as to maintain the dry state of the material, particularly the nature fibers, the nature fibers are not easily subjected to mildew deterioration, and the porosity is low so as to ensure performance stability of the product. With the method, the width of the reinforcing material and the nature fibers can be limited so as not to cause nature fiber deviation phenomenon during the subsequent production process.

The invention relates to a method for preparing a SiCp/Al electronic packaging component. The method adopts SiCp/Al composite materials as raw materials and adopts a centrifugal casting method to prepare the SiCp/Al electronic packaging component with a volume fraction between 40 and 75 percent. The materials of the component have the advantages of high thermal conductivity, low thermal expansion coefficient and high density. Moreover, the method has simple technique and equipment during preparation, short preparation period, can perform near-net forming, and has the advantages of low cost, low porosity and good material properties.

The invention provides a drum-type precision seeder, relates to a seeding machine and in particular relates to a spaced quantitative seeding machine. The drum-type precision seeder disclosed by the invention has no harm on seeds and has few faults. The drum-type precision seeder comprises a center shaft (1) and a shaft sleeve (2), wherein the shaft sleeve is capable of rotating around the center shaft; a center chain wheel (21), a first housing (31), a cylindrical peripheral wall (33), a second housing (32) and a duckbill (4) are fixed on the shaft sleeve. The drum-type precision seeder also comprises a plurality of guide parts, a seed wheel assembly, a fixed wheel (6), a roller brush shaft (71), a roller brush shaft chain wheel (72) and a roller brush (73), wherein the roller brush shaft chain wheel is connected with the center chain wheel through a chain; a seed chamber (61) is arranged in the fixed wheel; the lower end of the sidewall of the seed chamber fits with the roller brush and a seed wheel body (51); a seed falling opening (62) is further formed in the fixed wheel; the seed wheel assembly comprises the seed wheel body (51); a plurality of indent grooves (5121) are formed in the outer peripheral wall of a wheel body part (512) of the seed wheel body at equal intervals.

The invention provides a normal forming method for a sodium alginate containing three-dimensional scaffold.The method includes steps: (1) preparation of the sodium alginate containing three-dimensional scaffold, to be more specific, dissolving sodium alginate into a solvent to obtain a sodium alginate solution, adding PVA (polyvinyl alcohol) into the sodium alginate solution, and well mixing at 80-95 DEG C to obtain slurry; taking the slurry as three-dimensional printing slurry to print at the normal temperature to obtain the sodium alginate containing three-dimensional scaffold; (2) forming, to be more specific, soaking the sodium alginate containing three-dimensional scaffold into a calcium salt solution at the normal temperature to react for 10-24h, and performing curing, washing and freeze drying to obtain the sodium alginate containing three-dimensional scaffold.The normal forming method for the sodium alginate containing three-dimensional scaffold is mild in condition and simple in process.

A composition comprising a nanoporous silica dielectric film having a void volume of about 30% or less based on the total volume of the nanoporous silica dielectric film, and having a dielectric constant of about 2.2 or less. A method of producing a nanoporous silica dielectric film having a void volume of about 30% or less based on the total volume of the nanoporous silica dielectric film, and having a dielectric constant of about 2.2 or less. A silicon containing pre-polymer is provided, which is capable of forming a film having a dielectric constant of about 2.8 or less. It is then combined with a porogen, and a metal-ion-free catalyst selected from the group consisting of onium compounds and nucleophiles, to thereby form a composition. A layer of the composition is coated on to a substrate, crosslinked to form a gelled film, and heated to remove substantially all of the porogen and to thereby produce a nanoporous silica dielectric film of the invention.

The invention relates to a nanometer hole sealing agent for a ceramic spayed coating. The nanometer hole sealing agent comprises the following components in parts by weight: 30-80 parts of water-soluble resin, 10-40 parts of inorganic nanoparticles, 10-30 parts of a corrosion inhibitor, 1-40 parts of fillings, 1-20 parts of a curing agent and 1-10 parts of other aids.

The invention discloses a surface treatment and coating technology for a magnesium alloy surface to resist a neutral salt spray test. The technology comprises the steps of micro-arc oxidation, electrophoresis, spraying of acrylic primer and spraying of organosilicon ceramic composite finish paint, wherein the materials of the organosilicon ceramic composite finish paint include organosilicon coating and nano ceramic coating. In the invention, the magnesium alloy surface is subjected to the surface treatment and coating technology resisting the neutral salt spray test; after the micro-arc oxidation treatment, the electrochemical impedance of the magnesium alloy surface is remarkably improved; and meanwhile, the magnesium alloy micro-arc oxidation protection layer contains a high-temperature change phase, and the film layer has high hardness and toughness and good wear resistance. After the electrophoresis, the film has uniform thickness, strong cohesion and high corrosion resistance and is compatible with multiple finish paints. Particularly, the acrylic resin with strong adhesion, low pollution and low cost can be densely attached to the electrophoretic paint so as to further improve the impact resistance; and after the organosilicon ceramic composite finish paint is sprayed to the surface of the acrylic primer, the magnesium alloy obtains the characteristics of heat and cold resistance, wear resistance, high hardness and the like.

The invention relates to a method of cast steel workpiece surface high speed flame plating fireproof alloy, comprising the steps: 1) pretreatment and roughening treatment are carried out on the surface of the cast steel workpiece; 2) a high speed oxygen-acetylene flame hot spray method is adopted to spray a priming coat on the surface of the cast steel workpiece; 3) working layers are sprayed on the surface of the cast steel workpiece by adopting the high speed oxygen-acetylene flame hot spray method, and 2-4 working layers are repeatedly sprayed by using the method and under the condition of the step 3). The parts prepared by the technique of cast steel workpiece surface high speed oxygen-acetylene flame plating fireproof alloy have higher inoxidability and thermal shock resistance, and can greatly prolong the service life of the cast steel workpiece. Meanwhile, the technology of the invention has the characteristics of simple and convenient operation, low cost and strong applicability, and is convenient for popularization and application.

The invention relates to a method for treating methylene blue dye wastewater. Firstly, diatomite is evenly mixed with calcium raw materials, alkali activator and water, and is put in a high-pressure hydrothermal reaction kettle after the compression molding to react for 1-48 hours at the temperature of 100-200 DEG C to obtain a diatomite-based porous adsorbent containing C-S-H, tobermorite and analcite; then, the diatomite-based porous adsorbent is put in a conical bottle accommodated with a liquid culture medium; 5-20% of yeast powder by mass is added to regulate the pH to be 5-8 and to cultivate for 2-48 h under the constant-temperature condition of 15-35 DEG C on a reciprocal shaking table with the speed of 60-120 rpm so as to obtain a yeast-loaded diatomite-based porous adsorbent; finally, 1-10 g of the yeast-loaded porous adsorbent is added in the methylene blue dye wastewater with per liter concentration of 100-1000 mg/L to treat for 1-48 h at the temperature of 25-45 DEG C on the reciprocal shaking table with the pH of 4 to 10 and the speed of 60-120 rpm; the concentration of the treated methylene blue wastewater is measured through a spectrophotometer method; the result shows that the removal rate of the methylene blue dye exceeds 90%. The method has the advantages of simple process, low cost and no secondary pollution, and is suitable for the industrial treatment of the methylene blue dye wastewater.

The invention relates to cement-based materials and particularly discloses a basalt fiber reinforced cement based material and a preparation method therefor. The basalt fiber reinforced cement based material contains the following ingredients: 400-800kg/m<3> of cement, 150-330kg/m<3> of active mineral admixture, 800-1,500kg/m<3> of fine aggregate, 10-40kg/m<3> of water reducing agent, 0.01-0.05kg/m<3> of setting retarder, 0.5-3.0% (volume percent) of basalt fibers and 0.2-1.0% (mass percent) of fiber surface modifier. According to the basalt fiber reinforced cement based material and the preparation method therefor, through optimizing a formula, the compactness of the material is improved, meanwhile, the property of an interface layer between the basalt fibers and a cement bonding material is improved, and the interfacial bonding strength is improved. The structure and mechanical properties of the basalt fiber reinforced cement based material disclosed by the invention are improved relatively greatly, and the compression strength, folding strength and toughness are improved greatly.

The invention relates to a preparation method of aluminum-zinc-magnesium-copper-zirconium series high-strength aluminum alloy. Specifically, the method comprises the following steps of: preparing Al, Zn, Mg, Cu and Zr pure element powder for dosing, wherein, by mass, Zn is 5.0-6.5%, Mg is 1.7-2.1%, Cu is 1.6-2.1%, Zr is 0.17-0.25%, and the balance is Al, and the sum of the constituents is 100%; with an element powder method, obtaining a hot-press test sample of aluminum-zinc-magnesium-copper-zirconium series high-strength aluminum alloy by the method of mixing, low-temperature high-pressure vacuum hot pressed sintering, high-temperature solid solution heat treatment, hot extrusion and after heat treatment. The aluminum-zinc-magnesium-copper-zirconium series high-strength aluminum alloy prepared by the preparation method has fine and uniform crystalline grains, the preparation method is simple to operate and has excellent controllability, and expands the industrialized application of the aluminum alloy in the field of medium and high-strength structure materials.

The invention discloses a casting and pouring device. The casting and pouring device comprises a pouring gate (1), a first main flow channel (2), a stirring furnace (3), shunting channels (4), a flow balancing channel (5) and casting molds (6), wherein the pouring gate (1) is arranged above the stirring furnace (3); the pouring gate (1) is connected with the stirring furnace (3) through the first main flow channel (2); the shunting channels (4) are arranged below the stirring furnace (3); the flow balancing channel (5) is arranged on the lower parts of the shunting channels (4); the casting molds (6) are connected below the shunting channels (4). By adopting the casting and pouring device, one-step pouring of a plurality of casting molds can be realized, and the production efficiency is increased; the casting molds are poured simultaneously, and liquid metal uniformly flows into each casting mold through the flow balancing channel, so that the controllability and synchronicity of a casting process are enhanced; the liquid metal is stirred uniformly and pouring is performed after bubbles are discharged, so that the quality of a casting is improved.

A ceramic matrix composite laminate includes at least two directional, continuous ceramic fiber preform lamina each being formed of interwoven or braided fibers. A layer of non-woven mat includes a plurality of chopped ceramic fibers mixed with a bonding agent. The non-woven mat layer is interposed between adjacent directional, continuous ceramic fiber preform lamina to substantially eliminate inter-laminar gaps formed between the adjacent directional, continuous ceramic fiber preform lamina. The additional chopped fiber content improves the interlaminar mechanical and thermo-mechanical material properties of resulting ceramic matrix composite laminate.

The invention relates to a method used for welding a boiler barrel, in particular to a boiler barrel welding method in order to solve the problem that due to the fact that in existing boiler barrel welding, X-ray flaw detection is adopted after welding, the back repair rate is high. According to the first scheme, the boiler barrel welding method comprises the steps that 1 the plate thickness of a first welded barrel section is 26 mm-28 mm and grooves are formed in the inner side of a butt-joint opening position and the outer side of the butt-joint opening position respectively; 2 butt joint positions are aligned tightly; 3 spot welding is conducted on the outer side; 4 full-length butt welding is conducted on the inner side; 5 back gouging is conducted on the outer side by the adoption of a carbon arc gouging welding machine; 6 full-length welding is conducted on the outer side, and weld seams are removed through grinding after welding is completed. According to the second scheme; 1 the plate thickness of a second welded barrel section is 16 mm-24 mm, and a groove is formed on the inner side; 2 butt joint positions are aligned tightly; 3 spot welding is conducted on the outer side; 4 full-length welding is conducted on a butt-joint opening of the inner side through automatic submerged arc welding. According to the third scheme; 1 the plate thickness of a third welded barrel section is 8 mm-14 mm, and the position of a butt-joint opening is ground to be neat; 2 butt joint positions are aligned tightly; 3 a coal firing weld bead is welded; 4 full-length welding is conducted on the inner side; 5 back gouging is conducted on weld seams by the adoption of the carbon arc gouging welding machine on the outer side.

The invention discloses a method for selecting particle size distribution ranges and the filling amount ratio of heat-conducting silica gel thermal interface material powder filler. The method comprises the following steps of 1, selecting several types of heat-conducting powder filler different in particle size distribution range; 2, selecting the particle size distribution ranges and the filling amount ratio of the heat-conducting powder filler different in particle size distribution range; 3, adding the heat-conducting filler different in particle size distribution range into a silicone rubber base body in sequence from large particle size to small particle size according to the determined filling amount ratio, and conducting uniform mixing by mechanical manners such as stirring or smelting or banburying, so that a heat-conducting powder filler and silicone rubber mixture is obtained; and 4, further improving density of the silicone rubber mixture through a physical vibration method. The method for theoretically researching the filling amount ratio of the heat-conducting powder filler different in particle size distribution range is mainly provided. By means of the research method, a silicone rubber thermal interface material which is high in powder filler stacking density, high in heat conductivity coefficient and stable in performance can be prepared. The method has great theoretical instruction significance for selection of types and particle sizes of the powder filler and optimization of the filling amount of the heat-conducting powder filler different in particle size distribution range.

The invention relates to the technical field of refractory materials, and provides a spinel micro-powder castable for a steel ladle and a method for preparing a prefabricated part from the castable. The spinel micro-powder castable for the steel ladle is prepared from the following components in parts by mass: 25-40 parts of tabular corundum particles, 15-25 parts of white corundum particles, 15-20 parts of fused magnesia-alumina spinel particles, 8-12 parts of white corundum fine powder, 6-10 parts of alpha-Al2O3 micro powder, 3-5 parts of sintered spinel micro powder, 6-7 parts of cement, 1-2 parts of steel fibers and 1-3 parts of additives. Through the sintered spinel micro powder, the castable is more compact, the porosity is reduced, the pore diameter is reduced, and meanwhile, the generation of calcium hexaluminate (CA6) is promoted, so that the matrix structure is optimized. The castable has high normal-temperature strength and high-temperature strength and excellent high-temperature breaking strength, slag corrosion resistance and thermal shock resistance, and the service life of a steel ladle material is effectively prolonged.

Components of a subsurface safety valve are cast instead of machined for dramatic cost savings. In particular, the flapper is cast from a 718 nickel alloy and treated with the HIP process to increase strength and corrosion resistance while reducing porosity. Other downhole valve components are contemplated to be produced by the same technique and the materials can also be varied. Depending on the specific alloys, the resulting HIP components are either superior in performance (e.g. strength, corrosion resistance) or considerably cheaper to manufacture than their wrought counterparts.

The invention relates to a precursor carbonization plasma cladding reaction synthesized WC reinforced metal based alloy coating, which is characterized in that preparation of the coating combines precursor carbonization compounding, plasma cladding and reaction synthesis technologies. Specifically, the involved mixed powder comprises the following elements by mass: 10-30% of W, 0.5-2% of C, 9-12% of Cr, 1-1.5% of B, 0.8-1.1% of Si, 0.5- 0.8% of Mo, and the balance Fe, wherein the C is obtained by carbonization of a sucrose precursor at a low temperature and wraps the surface of the W powder. The coating has thickness of 2-5mm, the width of a single-channel cladding layer is 3-12mm, and the porosity is low. The coating is mainly based on an iron-based solid solution, WC, (Fe, Cr, W)7C3, (Fe, Cr, W)23C6, and Fe3W3C-Fe4W2C and other phases, the coating section hardness is 900-1650HV0.1, and the surface hardness is 60-70HRC. According to the invention, the problems of interfacial contamination, generation of a brittle phase and the like in the coating are improved, and also the production of the WC reinforced phase in the coating is substantially improved. The coating has excellent wear resistance and excellent corrosion resistance.

The invention discloses a PTFE hollow fiber film used for bubbleless aeration oxygenation, and a preparation method thereof. According to the PTFE hollow fiber film used for bubbleless aeration oxygenation, a hollow tubular structure is adopted, micropores with an average pore diameter ranging from 1000 to 8000nm are uniformly distributed on the surface layer and the interior; and the porosity of the micropores ranges from 70 to 90%. The PTFE hollow fiber film is low in pore diameter, high in porosity and strength, and excellent in physical and chemical properties, is especially suitable for bubbleless aeration oxygenation; aeration resistance is low; operation is stable and reliable; adaptability is high; the PTFE hollow fiber film is suitable for aeration of a plurality of waste water; oxygen utilization rate is high; generated micron order bubbles are small and uniform; service life is long; no film pollution is caused; film washing is not needed in long term of application; the preparation method is simple; no environment pollution is caused; operation is convenient; and the preparation method is suitable for industrialized production.