165results about How to "High temperature oxidation resistance" patented technology

The invention provides an aluminum electrolysis inert anode of which the material is a high-entropy alloy. The high-entropy alloy contains 5-10 alloy elements of which the mole ratio can be identical or different; and the atomic percent of each main element is 5-35%. The high-entropy alloy inert anode has the characteristics of favorable high-temperature oxidation resistance, high aluminum electrolysis salt corrosion resistance, high electric conductivity and the like. The high-entropy alloy prepared by the smelting method has the advantages of simple technique and low cost, and is easy for connection. When being used for aluminum electrolysis, the high-entropy alloy can avoid the consumption of the carbon anode and the emission of the CO2 gas, and has the advantages of energy saving and emission reduction.

Ferritic nitrocarburized surface treatment of cast iron brake rotors providing oxidation resistance, good braking performance and absence of distortion. Machined brake rotors are pre-heated, then immersed into a high temperature molten nitrocarburizing salt bath for a first predetermined dwell time. After removing the brake rotors from the nitrocarburizing salt bath, the brake rotors are directly immersed into an oxidizing salt bath at a lower temperature than the nitrocarburizing salt bath so that the brake rotors are thermally quenched. After a predetermined second dwell time in the oxidizing salt bath, the brake rotors are removed therefrom and further cooled to room temperature, either by water application thermal quenching or slow cooling in air. A fixture provides stable holding the brake rotors with a minimum of contact during placement in the salt baths.

The invention relates to a preparation method of copper-silver composite powder. The copper-silver composite powder has a coated nuclear-shell structure; a nuclear layer is made of copper-silver alloy, and the shell layer is made of silver. The preparation method comprises the steps: firstly, adding a mixed aqueous solution of AgNO3 and Cu(NO3)2.3H2O into a mixed aqueous solution consisting of a reducing agent and a dispersing agent to obtain a copper-silver alloy solution containing the reducing agent; then adding an AgNO3 aqueous solution into the copper-silver alloy solution containing the reducing agent, and leading silver to be deposited and coated on the surface of the copper-silver alloy; and then obtaining the 0.3-3mum copper-silver composite powder after filtering, cleaning, drying and surface densified treatment. In the obtained copper-silver composite powder, the coating of the outer-layer silver is uniform, the compact density is high, the conductivity is good, and the high-temperature oxidation resistance is strong.

Provided is a ferritic stainless steel for heat pipes of high-temperature exhaust heat recovery systems, which comprises, in terms of % by mass, from 16 to 32% of Cr, at most 0.03% of C, at most 0.03% of N, at most 3% of Si, at most 2% of Mn, at most 0.008% of S, from 0 to 0.3% of Al, and at least one of at most 0.7% of Nb, at most 0.3% of Ti, at most 0.5% of Zr and at most 1% of V, and optionally at least one of at most 3% of Mo, at most 3% of W, at most 3% of Cu, at most 0.1% of Y, at most 0.1% of REM (rare earth metal) and at most 0.01% of Ca, with a balance of Fe and inevitable impurities, and which satisfies at least the following formula (1), formula (2) and formula (5):

Cr+3(Mo+Cu)≧20  (1)

Cr+3(Si+Mn+Al−Ti)≧20  (2)

0.037{(C+N)/(V+Ti+0.5Nb+0.5Zr)}+0.001≦0.01  (5).

The invention discloses environment-friendly type oil for a heavy-duty industrial gear. The oil comprises base oil, an anti-wear reagent at extreme pressure, an antioxidant corrosion-resistant agent, a metal passivator, an antirust agent, a demulsifier, an antifoaming agent, an oiliness agent, and a viscosity index improver. The oil for the heavy-duty industrial gear is good in comprehensive property, not only has good antioxidant and corrosion-resistant properties, antirust property, anti-wear and corrosion-resistant properties, friction reduction, bearing, high torque, high-temperature stability, demulsibility, antifoaming property and the like, and is capable of reducing emission, good in biodegradability, and lower in cost, but also can be used for enabling an industrial gear to form an anti-wear, high temperature-resistant and extrusion-resistant boundary lubricating oil film under the high torque or impact load, so as to ensure that the gear is well lubricated. Additives are selected by adopting an artificial neural network algorithm, the optimal formula can be selected by a genetic algorithm, and the environment-friendly type oil for the heavy-duty industrial gear can meet the performance requirements of the GB5903-1995 heavy-duty industrial gear on the oil with the viscosity grades of 100, 150, 220, 320, 460 and 680.

The invention relates to a preparation method of a mullite oxidation resistant coating, particularly to a method for preparing a mullite/SiC bilayer-structure oxidation resistant coating on the surface of a carbon/carbon composite material. The preparation method comprises the following steps: pre-calcining mullite powder A and mullite precursor powder B according to the mass ratio of (4-6):1 to prepare pre-calcined mullite powder A and mullite precursor powder B, preparing a coalescing agent and a drying inhibitor according to certain ratio, uniformly mixing the pre-calcined mullite powder A, the pre-calcined mullite precursor powder B, the coalescing agent and the drying inhibitor to obtain a sizing agent, dipping a matrix in the sizing agent, performing sizing agent coating by adopting the dip-coating technology, and after the sizing agent coating, calcining at 1480-1515 DEG C to obtain the mullite oxidation resistant coating. According to the invention, the technology is simple, the raw material is cheap and available, the industrial production is facilitated, and the obtained coating has the advantages of high uniformity and compactness, excellent binding property, and high high-temperature oxidation resistant capacity.

The invention discloses scaling powder for lead-free solder paste. The scaling powder for the lead-free solder paste comprises, by weight, 35.0%-45.0% of colophony, 2.0%-5.0% of activating agent, 3.0%-8.0% of thixotropic agent, 1.5%-3.0% of surface active agent and 0.1%-1.5% of corrosion inhibitor, the other part is solvent. The scaling powder for the lead-free solder paste is wide in viscosity range, good in activity and strong in high temperature oxidation resistance, no halogen residues exist on a welded base plate, washing is not needed, insulation resistance is beyond 108 ohms, and the scaling powder for the lead-free solder paste can be widely applied to the field of welding of electronic materials.

The invention discloses a Ti3SiC2-based composite material coating and a preparation method thereof, wherein the preparation method of the Ti3SiC2-based composite material coating comprises the following steps: S1, weighing raw materials; S2, carrying out ultrasonic dispersion; S3, ball-milling Ti powder, SiC powder and C powder after ultrasonic dispersion, so as to form mixed slurry; S4, spray drying the mixed slurry to prepare micronmeter agglomerated particles; S5, drying the prepared micronmeter agglomerated particles and sieving the dried micronmeter agglomerated particles; S6, carrying out surface pre-treatment on a to-be-sprayed substrate and fixing the substrate; and S7, spraying the micronmeter agglomerated particles dried in the step S4 onto the substrate treated in the S6 by virtue of a plasma spray method. The preparation method is simple to operate, convenient and controllable and high in efficiency and the thickness of the coating is flexibly controlled, and the prepared Ti3SiC2-based composite material coating has the performances of wear resistance, corrosion resistance, high-temperature oxidization resistance and the like and has a wide application prospect.

Provided is a Ni-based single crystal superalloy containing

• • 6% by mass or more and 12% by mass or less of Cr,
  • 0.4% by mass or more and 3.0% by mass or less of Mo,
  • 6% by mass or more and 10% by mass or less of W,
  • 4.0% by mass or more and 6.5% by mass or less of Al,
  • 0% by mass or more and 1% by mass or less of Nb,
  • 8% by mass or more and 12% by mass or less of Ta,
  • 0% by mass or more and 0.15% by mass or less of Hf,
  • 0.01% by mass or more and 0.2% by mass or less of Si, and
  • 0% by mass or more and 0.04% by mass or less of Zr, and
  • optionally containing at least one element selected from B, C, Y, La, Ce, and V,
  • with a balance being Ni and inevitable impurities.

The present invention provides alpha-sialon ceramics doped with composite rare earth and a preparation method thereof, and relates to the alpha-sialon ceramics and the preparation method. The present invention solves the problem that the hot pressing and no pressure can not easily prepare Sc-alpha-sialon phase in the existing sintering method, thus restricting the application of scandium oxide. The ceramics has a formula (ScxRy)Si<12-(m+n)>AlOnN<16-n>. The preparation method comprises the following steps: raw materials are mixed in wet environment, dried and then arranged in a mould; under the conditions of protective nitrogen and pressure of 30MPa, the temperature is raised and maintained; thus the ceramics can be prepared. With the common influence of Y<3+>, the preparation method adopts Sc<3+> in the alpha-sialon structure and makes full use of the scandium oxide. The prepared ceramic material has the hardness of 21GPa; and the formation of alpha-sialon grains, which are shaped like a long rod, results in excellent toughness of the ceramic material, which is about 5.3MPm<1/2>.

The invention relates to a laser forming method of a TiC-Ti metallic composite structural component. The adopted formula of raw material powder comprises 2.36-4.55wt% of graphite, 0.11-0.22wt% of rare earth oxide and the balance of Ti. Quantitative powder distribution and mixing, required by laser forming are finished by a multi-hopper spiral powder conveying and mixing system, and coaxial discontinuous powder sprayers are used as laser forming nozzles. The forming of the inner and outer layered structure of the composite component is realized by using the system to control powder conveying and laser, and the dynamic performance of the composite can reach more than 70% of a base metal material.

The invention relates to preparation methods of a carbon-carbon composite material and a carbon-ceramic composite material with inner holes. According to the preparation methods, by a method of embedding a plastic mould or a graphite mould with a predetermined shape and a predetermined size and coating the surface thereof with graphite paper with a special structure and special functions, or pretreated graphite paper or carbon fiber paper, a carbon fiber needle-punched preform is woven and moulded, then the carbon fiber needle-punched preform is degummed at high temperature in a protective atmosphere, then CVI densification and/or resin impregnation-cracking densification is performed, and finally after high-temperature graphitization or siliconizing treatment, the embedded plastic mould is removed or the graphite mould is taken out to obtain the carbon-carbon composite material and the carbon-ceramic composite material with special internal pore structures and functions. The preparation methods are simple and controllable, and are particularly suitable for preparing the carbon-carbon composite material and the carbon-ceramic composite material which have special functional requirements on the inner holes, such as heat dissipation, heat conduction and electricity conduction, and have very complicated inner holes.

The invention discloses ultrafine-grained Al-bearing multiple-principal-element high-entropy alloy and a preparation method thereof. The ultrafine-grained Al-bearing multiple-principal-element high-entropy alloy is composed of Al, Co, Cr, Fe, Ni, Ti and Nb, marked in an atomic ratio as Al20-xCo20Cr20Fe20Ni20(TiyNb1-y)x, wherein 0<x<20, and 0<y<1. The ultrafine-grained Al-bearing multiple-principal-element high-entropy alloy is prepared by the combination of vacuum arc melting and equal channel angular extrusion; firstly, an alloy rod is made by vacuum arc melting; a super-large block of ultrafine-grained high-entropy alloy is prepared via equal channel angular extrusion; secondly, subsequent annealing is performed to adjust strength and plasticity of the alloy. By adding certain Ti and Nbto replace Al, high-temperature creep resistance of the alloy herein is improved; BCC (body center cubic) solid solution is formed, so that antioxidant property is improved; equal channel angular extrusion and annealing help improve strength, plasticity and antioxidant property.

The present invention relates to a high conductivity solid oxide fuel cell high temperature oxidation resistance flexible connection part. According to the present invention, a coating material is coated on the surface of an alloy network body or foam-like body to form a high temperature oxidation resistance protection coating, and the good conductivity is provided, such that the prepared flexible connection part having high conductivity at a high temperature oxidation atmosphere has characteristics of high conductivity and high temperature oxidation resistance, wherein the coating coated on the surface contains one or more than two materials selected from an oxide having a perovskite structure, an oxide having a spinel structure, an oxide having a fluorite structure and an oxide having a rutile structure, and at least one of the oxides has the conductivity of more than 1 S/cm at a temperature of 500-900 DEG C; and the flexible connecting part can be provided for improving contact between the electrode or connector of the solid oxide fuel cell and the current collection part, eliminating high temperature expansion damage caused by rigid contact and improving the electricity generation performance of the fuel cell, and has advantages of high temperature oxidation resistance, good electrical conductivity, simple battery stack assembly and the like.

Method of forming an outwardly grown aluminide diffusion coating on a superalloy substrate disposed in a coating retort including the steps of heating the substrate to a temperature of 900 to 1200 degrees C., flowing a coating gas comprising aluminum trichloride and a carrier gas through the coating retort at a flow rate of the coating gas of about 100 to about 450 standard cubic feet per hour, providing a concentration of aluminum trichloride in the retort of less than 1.4% by volume of the coating gas, and providing a total pressure of the coating gas in the coating retort of about 100 to about 450 Torr.

The present invention relates to a kind of hard protection film, and this hard protection film is the hard protection film that forms by physical vapor deposition method, is made of transition metal elements selected from Group 4a, 5a and 6a of the periodic table, Al and B At least one metal element of Si and at least one non-metallic element selected from C, N and O, the above-mentioned hard protective film has a columnar structure, and the columnar structure has a plurality of layers with different Si contents In the formed multi-layer structure, the lattice bands are continuous in the boundary region between the above-mentioned layers, and the thickness of each layer is 0.1-100 nm.

This invention discloses a ceramic-carbon heating pipe having a heating matrix, an electrode lead-out rod is connected with both ends of matrix sleeved with a protection pipe, insulation and heat conduction powder is filled between matrix and protection pipe. Its electric-heat transformation rate reaches as high as 99.6% and is oxidation resistant, not easy to be broken with a long work life to 50000 hours, 1.5 times higher than that of the national standard.