11 results about "Thermal spraying" patented technology

This invention provides a multi-metal co-doped WC-Co coating and its preparation method, belonging to the field of metal-ceramic coating technology. The preparation method includes: weighing tungsten, yttrium, cerium, chromium, and vanadium sources, mixing and dissolving them in deionized water, adjusting the pH to 3-4, and obtaining a precursor through co-precipitation, washing, and drying; subjecting the precursor to sequential aerobic calcination, hydrogen reduction, and carbonization treatments to generate a WC phase, resulting in a rare-earth-transition multi-metal co-doped WC-based composite material; using the WC-based composite material, cobalt powder, and additives as raw materials, spraying the raw materials onto the substrate surface via thermal spraying to form a multi-metal co-doped WC-Co coating. The WC-Co coating prepared by this invention incorporates four elements—yttrium, cerium, chromium, and vanadium—forming a multiple synergistic mechanism of grain refinement, interface strengthening, and decarburization inhibition, effectively improving the hardness, wear resistance, corrosion resistance, and toughness of the WC-Co coating.

This invention discloses a high-thickness, high-purity MAX phase coating and its preparation method. The method includes: 1. Mixing a metal oxide and a carbon source, followed by high-energy ball milling and spray granulation to prepare spherical precursor powder; 2. Depositing a transition layer on a sandblasted substrate surface using plasma spraying, and then depositing the spherical precursor powder on the transition layer to form a precursor coating; 3. Immersing the substrate with the precursor coating in molten salt for electrolysis, causing the precursor coating to be electro-deoxidized and converted into a MAX phase coating. This invention employs a synergistic process of "plasma spraying-molten salt electrochemical conversion," converting the sprayed precursor coating into a MAX phase coating through in-situ electro-deoxidation in molten salt electrochemistry. This process has high deposition efficiency and avoids the defects of carbon loss, phase decomposition, and oxidation in the coating product when directly thermally spraying MAX materials. It achieves the preparation of a high-thickness, high-purity MAX phase coating, suitable for the field of surface protection.

This invention discloses a preparation process for high-carbon ferrochrome based on plasma spheroidization technology, belonging to the field of powder metallurgy. The process involves crushing and ball milling high-carbon ferrochrome blocks to obtain pre-formed powder, adding tannic acid, urea, nickel acetate tetrahydrate, and citric acid for coating, followed by spray drying. After pre-reduction carbonization in an argon-hydrogen atmosphere, the powder is then spheroidized using a radio frequency inductively coupled plasma torch. In-situ nanostructure growth is achieved in a mixed atmosphere of argon, hydrogen, and acetylene. Nickel acetate is reduced to catalytically active elemental nickel nanoparticles under the action of hydrogen and carbon monoxide. The powder is then cooled, graded, and inertly encapsulated to obtain a high-sphericity, low-oxygen-content, high-carbon ferrochrome-based core-shell structured spherical powder. The process flow of this invention is continuous and controllable, effectively improving powder flowability, bulk density, hardness, and corrosion resistance, and is applicable to additive manufacturing, thermal spraying, and powder metallurgy forming.

The present invention discloses a method for depositing a tantalum carbide composite coating, comprising five steps: S1: generating a powder composition signal; S2: based on the powder composition signal, pre-depositing a tantalum carbide transition layer on the substrate surface and curing it through heat treatment to form a transition layer interface signal; S3: based on the transition layer interface signal, activating a three-layer combined atmosphere protection system comprising overall cavity atmosphere protection, flame annular gas curtain protection, and substrate back cooling protection, generating an oxygen concentration monitoring signal and a protective gas flow control signal, and simultaneously generating a coating thickness signal; S4: based on the coating thickness signal, switching the thermal spraying gun to a low-power plasma beam mode to form a densified coating signal; S5: changing the proportion of carbon powder in the composite powder, repeating steps S3 and S4 at least once, and outputting the final coating signal. The tantalum carbide composite coating deposition method of the present invention can solve the problems of low bonding strength, easy oxidation, and high porosity of existing thermally sprayed tantalum carbide coatings.

This invention relates to the field of surface spraying technology, and discloses a thermally sprayed wear-resistant and corrosion-resistant composite coating for metal substrates and its preparation method. The method includes: degreasing, sandblasting, purging, and preheating the surface of the metal substrate; dispersing, drying, and pre-curing Cr3C2 particles in a coating slurry containing flake Cr2O3 particles, borosilicate glass particles, aluminum phosphate particles, and silica sol to obtain barrier-coated hard reinforcing particles; spraying NiCrBSi alloy powder, barrier-coated hard reinforcing particles, and Al2O3 particles into granules, followed by thermal spraying, and then impregnating and sealing under negative pressure and curing to obtain the composite coating. This invention distributes the barrier phase at the particle interface around the Cr3C2 hard phase, limiting the spread of corrosive media along the particle interface and wear grooves after wear, thereby improving the service stability of the coating under wear-corrosion coupled conditions.

This invention discloses a method for preparing a modified proton exchange membrane water electrolyzer, belonging to the technical field of proton exchange membrane water electrolyzers. The method specifically includes the following steps: S1) Degreasing a titanium substrate with acetone, then ultrasonically cleaning it in ethanol and deionized water to remove residual impurities, followed by acid treatment, cleaning with deionized water, and finally drying; S2) Treating the titanium substrate treated in S1) with a thermal spraying method to obtain a titanium bipolar plate with a tantalum coating; S3) Nitriding the titanium bipolar plate obtained in S2) using a powder immersion reaction-assisted coating method to obtain a titanium bipolar plate with a tantalum / titanium nitride composite coating. This invention improves the corrosion resistance and conductivity of titanium sheets by forming a dense and uniform conductive coating on the surface of the titanium sheet through powder embedding reaction-assisted coating and nitriding in metal nitride powder.

A method of repairing a divertor or first wall surface in a tokamak plasma vessel. The divertor or first wall surface comprises a refractory metal having a melting point of at least 2000° C. A pressure of less than 25 mbar is maintained within the plasma vessel following the end of operation of the plasma vessel. The refractory metal is deposited onto the divertor or first wall surface within the plasma vessel via a deposition process which is one of: additive manufacturing; physical vapour deposition; thermal spray; arc ion plating; diode laser cladding; and chemical vapour deposition.

Disclosed in the present invention are a composite thermal insulation coating containing a rare earth oxide, and a preparation method therefor and the use thereof. The preparation method comprises: preparing a non-Ce rare earth metal RE, Ce and a metal M into an RE-Ce-M alloy target according to a preset stoichiometric ratio; and sputtering the RE-Ce-M alloy target material onto the surface of a ceramic transition layer on a high-temperature alloy substrate, and treating same in a certain oxidizing atmosphere, so as to form a composite thermal insulation coating containing a rare earth oxide on the high-temperature alloy substrate, wherein the composition of the composite thermal insulation coating containing a rare earth oxide is (RE)2-x(Ce1-yMy)2+xO7±z. The present invention effectively avoids the problem of component deviation caused by the difference in properties such as the saturated vapor pressure of a certain component during thermal spraying and plasma physical vapor deposition, thereby ensuring that the obtained coating conforms to the stoichiometric ratio, and improving the consistency and stability of the coating.

The utility model discloses a protection tool and a spraying device, and relates to the technical field of thermal spraying. The protection tool comprises a first shielding piece and a second shielding piece, the first shielding piece comprises a first surrounding wall and a first side wall, the first surrounding wall is arranged on the peripheral side of the first side wall in a surrounding mode and connected with the first side wall, and a first through hole is formed in the first side wall; the first shielding part comprises a first surrounding wall and a first side wall, the second shielding part comprises a second surrounding wall and a second side wall, the second surrounding wall is arranged on the peripheral side of the second side wall in a surrounding mode and connected with the second side wall, a second through hole is formed in the second side wall, and the end, away from the first side wall, of the first surrounding wall is connected with the end, away from the second side wall, of the second surrounding wall in a sealed mode. According to the protection tool, the part, needing to be shielded, of the valve plate shaft workpiece is completely contained in the protection tool, the surface needing to be protected is completely covered with the protection tool, the size precision of the part, needing to be shielded, of the valve plate shaft is high, and the spraying effect and spraying precision of the valve plate shaft are improved.

The present invention relates to a method for manufacturing ceramic coatings on a thermoplastic polymer substrate by atmospheric plasma thermal spraying. Specifically, it relates to the manufacture of a multilayer coating consisting of layers of titania, hydroxyapatite, and bioactive glass. The method establishes the steps for controlling the heating / cooling rates of the polymer substrate during the application of the ceramic coatings, in order to preserve the integrity of the substrate and ensure good adhesion between it and the applied coating layers. Using this methodology, it will be possible to manufacture biocompatible ceramic coatings on PEEK for use in the fabrication of implants in various applications, such as columns, jaws, or dental implants.To control the heating / cooling conditions, a sample holder was constructed that includes a substrate cooling system manufactured using additive manufacturing and a control device based on the use of commercially available thermocouples and industrial controls. The sample holder, and its component systems, are used to position the PEEK substrates and apply the ceramic coatings via atmospheric plasma under controlled conditions.

This invention discloses a method for repairing the dimensions of mating surfaces of an aero-engine combustor outer sleeve, comprising: cleaning and drying the mating surfaces after cutting; protecting the non-mating surface areas of the combustor outer sleeve and then sandblasting the mating surface areas; drying NiAl powder and NiCrW powder; sequentially spraying a base layer and a top layer onto the mating surfaces using plasma equipment, wherein the base layer is sprayed with NiAl powder multiple times until the base layer thickness is 0.25 mm to 0.3 mm, and the top layer is sprayed with NiCrW powder multiple times until the base layer thickness is 0.5 mm to 0.7 mm; machining the sprayed combustor outer sleeve mating surfaces until the diameter of mating surface A is 793.86 mm to 799.86 mm and the diameter of mating surface B is 852.77 mm to 854.77 mm. This invention restores the dimensions of worn surfaces through machining and thermal spraying, shortening the process to only 6 steps and reducing the repair cycle; the use of NiAl powder and NiCrW powder thermal spraying to form a coating on the mating surfaces of the combustor outer sleeve improves the performance of the combustor outer sleeve.