761 results about "Alloy coating" patented technology

The invention relates to the technical field of alloy coatings, and discloses a laser cladding high-entropy alloy coating and a preparation method thereof.The laser cladding high-entropy alloy coating is prepared from, by mass, 25%-45% of Fe, 15%-25% of Cr, 10%-20% of Ni, 5%-15% of Mn, 3%-10% of Al, 0%-5% of Ti, 1%-5% of a nanometer reinforcing phase and 0.1%-0.5% of a flow promoter. Lorentz force generated by an alternating electromagnetic field drives melt convection, so that the diffusion coefficient of segregation-prone elements such as Cr and Ni is increased, the ultrasonic cavitation effect is matched to crush dendritic crystals and promote dispersion of nanoparticles, the segregation index of the elements is reduced, a uniform nanocrystalline-amorphous composite structure is formed through the synergistic effect, and uniform distribution of elements in a molten pool is achieved.

The invention discloses a gradually-changed Si-Al alloy coating diamond / aluminum-based composite material and a preparation method and application thereof, and the gradually-changed Si-Al alloy coating diamond / aluminum-based composite material is composed of an aluminum matrix and modified diamond evenly dispersed in the aluminum matrix. The modified diamond comprises diamond particles and a gradually-changed Si-Al alloy coating wrapping the surfaces of the diamond particles, in the gradually-changed Si-Al alloy coating, the mass fraction of Si is linearly decreased from 100% to 0% from inside to outside, and the mass fraction of Al is linearly increased from 0% to 100% from 0%. According to the method, the Si-Al alloy coating with gradually-changed and controllable components is constructed on the surface of the diamond, so that a SiC transition layer with strong binding force can be formed with the diamond, the gradient gradient coating is formed from inside to outside, internal stress can be released, good metallurgical bonding with an aluminum matrix can be achieved, formation of an Al4C3 phase is inhibited, and therefore the performance of the composite material is remarkably improved.

The invention relates to a preparation method of a seawater wear and corrosion resistant high-entropy alloy coating, and belongs to the technical field of coating preparation and treatment. The preparation method comprises the steps that matching calculation is conducted according to the chemical formula FeCrCoMnSix of the high-entropy alloy, Fe, Cr, Co, Si and Mn-Fe alloy powder are weighed, and x is equal to 0.1-1; the weighed powder is mixed and then subjected to ball milling, and a mixture is obtained; mixing the mixture with an adhesive, coating the mixture on a substrate to form a plurality of prefabricated layers, distributing the prefabricated layers on the substrate in parallel, and then drying the coated substrate; under the protection atmosphere of inert gas, the dried base body coated with the prefabricated layer is subjected to multi-channel laser cladding; and then annealing treatment is conducted, and the high-entropy alloy coating is obtained. According to the method, the seawater corrosion resistance and wear resistance of the high-entropy alloy coating are improved by adjusting the content of the Si element, utilizing the laser cladding technology and further performing annealing treatment.

The invention discloses a double-gradient high-temperature-resistant high-entropy alloy wear-resistant layer and an ultrasonic-assisted laser cladding preparation method thereof, and belongs to the technical field of metal material coatings and surface modification. A proper amount of refractory element W with anti-oxidation and solid solution strengthening effects is introduced into a CoCrFeNi high-entropy alloy coating, an ultrasonic-assisted laser cladding process is adopted, the wear-resistant layer with the grain size and the precipitated phase volume fraction in a gradient structure from exterior to interior is prepared, local stress concentration caused by W aggregation in the laser cladding process is improved, and the wear-resistant performance of the CoCrFeNi high-entropy alloy coating is improved. And the metallurgical bonding strength of the cladding layer and the matrix is improved, and the high-temperature friction and wear resistance of the cladding layer is enhanced. The cladding layer is fine and compact in structure, in gradient distribution, good in mechanical property and excellent in high-temperature wear resistance. The method is easy to operate and low in cost, and an effective method is provided for improving highly coordinated regulation of process-structure-performance and preparing the novel high-temperature-resistant high-entropy alloy wear-resistant layer.

The invention belongs to the technical field of protective coatings, and particularly relates to a titanium alloy surface anti-oxidation coating and a preparation method. The diffusion aluminide coating with the aluminum content gradually reduced from outside to inside is prepared on the surface of the titanium alloy, and the coating is free of penetrating cracks and can contain elements such as Si. Firstly, an aluminum or aluminum alloy coating is pre-deposited on the surface of the titanium alloy, and then the diffusion aluminide coating is prepared through thermal diffusion treatment under vacuum. By adopting the method, not only is the prepared coating free of penetrating cracks, but also the formation of the cracks is inhibited in the thermal cycle process, and the high-temperature oxidation resistance of the coating is excellent.

The present invention provides a method for preparing tin or tin alloy-coated copper powder and a low-temperature conductive paste, wherein the method comprises the following steps: S10, pretreating the surface of the copper powder to remove oxides and impurities on the copper powder surface; S20, placing the pretreated copper powder in an electroplating solution containing an organic phosphine compound additive; electroplating the copper powder using tin metal or tin alloy as an anode and copper powder as a cathode, wherein the copper powder is dispersed during the electroplating process; S30, after the electroplating is completed, filtering, washing, and drying to obtain the tin or tin alloy-coated copper powder. The addition of the organic phosphine compound in the present invention greatly improves the compactness of the tin or tin alloy coating formed on the surface of the copper powder, thereby making the prepared tin-coated copper powder or tin alloy-coated copper powder have the advantage of better oxidation resistance.

The present invention provides a high-entropy alloy coating material, comprising: FeCoCrNiAl high-entropy alloy powder and yttrium powder; the weight of the yttrium powder is 0.5-1.0 wt.% of the weight of the FeCoCrNiAl high-entropy alloy powder. A method for preparing a wear-resistant coating by plasma cladding is also provided. By using the plasma cladding process with the high-entropy alloy-based coating material, a FeCoCrNiAl coating with a single BCC structure can be directly prepared on the surface of a substrate without further heat treatment, and a high-performance wear-resistant coating can be obtained while effectively reducing costs.

The invention discloses a wide-temperature-range wear-resistant high-entropy alloy coating as well as a preparation method and application thereof, and belongs to the technical field of wear-resistant materials. The wide-temperature-range wear-resistant high-entropy alloy coating comprises a high-entropy alloy bottom layer and a high-entropy alloy oxide surface layer, the high-entropy alloy in the high-entropy alloy bottom layer comprises at least four elements of Ti, Nb, Cr, Mo, V and Ta; the high-entropy alloy oxide surface layer is formed after high-entropy alloy in the surface area in the high-entropy alloy bottom layer is subjected to in-situ oxidation. The wide-temperature-range wear-resistant high-entropy alloy coating has high hardness and wide-temperature-range mechanical property stability, has excellent wear resistance and corrosion resistance in the range of room temperature to 700 DEG C, and can greatly improve the use performance and prolong the service life of a high-temperature moving part.

The invention relates to the field of coatings, and discloses a wear-resistant and corrosion-resistant high-entropy alloy composite coating and a preparation method thereof.The wear-resistant and corrosion-resistant high-entropy alloy composite coating is prepared by depositing functional high-entropy alloy composite powder on the surface of a base body in a laser cladding mode, the functional high-entropy alloy composite powder comprises high-entropy alloy powder, a modified additive and composite ceramic powder, the modified additive is prepared by using urea and titanium tetrachloride as raw materials, growing nano titanium nitride particles on the surface of a silicon carbide nanowire in situ to prepare a nano titanium nitride / silicon carbide nanowire composite material, and then coating a layer of nano titanium dioxide particles on the surface of the nano titanium nitride / silicon carbide nanowire composite material by using tetrabutyl titanate; and the composite ceramic powder is prepared by compounding zirconium carbide, niobium carbide, hafnium carbide and tantalum disilicide. The hardness, wear resistance and corrosion resistance of the high-entropy alloy coating are enhanced by adding the modified additive and the composite ceramic powder.

The invention relates to the technical field of metal material surface treatment, in particular to a preparation method of a hot galvanizing layer of a hot-rolled high-strength steel plate with high corrosion resistance. Firstly, a hot-rolled steel plate is formed after smelting, continuous casting and hot rolling; secondly, the corrosion-resistant hot-rolled high-strength steel plate is subjected to oil removal through alcohol and then put into a heat treatment furnace into which shielding gas can be introduced for hydrogen reduction; then, the corrosion-resistant hot-rolled high-strength steel plate subjected to hydrogen reduction is placed in a plating assistant agent to be soaked; then, the corrosion-resistant hot-rolled high-strength steel plate soaked with the plating assistant is soaked in a Zn-Al-Mg alloy plating solution for hot dipping; and finally, the hot-rolled high-strength steel galvanized plate obtained after hot dipping is taken out of the plating solution in the high-purity Ar protective atmosphere, and the hot-rolled high-strength steel galvanized plate is placed in a protective cover full of the high-purity Ar protective atmosphere to be naturally cooled to the room temperature. The corrosion resistance of the Zn-Al-Mg alloy coating on the surface of the hot-rolled steel plate can be effectively improved, and meanwhile, compared with other hot galvanizing technologies, the corrosion resistance is higher.

A hot-stamped coated steel part includes a steel substrate and an aluminum alloy coating comprising, proceeding from steel substrate outwards, an interdiffusion layer and an outer layer. The total thickness of the coating ecoating and the thickness of the interdiffusion layer eIDL satisfy the following condition:40≤Ep⁢c≤8⁢0withEpc=(3⁢3.3-eIDL0.9+eIDL-ecoating)2-1⁢4⁢8⁢(eIDL-ecoating)-(3⁢3.3-eIDL0.9+eIDL-ecoating)The hot-stamped coated steel part comprises an undeformed portion having a thickness ePflatfrom 0.6 mm to 3.5 mm, and at least one deformed portion. A lineic density of cracks dC in the coating in the undeformed portion is higher than or equal to a minimum lineic density of cracks dCmin(ePflat) defined as:dCmin(epflat)=1⁢5.5+9⁢1*e-7.44-2.88*arctan⁡(5.49*(epflat-1.7⁢1))-106.5*e-8.62-3.3⁢4*arctan⁡(5.49*(epflat-1.71))

The invention discloses a preparation method of a high-hardness wear-resistant coating, the high-hardness wear-resistant coating comprises FeCoCrNiMn high-entropy alloy powder and TiC powder, the TiC powder accounts for 0%-20% of the mass fraction of the FeCoCrNiMn high-entropy alloy powder, and the mechanical property and wear resistance of the coating material are effectively improved. The high-entropy alloy coating material is used for preparing a coating, and the method is specifically implemented according to the following steps that firstly, the surface of a base material is pretreated; 2, the FeCoCrNiMn high-entropy alloy powder and the TiC powder are subjected to ball milling, mixing and machining; and 3, laser power parameters and the scanning speed are set, the coating is prepared through laser cladding equipment, and the method is used for preparing the high-entropy alloy coating.

The invention belongs to the technical field of surface engineering protective coatings, and discloses a nitrogen heterocyclic compound modified corrosion-resistant high-entropy alloy coating as well as a preparation method and application thereof. The preparation method comprises the following steps that firstly, a magnetron sputtering technology is adopted, a CoCrFeMnNi target serves as a cathode target material, and a corrosion-resistant high-entropy alloy coating is obtained through deposition on the surface of a base body; and then, in a three-electrode system, the corrosion-resistant high-entropy alloy coating is placed in an electrolyte containing a nitrogen heterocyclic onium salt compound to be subjected to electro-deposition, and the nitrogen heterocyclic compound modified corrosion-resistant high-entropy alloy coating is prepared. The corrosion-resistant inorganic-organic hybrid coating prepared by the invention has excellent corrosion resistance, can keep high stability and durability in a complex corrosion environment, and has relatively high corrosion potential and relatively low corrosion current density. The coating can remarkably prolong the service life of a structural base material, is suitable for various harsh working conditions, and provides an efficient and reliable protection solution for industrial application.

The invention discloses a method for improving the quality of a laser cladding refractory high-entropy alloy coating, and belongs to the technical field of alloy coatings. The refractory high-entropy alloy coating is composed of WMoTaNb and hydride of Ti or V, the refractory high-entropy alloy coating is a single BCC phase, and the refractory high-entropy alloy coating is prepared through coaxial powder feeding laser cladding. The laser cladding refractory high-entropy alloy coating prepared through an introduction method (solid solution strengthening and in-situ deoxidation) has excellent wear resistance and high-temperature oxidation resistance, the quality and performance of the refractory high-entropy alloy coating are improved through additional powder, and the microhardness of the section of the refractory high-entropy alloy coating reaches up to 674.52 HV0. 2. The coating can be applied to the fields of aerospace, nuclear reactors and the like.

The invention discloses high-strength stainless steel for a wheel hub cover and a machining process of the high-strength stainless steel, and relates to the technical field of stainless steel machining. The specific processing technology comprises the following steps: weighing a stainless steel raw material, smelting under nitrogen pressurization, carrying out protective pouring to obtain a cast ingot, carrying out hot forging and hot rolling to obtain a hot-rolled plate, carrying out solution treatment and water quenching, sequentially carrying out multi-pass cold rolling and single-pass liquid nitrogen heat preservation cold rolling, annealing and aging treatment to obtain a stainless steel base material, and sequentially carrying out grinding, polishing, oil removal and acid activation to obtain the stainless steel plate. And then placing in an electroplating solution for electro-deposition of an alloy plating layer, cleaning after electro-deposition is finished, then carrying out laser cladding, finally carrying out heat treatment, and cutting a thin layer to obtain the high-strength stainless steel. Wherein cladding powder adopted for laser cladding comprises cobalt powder, chromium powder, nickel powder, aluminum powder, molybdenum powder, titanium powder, zirconium powder, nano carbon-nitrogen metal and tungsten carbide.

The invention provides a preparation method of a nickel-based WC alloy coating on the surface of a glass mold punch. The preparation method sequentially comprises the steps of matrix pretreatment, hypersonic flame spraying, ultrahigh-speed laser remelting and aftertreatment. The nickel-based WC alloy coating is prepared on the surface of the glass mold punch by adopting a supersonic spraying and ultra-high-speed laser remelting composite process, on one hand, a mechanical interlocking framework is formed by adopting nano-scale WC powder and micron-scale WC powder composite double-peak gradient powder, rare earth oxide is doped, nano-particle aggregation is inhibited through a vacuum ball-milling process, and the mechanical interlocking framework is formed by adopting a double-peak gradient powder composite double-peak gradient powder; the compactness of a cladding layer is improved; and on the other hand, the parameters of the composite technology are controlled, it is guaranteed that nanoscale WC is completely dissolved in a molten pool, a W-C-Fe diffusion layer is formed on an interface, a WC / W2C hard phase is separated out after micron-sized WC is partially dissolved, the bonding strength is improved, and the compactness and hardness of the coating are improved.

The invention discloses a preparation method for laser cladding of an iron-based alloy wear-resistant coating on the surface of an automobile brake disc, which comprises the following steps: (1) before cladding, putting iron-based alloy powder into a drying oven at 60 DEG C and drying for 120 minutes; (2) pretreating a matrix sample, removing rust and an oxide layer on the surface, cleaning the surface with absolute ethyl alcohol, and wiping to keep the surface dry; and (3) setting cladding process parameters, wherein the cladding process parameters comprise laser power, powder feeding amount, scanning speed, lap joint rate and scanning linear speed. And (4) a cladding experiment is started, and a cladding scanning path and mode are set, wherein the cladding scanning path and mode comprise a single-channel coating, a multi-channel lap joint coating and a whole-surface brake disc. And (5) after cladding is finished, waiting for natural cooling of the brake disc. The iron-based powder is used for preparing the coating on the surface of the automobile brake disc, technological parameters are optimized, the cladding procedure is simplified, the powder cost is low, the prepared coating is good in performance, and a single-layer coating scheme is provided for strengthening and repairing the brake disc.

The invention provides a magnesium alloy surface alloy coating performance regulation and control method based on multi-scale numerical simulation. The magnesium alloy surface alloy coating performance regulation and control method comprises the steps that S1, microscopic coordination structure and solvation structure characteristics of all metal ions in multi-metal ion liquid electrolyte are simulated and analyzed; s2, fitting a reduction reaction mechanism and kinetic parameters of solvated ions on an electrode interface under an atomic scale; s3, verifying and optimizing an electrochemical reduction path of an electrode interface; s4, obtaining an influence rule of electrode interface microenvironment evolution on the performance of the plating layer; s5, constructing a process parameter-performance mapping relation database, and reversely and dynamically optimizing the electro-deposition parameters; and S6, based on the optimized electro-deposition parameters, magnesium alloy is used as a cathode for electroplating, and a surface alloy coating which is high in bonding strength, resistant to abrasion and resistant to corrosion is obtained. According to the method, by combining atom-molecule-macroscopic multi-scale numerical simulation and machine learning, screening and performance optimization of the magnesium alloy surface coating can be rapidly and accurately achieved, and the screening period is shortened.

The invention discloses a high-entropy alloy wear-resistant coating with a silicon-containing transition layer for improving the wettability of a copper surface and a laser cladding method, and relates to the technical field of alloy coatings. The method comprises the following steps: providing silicon-containing transition layer alloy powder and CoCrFeNiTi series high-entropy alloy powder; providing a copper base material, and cleaning the surface to be cladded of the copper base material; cladding silicon-containing transition layer alloy powder on the surface of the copper base material by adopting a laser cladding process under a protective atmosphere to form a silicon-containing transition layer; and under the protective atmosphere, CoCrFeNiTi series high-entropy alloy powder is cladded on the surface of the silicon-containing transition layer through a laser cladding process, and the high-entropy alloy wear-resistant coating is formed. According to the high-entropy alloy coating disclosed by the invention, the Si element in the transition layer can be subjected to interface reaction with a copper substrate to form a Cu-Si solid solution phase with low interface energy, so that the interface tension between copper and a subsequent cladding coating is remarkably reduced, and the wettability between the copper substrate and a coating material is fundamentally improved; the high-entropy alloy coating is successfully cladded on the copper surface with poor wettability.

The invention discloses a porous high-entropy alloy structure layer for strengthening aluminum / steel heterogeneous interface connection and a selective laser melting forming method of the porous high-entropy alloy structure layer, and belongs to the field of high-entropy alloy materials. The porous high-entropy alloy structure layer comprises FeCoCrNiMn high-entropy alloy and is of a single cubic array stacking structure formed through selective laser melting. The selective laser melting forming method comprises the steps that a porous cubic structure model is designed through Majics three-dimensional software and guided into selective laser melting manufacturing equipment, a metal powder rapid forming system is started, FeCoCrNiMn high-entropy alloy powder is subjected to selective laser melting forming, and the high-strength and high-toughness high-entropy alloy coating is obtained. By effectively controlling the laser power and the three-dimensional model parameters, free energy of an alloy system is effectively reduced, formation of intermetallic compounds is inhibited, the mechanical property of aluminum / steel dissimilar metal connection is improved, and the method has wide application prospects in the aspect of aluminum / steel dissimilar metal connection.

The present invention relates to a rare earth oxide dispersion-strengthened FeCoNiCrMn high-entropy alloy coating and a preparation method thereof. The FeCoNiCrMn high-entropy alloy powder comprises: a molar fraction of Fe of 18-22%, a molar fraction of Co of 18-22%, a molar fraction of Ni of 18-22%, a molar fraction of Cr of 18-22%, and a molar fraction of Mn of 18-22%. The FeCoNiCrMn high-entropy alloy powder and rare earth oxide particles are mixed in any reasonable mass ratio. The present invention primarily increases component supercooling by adding rare earth elements, thereby increasing the internal nucleation rate of the coating and achieving grain refinement under laser cladding technology, ultimately enhancing the mechanical properties of the high-entropy alloy composite coating, including hardness, wear resistance, and corrosion resistance. When the Sm2O3 mass content is 2%, the hardness of the composite coating is the highest, which is 15.85% higher than that of the high-entropy alloy coating; with the increase of Sm2O3 mass content, the wear resistance and corrosion resistance of the composite coating tend to first increase and then decrease. When the Sm2O3 mass content is 2%, its wear resistance and corrosion resistance reach the maximum.

The invention relates to the technical field of preparation of high-entropy alloy coatings, in particular to a preparation method of a high-entropy alloy coating, which comprises the following steps: by taking a Q235 carbon steel plate as a substrate, carrying out cladding operation on a high-entropy alloy stranded welding wire only containing four components of Al, Co, Cr and Ni through laser cladding; wherein the AlCoCrFeNi high-entropy alloy coating with different Fe proportions is prepared by changing the wire feeding speed of the laser cladding. According to the method, the proportion of the Fe element of the substrate in the high-entropy alloy coating can be controlled by changing the wire feeding speed of laser cladding, the components of the coating are regulated and controlled, the high-entropy alloy coating with different mechanical properties and corrosion resistance can be prepared, the requirements of different application scenes are met, the laser fuse cladding method is adopted, and the production cost is reduced. The method has the advantages of high efficiency, accuracy and automatic operation, and avoids the problem of component deviation of the high-entropy alloy coating caused by the dilution rate.

The invention provides a gradient nano composite high-entropy alloy coating system with a self-monitoring function and a preparation method, and relates to the technical field of material surface engineering.The system comprises a functional gradient coating module used for achieving gradient dispersion distribution of nano ceramic particles on the curved surface of a shield hob so as to form a gradient nano composite high-entropy alloy coating; the fiber bragg grating sensing module is used for collecting strain data of the shield hob through a fiber bragg grating sensor integrated on the shield hob; the surface thermal image monitoring module is used for collecting temperature data and image data of the surface of the shield hob through an infrared thermal imager; and the self-adaptive repairing module is used for determining repairing parameters of the shield hob and generating a repairing instruction, so that self-adaptive repairing is carried out on the shield hob through preset repairing equipment according to the repairing instruction. According to the invention, the sensor network is successfully integrated in the gradient coating, and integrated fusion of structural health monitoring and protection functions is realized.

The invention provides a preparation method of a hard nitride ceramic coating on the surface of a magnesium alloy, and belongs to the technical field of magnesium alloy coatings. According to the method, intermittent plasma flow is formed by controlling intermittent discharge of a cathode target in the PVD process, heat accumulation generated by continuous bombardment of matrix-coating interface ions is reduced by regulating and controlling the discharge / arc extinguishing period of the target, so that thermal expansion of the matrix-coating interface is reduced, and the thermal conductivity of the matrix-coating interface is improved. And growth defects (pores and cracks) caused by thermal expansion difference between the nitride ceramic coating and the substrate are reduced, and the method has a good industrial application prospect.

The present disclosure provides a high-pressure and multi-atmosphere assisted SLM gradient material preparation method and an aluminum-lithium alloy coating. The high-pressure and multi-atmosphere assisted SLM gradient material preparation method includes the following steps: injecting a first gas mixture into a working box, and enabling, by laser irradiation, molten materials in a micro-melt pool to react with a carbon-containing gas to form a carbide-doped first gradient aluminum-lithium alloy coating; injecting a second gas mixture into the working box, and enabling, by laser irradiation, molten materials in a micro-melt pool to react with a carbon and nitrogen-containing gas to form a carbide and nitride-doped second gradient aluminum-lithium alloy coating; and injecting a third gas mixture into the working box, and enabling, by laser irradiation, molten materials in a micro-melt pool to react with a nitrogen-containing gas to form a nitride-doped third gradient aluminum-lithium alloy coating. The present disclosure improves the surface forming quality of an aluminum-lithium alloy material, and the material is hard outside and tough inside.

The invention discloses a high-wear-resistance hard alloy CVD (Chemical Vapor Deposition) coated cutting tool and a preparation method thereof, WC-Co (4-8) Ti (1-5) Ta (1-5) Nb (0.2-2) Cr (0.2-2) Fe (0.2-2) Al (0.2-2) is used as a blade substrate, TiN, TiCN, Al2O3 and a surface TiN coating are deposited firstly, and then the coated blade is subjected to subzero treatment and tempering treatment. According to the method, through subzero treatment between the base body and the coating, the compressive stress is introduced into the coating or an interface by utilizing the difference of the extremely low temperature shrinkage rates of the coating and the base body, the tensile stress caused by the compressive stress neutralization deposition is utilized, and the uniform distribution of nanoscale carbide precipitates is promoted by utilizing a proper tempering process; and the cold brittleness phenomenon caused by subzero treatment and the generated high residual compressive stress are avoided, and the abrasion resistance and the anti-stripping capacity of the base body are further improved. According to the method, the driving effect of residual tensile stress in the CVD coating on crack initiation is reduced, the crack density is greatly reduced, the mechanical property of a hard alloy matrix and the stress state of the coating are synergistically improved, and the mechanical property of the cutter is enhanced.

The application discloses a nodular cast iron pipe with a composite coating and belongs to the technical field of metal corrosion prevention, comprising a nodular cast iron pipe base body, a composite outer coating coated on the outer surface of the nodular cast iron pipe base body and an inner coating closely attached to the inner surface of the nodular cast iron pipe base body, characterized in that the composite outer coating comprises an alkali-activated gel layer and a zinc-based coating, the zinc-based coating is arranged between the outer surface of the nodular cast iron pipe base body and the alkali-activated gel layer, the alkali-activated gel layer is an alkali-activated slag fly ash corrosion-resistant gel material, and the zinc-based coating is one or more of a pure zinc coating, a zinc-aluminum alloy coating or a zinc-rich coating layer. The alkali-activated gel layer provided by the application is coated on the inner or outer surface of the pipe and provides further corrosion protection for the nodular cast iron pipe, so that the pipe can be used in extremely harsh construction environments, and has extremely strong weather resistance in acidic soil and overhead fields.

The invention discloses a high-entropy alloy coating and a preparation method thereof, and relates to the technical field of preparation of high-entropy alloy coatings. The high-entropy alloy and the coating of the high-entropy alloy do not contain silicon elements, and the preparation method comprises the steps that according to the composition proportion of the high-entropy alloy, a magnetron sputtering technology is adopted, metal elementary substance targets of all components serve as sputtering target materials for sputtering, elementary substance films are sequentially deposited on a base body, and a multi-layer film precursor is formed; and then the multi-layer film precursor is subjected to vacuum annealing, so that the single-layer uniform high-entropy alloy coating is obtained. According to the method, accurate preparation of the multi-layer film precursor can be achieved by accurately controlling the sputtering rate or sputtering power of all elements, then the elements in the multi-layer film precursor are fully mixed through vacuum annealing treatment, and the uniform high-entropy alloy coating is formed. The high-entropy alloy coating prepared by the process, such as an AlCoCrFeNi high-entropy alloy coating, has excellent structural uniformity, and is suitable for the high and new technical fields of aerospace, energy engineering and the like.

The present application relates to a kind of high-entropy alloy coating for hydrogen blocking and preparation method thereof, belong to and hydrogen pipeline hydrogen damage prevention technical field.The high-entropy alloy coating includes Al, Fe, Cr, Mo, Ti and Pd, and the mass ratio of the total mass of Al, Fe, Cr, Mo and Ti to the mass of Pd is 1-x:x, wherein, 0≤x≤1.The high-entropy alloy target material is obtained by virtue of electric arc smelting advantage, and the high-entropy alloy coating is obtained on the surface of pretreated substrate by magnetron sputtering.The corrosion resistance of high-entropy alloy, the good hydrogen blocking characteristics of alloy formed by Al, Fe, Cr and other elements, and the advantages of Pd in hydrogen storage are perfectly combined to further improve the hydrogen blocking performance of the coating.The high-entropy alloy coating prepared by the method is controllable in composition and performance, and the coating has strong adhesion to the substrate, thereby achieving good hydrogen blocking effect, and the coating prepared by the process is controllable in thickness, which is convenient for performance regulation and testing.

The invention relates to the technical field of thermal spraying and surface nitriding, in particular to a high-thermal-conductivity wear-resistant hot-corrosion-resistant high-entropy alloy coating with a multi-layer structure and a preparation method thereof, and the high-thermal-conductivity wear-resistant hot-corrosion-resistant high-entropy alloy coating comprises a first NiCr bonding layer, a second AlCoCrNiMo high-entropy alloy transition layer, a third AlCoCrNiMoBSi high-entropy alloy functional layer and a fourth nitriding modification layer. According to the method, the high-entropy alloy powder is prepared through step-by-step mechanical alloying and solid solution-aging treatment, and compared with a traditional method, the preparation process is remarkably simplified. Based on the inherent wear resistance and thermal corrosion resistance of the high-entropy alloy, a coating system with a gradient function is prepared by adopting an oxygen-kerosene supersonic flame spraying technology, and then a nitriding modified layer is formed through nitriding treatment. According to the multi-layer structural design, good transition and bonding strength between layers are achieved, meanwhile, excellent heat conduction performance is achieved, and the abrasion resistance and the heat corrosion resistance of the coating are remarkably improved.