74 results about "Laves phase" patented technology

The invention provides a preparation method of a high-temperature wear-resistant high-entropy alloy layer with a heterostructure, and belongs to the technical field of metal materials and surface engineering thereof. According to the method, a CoCrFeNiTi high-entropy alloy cladding layer is deposited on the surface of a base body through the laser cladding technology, and the thickness of the cladding layer is controlled to be 0.5-2 mm. The component of the cladding layer is CoCrFeNiTi, the atomic ratio content of Ti is controlled not to exceed 8%, so that the structure of the cladding layer is an FCC phase, and cracking of the cladding layer induced by precipitation of a BCC phase is avoided. A high-entropy alloy cladding layer is heated to 550-950 DEG C and subjected to heat preservation for 2-4 h for annealing treatment, alloy elements in the cladding layer are promoted to be separated out, and small heterogeneous strengthening phases such as a Ni3Ti phase and a laves phase are generated in situ. According to the method, a heterogeneous strengthening structure is formed under the condition of not adding exogenous elements, the strength and hardness and high-temperature wear resistance of the cladding layer are greatly enhanced, the method has the advantages of being simple in process, low in cost, high in applicability and the like, and an effective technical scheme is provided for repairing and remanufacturing of the high-entropy alloy.

The invention discloses a method for improving gap sensitivity of GH2909 alloy and an alloy part, and relates to the technical field of aero-engine production, in particular to the method for improving gap sensitivity of GH2909 alloy and the alloy part, and the method comprises the following steps: carrying out solution treatment on a GH290 alloy sample at a selected temperature, and determining the heat preservation time according to the section thickness; after solution treatment and heat preservation are finished, a GH290 alloy sample is firstly subjected to furnace cooling, and a Laves phase is promoted to be evenly and dispersedly separated out in a short rod shape along a grain boundary; then discharging and air-cooling to room temperature, and then carrying out standard aging treatment; the alloy sample is a GH2909 alloy sample. According to the method disclosed by the invention, through a mode of controlled cooling and heating treatment, the intergranular dispersion precipitation behavior of a Laves phase can be promoted, so that the notch sensitivity of the GH2909 alloy is improved, and the endurance life of the alloy is prolonged.

The invention discloses an oscillation laser directional energy deposition core-shell type heterogeneous CoCrAlY coating and a method, the oscillation laser directional energy deposition core-shell type heterogeneous CoCrAlY coating comprises a plurality of cladding layers which are sequentially stacked from bottom to top, each cladding layer is formed by sequentially stacking a plurality of alloy channels in the direction perpendicular to the stacking direction of the cladding layers, each alloy is of a heterostructure formed by a gamma-Co phase; the heterostructure comprises a beta-CoAl phase and a Laves phase, the Laves phase wraps the beta-CoAl phase to form a core-beta / shell-Laves structure, and the core-beta / shell-Laves structure is dispersed and distributed in the gamma-Co phase; and the Laves phase is CrMoSi4, and the Laves phase is CrMoSi4. According to the core-shell type heterogeneous CoCrAlY coating, due to the unique core-beta / shell-Laves structure, compared with a traditional CoCrAlY coating, the hardness is improved by 1.5-2 times, the oxidation weight gain is reduced by 60% or above, and the service temperature can be improved by 100 DEG C and reaches 1100 DEG C.

The invention discloses a preparation method and application of a Co-Ni-C-based high-temperature alloy material. The preparation method comprises the following steps that S1, raw materials are prepared according to the proportion; s2, the other raw materials except TiC, Co and Ni are sequentially placed in a smelting furnace from high melting point to low melting point to be smelted, the raw materials with the low melting point are placed at the bottom, TiC is placed at the bottoms of all the raw materials, and Co and Ni are placed at the topmost part; smelting to obtain an alloy ingot; s3, the obtained alloy cast ingot is ground and polished, and an oxide layer is removed; and S4, the alloy ingot is packaged in a quartz tube for heat treatment. According to the preparation method of the Co-Ni-C-based high-temperature alloy material, the mechanical property and the high-temperature oxidation resistance of the Co-Al-V system high-temperature alloy are improved, the hardness of the alloy can be improved by increasing the C element, the strength of the alloy can be improved by the Laves phase dispersed and distributed at the grain boundary after the alloy is subjected to solid solution aging treatment, the structure of the alloy is refined by the C element, and the mechanical property of the Co-Ni-C-based high-temperature alloy material is improved. And the mechanical property is improved.

This invention belongs to the field of laser surface engineering and metal matrix composite technology, and provides a Ti / Nb microalloyed Inconel 625 toughening coating, its composite powder, and preparation method. The composite powder is composed of gas-atomized Inconel 625 alloy powder, titanium powder, and niobium powder, with a Ti to Nb mass ratio of (0.8–1.2):1 and a total addition amount of 0.8–1.5 wt%. A dual-laser cladding process is employed. An initial coating is first formed by laser cladding in an inert atmosphere, followed by in-situ pulsed laser shock blasting when cooled to 900–1000℃. After slow cooling, a toughened coating is obtained. The resulting coating contains 10–20 nm dispersed Ni3(Nb,Ti) composite γ-rays. , The coating contains no Ni2(Nb,Si) Laves phase. It exhibits both high strength and high toughness, along with excellent high-temperature stability.

The application discloses a high-compression-strength high-plasticity iron-based alloy and a preparation method and application thereof, and relates to the technical field of high-performance metal structural materials.The application provides an element composition of the high-compression-strength high-plasticity iron-based alloy; the microstructure of the alloy comprises a Fe2Nb Laves phase network structure distributed along grain boundaries and an intracrystalline nanometer-scale composition modulation structure; the room-temperature compression yield strength of the high-compression-strength high-plasticity iron-based alloy is not less than 2000 MPa, and the compression fracture strain is not less than 30%. The application further provides a preparation method and application of the alloy. The application forms a multi-level micro-nano strengthening structure in-situ in an alloy block through a specific non-equilibrium solidification process, so that the alloy simultaneously has ultrahigh strength and high plasticity under compression load, and can be applied to high-pressure-resistant structural parts, and effectively solves problems of a complicated preparation process of traditional high-strength materials, high strength necessarily accompanied by low plasticity and the like.

The invention discloses a rare earth-nickel-based AB2 type hydrogen storage alloy material and a preparation method thereof, and relates to the field of solid hydrogen storage materials, the alloy comprises rare earth elements La, Ce and Sc and transition metals Ni, Mn, Al and Zr according to a specific proportion, the raw materials are melted through electric arc melting and are subjected to alloying reaction to form a master alloy ingot, and the master alloy ingot is subjected to high-temperature sintering to obtain the rare earth-nickel-based AB2 type hydrogen storage alloy material. Non-equilibrium solidification is achieved through single-roller rapid quenching, a thin strip of a metastable-state structure is obtained, grain arrangement and second-phase precipitation are regulated and controlled through gradient annealing, finally, a surface oxide layer is removed through crushing and acid etching, and hydrogen storage alloy powder is obtained through vacuum drying. An AB2 type Laves phase main body structure is formed through multi-element rare earth solid solution, grain coarsening is inhibited by combining a rapid quenching process, a microstructure is optimized through gradient annealing, the hydrogen storage capacity, hydrogen absorption dynamic performance and cycling stability of the alloy are synergistically improved, and the alloy is suitable for preparation and application of an efficient hydrogen storage material.

This invention discloses a high-boron Y–Ce–Co co-substituted nanocrystalline material and its preparation method. The general chemical formula of the nanocrystalline material, expressed as a percentage by mass, is: [RE x (Y y Ce 1‑y ) 1‑x ] z Fe 100‑z‑u‑v‑w Co u M v B w The composition is defined as follows: 0 ≤ x ≤ 0.9, 0.05 ≤ y ≤ 0.9, 25 ≤ z ≤ 35, 5 ≤ u ≤ 50, 0 ≤ v ≤ 3, 1.7 ≤ w ≤ 3. This invention utilizes Y–Ce–Co co-substitution to synergistically regulate the lattice occupancy, elemental valence states, and magnetic exchange interactions of the main phase, significantly improving the temperature stability of the Ce-rich system. Addressing the issues of abnormal grain growth and excessive Laves phase precipitation caused by Co introduction, increasing the mass percentage of B significantly enhances the alloy's amorphous forming ability, refines the main phase grains, and suppresses the formation of harmful second phases. Based on this compositional design, a low-linear-velocity melt rapid quenching process (12 to 18 m / s) can directly prepare materials with uniform nanocrystalline structures without subsequent crystallization annealing, achieving high coercivity and high temperature resistance while significantly reducing raw material costs.

Gas sensor (1), comprising: a housing (2) with a receiving hole (21); a sensor element (3) comprising a solid electrolyte (31) and electrodes (32A, 32B) located on both sides of the solid electrolyte (31), wherein the sensor element (3) is inserted into the receiving hole (21) alone or via an insulator (4); and a sealing element (51) formed from a ceramic powder, which fills a gap (S1) between the receiving hole (21) and the sensor element (3) or the insulator (4), and wherein the sealing element (51) is compressed by a part of the housing (2) so that the gap (S1) is sealed, and wherein The material of which the casing (2) is made is ferritic stainless steel which, based on mass, contains 15 to 25% Cr, 0.01 to 1.0% Nb, 0.5 to 4% of at least one of the elements W and Mo alone or in combination and the following remainder: Fe and unavoidable impurities including C, N, Mn and Si, where: after heating the material forming the casing (2) to a heat treatment temperature of 850°C or more, the Laves phase of Fe2W or Fe2W and Fe2Mo is formed as intermetallic compounds in a mother phase of the casing (2), and a quantity of Laves phase excreted into the mother phase of the shell (2) is less than 0.1 mass percent.

The invention relates to the technical field of novel hydrogen storage alloys, and discloses a high-performance A1 + mB2-m type titanium-manganese-based hydrogen storage alloy and a preparation method thereof, the chemical general formula of the hydrogen storage alloy is Ti < 1 + a-x > Zr Mn < c > Cr < 2-a-b-c > Fe < x >, a < lt >; 0.2 part; 0 lt; blt; 0.1 part; 1.0 lt; clt; ct; 1.7, 1.7; 0 < = xlt; and 0.2 part. The preparation method comprises the following steps: carrying out vacuum high-temperature short-time heat treatment on as-cast alloy, and naturally cooling along with a furnace. The invention designs a vacuum high-temperature short-time heat treatment process, so that the A1 + mB2-m type titanium-manganese-based alloy is converted into a single Laves phase from an as-cast multiphase structure, and the platform characteristics are remarkably improved. Compared with an as-cast alloy, the platform slope of the annealed alloy can be reduced to 0.33, and the hysteresis coefficient is only 0.06. In addition, by partially replacing A-side Ti with a B-side element Fe and combining a specific vacuum high-temperature short-time heat treatment process, the alloy keeps a single Laves phase structure, and the reversible hydrogen storage capacity and the hydrogen desorption rate are remarkably improved. The problems that an existing titanium-manganese-based hydrogen storage alloy is poor in platform characteristic, low in reversible capacity, complex in process and the like are solved, and the titanium-manganese-based hydrogen storage alloy has the large-scale application potential.

The invention discloses a cavitation-erosion-resistant medium-entropy alloy coating as well as a preparation method and application thereof, and belongs to the technical field of functional alloys and surface strengthening materials. The chemical formula of the cavitation-erosion-resistant medium-entropy alloy coating is CoCrNiNbx, x ranges from 0.6 to 1.0, and the atomic ratio of the coating ranges from 0.6 to 1.0. Under a phase change mechanism triggered by Nb regulation and control, the cavitation-erosion-resistant medium-entropy alloy coating with an FCC + Laves double-phase structure is obtained through accurate control over the Nb content, balance of strength and toughness is achieved, the FCC + niobium-rich Laves phase is continuously distributed in the cavitation-erosion-resistant medium-entropy alloy coating, impact loads are effectively dispersed, crack propagation is blocked, and the cavitation-erosion-resistant performance of the coating is greatly improved. In an ultrasonic cavitation experiment, the cumulative mass loss of a cavitation-resistant medium-entropy alloy coating sample with x equal to 1.0 is only 2.8 mg, the average loss rate is 0.2333 mg / h, the cumulative mass loss is increased by about 26 times compared with that of a 316L matrix, and the average loss rate is increased by about 20 times compared with that of a sample without Nb.

The invention relates to the technical field of high-performance iron alloys, in particular to high-temperature-resistant and corrosion-resistant low-density steel and a preparation method thereof.The high-temperature-resistant and corrosion-resistant low-density steel is prepared from, by weight, 55%-65% of iron, 15%-20% of manganese, 8%-12% of aluminum, 0.8%-1.5% of carbon, 1.0%-2.5% of niobium, 0.5%-1.5% of molybdenum, 3.0%-5.0% of chromium and the balance trace elements and impurities. According to the method, the target Laves phase structural features are fused into initial parameter calculation, the surface temperature, rolling force and gray pixel data of the steel plate are collected in real time during rolling, the model is input to predict the Laves phase structural features, and the average particle size and the grain boundary density deviation value of the target features are accurately calculated; and the frequency and the cooling rate of the alternating stress field are dynamically and iteratively optimized and adjusted, so that the Laves phase structure of the iron-based material is accurately formed and finely regulated and controlled, the overall performance stability and reliability of the material are effectively improved, the excellent performance in an extreme environment is ensured, and the application potential of the material is fully explored.

The present application belongs to the technical field of high-temperature alloy smelting production, and particularly relates to a method for improving the as-cast solidification quality of Inconel718 high-temperature alloy and an alloy ingot thereof. The method comprises: short-time ultrahigh-temperature treatment of completely melted alloy at 1550-1600 DEG C and falling back to pouring temperature to realize melt purification and activation; then, a nickel-magnesium-molybdenum intermediate alloy with specific components is put in, and the magnesium content is accurately controlled in the range of 0.0040%-0.080%; finally, stepwise treatment of rapid cooling and isothermal holding is carried out in the critical temperature range of 1350-1380 DEG C. Through the synergistic effect of physical purification, chemical alloying and solidification control, the primary dendrite arm spacing is significantly refined, the Laves phase and MC carbide are in fine granular and dispersed distribution, and the as-cast structure uniformity is fundamentally improved, thereby providing a reliable solution for obtaining high-performance Inconel718 alloy ingot.

The invention provides a Ti / B regulated and controlled FeCoCrNi-based wear-resistant high-entropy alloy and a preparation method thereof. Ti and B are accurately proportioned in a (FeCoCrNi) 100-3xTixB2x (x is greater than or equal to 1.5 and less than or equal to 2.5 at.%) system, vacuum electric arc melting is adopted, heat treatment is performed at 700-800 DEG C for 0.5-1.5 h, quenching is performed, and a dispersed TiB2 strengthening phase and a Cr-rich Laves phase are formed in situ. The addition proportion of Ti / B is optimized to realize grain refinement and inter-phase synergistic toughening, the room temperature friction coefficient is about 0.62, the minimum wear volume is about 0.326 mm < 3 >, and the wear mechanism is oxidation and abrasive particle synergistic wear. And by regulating and controlling the Ti / B ratio and heat treatment parameters, excessive aggregation and brittle spalling of the Laves phase are inhibited, so that the wear resistance and mechanical stability of the material are remarkably improved, and the method is suitable for design and preparation of engineering component materials in a high-load wear-resistant environment.

The invention relates to the technical field of metal material processing, in particular to a manufacturing process of an In625 forge piece with a high energy absorption characteristic, which comprises the following steps: preparing the following components in percentage by weight: 20.0-23.0% of Cr, 8.0-10.0% of Mo and the like, and the balance of Ni, preparing a master alloy ingot by a VIM + ESR duplex process, homogenizing at 1180-1220 DEG C, performing multidirectional forging, and performing solid solution, supersonic particle bombardment, aging and cryogenic circulation treatment on the forge piece to obtain the In625 forge piece with the high energy absorption characteristic. And a 50-200nm nanoscale Laves phase reinforcement is formed, so that the energy absorption capability is improved. According to the method, through cooperative regulation and control of a multi-field coupling process and microelements, gradient nanocrystalline layers and high-density dislocation entanglement are formed on the In625 forge piece, and nano Laves phase strengthening bodies are evenly distributed; the corrosion resistance and fatigue resistance are remarkably improved, the process energy consumption is reduced, the material utilization rate is increased, and the extreme working condition requirements are met.

Provided is an alloy material in which coarse growth or aggregation and precipitation of an undesired intermetallic compound phase can be suppressed, an alloy product formed of the alloy material, and a mechanical device including the alloy product. The alloy material according to the present invention includes: 5 at % or more and 40 at % or less of each of Co, Cr, Fe, and Ni; more than 0 at % and 8 at % or less of Mo; 1 at % or more and less than 8 at % of Ti; more than 0 at % and 4 at % or less of at least one kind of Ta or Nb; and a remainder consisting of unavoidable impurities, in which a total content of Ti and the at least one kind of Ta or Nb is 3 at % or more and 8 at % or less. In the alloy product formed of the alloy material, a total occupancy of η phase and Laves phase precipitates having a size of 1 μm or more is suppressed to be 5 area % or less.

The invention discloses a double-scale heterostructure continuous precipitation strengthening type high-entropy alloy and belongs to the technical field of high-entropy alloys, the double-scale heterostructure continuous precipitation strengthening type high-entropy alloy comprises Al, Fe, Ni, Cr, Cu and Ti, the expression of the components of the double-scale heterostructure continuous precipitation strengthening type high-entropy alloy is Al < x > Fe < Ni > Cr < Cu > Ti < 2-x >, and x is 0.5-1.5; the microstructure of the double-scale heterostructure continuous precipitation strengthening type high-entropy alloy comprises a B2 matrix, an FCC phase, a Laves phase and a precipitation phase, and the technical problem that existing precipitation strengthening type high-entropy alloy is mostly concentrated in a single strengthening phase, and consequently the alloy strength and plasticity matching performance is poor is solved.

The invention relates to the field of high-entropy alloy material manufacturing and processing, and discloses a NiFeCrCoNbAl series high-entropy alloy hot working process which comprises the following steps: preparing a high-entropy alloy: taking Ni, Fe, Cr, Co, Al and Nb metals with the purity of 99.9 wt% as raw materials, carrying out weight balancing according to the atomic ratio and the mass ratio of elements required by the high-entropy alloy, smelting by utilizing vacuum smelting equipment, and carrying out hot pressing to obtain the high-entropy alloy. And remelting an alloy ingot obtained by smelting for three times, and casting into an alloy cast ingot. According to the method, through the synergistic effect of solution treatment, aging treatment and hot isostatic pressing treatment, a three-phase structure in an as-cast alloy is successfully optimized into a complete gamma (FCC) + BCC two-phase structure, hot isostatic pressing treatment promotes an HCP phase to be completely decomposed into a gamma phase and a BCC phase, unrecognized complex phases possibly existing after aging treatment are eliminated, and the mechanical property of the alloy is improved. The adverse effects of brittle harmful phases such as a sigma phase and a Laves phase HCP on the plasticity and toughness of the alloy are effectively avoided.

The invention belongs to the technical field of new materials, and particularly relates to a Laves phase composite material for thermomagnetic power generation and preparation and application thereof.According to the preparation method, Ta and Nb elements are introduced into a Laves phase intermetallic compound firstly, hexagonal-phase Hf0. 9R0. 1Fe2 is synthesized, R is Ta and / or Nb, so that the Laves phase intermetallic compound has the magnetic phase change characteristic at the room temperature, then tetragonal-phase In is introduced, and the two-phase composite material is constructed; wherein the Hf0. 9R0. 1Fe2 phase shows room-temperature ferromagnetism, the tetragonal phase In provides excellent thermal conductivity, and the excellent thermomagnetic power generation Laves phase composite material is obtained by adjusting the components of the two phases. According to the Laves phase composite material for thermomagnetic power generation prepared by the invention, a room-temperature ferromagnetic / high-thermal-conductivity heterostructure is constructed, the preparation process is simple, an excellent induced voltage value is realized through a two-step method, and the series of materials are expected to be used in the field of thermomagnetic power generation.

The application discloses an oscillation laser directional energy deposition core-shell type heterogeneous CoCrAlY coating and a method, and the oscillation laser directional energy deposition core-shell type heterogeneous CoCrAlY coating comprises a plurality of cladding layers stacked from bottom to top, each cladding layer is formed by a plurality of alloy tracks stacked in a direction perpendicular to the stacking direction of the cladding layer, and each alloy track is a heterogeneous structure composed of a gamma-Co phase; the heterogeneous structure comprises a beta-CoAl phase and a Laves phase, the Laves phase wraps the beta-CoAl phase to form a core-beta / shell-Laves structure, and the core-beta / shell-Laves structure is dispersedly distributed in the gamma-Co phase; and the Laves phase is CrMoSi4. The core-shell type heterogeneous CoCrAlY coating provided by the application has a core-beta / shell-Laves structure, and the hardness of the core-shell type heterogeneous CoCrAlY coating is 1.5 to 2 times higher than that of a conventional CoCrAlY coating, the oxidation weight gain is reduced by more than 60%, the service temperature can be increased by 100 DEG C, and the service temperature reaches 1100 DEG C.

The invention discloses preparation and application of a Laves phase intermetallic compound with high strength and low expansion. The chemical formula of the high-strength low-expansion Laves phase intermetallic compound is (Zr0. 65Nb0. 35) Fe2Bx, x is larger than or equal to 0.05 and smaller than or equal to 0.2, the crystal structure is a cubic system, the space group is Fd-3m, Zr and Nb occupy 8a (0, 0, 0) sites, and Fe occupies 16d (5 / 8, 5 / 8 and 5 / 8) sites. And the Curie temperature reaches 370K. The element B is introduced into the (Zr, Nb) Fe2 ternary metal, a low-expansion temperature zone is effectively widened, the thermal expansion behavior is regulated and controlled, and the obtained high-strength low-expansion Laves phase intermetallic compound has excellent thermal stability and high precision, has the remarkable characteristics that the shape and the size are not influenced by temperature change, and is suitable for large-scale production. The constant length / volume, namely low thermal expansion characteristic, in a specific temperature interval range is realized.

The invention relates to a method for regulating and controlling the Laves phase morphology in the solidification process of a high-temperature alloy melt and a product. The method comprises the following steps: putting a high-temperature alloy raw material into a crucible, and carrying out heating and heat preservation I in a resistance furnace to obtain a melt; continuously keeping the temperature of the melt, adding a Ce-Fe alloy raw material wrapped by nickel foil, and stirring; inserting two parallel graphite electrodes with pulse current into the melt, and preheating for a period of time; setting pulse voltage, pulse current and pulse frequency parameters according to the Ce content of the Ce-Fe alloy added in the high-temperature alloy, and applying 10-60 min electric pulse treatment to the melt for a period of time in the heat preservation stage; and closing the resistance furnace and the pulse power supply after the treatment is finished, and cooling the obtained sample along with the furnace. According to the method for regulating and controlling the Laves phase form in the solidification process of the high-temperature alloy melt through the cooperation of the pulse current and the rare earth Ce, the Laves phase form can be regulated and controlled in the smelting and solidification process of the high-temperature alloy, and purification of the high-temperature alloy melt is achieved.

The invention discloses a characterization and evaluation method for macrosegregation of alloy elements in ferritic stainless steel, which comprises the following steps: selecting a proper heat treatment process according to a Laves phase solid solution temperature calculated by thermodynamic software, and carrying out heat treatment on a ferritic stainless steel plate; determining whether a banded structure, namely macrosegregation, exists or not through a metallographic microscope; and an electronic probe is adopted to test the segregation degree of alloy elements in the ferritic stainless steel. The method is simple and easy to implement, and has definite guiding significance on the actual service behavior of the ferritic stainless steel in the high-temperature field.

The application provides a method for regulating Laves phase of additive manufacturing nickel-based superalloy, relates to the technical field of composite additive manufacturing of metal materials, and can regulate the size and content of the Laves phase by changing the interlayer deformation and additive manufacturing heat input, so that a nickel-based superalloy forming part with more excellent mechanical properties can be obtained.

The application provides a kind of corrosion-controllable atmosphere modification-heat treatment synergistic GH4169 alloy Laves phase accurate display method, comprising: sample targeted corrosion: after sample is polished, it is immersed in targeted corrosion agent and corroded, sample presents light gray, stop and blow dry when;Controllable atmosphere oxidation interface modification: sample is placed in controllable atmosphere tube furnace, high-purity argon is used as carrier gas in furnace, high-purity oxygen is doped, temperature is raised to 300-350 DEG C and then kept, temperature is reduced to room temperature after keeping, sample is taken out and washed and then blown dry;Ladder type temperature difference differential dyeing: the following processing is carried out in box furnace: temperature is raised to 340 DEG C and kept, temperature is raised to 440 DEG C and kept, temperature is raised to 480 DEG C and kept, temperature is kept, and then temperature is quickly reduced to 200 DEG C and kept, then air cooling to room temperature with furnace, then sample is washed;Microscope observation: magnification observation is carried out using optical microscope, Laves phase, matrix, NbC carbide and other alloy precipitated phase are identified.The application realizes Laves phase display with high phase distinction, strong reproducibility and full-size accurate identification.

This invention discloses a method for detecting the volume fraction of W-containing Laves phase in a sample, belonging to the field of metallic material testing technology. This invention provides a method for intuitively detecting the volume fraction of W-containing Laves phase in steel. The laser-clad sample containing the W-containing Laves phase undergoes surface pretreatment to remove surface oxide scale and processing burrs. Ultrasonic cleaning thoroughly removes residual oil, wear debris, and other impurities from the sample surface. High-temperature heat treatment makes the previously difficult-to-distinguish W-containing Laves phase clearly visible. Fine processing of the detection surface ensures a smooth and flat surface, providing a clear observation interface for microscopic morphology observation and compositional analysis. After sample characterization, EDS energy dispersive spectroscopy is used to obtain elemental distribution characteristics. Quantitative calculations are performed on the unoxidized areas of the sample to obtain the volume fraction of the W-containing Laves phase. This provides important data support for material composition design, heat treatment process optimization, service life assessment, failure analysis, and mechanism analysis.

The invention belongs to the field of application of high-entropy alloy in catalysis and hydrogen storage materials, and particularly relates to a carbon-coated high-entropy alloy composite material and a preparation method and application thereof.The molecular formula of the carbon-coated high-entropy alloy composite material is Ti < 0.5 > Zr < 0.5 > V < 0.2 > Mn < 0.2 > Cr < 0.4 > Fe < x > Ni < 1.2-x (at) C, x is equal to 0.2-1.0, and the specific surface area is 14.9064 m < 2 > / g. According to the composite material, precursor alloy obtained after electric arc melting is subjected to ball milling and refining into high-entropy powder, and the high-entropy powder is obtained. And then glucose is used as a carbon source, hydrothermal carbonization is carried out in a reaction kettle, calcination is carried out in an argon atmosphere, and the carbon-coated high-entropy alloy composite material can be obtained. According to the preparation method, a multi-element synergistic effect and Fe / Ni proportion regulation are combined with a carbon coating layer with a unique morphology to construct a multifunctional system integrating efficient electro-catalysis oxygen evolution and rapid hydrogen storage, so that the problems of element segregation and dissolution of an electro-catalysis material in a long-time reaction process are effectively inhibited while the alloy intrinsic performance of the alloy material is maintained, and the service life of the electro-catalysis material is prolonged. And meanwhile, the conductivity of the material is improved, the diffusion energy barrier of hydrogen in the Laves phase is reduced through the carbon defect on the surface layer, and the hydrogen storage dynamic performance can be improved.

The invention provides a treatment method for optimizing the grain boundary of a nickel-based high-temperature alloy, which comprises the following steps: carrying out pulse current treatment on the nickel-based high-temperature alloy, so that the proportion of the sigma 3 grain boundary in the treated nickel-based high-temperature alloy is greater than 50%. According to the method, annealing twin crystals are promoted to be formed through pulse current treatment, then more sigma 3 grain boundaries are formed, and the sigma 3 grain boundaries have low interface energy and high crack initiation and propagation resistance, so that the plasticity of the nickel-based high-temperature alloy can be improved, and the service life of the alloy is remarkably prolonged; on one hand, the pulse current can quickly eliminate Laves phases in the alloy, reduce element segregation and reduce stacking fault energy (SFE) of an alloy matrix, and creates favorable conditions for annealing twin crystal formation; and on the other hand, the Joule heating effect of the pulse current can improve the temperature of the alloy, reduce the grain boundary atomic diffusion barrier, increase the grain boundary mobility, effectively promote recrystallization nucleation and facilitate annealing twin crystal formation.

The invention belongs to the technical field of alloy materials, and particularly relates to a refractory multi-element main alloy and a preparation method and application thereof. The refractory multi-element main alloy provided by the invention comprises Ti, Zr, Ta and Ni, wherein the atomic percentage content of Ni in the refractory multi-element main alloy is 0-25%; the atomic ratio of Ti to Zr is (0.8-1.2): (0.8-1.2), and the atomic ratio of Ti to Ta is (0.8-1.2): (0.8-1.2). Ti, Zr and Ta are all high-melting-point metals, a BCC solid solution phase with a high entropy value can be formed, and excellent high-temperature stability and softening resistance are achieved; and meanwhile, by introducing 0-25 at.% of adjustable Ni element, a dispersed Laves phase is formed in a solid solution matrix, the precipitation strengthening effect is achieved, and the hardness and high-temperature strength of the alloy are remarkably improved. The refractory multi-element main alloy provided by the invention shows the characteristic of low wear rate in the range of 25-600 DEG C.

The invention belongs to the technical field of high-entropy alloy brazing filler metal, and particularly relates to low-liquidus-temperature Ti-Zr-Nb-Ni high-entropy alloy brazing filler metal and a preparation method thereof.The high-entropy alloy brazing filler metal is of an amorphous structure or an amorphous / nanocrystalline structure and comprises, by atomic percent, 30%-40% of Ti, 20%-25% of Zr, 20%-25% of Nb and 20%-25% of Ni or comprises, by atomic percent, 20%-25% of Ti, 30%-40% of Zr, 20%-25% of Nb and 20%-25% of Ni. The high-entropy alloy brazing filler metal has low liquidus temperature (870-939 DEG C) and good amorphous forming ability, a Ti2AlNb joint brazed by the high-entropy alloy brazing filler metal is mainly composed of a beta-(Ti, Nb) solid solution and a Laves phase and shows excellent room-temperature and high-temperature (650 DEG C) mechanical property, and the compression shear strength of the high-entropy alloy brazing filler metal reaches 260 MPa and 243 MPa respectively.