48 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 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.

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.

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 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 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 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 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 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.

The application discloses a dual-phase high-entropy hydrogen storage alloy, a preparation method thereof and a hydrogen storage component. a Ti b Cr c Fe d Ni e Mo f X g , X is one or more of La, Ce, Si and Nb; wherein 5 at%<=a<=35 at%, 5 at%<=b<=35 at%, 5 at%<=c<=35 at%, 5 at%<=d<=35 at%, 2 at%<=e<=20 at%, 2 at%<=f<=20 at%, 0.1 at%<=g<=1 at%, and a+b+c+d+e+f+g=100; the high-entropy hydrogen storage alloy has a BCC and C14 Laves dual-phase structure; wherein the volume fraction of the C14 Laves phase is 5%-30%, the average grain size is 0.2-5 mu m, and the average grain size of the BCC phase is 1-10 mu m. The high-entropy hydrogen storage alloy mainly has a BCC phase structure and a small amount of Laves phase structure by adjusting the proportions of the elements, the dual-phase structure is beneficial to hydrogen storage and diffusion, is superior to traditional TiMn2 and TiFe alloys, and the addition of X can further optimize the performance by using the cocktail effect of the high-entropy alloy.

The invention provides an in-situ high-temperature solid solution Laves phase alloy workpiece laser additive manufacturing method, which relates to the field of additive manufacturing, and comprises the following steps: S1, placing a steel substrate in an inert gas protection box, fixing, sealing the box, and introducing inert gas; s2, first-time laser deposition is conducted, specifically, laser is turned on, a powder feeding system is turned on, and first-layer laser deposition is conducted on the alloy powder according to a preset path; after the first layer of laser deposition is completed, the laser head returns according to the original path to perform second layer of laser deposition; s3, performing laser remelting for the first time; s4, performing laser deposition for the second time; s5, secondary laser remelting is carried out; and S6, the method of the steps S2 to S5 is repeated, and alloy powder is deposited layer by layer with every three layers as a group. According to the method, laser in-situ heat treatment is added on the basis of a traditional laser three-dimensional forming process, the Laves phase is eliminated, meanwhile, the columnar crystal structure of the material is reserved, the side effect of high-temperature heat treatment is avoided, and the performance of an alloy workpiece is improved.

A sliding member includes a metal substrate, a porous layer on one surface of the metal substrate, and a sliding layer covering the porous layer. The sliding layer has a resin composition, and the porous layer has a matrix phase including copper and tin, and hard particles that are dispersed in the matrix phase and include a Laves phase constituted of cobalt, molybdenum and silicon.

The invention discloses a high-compression-strength and high-plasticity iron-based alloy and a preparation method and application thereof, and relates to the technical field of high-performance metal structure materials. The invention provides the element composition of the high-compression-strength and high-plasticity iron-based alloy. The microstructure of the alloy comprises a Fe2Nb Laves phase net structure distributed along the grain boundary and an intragranular nanoscale component modulation structure, the room-temperature compressive yield strength of the high-compressive-strength and high-plasticity iron-based alloy is not lower than 2000 MPa, and the compressive fracture strain is not lower than 30%. The invention further provides a preparation method and application of the alloy. Through a specific non-equilibrium solidification process, a multi-stage micro-nano reinforced structure is formed in the alloy block in an in-situ self-forming manner, so that the alloy block has ultrahigh strength and high plasticity at the same time under a compression load, and can be applied to high-pressure-resistant structural components; the problems that a traditional high-strength material preparation process is tedious, and high strength is inevitably accompanied by low plasticity are effectively solved.

The application belongs to the technical field of new materials, and particularly relates to a Laves phase composite material for thermomagnetic power generation and a preparation and application thereof. 0.9 R 0.1 Fe2, wherein R is Ta and / or Nb, so that the material has a magnetic phase transition characteristic at room temperature, and tetragonal phase In is introduced to form a two-phase composite material, wherein the Hf 0.9 R 0.1 Fe2 phase has ferromagnetism at room temperature, and the tetragonal phase In provides excellent thermal conductivity, and through adjustment of the two-phase components, the excellent thermomagnetic power generation Laves phase composite material is obtained. The Laves phase composite material for thermomagnetic power generation prepared by the application constructs a heterostructure of room-temperature ferromagnetism / high thermal conductivity, the preparation process is simple, and the 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 present application relates to a kind of high pressure coal slurry conveying valve spool surface strengthening high-entropy alloy composite powder and its laser cladding method.The component of the composite powder is as follows in percentage by mass: rare earth oxide powder 0~3 wt.%, Nb powder 28.33~29.18 wt.%, the balance is CoCrFeNi pre-alloy powder.The present application uses the regulating effect of rare earth oxide in the process of laser cladding rapid solidification to change the Laves phase in CoCrFeNiNb high-entropy alloy cladding layer from coarse continuous network distribution to fine dispersed distribution by the above-mentioned powder ratio and laser cladding process, which eliminates the hidden danger of brittle peeling of coating under the condition of high-speed coal slurry particle erosion.The surface hardness of cladding layer is not less than 670 HV 0.5 , the friction coefficient is not more than 0.60, and the corrosion current density is as low as 30.36 μA·cm ‑2 , which can meet the use requirements of high pressure coal slurry conveying valve spool under the coupling condition of coal chemical plant high pressure coal slurry erosion, abrasive wear and corrosion.

The chemical formula of the high-entropy alloy is VaTibCrcFedMneZrf, a is larger than or equal to 28 and smaller than or equal to 32, b is larger than or equal to 36 and smaller than or equal to 40, c is larger than or equal to 8 and smaller than or equal to 12, d is larger than or equal to 10 and smaller than or equal to 14, e is larger than or equal to 6 and smaller than or equal to 10, f is larger than or equal to 1 and smaller than or equal to 5, and a + b + c + d + e + f = 100. According to the method, serious lattice distortion is caused by multiple principal elements of the high-entropy alloy, a large number of catalytic active sites are provided through the synergistic effect of the multiple elements, MgH2 is catalyzed to be rapidly decomposed through the double principal phases of the BCC phase and the C14 Laves phase in a synergistic mode, and therefore the remarkable low-temperature catalytic effect on MgH2 is shown, the hydrogen desorption dynamic performance of the Mg-based hydrogen storage alloy is greatly improved, and the Mg-based hydrogen storage alloy has the good hydrogen desorption performance. And efficient hydrogen desorption of the Mg-based hydrogen storage alloy is catalyzed, and the hydrogen desorption rate can be increased by about ten times. The high-entropy alloy is low in cost and simple to prepare, and has a wide commercial application prospect.

The application provides a heat treatment method for improving the notch sensitivity of GH2909 alloy after brazing, and belongs to the field of high-temperature alloy heat treatment. The method comprises the following steps: placing the GH2909 alloy into a vacuum brazing furnace for connection, keeping the alloy at the brazing temperature for 8-12 min, and dissolving all the strengthening phase gamma prime phase in the alloy, and the content of Laves phase is not more than 1.5%; after keeping, argon is introduced into the furnace to cool the alloy to room temperature; then, the alloy is subjected to solid solution treatment at a temperature of 980±10 DEG C, so that 3.1%-4.3% of Laves phase is precipitated in the structure, the notch sensitivity of the alloy after brazing is improved; and no epsilon phase is precipitated, so that the strength of the alloy is avoided from being reduced; after the solid solution treatment, the alloy is subjected to standard aging treatment, so that the gamma prime phase is fully precipitated, and the yield strength of the alloy at room temperature and high temperature is improved. The application solves the problem of the notch sensitivity of the GH2909 alloy after brazing, and guarantees the strength of the alloy.

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.