180results about How to "Grain refinement" patented technology

The invention discloses a rare earth aluminum alloy cable material and a preparation method and application thereof, and relates to the technical field of aluminum alloy material preparation. The rare earth aluminum alloy cable material is prepared from the following raw material components in percentage by mass: 0.3 to 0.6 percent of Ce, 0.3 to 0.6 percent of Sc, 0.05 to 0.15 percent of Y, 0.10 to 0.20 percent of Fe, 0.05 to 0.15 percent of Si and the balance of Al. The preparation process comprises the steps of melting, refining, casting, homogenizing treatment, hot rolling, drawing and aging treatment. The rare earth elements Ce, Sc and Y are added, a specific heat treatment process and a processing process are combined, and the three rare earth elements Ce, Sc and Y have a synergistic effect, so that the performance and the electric conductivity of the cable material are balanced, and the cable material has good electric conductivity and elongation on the premise of ensuring certain tensile strength, and can meet the requirements of the cable industry.

The invention discloses a laser bending process and a laser bending device, and belongs to the technical field of laser machining, and the laser bending process comprises the steps that a to-be-bent area in a to-be-bent part is subjected to laser tempering treatment to obtain a tempered to-be-bent part, and the tempered to-be-bent part is subjected to bending treatment to obtain a bent part. Wherein in the laser tempering treatment and bending treatment process, an external magnetic field is applied to the to-be-bent part, the direction of the external magnetic field is parallel to the plane where the to-be-bent part is located, and at least part of the external magnetic field penetrates through the to-be-bent part. The electromagnetic force effect can be applied to the to-be-bent area subjected to laser tempering treatment through the external magnetic field, grains are refined, energy distribution in the laser tempering treatment process can be adjusted, the tempering treatment stability is guaranteed, the bending stress is reduced, the conditions of deformation of a bent part and coarse grains are relieved, and the quality of the bent part is improved.

The invention relates to the technical field of alloy preparation, particularly provides a 650 DEG C high temperature resistant titanium-based composite material plate, and further provides a preparation method of the plate. The titanium-based composite material plate resistant to the high temperature of 650 DEG C, provided by the invention, is prepared from the following chemical components in percentage by mass: 6.0 percent to 7.0 percent of Al, 1.0 percent to 3.0 percent of Zr, 0.5 percent to 2.0 percent of Mo, 0.4 percent to 1.0 percent of Nb, 0.4 percent to 1.0 percent of W, 0.1 percent to 0.4 percent of Si, 0.4 percent to 0.7 percent of B, 0.01 percent to 0.10 percent of C and the balance of Ti and inevitable impurities. According to the titanium-based composite material component system provided by the invention, a vanadium element which is easy to generate interface reaction at high temperature is abandoned, and refractory metal elements such as niobium and tungsten are adopted to cooperate with a ceramic reinforced phase formed by boron, carbon and the like, so that the high-temperature performance and the thermal stability of the material are improved; meanwhile, by controlling the content of molybdenum, aluminum and other elements within a specific interval, the hot working performance of the material is remarkably improved while high strength is maintained, and the contradiction between insufficient high-temperature performance and poor hot working performance of a traditional titanium-based composite material is effectively solved.

The invention discloses a martensite reinforced self-lubricating copper-based alloy coating and a laser cladding preparation method thereof, the martensite reinforced self-lubricating copper-based alloy coating comprises the following components in percentage by mass: 66 to 84 weight percent of Cu, 10 to 20 weight percent of Al, 3 to 10 weight percent of Ni, 3 to 10 weight percent of Mn, 0 to 2 weight percent of Sn and 0 to 2 weight percent of Pb. In the preparation process, the laser input energy density is controlled within the range of 8.96-13.27 J / mm, and the double strengthening effects of grain refinement and martensite content increase can be synchronously achieved. The main phase structure of the obtained coating is twin-crystal martensite, meanwhile, the coating contains a small amount of alpha-Cu lubricating phase, gamma phase and Fe-rich hard phase, and the dry friction coefficient of the coating is 1t; 0.35, and the solidification hardness gt; and the voltage is 350HV. Compared with the existing self-lubricating tin-based babbitt metal and copper-tin alloy with similar friction coefficients, the coating disclosed by the invention realizes synergistic improvement of high hardness and low friction performance, and is particularly suitable for dynamic friction and wear working conditions with higher impact resistance requirements, such as robot motion joints, precision mechanical transmission parts and the like.

The invention relates to a high-plasticity GH4141 alloy cold-drawn bar with a uniform structure and a preparation method of the high-plasticity GH4141 alloy cold-drawn bar, belongs to the field of high-temperature alloy materials, and solves at least one of the problems that in the prior art, a GH4141 bar is poor in grain size uniformity, and a fastener is poor in performance stability, low in forming qualification rate and the like due to insufficient plasticity. The preparation method of the high-plasticity GH4141 alloy cold-drawn bar with the uniform structure comprises the steps that a hot-rolled GH4141 alloy bar blank is subjected to solution treatment, and then first-time cold drawing, first-time intermediate annealing treatment, second-time cold drawing, second-time intermediate annealing treatment, finished product cold drawing and finished product annealing treatment are sequentially carried out. According to the method, the plasticity is remarkably improved while the strength of the GH4141 alloy cold-drawn bar is guaranteed, and the upsetting qualification rate of a fastener and the product performance consistency are effectively improved.

This invention relates to the field of zinc alloy surface modification technology, and particularly to a corrosion-resistant medical zinc alloy, its preparation method, and its applications. The preparation method includes the following steps: weighing raw materials according to the chemical composition of the zinc alloy; cleaning the surface of the raw materials; smelting, refining, and casting to obtain an ingot; subjecting the ingot to equal-channel angular extrusion deformation to obtain an extruded zinc alloy; performing high-energy ion implantation on the zinc alloy to obtain a nitrogen-ion-implanted zinc alloy; and preparing a coating on the surface of the nitrogen-ion-implanted zinc alloy to obtain the final product. This invention achieves a high-adhesion, dense, and uniform deposition effect on the alloy surface through the synergistic control of "equal-channel angular extrusion + high-energy nitrogen ion implantation + biomimetic coating deposition," solving the problem of severe galvanic corrosion at localized sites in existing zinc alloys under corrosive environments. Simultaneously, the dense deposition layer helps inhibit rapid dissolution of the zinc alloy surface, significantly reducing the corrosion rate of the zinc alloy in corrosive environments.

This invention relates to the field of casting technology, and more particularly to a high-strength drive wheel casting process. The steps include: Step 1, alloy material preparation; Step 2, melting and micro-alloying treatment; Step 3, mold preparation and pouring; Step 4, solidification and cooling staged control; and Step 5, heat treatment process. By optimizing the alloy composition, improving the mold structure, precisely controlling melting and pouring, and adapting the heat treatment process, this invention solves the technical problems of insufficient strength, high defect rate, and poor forming accuracy in existing drive wheels. The invention also improves the structure and adapts the cooling chamber to the process, combining a controlled atmosphere cooling chamber with a staged cooling process. It incorporates partition isolation components, waste heat recovery components, and a temperature control unit, achieving independent partitioned cooling of the casting, precise temperature control, and waste heat reuse. This solves the problems of "airflow interference, uneven cooling, and energy waste" in existing cooling chambers.

A method for manufacturing high-strength, hydrogen-embrittlement-resistant bolts based on microsphere shot peening, and the bolts themselves, are disclosed. The manufacturing method includes: S1, cold heading and thread rolling of alloy structural steel billets to obtain bolt forming parts; S2, surface cleaning of the bolt forming parts, followed by overall surface peening with microspheres driven by high-pressure air; after overall peening, targeted strengthening peening treatment is performed on stress concentration areas such as thread roots, undercut grooves, and flange transition corners to obtain reinforced bolt parts; S3, the reinforced bolt parts are cleaned, dried, and phosphated to obtain finished bolt parts. This design, through a "overall + targeted" composite microsphere shot peening strategy, introduces a uniform residual compressive stress field and a micron-level fine-grained plastic deformation layer on the bolt surface, forming a thicker strengthening layer in stress concentration areas, significantly improving the fatigue strength and delayed fracture resistance of high-strength bolts, while ensuring uniform surface roughness and stable assembly friction coefficient.

The application relates to the technical field of welding materials, and particularly discloses a high-temperature-resistant flux-cored wire containing rare earth elements and a preparation method thereof. The high-temperature-resistant flux-cored wire containing rare earth elements comprises a wire sheath and a core; the core comprises the following raw materials: dehydrated rutile, dehydrated potassium feldspar, zircon sand, metal chromium powder, metal nickel powder, electrolytic manganese, ferrotitanium, aluminiferous iron, potassium cryolite, potassium titanate, sodium titanate, iron powder, yttrium-based iron alloy powder, atomized ferrosilicon, chromium-iron nitride, bismuth oxide, an additive, and the balance of reduced iron powder; the additive is a mixture of zirconium-iron alloy, ferrotitanium alloy and aluminum-magnesium alloy. The application introduces a specific alloy additive into the core to protect the transition of the rare earth yttrium, optimizes the welding performance of the yttrium and multiple components in cooperation, matches the 253MA heat-resistant steel, adjusts the components of the molten slag and the electric arc, and reasonably processes the technology, so that the welding quality of the wire is improved.

The application discloses a preparation method of a large-bore air-cooled diesel engine piston and specifically comprises the following steps: S1, modeling and dividing regions; S2, gradient printing; and S3, coating addition; and relates to the technical field of diesel engine pistons. The preparation method of the large-bore air-cooled diesel engine piston realizes the synergistic optimization of the overall performance of the piston through gradient printing of the piston, realizes the lightweight of the piston in cooperation with the honeycomb lattice structure, reduces the abrasion amount by using silicon carbide, improves the wear resistance of the top region, forms zirconium tri-aluminum nano precipitated phases by zirconium, refines the grains, forms a composite precipitated phase by using scandium, zirconium and aluminum, improves the high-temperature strength, constructs an efficient heat conduction network by using graphene nanosheets, improves the heat conductivity of the middle region, forms a three-dimensional network by using carbon nanotubes, improves the toughness of the skirt region, and has high interfacial bonding strength by spraying a wear-resistant and corrosion-resistant coating on the surface of the piston, reduces the friction, improves the service life of the piston and effectively reduces the maintenance cost.

This invention relates to the field of metallic materials and hot working technology. The invention discloses a high-temperature resistant, low-activation steel and its preparation method. The chemical composition of the raw materials is as follows (by mass percentage): Cr: 8.0–10.0%, W: 1.0–2.0%, V: 0.2–0.5%, Ta: 0.05–0.2%, Y: 0.005–0.02%, Ce: 0.001–0.005%, B: 0.001–0.005%, C: 0.08–0.16%, N: 0.015–0.035%, Mn: 0.3–0.8%, with the balance being Fe. The steel matrix is ​​tempered martensite, with the original austenite grains having an equivalent size of less than 10 μm, and containing dispersed MX-type carbides (nitrides) and M... 23 C6 type carbides. The preparation process involves vacuum induction melting, homogenization and forging, multi-cycle thermomechanical treatment (TMT), and tempering. This significantly refines the austenite grains and martensite substructure, thereby enhancing the synergistic effect of strength and toughness. The material achieves excellent tensile strength at 650 °C while maintaining an impact absorption energy greater than 150 J at room temperature and -20 °C, making it suitable for use in nuclear fusion reactor core structural materials.

The invention discloses a processing method of a large-diameter seamless steel pipe for a nuclear power conventional island. The method comprises the following steps: preparing and smelting raw materials; a centrifugal casting step; post-processing the pipe blank; a finish machining and detection step; the centrifugal casting comprises the following steps: a casting mold pretreatment stage; a centrifugal casting stage; in the pipe blank cooling and solidifying stage, the rotary hot extrusion part is introduced into an inner cavity of the pipe blank, the outer wall of the rotary hot extrusion part is further coated with a heat insulation coating, and when the rotary hot extrusion part rotates, at least one working part on the outer wall of the rotary hot extrusion part and the inner wall of the pipe blank periodically move close to or away from each other in the radial direction; therefore, the rotary hot extrusion part can apply periodic radial compaction force to the inner wall of the pipe blank. Acting force can be directly applied to the inner wall of the hollow pipe blank in the cooling and solidification stage of the hollow pipe blank, the quality of the inner wall is fundamentally improved, and the hollow pipe blank of the high-quality large-diameter seamless steel pipe with the smooth inner wall, the compact structure and the uniform performance is produced.

A high-alloy steel electroslag ingot and its homogenization method are provided, comprising the following steps: S1, electroslag ingot pretreatment: removing surface oxide scale and crack defects, and grinding to a surface roughness Ra≤6.3μm; S2, staged heating: heating to 800-900℃ at a rate ≤100℃ / h and holding for 2-6h; heating to 1000-1100℃ at a rate ≤100℃ / h and holding for 2-6h; heating to 1200-1300℃ at a rate ≤150℃ / h and holding for 10h. -20h; S3, Stepped cooling: Turn off the heating device and cool with the furnace to 800-1000℃, hold for 2-6h; cool to 500-650℃ at a rate of ≤50℃ / h, hold for 2-6h; open the furnace door and introduce cooling air at a speed of 0.5-3m / s to cool to room temperature, obtaining homogenized high-alloy steel electroslag ingots; S4, Post-homogenization testing: the relative standard deviation of each alloying element is ≤5%; the average grain size is ≤10μm; the Brinell hardness fluctuation range is ≤15HBW. This invention eliminates component segregation, refines grain structure, optimizes process parameters, is highly efficient and energy-saving, easy to promote, and has strong practicality.

The invention belongs to the technical field of metallurgy, and particularly relates to 590MPa-grade hot galvanizing dual-phase steel and a production method thereof, and the steel comprises the following chemical components in percentage by mass: 0.02%-0.06% of C, 0.01%-0.03% of Si, 0.90%-1.8% of Mn, less than or equal to 0.025% of P, less than or equal to 0.010% of S, 0.005%-0.010% of Al, 0.05%-0.30% of Cr, 0.05%-0.30% of Mo, less than or equal to 0.0060% of O, 0.010%-0.020% of N, and the balance of Fe and inevitable impurities. The method has the advantages that low carbon-silicon-aluminum and high nitrogen are cooperatively regulated and controlled in component design, and in the hot rolling process, premature precipitation of AlN particles in the hot rolling process is effectively inhibited by controlling the low coiling temperature, so that a large amount of nitrogen is reserved in a hot rolled plate in a solid solution state.

This invention belongs to the field of alloy preparation technology, and specifically relates to a TB5 titanium alloy wire and its cold drawing preparation method. Firstly, the forging and rolling of the TB5 titanium alloy involves selecting a large deformation amount and a low processing temperature, effectively ensuring that the coarse microstructure is broken down to a certain extent, improving the internal structure and increasing plasticity. Then, the surface oxide scale of the TB5 titanium alloy wire is removed to avoid introducing oxygen, hydrogen, nitrogen, and carbon elements. Next, online solution treatment is used to regulate the microstructure, improving the cold working performance and microstructure uniformity of the wire. Finally, roll drawing is performed to cold work the wire to reduce its diameter, effectively avoiding problems such as film adhesion and surface scratches, extending the service life of the drawing die. Simultaneously, the TB5 titanium alloy wire exhibits good grain size and microstructure uniformity, meeting the requirements for use. The final TB5 titanium alloy wire is delivered directly in a bright state and can be used for subsequent processing.

The present application belongs to the field of light metal plastic forming, and particularly relates to a device and method for preparing fine-grained magnesium alloy rod by asymmetric multi-directional shear extrusion. The wedge block combination in the present application can combine multi-directional shear extrusion deformation and differential speed torsional deformation, effectively weaken the magnesium alloy basal plane texture, and improve the mechanical properties of the magnesium alloy. While the magnesium alloy material is subjected to torsional extrusion in the torsional extrusion deformation zone, the sectional area of the channel gradually decreases, and the angle of the channel deflection is different, so that the frictional force of the magnesium alloy material on the surface of the convex and concave dies at the contact position is different, and the degree of torsional deformation is also different, so that the material realizes differential speed torsional deformation, and the grain refinement effect of the magnesium alloy rod is more remarkable. When the magnesium alloy material passes through the large and small concave dies, the deformation degrees of the magnesium alloy material are different due to the particularity of the structure, so that the grain refinement is effectively realized. At the same time, the flowability of the magnesium alloy material is also different, causing differential speed flow to deflect the c-axis, thereby weakening the texture.

The invention belongs to the technical field of low-pressure casting, and particularly relates to a low-pressure casting device and method for a large-size aluminum alloy shell metal outer mold composite sand core, the height of a large-size aluminum alloy shell casting is not lower than 600 mm, the inner diameter is not lower than 700 mm, and the average wall thickness is 14-20 mm; the low-pressure casting device comprises a mold system, a sand core system, a pouring system, a chilling block system and a dead head, the pouring system adopts a bottom pouring and stepped pouring mode, the structure of the pouring system is designed according to the height, the transverse characteristic size and the average wall thickness of a casting, the pouring system is deeply optimized, and the casting quality is improved. By adopting the design mode of multiple sprues and circumferentially and uniformly distributed transverse sprues, it is ensured that a feeding channel is solidified later than a casting, the pressure maintaining pressure is continuous and effective, the casting defects of cold shut, air holes, shrinkage cavities, shrinkage porosity and the like are avoided, the mechanical property and air tightness of the large-size casting are remarkably improved, and the cost rate is increased.

The application relates to the field of ceramic materials, and particularly discloses high-thermal-conductivity alumina ceramics and a preparation process thereof. The high-thermal-conductivity alumina ceramics are prepared from 50-70 parts of alumina powder, 40-50 parts of alumina fiber, 8-15 parts of a sintering aid, 0.7-1.5 parts of a dispersant and 0.2-0.3 parts of a binder, wherein the sintering aid is beryllium-zirconium composite fiber. The high-thermal-conductivity alumina ceramics have excellent thermal conductivity and mechanical properties, and have important application prospects in the field of heat dissipation of high-performance electronic devices. In addition, the preparation process can reduce the sintering temperature of the alumina ceramics, form a more uniform and refined grain system in the alumina ceramics, and significantly improve the thermal conductivity of the alumina ceramics.

The invention discloses high-purity heat-resistant quartz ceramic and a preparation method and application thereof, and belongs to the technical field of inorganic non-metallic materials, the high-purity heat-resistant quartz ceramic comprises the following raw materials by mass fraction: 50-80% of a fused high-purity quartz raw material, 10-50% of fused high-purity quartz fine powder, 0.1-1% of a composite mineralizer, and 0.1-5% of a binder; the content of CaO in the high-purity heat-resistant quartz ceramic is less than or equal to 0.1%. The aspects of raw material deep processing, additives, the preparation process and the like are strictly controlled, the addition of calcium-containing substances is avoided, the eutectic point phase is fundamentally reduced, the alkali corrosion resistance and the high-temperature strength are further improved, and the finally obtained quartz ceramic has the advantages of high refractoriness under load, excellent thermal shock resistance and corrosion resistance, and the service life of the quartz ceramic is prolonged. The method is suitable for severe environments such as oxy-fuel combustion glass kilns.

The application provides a method for preparing high-strength and high-toughness 316L stainless steel through DS warm rolling, and comprises the following steps: step a, hot forging is performed on a 316L steel ingot to obtain a forged 316L steel plate; step b, heating treatment is performed on the forged 316L steel plate; step c, DS rolling is performed on the heated 316L steel plate; step d, steps b and c are repeated for ten to twenty times; and step e, flattening treatment is performed on the 316L steel plate to obtain a high-strength and high-toughness 316L austenitic stainless steel plate. The application adopts the DS warm rolling process for rolling, compared with the synchronous warm rolling process, the mechanical properties of the 316L austenitic stainless steel are obviously improved, the yield strength of the 316L austenitic stainless steel at room temperature can reach 845 MPa, and the elongation can reach 22%; the yield strength at the liquid nitrogen temperature of -196 DEG C can reach 1130 MPa, the maximum tensile strength can reach 1712 MPa, and the elongation can reach more than 58%, the mechanical properties are obviously improved, the technical difficulty is low, and the method can be widely used in the fields of low-temperature containers, ships, ocean chemical industry and nuclear industry.

The application discloses a preparation process of a high-performance Cu-Ni-Fe alloy based on first-principle calculation design, and relates to the technical field of alloy material preparation. The process constructs a precise Cu-Ni-Fe ternary alloy thermodynamic database by combining a first principle with a CALPHAD method, determines a composition range based on database calculation of a multivariate phase diagram, optimizes the composition by calculating a work function, an elastic constant and a thermal expansion coefficient through a first principle, and obtains a finished product through smelting, heat treatment and forming processing. The final alloy has an atomic percentage composition of Cu 30%-75%, Ni 10%-30% and Fe 10%-30%, a tensile strength of greater than or equal to 816.4 MPa, a total elongation at break of greater than or equal to 34.27%, and a thermal expansion coefficient of less than 20*10 ‑6 / K, and has excellent mechanical properties and thermal stability, thereby solving the problems of blind composition design and large performance fluctuation of a traditional process and being suitable for multiple fields such as ocean engineering and electronic packaging.

The application provides a preparation method of high-purity low-alloy ultrahigh-strength steel rods, and adopts LF refining+RH circulation degassing+vacuum consumable smelting double synergistic smelting process, cooperates with accurate optimization of full-process chain parameters and multi-pass forging-heat treatment synergistic process, realizes synergistic control of gas removal and inclusion floating of the molten steel through design of the molten steel circulation parameters of RH degassing and the molten pool convection parameters of vacuum consumable remelting, refines the grains and optimizes the structure, and prepares the 300M steel rod with high purity and excellent strength-toughness matching, so that the tensile strength is maintained at 1930-2070 MPa, and the fracture toughness breaks through the technical bottleneck that the purity and the mechanical properties are difficult to be considered at the same time in the traditional process.

The application discloses a copper-aluminum composite pipe blank preparation device and method based on bidirectional cooling control, and belongs to the technical field of metal composite solid-liquid casting. The device comprises coaxially arranged inner and outer crystallizers, a positioning base, an aluminum pipe outer mold and a split runner. The aluminum pipe and the inner crystallizer form an annular casting cavity, and the inner and outer crystallizers are provided with bidirectional cooling channels. The method comprises coaxial assembly, copper melt smelting in a protective atmosphere, split uniform casting and inner-outer cooperative forced cooling. The application precisely regulates the temperature field through bidirectional cooling, shortens the high-temperature contact time of copper and aluminum, suppresses the growth of brittle intermetallic compounds, reduces interface oxidation, pores and inclusions and improves the metallurgical bonding strength. The device structure is simple, the specification is adjustable, the production efficiency is high, the problems of poor interface bonding and many defects in traditional composite pipe preparation are effectively solved, and the device is suitable for the industrialized production of copper-aluminum composite pipe blanks in the fields of electric power and automobiles.

The application belongs to the technical field of metal materials, and discloses a high-strength and high-toughness medium-manganese steel based on warm rolling and deep cryogenic treatment and a preparation method thereof. The preparation method comprises the following steps: combining a specific warm rolling process (720 DEG C~760 DEG C) with liquid nitrogen deep cryogenic treatment (soaking for 0.3~0.6h) and supplementing low-temperature tempering (180 DEG C~220 DEG C). The process induces deformation through warm rolling, promotes the transformation and refinement of austenite into martensite in combination with deep cryogenic treatment, and then eliminates internal stress and precipitates fine carbides through low-temperature tempering, so as to synergistically control the microstructure. The technical bottleneck that the strength and plasticity of traditional medium-manganese steel are difficult to be compatible is effectively solved, and the organization is super-refined and the stability is improved. The obtained medium-manganese steel has a good match between ultra-high strength and excellent plasticity, the yield strength is greater than 1800MPa, the tensile strength is as high as 2300MPa, the elongation after fracture is more than 17%, and the comprehensive mechanical properties are significantly improved.

This application relates to a polypropylene composite material, its preparation method and application, and cables. By weight, the polypropylene composite material comprises the following components: 60-80 parts polypropylene, 20-40 parts ungrafted elastomer, 0.5-1.5 parts grafted elastomer, 0.01-0.2 parts β-nucleating agent, and 3-6 parts hydrophilic agent; the hydrophilic agent includes at least one selected from ethylene-acrylic acid copolymer, polyvinyl butyral, polyacrylic acid, polyvinyl alcohol, and ethylene vinyl alcohol copolymer. The components in this polypropylene composite material interact with each other, effectively improving the water-tree resistance of the polypropylene composite material, while also exhibiting high tensile strength and elongation at break.

The invention discloses an aluminum alloy surface anti-corrosion composition and a preparation method and application thereof.In the surface anti-corrosion composition, a WC hard phase provides the framework hardness of a coating, a Co-Cr metal phase endows the coating with good toughness, and the WC hard phase and the Co-Cr metal phase act synergistically, so that the obtained coating has excellent hardness, wear resistance and corrosion resistance; according to the surface anti-corrosion composition, rare earth powder is introduced to serve as an auxiliary, grains can be refined, grain boundaries can be purified in the coating, formation of a denser coating is promoted, an optimized Co-Cr metal phase is combined, and the corrosion resistance of the surface anti-corrosion composition is greatly improved. The long-acting corrosion resistance of the coating in severe environments such as salt mist and damp and hot environments is remarkably improved through synergism, bubbling and stripping of the coating and corrosion of a base body are effectively inhibited, and the remarkable corrosion resistance effect is achieved on the whole.

The application relates to the field of metal materials and discloses a 2.2GPa-grade grinding steel rod and a preparation method thereof. The steel rod is composed of C: 0.45%-0.55%, Mn: 4.5%-5.5%, Cr: 0.45%-0.55%, Mo: 0.15%-0.25%, Si: 0.45%-0.55%, V: 0.025%-0.035% and the like. The preparation method of the steel rod is a one-heat forming rolling process, and square hole, oval hole and round hole progressive rolling is adopted in finish rolling. The one-heat forming rolling process adopts medium-carbon high-manganese component design, improves the plasticity and toughness matching property of the matrix, reduces the full austenitizing temperature of the steel grade due to high Mn, provides an ample deformation time window for the one-heat forming, avoids grain coarsening defects caused by multiple high-temperature heating and the like, and makes the three-stage hole type act in sequence, so that the rolled piece experiences complex stress in the direction alternation, a larger cumulative strain is obtained, and the grain structure is refined.

The application relates to the technical field of metal additive manufacturing, in particular to an SLM additive manufacturing method and system based on ultrafast laser in-situ assistance and application, which comprises the following steps: a three-dimensional model of a part to be formed is established and slice processing is carried out to generate a scanning path of a main laser; an ultrafast laser is coaxially combined with the main laser, and working parameters of the main laser and the ultrafast laser are set; a layer of metal powder is laid in a forming area, the main laser scans and melts the metal powder according to the scanning path to form a molten pool, and the ultrafast laser acts on the tail of the molten pool or the solidification front of the point after the main laser scans the point at a preset time interval; layer-by-layer processing is carried out until the whole part is manufactured. The ultrafast laser is coaxially integrated with the main laser, and in a preset time interval after the main laser scans a point to melt the metal powder and form a molten pool, the ultrafast laser is used to impact and inject energy into the tail of the molten pool or the solidification front which is advancing, so that grain refinement, defect elimination and stress regulation can be realized, and high-performance metal parts with small and uniform microstructure, few internal defects, low residual stress, excellent mechanical properties and significantly improved isotropy can be prepared.

The invention relates to the technical field of composite electroplating, in particular to an electroplating method for preparing a high-wear-resistance self-lubricating plating layer, which comprises the following steps: firstly, carrying out pretreatment of oil removal and acid pickling activation on a metal workpiece; then preparing a nano composite nickel plating solution in which a nickel plating basic solution contains a nano particle composite phase subjected to pre-dispersion treatment, and the total concentration of composite particles is 10-60g / L; then the dispersion stability of the nano-composite nickel plating solution is maintained in a circulating filtration and mechanical stirring combined mode, and the pretreated workpiece is electroplated; and finally, after electroplating is completed, the workpiece is cleaned and dried. According to the electroplating process for preparing the nickel-based composite coating with high wear resistance and low friction coefficient, the pulse current is adopted, and the high instantaneous current density and turn-off time of the pulse current are utilized, so that desorption and rearrangement of adsorbed particles are facilitated, uniform embedding of the particles is promoted, nickel matrix crystal grains are refined, and the compactness and comprehensive mechanical properties of the coating are further optimized.

This invention relates to the field of laser cladding technology, specifically to a toughened and reinforced laser cladding alloy powder and its preparation process. It solves the problem of poor hardness and toughness of the cladding layer formed by existing laser cladding alloy powders during use. This laser cladding alloy powder incorporates scandium / erbium-loaded nano-silica and tannic acid-hydroxypropyl cellulose-coated boron nitride. Loading scandium and erbium onto the nano-silica improves the wear resistance and tensile strength of the cladding layer. Coating the boron nitride surface with tannic acid-hydroxypropyl cellulose powder improves the wettability between boron nitride and the metal matrix, reducing interface defects. The synergistic effect of rare earth elements and boron nitride reduces porosity and cracks in the cladding layer. It also improves density by refining grains and strengthening interfacial bonding, further enhancing the material's wear resistance and tensile strength, ensuring service life and reliability under high temperature and high stress environments.