395 results about "Grain structure" patented technology

The invention relates to the technical field of mechanical property analysis, in particular to an inorganic mineral casting stress analysis method and system based on a virtual simulation system.The method comprises the following steps that grain voxel density difference is obtained, boundary points are screened, a boundary curve data set is generated, a defect appearance is formed through fitting, and a defect area grid model is constructed; and extracting a fatigue path node distribution diagram, screening thermal collaborative risk nodes, and drawing a concentrated stress area labeling result. According to the method, the density mutation feature is introduced as an identification basis when the grain structure boundary is obtained, boundary offset caused by traditional geometric approximation modeling is avoided, the closed curve network is established through boundary point space continuous connection, the refining degree of grain structure modeling is improved, and the modeling precision is improved. For a fatigue path calibration link, a continuous change relation of a node displacement trend is adopted to replace concentrated strain point acquisition, so that fatigue path identification is independent of single-point measurement, and the stress judgment integrity of a virtual simulation system under a multi-field condition is enhanced.

The invention relates to the technical field of aluminum alloy wire processing, and particularly discloses a high-modulus high-conductivity heat-resistant aluminum alloy material, an aluminum wire, a preparation method and a power transmission cable. According to the high-modulus, high-conductivity and heat-resistant aluminum alloy material provided by the invention, the nanoscale TiB2 particles and the micron-sized SiC particles are compounded in the aluminum alloy powder, a dual-reinforcement system is constructed, and the mechanical property and the electrical property of an aluminum conductor are synergistically improved. The invention further provides a preparation method of the high-modulus and high-conductivity heat-resistant aluminum conductor. According to the process, a multi-stage coupling plastic processing technology of hot extrusion, continuous rolling, drawing and surface treatment is adopted. The grain structure is refined through the dynamic recrystallization effect in the series of machining processes, oxidation film defects on the surface and in the structure are damaged through plastic deformation, the rigidity and the conductivity of the aluminum wire are further optimized, and the technical bottleneck that high modulus, high conductivity and heat resistance of traditional aluminum alloy are difficult to consider at the same time is effectively solved.

The invention discloses a heat-resistant aluminum alloy material and a preparation method and application thereof, and belongs to the technical field of additive manufacturing aluminum alloy materials. The heat-resistant aluminum alloy material comprises the following components in percentage by mass: 0.5-6% of Fe, 0.5-6% of Cr, 0.5-3% of Ti, less than or equal to 2% but not equal to 0 of Mn, less than or equal to 2% but not equal to 0 of Sc, less than or equal to 2% but not equal to 0 of Zr and the balance of Al and inevitable impurities. By optimizing the component proportion, the preparation method and the like, in the microstructure of the heat-resistant aluminum alloy material, the interior of the heat-resistant aluminum alloy material is of a bimodal grain structure, the boundary of a molten pool is mainly isometric crystals, the center of the molten pool is columnar crystals, and an icosahedron nanometer quasi-crystal phase and an intermetallic compound strengthening phase are further distributed on the boundary of the molten pool and the center of the molten pool in a dispersed mode; the problems that when a traditional aluminum alloy material is used for additive manufacturing forming, hot cracks or macroscopic cracks occur, and the mechanical property of a formed product is poor are fundamentally solved.

The invention relates to a preparation process optimization method of a zirconium alloy material with high fretting wear resistance, which comprises the following steps: setting a chemical component optimization range of a zirconium alloy, including specific proportions of tin, iron, niobium, chromium and oxygen elements; establishing a computer simulation model, and predicting the wear volume, tribological stability and microstructure evolution of the material under the fretting wear condition; then, a complete optimization scheme is output based on the model optimization homogenization treatment temperature interval, the hot working deformation range, the cold working cumulative deformation degree and the annealing system; and finally, a preparation process sequence including smelting, homogenization treatment, hot working deformation, cold working deformation and final heat treatment is implemented, the zirconium alloy material with the equiaxed grain structure is prepared, and the wear resistance of the zirconium alloy material is verified through an experimental fretting wear performance test. Compared with the prior art, the method has the advantages that through systematic component design and process parameter simulation optimization, the material performance is remarkably improved, and the application reliability is enhanced.

The invention relates to the technical field of aluminum alloy forging, in particular to a forging process capable of reducing reverse forging coarse grains of 6061 aluminum alloy, which comprises the following steps: acquiring a 6061 aluminum alloy ingot, homogenizing and annealing the 6061 aluminum alloy ingot at 480-520 DEG C for 12-16 hours, cooling to room temperature by water, performing ultrasonic flaw detection, performing turning surface treatment, and alternately forging and pressing in three directions, thereby obtaining the 6061 aluminum alloy. The method comprises the following steps: placing a fine-grain 6061 aluminum alloy forge piece in a graded heating furnace, completing sub-dynamic recrystallization, applying directional pressure stress of 50-80MPa to the 6061 aluminum alloy forge piece, analyzing grain boundary characteristic distribution by adopting an electron back scattering diffraction technology, and obtaining the grain boundary optimized 6061 aluminum alloy forge piece with a discontinuous coarse-grain structure through laser shock strengthening and stress relief annealing. According to the method, the problems that reverse forging coarse grains are caused by uneven strain distribution during forging and pressing, and fine grains and high-density nanoprecipitation cannot be effectively obtained and a grain boundary structure cannot be optimized due to the fact that follow-up forging, heat treatment and stress treatment parameters are difficult to accurately control can be solved.

The invention relates to the technical field of metal material surface strengthening, in particular to a TC4 titanium alloy surface gradient nanostructure construction method based on high-temperature ultrasonic rolling, which comprises the following steps: constructing a thickness-controllable gradient nanostructure layer on a TC4 titanium alloy surface through a thermal-mechanical coupling effect, refining surface grains to be less than 100nm, forming submicron transition grains on a subsurface layer, and forming a gradient nanostructure on the surface of the TC4 titanium alloy. And the core part retains a coarse grain structure. According to the method, the fatigue resistance, fretting fatigue resistance and high-temperature creep resistance of the TC4 titanium alloy can be remarkably improved, meanwhile, the equipment cost and energy consumption are reduced, and the method is suitable for aero-engine manufacturing and overhaul environments and has the high industrialization advantage.

The invention discloses a high-Al and Ti difficult-to-deform high-temperature alloy hot working method, which avoids the melting risk of low-melting-point intermetallic compounds through high-temperature diffusion on one hand, and can realize effective and uniform diffusion of chemical elements on the other hand; on the other hand, through gradual heating number cooling forging, a high-temperature small-deformation forging process is carried out in an as-cast structure interval, and a low-temperature large-deformation process is adopted after the as-cast structure is crushed, so that an ideal uniform and fine recrystallized grain structure is finally realized, and the problems of high possibility of cracking, non-uniform forging structure, coarse grains and the like in a high-temperature alloy forging process are solved; and the high-quality requirement for use of downstream aero-engine components is met.

The invention relates to the technical field of high-speed cable shielding materials, and discloses a manufacturing method of rolled copper foil for high-speed cable shielding. The method comprises the following steps: preparing a copper plate; performing multi-pass cold rolling on the copper plate to form an elongated grain structure oriented along the rolling direction; performing controlled annealing on the cold-rolled copper foil to recover plasticity and inhibit complete recrystallization; the target thickness is obtained through finish rolling; carrying out finishing rolling on at least one surface of the copper foil by adopting a mirror surface working roller so as to reduce the surface roughness; and performing surface smoothing or passivating treatment to inhibit oxidation and performance degradation. Therefore, the obtained rolled copper foil has good ductility, structural stability and high-frequency performance.

The invention provides a rolling pre-deformation method for improving toughness and plasticity of 2-series aluminum alloy, and belongs to the technical field of aluminum alloy material processing. The rolling pre-deformation method comprises the following steps: sequentially carrying out solid solution quenching treatment, ultralow-temperature transverse rolling pre-deformation, rolling pre-deformation and aging treatment on a 2-series aluminum alloy hot-rolled plate. The quenching-state 2-series aluminum alloy is sequentially subjected to transverse and rolling-direction variable-temperature pre-deformation, the grain structure, dislocation configuration and distribution can be well regulated and controlled, a fine and uniform precipitated phase is obtained after aging, and the strength, toughness and forming performance of the 2-series aluminum alloy are improved while the anisotropy of the plate is reduced. The method is simple in process, convenient to operate and easy to industrialize.

The invention belongs to the field of profile steel production, and particularly relates to a rolling method of hot-rolled Q450NQR1 weather-resistant H profile steel, which adopts a reversible cogging mill and a universal finishing mill group for rolling: after the cogging mill rolls for 3-5 passes for cogging, a universal continuous rolling mill is adopted for finish rolling 9 continuous rolling, and the arrangement sequence of finish rolling hole patterns is U1-U2-U3-E4-U5-U6-U7-E8-U9; wherein the U3 and the U6 are curved web hole patterns, and the vertical roll is in drum-shaped design. The method has the advantages that one BD cogging mill is used for large-rolling-reduction rolling to crush crystal grains, and then the nine-rack universal continuous rolling mill is used for finish rolling, so that the metal flowing and steel biting conditions are improved. The grain structure is refined through large rolling reduction and low-temperature rolling, the problems that the Q450NQR1 weathering resistant steel is poor in metal fluidity, prone to cracking and the like due to alloy elements are effectively solved, and meanwhile the mechanical property, the size precision and the surface quality of products are guaranteed.

The invention discloses a process for preparing a high-strength aluminum alloy profile through gradient cooling die-electromagnetic vibration combined extrusion, and belongs to the technical field of aluminum alloy machining. According to the technology, the uniform fine grain structure and high performance of the aluminum alloy profile are achieved through the design of the length of a die working tape and the flow gradient of a cooling channel in cooperation with an electromagnetic vibration device. After a blank is subjected to homogenization treatment, the blank is extruded through a gradient cooling die, a thin-wall area working zone is 20-25 mm, the cooling water flow is 15-20 L / min, a thick-wall area working zone is 10-15 mm, the cooling water flow is 5-10 L / min, 20-50 Hz electromagnetic vibration is applied at the same time, water mist quenching and aging treatment are conducted immediately after extrusion, zinc ions serve as heterogeneous nucleation cores to promote generation of new crystal grains, ferrocene sulfenyl is adsorbed to the surfaces of the crystal grains to inhibit growth, and the thickness of the crystal grains is 10-15 mm. The average grain size is refined, and the effect is improved.

The invention discloses a bismuth ferrite-based ceramic material with low energy consumption and high energy storage and a low-temperature rapid sintering preparation method of the bismuth ferrite-based ceramic material, a flash sintering technology is applied to 0.55 BiFeO3-0. 4SrTiO3-0.05 NaNbO3 (BFST-0. 05NN) ceramic, on one hand, the component of 0.6 BiFeO3-0. 4SrTiO3 is close to a morphotropic phase boundary (MPB) to provide high polarization, and the introduction of NaNbO3 improves the structure disorder and promotes the relaxation behavior, so that the energy storage efficiency is improved; on the other hand, by optimizing the electric field (100-250 V / cm) and the flash sintering time under the fixed current density (40 mA / mm < 2 >), reactive densification can be achieved at the very low temperature and within the ultra-short time, and compared with traditional solid sintering, the furnace temperature is reduced by nearly 500 DEG C; flash sintering can realize densification of the ceramic, inhibit grain growth of the ceramic, refine a grain structure, inhibit volatilization of volatile elements and inhibit leakage conductance current at the same time, the lead-free bismuth ferrite-based ceramic with high breakdown and high energy storage and excellent ferroelectric, piezoelectric and energy storage performance is obtained, and green development and high energy storage are realized at the same time.

The invention discloses an electrolytic copper foil and a preparation method and application thereof. The preparation method of the electrolytic copper foil comprises the following steps that raw foil is sequentially subjected to acid pickling, grain structure optimization treatment, roughening treatment, functional layer plating and silane coupling treatment, then drying and rolling are conducted, and the electrolytic copper foil is prepared. Crude foil is subjected to grain structure optimization treatment to form a copper layer with a special grain structure, and the rough structure of the surface of the copper layer is optimized by accurately controlling rough curing treatment conditions, so that the high-frequency transmission and interface bonding performance of the electrolytic copper foil is synergistically improved; the prepared electrolytic copper foil has the characteristics of lower signal transmission loss and high peel strength, is low in warping degree and excellent in mechanical property, and can meet the use requirements of ultrahigh-speed communication on electromagnetic shielding layer materials with low transmission loss and high reliable bonding strength.

The invention relates to the technical field of motor clamp springs, and particularly discloses a high-strength ultrathin titanium alloy for a motor clamp spring and a preparation method thereof.The preparation method comprises the steps that firstly, a titanium alloy cast ingot is subjected to hot forging machining, coarse and large crystal grains are crushed, then hot rolling is conducted, and in the hot rolling process, pulse current is adopted for assisting, and the high-strength ultrathin titanium alloy is obtained through the electroplastic effect; the method comprises the following steps: carrying out hot rolling to obtain a grain structure finer and more uniform than traditional hot rolling, then carrying out shot blasting treatment and carbonitriding treatment on the surface of a titanium alloy matrix to enhance the hardness, strength, wear resistance and fatigue resistance of the material, and finally, introducing a residual compressive stress field while eliminating surface defects and increasing surface compactness by adopting a heat-assisted ultrasonic rolling process, so as to improve the wear resistance of the material. The generation and expansion of fatigue microcracks are inhibited, and the anti-fatigue performance of the material is enhanced.

The invention discloses a processing method for solving grain growth in a solution treatment process of a high-temperature alloy, which comprises the following steps of: 1, obtaining a basic bar by adopting a hot working mode, specifically, carrying out forging cogging on a steel ingot, then carrying out hot working on the steel ingot through a fast forging machine or a rolling mill to obtain the required basic bar, and reserving a certain deformation amount; 2, stress relief annealing is conducted on the basic bar obtained in the step 1, and water cooling is conducted immediately after heat preservation is completed; 3, the bar obtained in the step 2 is subjected to cold drawing; and 4, the finished bar obtained after cold drawing is subjected to solution treatment. According to the method, firstly, residual cold deformation of the bar in the hot working process is eliminated through high-temperature stress relief annealing, then the bar reaches the specified size through cold drawing machining, the cold deformation of the bar is larger than critical deformation, finally, after standard solution treatment, grain structures of all parts of the bar are uniform, and abnormal growth of grains does not exist. The process has the advantages of environmental protection, convenience, flexibility and low cost.

The invention belongs to the technical field of aluminum alloy materials, and provides a heat-resistant aluminum alloy and a preparation method thereof.The heat-resistant aluminum alloy is prepared by designing a multi-element formula with main alloy elements including copper (Cu), magnesium (Mg) and manganese (Mn) and microalloying elements including nickel (Ni), silver (Ag), zirconium (Zr), cerium (Ce), samarium (Sm), iron (Fe) and silicon (Si). A material basic condition can be created for the functions of cultivation, formation, grain refinement and the like of a thermal stable phase and a strengthening phase in the preparation process of the heat-resistant aluminum alloy; the main alloy elements and the microalloying elements can separate out a thermal stable phase in the preparation process, meanwhile, the as-cast grain structure is remarkably refined, the grain structure with the small grain size is obtained, and therefore the degree of reduction of the mechanical property of the aluminum alloy caused by analysis phase coarsening under the high-temperature condition is reduced.

The invention relates to an ultrasonic rolling parameter calculation method based on nano-grain structure prediction. The method comprises the following steps: (1) determining a target grain size; and (2) negative feedback adjustment of the ultrasonic rolling parameters: obtaining the current ultrasonic rolling parameters, predicting the theoretical minimum value of the surface grain size of the metal surface deformation layer under the current ultrasonic rolling parameters, negative feedback adjustment of the current ultrasonic rolling parameters according to the surface grain size, and outputting target ultrasonic rolling parameters. According to the method, the nanocrystalline structure of the metal surface deformation layer serves as a machining target, the corresponding ultrasonic rolling parameters are developed by establishing a quantitative calculation method between the target grain size and the ultrasonic rolling parameters and combining the determined relation between the metal mechanical performance and the nanocrystalline structure according to the specific metal mechanical performance requirement, and the blindness of an experiment is avoided.

The invention discloses an additive manufacturing method of a titanium alloy with a double-peak heterogeneous grain structure, which comprises the following steps: in an inert gas protection environment, carrying out layer-by-layer deposition forming on a substrate by adopting powder feeding type laser directional energy deposition equipment, alternately feeding titanium alloy fine powder with the particle size of 20-63 microns and titanium alloy coarse powder with the particle size of 90-150 microns, and after 1-10 layers of powder with the same particle size are deposited every time, the powder with the other particle size is switched to, and the titanium alloy with the double-peak heterogeneous grain structure is obtained after deposition is completed. According to the method, under the conditions that the chemical components of the titanium alloy are not changed, a multi-material interface is not introduced and an external field auxiliary means is not needed, the melting and solidification behaviors are regulated and controlled through the powder particle size difference, layered difference distribution of the grain size is achieved, and then the titanium alloy component with the strength and plasticity cooperatively improved is obtained; and a technical scheme which is simple in process and high in engineering applicability is provided for preparation of the high-performance additive manufacturing titanium alloy component.

The invention relates to the technical field of wear-resistant steel ball casting, and discloses a process for producing as-cast wear-resistant steel balls by using a multi-element modified alloy, which comprises the following steps of: smelting molten steel, namely putting raw materials into an electric arc furnace or an induction furnace, heating to 1550-1650 DEG C, and smelting to obtain basic molten steel; multi-element modified alloy is added, specifically, the multi-element modified alloy is added into the smelted molten steel, the adding amount of the multi-element modified alloy accounts for 0.5%-2.0% of the total weight of the molten steel, stirring is conducted for 10-30 minutes at the temperature of 1500-1600 DEG C, and the alloy is made to be evenly dispersed; performing modification treatment; according to the multi-element modified alloy, through the synergistic effect of the rare earth element RE and the alkaline metal components Ba and Ca, deep deoxidation and impurity purification are achieved in the molten steel smelting stage, the oxygen activity is reduced, non-metallic inclusion residues are reduced, meanwhile, the grain structure is refined through a solid solution strengthening mechanism of MnN and CrN, a uniform and compact matrix structure is formed, and therefore the corrosion resistance of the alloy is improved. And the overall compactness and impact toughness of the wear-resistant steel ball are improved.

The invention discloses a heat treatment process for eliminating coarse grains of a GH4099 alloy hot-rolled bar strip. The heat treatment process comprises a rolling stage, a solid solution stage and an aging stage, the rolled alloy is heated to 1130-1140 DEG C, heat preservation is conducted for 5-10 min, and the alloy is discharged out of the furnace and subjected to water cooling to the room temperature; in the second solid solution stage, the temperature of the alloy treated in the first solid solution stage is increased to 1060-1100 DEG C, heat preservation is conducted for 1-3 h, and the alloy is discharged out of the furnace and water-cooled to the room temperature; and in the aging stage, the alloy treated in the second solid solution stage is heated to 880-920 DEG C, heat preservation is conducted for 4-6 h, and then the alloy is discharged out of the furnace and air-cooled to the room temperature. Through the hot rolling technology, the high-temperature short-time pre-solid solution technology, the conventional solid solution technology and the one-time aging technology, the grain boundary pinning phase is re-dissolved, strip coarse grains are prevented from appearing on the longitudinal section of an alloy bar, it is ensured that the alloy grain structure is uniform, the average grain size is 4.8-5.2 level, and meanwhile the high-temperature durability stability of the alloy is improved.

The application provides a production method for improving the width direction performance stability of 800MPa grade complex phase steel and 800MPa grade complex phase steel produced by the method. In the production, the use of a width setting machine increases the edge deformation and promotes the grain structure of the edge to be more refined. The optimization of the water use strategy between the stands reduces the width direction temperature unevenness during the finishing rolling. The laminar flow cooling front section fast cooling technology is used to quickly cool the strip steel to the coiling target temperature, reduce the residence time of the strip steel in the water environment, and reduce the edge temperature drop during the period. The precise control laminar flow cooling edge shielding amount technology is used to make the edge of the strip product of different widths naturally flow through the cooling of the middle area cooling water, improve the edge temperature of the strip, and reduce the difference between the edge and the middle of the strip in the laminar flow cooling and the hot coiling cooling in the structure and performance. The product width direction tensile strength range is less than or equal to 35MPa, and the strength low point is greater than or equal to 815MPa.

The invention discloses a magnesium alloy with ultrahigh electromagnetic shielding effectiveness and excellent strength and a preparation method thereof. According to the magnesium alloy, through specific component design (Gd, Zn and Zr), the working procedures of cast ingot casting, homogenization pretreatment, hot extrusion forming and aging treatment are combined, a double-peak grain structure is successfully constructed in the magnesium alloy, and a large number of fine beta'strengthening phases are induced and separated out; wherein the excellent strength and plasticity of the magnesium alloy are guaranteed through the double-peak grain structure; the strength of the material is remarkably improved through the fine beta'strengthening phase, and meanwhile, a formed interface network is beneficial to enhancing multiple times of reflection and absorption of electromagnetic waves, so that the strength is improved, the ultrahigh electromagnetic shielding effectiveness is guaranteed, the tensile strength of the material reaches and exceeds 370 MPa, and meanwhile, in the broadband range of 30 MHz to 3000 MHz, the electromagnetic shielding performance of the material is greatly improved. The electromagnetic shielding effectiveness stability is larger than 105 dB, breakthrough collaborative improvement of performance indexes is achieved, and the electromagnetic shielding material is suitable for being applied to the fields with extremely strict requirements for the weight, the structural reliability and the electromagnetic environment.

The invention belongs to the field of ceramic material preparation, and discloses ultra-fine grain structure ceramic and a preparation method and application thereof. The grain size is controlled to be below 100 nm through an ultra-fast high-temperature sintering process, and the microstructure is uniform and compact. The preparation method comprises the following steps: uniformly mixing superfine precursor ceramic powder with a sintering aid, and sieving to obtain mixed powder; the mixed powder is placed in a sintering mold to be pre-pressed and formed, high-temperature sintering and cooling aftertreatment are carried out, and the ultra-fine grain structure ceramic is obtained; wherein the heating rate of the high-temperature sintering is 500 DEG C / min to 1500 DEG C / min, the temperature of the high-temperature sintering is 1500 DEG C to 1700 DEG C, the pressure of the high-temperature sintering is 5 MPa to 100 MPa, and the time of the high-temperature sintering is 10 seconds to 60 seconds; the initial particle size D50 of the ultrafine precursor ceramic powder is 100-300 nm, and the specific surface area is 8-16 m < 2 > / g. The method disclosed by the invention supports high-temperature sintering of ceramics with various structures, has the characteristics of short process period, good grain size controllability, excellent mechanical property and the like, and is suitable for the fields such as aerospace hot-end components, high-end bearings and the like which have strict requirements on material performance.

The application provides a processing method of an IN718 axial flow blade, uses incomplete recrystallization forging technology, makes the blade forgings without longitudinal low-magnification "bright strip", obtains more homogenized grain structure, improves the forging quality and production efficiency, the incomplete recrystallization forging technology is adopted, the blank temperature is controlled in a certain range through process parameters such as blank structure, equivalent strain and deformation rate in the die forging process, the blank temperature drop can be effectively reduced, meanwhile, the grain structure can be effectively refined under a small deformation amount, and the longitudinal low-magnification "bright strip" of the forged forgings after final forging is eliminated.

The invention belongs to the technical field of aluminum alloys, and particularly relates to a high-strength and high-toughness microalloyed Al-Cu-Mg alloy with good creep property as well as a preparation method and application of the high-strength and high-toughness microalloyed Al-Cu-Mg alloy. The preparation method of the microalloyed Al-Cu-Mg alloy comprises the following steps that raw materials are weighed and fully mixed; performing vacuum drying after mixing; a micro-alloyed Al-Cu-Mg alloy is prepared by adopting a selective laser melting technology; the raw materials comprise, by mass, 96% of Al-Cu-M alloy powder, 1%-2% of Si powder and 1%-2% of Zr powder. Based on Si-Zr composite microalloying, the alloy which is free of obvious hot cracks and high in compactness is prepared through the selective laser melting technology at the high scanning speed, and the double-peak grain structure of the alloy is promoted to be further refined or transformed into a fine equiaxed crystal structure, so that the strength plasticity and creep property of the aluminum alloy are obviously improved.

The application belongs to the technical field of aluminum alloy materials, and provides a heat-resistant aluminum alloy and a preparation method thereof.A multi-element formula is designed, in which main alloying elements include copper (Cu), magnesium (Mg) and manganese (Mn), and micro-alloying elements include nickel (Ni), silver (Ag), zirconium (Zr), cerium (Ce), samarium (Sm), iron (Fe) and silicon (Si), so that material basis conditions can be created for the cultivation, formation and grain refinement of heat-stable phases and strengthening phases in the preparation process of the heat-resistant aluminum alloy; the main alloying elements and the micro-alloying elements can precipitate heat-stable phases in the preparation process, and at the same time, the cast grain structure is significantly refined, so that a grain structure with small grain size is obtained, and the degree of reduction of the mechanical properties of the aluminum alloy caused by the coarsening of partially precipitated phases under high-temperature conditions is reduced.

The invention provides a niobium rotating target material and a preparation method thereof, and relates to the technical field of target materials and preparation thereof. The preparation method specifically comprises the steps that niobium powder is sequentially subjected to cold isostatic pressing, shaping, gradient pre-sintering, hot isostatic pressing and machining, and finally the niobium rotating target material is obtained. Compared with a common extrusion deformation process, the hot isostatic pressing process adopted by the invention has the advantages that complicated forging and extrusion deformation processes are avoided, the process flow is simplified, and the material utilization rate is increased; meanwhile, through the combination of the process steps of cold isostatic pressing, shaping, gradient pre-sintering, hot isostatic pressing and the like, controllable control over the grain structure of the niobium rotating target can be achieved, and the niobium rotating target which is uniform in grain structure and high in density and purity can be obtained easily. The invention also provides the niobium rotating target material which is prepared by adopting the preparation method.

The invention relates to a curtain wall plate base material and a machining method, and relates to the technical field of aluminum alloy plate strip foil machining. The machining method comprises the steps of double-roller continuous cast rolling, cold rolling and annealing. Wherein the annealing process adopts a step-by-step annealing mode and comprises a plurality of stages such as preheating, first-time oil removal, first-time heating, second-time oil removal, second-time heating, performance control, cooling and adjustment. According to the method, the specific alloy component proportion (Al-Mn-Fe-Si-Cu series) is combined with the multi-stage oil removal and recrystallization annealing process, rolling oil residues on the surface of the plate are effectively removed, internal stress is eliminated, and the grain structure is refined. The surface of the prepared curtain wall plate base material is clean and free of oil spots, the good mechanical property (the tensile strength is larger than or equal to 145 MPa, and the elongation is larger than or equal to 15%) and the good bending machinability are achieved, and the use requirements of high-quality building curtain walls are met.

This invention discloses a method for preparing high-elongation bars for cold forging, belonging to the field of aluminum alloy preparation technology. Through optimization of composition and process, the prepared bars possess high purity, uniform and fine equiaxed grain structure, and excellent plasticity, with significantly improved elongation. This meets the stringent requirements of cold forging for high material plasticity, resulting in a bright, crack-free surface and uniform grains after cold forging, overcoming problems such as oxide scale, coarse grains, and poor dimensional accuracy caused by hot forging. Furthermore, the introduction of modified talc and sodium nitrate as refining agents further promotes uniform microstructure, achieving high elongation and excellent cold forging performance.

This invention relates to a bimodal tungsten-copper alloy and its preparation method. The preparation method includes: using water-soluble tungsten salt, water-soluble copper salt, and coarse tungsten powder with controllable particle size as raw materials, adding a solvent to prepare a suspension; subjecting the suspension to spray pyrolysis and in-situ reduction reaction to obtain tungsten-copper composite powder; and finally pressing the tungsten-copper composite powder into a green blank and sintering it to obtain a tungsten-copper alloy material with bimodal tungsten grain structure. In the tungsten-copper composite powder prepared by this invention, fine tungsten powder and copper powder are coupled to each other and uniformly distributed on the surface of coarse tungsten powder, forming a structure in which fine tungsten-copper composite powder coats coarse tungsten powder. This effectively improves the uniformity of W and Cu element distribution, thereby enhancing the overall properties of the tungsten-copper alloy, such as density, electrical conductivity, and thermal conductivity.