116 results about "Tissue inhomogeneity" patented technology

The invention provides an ultrahigh-strength rare earth-magnesium alloy board and a preparation method thereof, relating to a magnesium alloy board and a preparation method thereof. By the invention, the problems of rough grains, non-uniform structure and poor performance of the magnesium alloy board prepared by the existing rolling method are solved. The ultrahigh-strength rare earth-magnesium alloy board is prepared from the components in percentage by mass: 2.0-17.0% of Gd, 3.0-18.0% of Y, 0.5-3.5% of Zn, 0.1%-1.5% of Zr and 76.0-94.0% of Mg. The preparation method comprises the following steps of: firstly preparing a rare earth-magnesium alloy cast ingot by sand casting, metal casting or semi-continuous casting; then homogenizing and annealing, cutting into rolling blanks, and then carrying out breakdown rolling to obtain a rolled board; and finally aging to obtain the ultrahigh-strength rare earth-magnesium alloy board. The preparation method provided by the invention is mainly used for preparing ultrahigh-strength rare earth-magnesium alloy boards.

The invention provides a preparation method for a TiAl alloy plate of a uniform structure and relates to the preparation method for the TiAl alloy plate. The preparation method for the TiAl alloy plate of the uniform structure aims at solving the problems that the structure of an existing TiAl alloy plate is nonuniform, and the comprehensive performance is reduced. The preparation method comprises the steps that 1, blank preparing is conducted to obtain a cuboid TiAl alloy rolling blank; 2, sleeving is conducted to obtain a sleeved TiAl alloy blank; 3, double-step heat treatment is conducted before high-temperature rolling to obtain a TiAl alloy blank subjected to double-step heat treatment; 4, high-temperature rolling and heat preserving during passes are conducted to obtain a TiAl alloy plate subjected to high-temperature rolling; 5, stress relief annealing is conducted to obtain an annealed TiAl alloy plate; and 6, a sleeve is removed through machining, so that the TiAl alloy plate is obtained. The preparation method for the TiAl alloy plate of the uniform structure has the advantage that the TiAl alloy plate of the uniform structure is obtained by adopting double-step heat treatment before rolling. The preparation method is mainly used for preparing the TiAl alloy plate of the uniform structure.

Provided are boron-containing weather-proof thin strip steel and a manufacturing method thereof. The manufacturing method comprises performing double roller thin strip continuous casting to produce boron-containing weather-proof steel; after a cast strip is processed through a crystallizing roller, adopting a mode of spraying dry ice to perform uniform strengthened cooling on the cast strip, cooling the cast strip to below 1,280 DEG C, and enabling the cooling speed to be 200-300 DEG C/s, so that precipitation of thick and large BN is promoted, emergency of low-melting-point-phase B203 and precipitation of tiny AlN are avoided, and the aims of homogenizing austenite grains and reducing yield ratio are achieved; then performing austenite on-line recrystallization rolling; then performing atomization cooling on the strip steel undergoing hot rolling, and enabling the cooling temperature to be 10-70 DEG C/s; and enabling coiling temperature to be 650-750 DEG C. Steel with low yield ratio can be obtained through the manufacturing method, and the problems that steel produced by thin strip continuous casting are universally uneven in structure, high in yield ratio and difficult to form and cannot meet the requirements for cold rolling materials are effectively solved.

The invention relates to super-thick steel and a heating process thereof, in particular to super-thick high-level boat plate steel and a normalizing process thereof. The super-thick steel comprises the following components by weight percent: 0.06% to 0.18% of C, 1.00% to 1.60% of Mn, smaller than or equal to 0.015% of P, smaller than or equal to 0.005% of S, smaller than or equal to 0.35% of Si, 0.03% to 0.30% of Ni, 0.03% to 0.20% of Cr, 0.02% to 0.25% of Cu, 0.020% to 0.050% of Alt, 0.010% to 0.040% of Nb, 0.003% to 0.060% of V and the balance of Fe. The normalizing temperature ranges from 880 DEG C to 940 DEG C; the temperature keeping time ranges from 0.8H minutes to 1.5H minutes, wherein H is the thickness of a steel plate; and the cooling speed is from 1 DEG C/S to 5 DEG C/S. The defects of nonuniform internal and external structures, obvious performance fluctuation, and the like in the rolling process of the super-thick plate are eliminated by normalization, thereby the productquality is improved, the product competitiveness is enhanced and the defects of the structure of the super-thick high-level boat plate steel are eliminated.

The present invention belongs to laser fast-molding technical field, relating to the improvement of laser melt-coated sintering molding method of the nickel substrate alloy powder. The steps of the invention comprises selecting nickel-copper-tin alloy powder as a sintering material, composing processing program and molding in sintering at the processing parameters of 1000 to 1300W laser power, 300 to 400mm/min scanning speed, 15 to 25mm defocusing amount and 15 to 25r/min powder feeding speed. The process is characterized in small alloy component segregation of the molded parts and uniform and compact organization, which solves the problems of alloy component segregation in the laser fast-molding process in the selected district and non-uniform organization.

The invention relates to steel made of boron containing microalloy and resisting atmosphere corrosion, and a manufacturing method of the steel. Steel containing boron and resisting atmosphere corrosion is produced through twin-roll thin strip continuous casting, a crystal roll produced through strip casting is sprayed with dry ice, cast strips are uniformly cooled in an strengthened manner, and are cooled below 1,280 DEG C quickly, the cooling rate is 200 to 300 DEG C/s, the strip steel subjected to boronizing is cooled in such a cooling way to promote the separation-out of thick and large BN (Boron Nitride), prevent the occurrence of low-melting-point B2O3 and the separation-out of fine ALN and achieve the purposes of uniforming austenite crystals and reducing the tensile ratio; and then, austenite is subjected to on-line recrystallization rolling, atomoization cooling and coiling. Through the invention, the steel with lower tensile ratio can be manufactured, the problems of steel produced through strip casting that the structure is non-uniform, the tensile ratio is higher, the moulding is difficult, and the requirement of cold rolled material cannot be met are effectively solved, the use requirement of cold rolled base materials is met, and the steel can be directly used in a way of replacing the cold rolling by the hot rolling.

The invention relates to boron-containing micro-alloy weather resisting steel and a manufacturing method thereof. The boron-containing weather resisting steel is continuously cast by a twin-roll thin strip, a cast strip is uniformly reinforced and cooled by spraying dry ice after exiting a crystallization roll, the cast strip is rapidly cooled to the temperature lower than 1280 DEG C at the speed of 200-300 DEG C/s, precipitation of thick BN can be promoted in the cooling mode, B2O3 with a low melting point and precipitation of thin AlN are prevented, accordingly, austenite crystal grains are homogenized, and the yield ratio is reduced. Online austenite recrystallization rolling and anti-oxidation rapid cooling at the speed of 80-200 DEG C/s are performed, and the coiling temperature is 500-600 DEG C. The steel with the low yield ratio can be obtained, and the ubiquitous problem that steel continuously cast by a thin strip is inhomogeneous in structure, high in yield ratio, difficult in forming and incapable of meeting the requirement of cold rolling of materials is solved.

Provided is a process for preparing an ultra-fine/nanometer W-Cu-Ni composite powder. Firstly according to the proportion of W-Cu-Ni ingredients, relative metal salt is prepared to mixed salt solution with a concentration of 10-30wt% percents, a small amount of acids are added to control the pH, and surfactant gels are added to control particles in solution to reunite, thereby obtaining a mixed salt sol colloid of a homogeneous system. The mixed salt sol colloid is sprayed, dried, burned, and two-stage or multi-stage reduction is applied between 150 and 900 DEG C and under H2 atmosphere, and the ultra-fine/nanometer W-Cu-Ni composite powder is obtained. By adopting the ultra-fine/nanometer W-Cu-Ni composite powder prepared by the invention, the proportion of ingredients can be adjusted, and the proportion of ingredients of each element in powder is capable of being adjusted according to the requirement of alloys property. The powder has good coking characteristic, the density of alloys is high, and the characteristic that inhomogeneous organization when the content of CU is high in W-Cu alloys system is overcome.

The invention relates to a preparation method of a high-performance TiAl alloy plate. The preparation method of the high-performance TiAl alloy plate aims at solving the problems that in the hot rolling process of existing TiAl alloy, due to the crystal grain growth, the nonuniform structure and stress concentration, a plate is cracked, the solid solution heat treatment process is tedious after rolling, the comprehensive performance of a TiAl alloy plate is lowered, and particularly plasticity is obviously lowered. The preparation method comprises the first step of preparation of TiAl alloy blank, the second step of sheathing, the third step of first-stage high-temperature rolling, the fourth step of second-stage high-temperature rolling, the fifth step of third-stage high-temperature rolling and the sixth step of mechanical machining and sheath removing. By means of the preparation method, crystal grains are thinned, the structure is made uniform, the plate is prevented from being cracked in the rolling process, the high-temperature deformation ability of the TiAl alloy plate is improved, and the large-size TiAl alloy plate with the excellent performance can be obtained.

A diffusion connection method of carbide ceramic relates to a carbide ceramic welding method. The diffusion connection method aims at solving the problem that when a metal middle layer is used for connecting the carbide ceramic and composite ceramic, a residual metal middle layer is formed in a welded joint, and the structure of the welded joint is inhomogenous. The diffusion connection method comprises the steps of: 1, carrying out surface cleaning; 2, electroplating a Ni metal layer; and 3, welding, thus completing the diffusion connection of the carbide ceramic. The diffusion connection method has the advantages that 1, the welded joint without the residual middle layer and with the homogeneous structure is formed, the welding residual stress caused by the residual middle layer in a common diffusion welding joint is relieved, the room-temperature mechanical property of the welded joint is increased, and the high-temperature mechanical property and oxidation resistance of the welded joint are also increased; and 2, the diffusion connection method is simple and practicable without needing complex working procedures and equipments. The diffusion connection method of the carbide ceramic, provided by the invention, is mainly used for diffusion welding of the carbide ceramic.

The invention relates to a tungsten-copper composite material, wherein tungsten and copper are mutually clad and through, and the tungsten-copper composite material comprises the following components in percentage by weight: 60-90 percent of tungsten and the balance of copper. A preparation method of the tungsten-copper composite material comprises the following steps of: washing a tungsten filament with acid, cleaning, and carrying out three-dimensional or two-dimensional braiding to obtain a tungsten filament braided body; placing a copper material into a graphite container, placing the obtained tungsten filament braided body on the copper material, and holding a temperature of 1200-1350 DEG C for 0.5-2h under a vacuum environment with the vacuum degree being larger than 1*10<-3>Pa; cooling to the room temperature in a furnace, and then removing redundant copper from the surface of the obtained green body to obtain the tungsten-copper composite material. The tungsten-copper composite material prepared with the preparation method has the advantages of avoiding the problem of nonuniform texture caused by nonuniform mixing of tungsten and copper alloy prepared by applying a traditional process.

The invention discloses a crystalline grain control method for a GH690 alloy shear cover of an explosion valve and belongs to the technical field of material machining. The method aims to solve the problems that the structure of a forge piece of the GH690 alloy material shear cover of the explosion valve is not even, and crystalline grains abnormally grow up. A heat treatment machining is organically combined with a forging machining, and the machining method that large deformation free forging is implemented at a high temperature (1020 DEG C to 1150 DEG C), small deformation foetal die forging is implemented at a medium temperature (710 DEG C to 850 DEG C), and the inhibition function of carbide second-phase particles on moving of a grain boundary is used for restraining the abnormal growth of the crystalline grains in forging machining of the shear cover in an auxiliary mode is provided. According to the crystalline grain control method for the GH690 alloy shear cover of the explosion valve, the forging piece forming and crystalline grain refinement are conducted synchronously, and the shear cover forge piece is obtained through heating twice; the machining limitation that a forging piece with the simple structure is subjected to high-temperature multiple-time hierarchical forging machining at present is overcome; the forging heating number is reduced; the follow-up heating treatment of the forging piece of the GH690 nickel-based alloy sheer cover is avoided. The structure with even carbides and refined crystalline grains of the GH690 alloy shear cover of the explosion valve forged through the method can be obtained.

The invention provides a preparation method of a tantalum 2.5 tungsten alloy. The preparation method comprises the following steps: after preparing tantalum powder and tungsten powder in proportion, putting the powder into a drum mixer to be mixed for 24 hours; sieving the mixed powder with a 120-mesh sieve to obtain fine powder; pressing the fine powder into an alloy bar with a 500ton oil press; putting the alloy bar into a vacuum sintering furnace to be sintered to obtain a raw ingot blank; smelting the raw ingot blank at least twice with a vacuum electron beam furnace to prepare an alloy ingot blank; putting the alloy ingot blank into a high frequency furnace to be heated to 1400 DEG C, then taking out the alloy ingot blank and forging the alloy ingot blank for many times, thus obtaining a finished product of ingot blank. The preparation method has the beneficial effects that through full mixing of tantalum powder and tungsten powder and many times of smelting, the problem of nonuniformity of ingot blank tissues is solved and the problems that the blanks easily fall off and become brittle are improved.

A technology for eliminating the mix-crystal structure of the Nb microalloyed steel manufactured by EAF-CSP flow features that the reasonable technological flow and chemical components, and reasonable technological steps including conticasting, soaking, removing scales, hot rolling and coiling are used.

The invention discloses a method for coating a surface of reinforcement in a composite material, and relates to a method for coating a surface of reinforcement. The method can be used for solving the problems of coated tissue non-uniformity, poor compactness and coverage incompleteness in the conventional method for coating the surface of the reinforcement. The method comprises the following steps: 1, mixing reinforcement with metal powder, and obtaining mixed powder after ultrasonic cleaning; 2, pouring the mixed powder into distilled water or a salt solution, heating, coating, and then taking out the reinforcement; and 3, sintering the reinforcement. According to the method for coating the surface of the reinforcement in the composite material, a netlike structural coating is uniformly covered on the surface of the coated reinforcement, and the coating has small and compact tissues; and in the later composite material preparation process, the wetting property between the reinforcement and a substrate is greatly promoted, and the interface reaction between the reinforcement and the substrate is effectively controlled. By utilizing the method for coating the surface of the reinforcement in the composite material, the surface state of the reinforcement can be preferably regulated, and a technical guarantee is provided for the later prepared composite material to achieve excellent mechanical property.

The invention relates to alloy steel for a high-pressure container. The alloy steel comprises the following components in percentage by weight: 0.27 to 0.33 percent of C, 0.60 to 1.00 percent of Mn, 1.40 to 1.70 percent of Si, less than or equal to 0.003 percent of S, less than or equal to 0.006 percent of P, 0.80 to 1.20 percent of Cr, 0.30 to 0.50 percent of Mo, 0.10 to 0.15 percent of V and the balance of Fe and inevitable impurities, wherein the total content of impurity elements and gas, namely, S+P+H+O+N is less than or equal to 100 ppm. In the smelting process of the invention, the form of electric furnace or electric furnace and electroslag remelting is replaced by the form of vacuum induction furnace and consumable electrode vacuum furnace, so that the problem of low toughness, particularly low fracture toughness caused by the low impurity of an original type of steel; in a processing procedure, high-speed forging or steam hammering of which the processing ratio is more than 5 is replaced by high-speed forging and radial forging of which the processing ratio is more than 10, so that the problems of non-uniform grain size and structure caused by non-uniform forging of the original type of steel are solved; and in a thermal refining process, the form of quenching and high temperature tempering is replaced by the form of quenching and low temperature tempering, and the sorbite structure of the original type of steel is replaced by a martensite structure, so that the problem of insufficient intensity is solved.

The invention discloses a forging process method of TI2AlNb alloy large-size disk parts. The forging process method optimizes the base technical parameters of thermal deformation of alloy according to the optimal deformation and organization control conditions of the alloy, by reasonable control to heating modes, heating temperature, forging deformation rate and deformation degree of blanks as well as final optimization of post-forming thermal treatment schedules, effectively solves the problems of crack proneness, uneven organization and the like during the forging process due to temperature rise and drop differences and uneven deformation of every parts, and accordingly can be applied to forging the large-size disk parts. The forging process method of the TI2AlNb alloy large-size disk parts sets norms and standards for alloy blank forging processes, can guarantee that the forged TI2AlNb alloy large-size disk parts are intact in appearance and has no defects such as cracks, the size allowance of the TI2AlNb alloy large-size disk parts can meet the machining requirements, the chemical components and the mechanical properties of the TI2AlNb alloy large-size disk parts can meet the design requirements. Therefore, the forging process method of the TI2AlNb alloy large-size disk parts is very applicable to popularization in application of large-size disc-shaped structural parts.

The invention provides a preparation method of a tantalum 10 tungsten alloy. The preparation method comprises the following steps: after preparing tantalum powder and tungsten powder in proportion, filling the powder into a drum mixer to be fully mixed and screening the powder to obtain fine powder; pressing the fine powder into an alloy bar with a 500ton oil press; putting the alloy bar into a vacuum sintering furnace to be sintered to obtain a raw ingot blank; smelting the raw ingot blank at least twice with a vacuum electron beam furnace to prepare an alloy ingot blank; putting the alloy ingot blank into a high frequency furnace to be heated to 1400 DEG C, then taking out the alloy ingot blank and forging the alloy ingot blank for many times, thus obtaining a finished product of ingot blank. The preparation method has the beneficial effects that through full mixing of tantalum powder and tungsten powder and many times of smelting, the problem of nonuniformity of ingot blank tissues is solved and the problems that the blanks easily fall off and become brittle are improved.

The invention discloses a temperature control device and method for additive manufacturing. According to the temperature control device, a front preheating part is arranged at the front end of a printing head, and a rear cooling part is arranged at the rear end of the printing head. Before a formed part enters a printing position, the difference between the surface temperature of the formed part and the temperature of a printing portion can be reduced, and the frequency of the phenomenon that due to the large temperature difference, the organizations of the formed part are not uniform can be reduced. Due to the fact that the rear cooling part is arranged behind the printing head, the formed part can be rapidly cooled by the cooling gas after printing is accomplished, the situation that dueto the fact that the temperature is too high, the formed part is oxidized by the surrounding air is avoided, and the surface quality of the formed part is improved. According to the temperature control system and method for additive manufacturing, on the basis of control over the temperature of a molten pool in the additive manufacturing deposition process and the cooling speed in the solidification process, the front preheating device and the rear cooling device are added, and therefore zone control of the temperature field of the formed part is achieved, the forming defect is avoided, the distribution of the temperature field in the additive manufacturing process is improved, and the internal property of the formed part can be improved.