525 results about "Melting point" patented technology

The invention discloses a high-strength silver-free copper-based brazing filler metal which is composed of P, Sn, Ni and Cu. The high-strength silver-free copper-based brazing filler metal is low in cost, safe, environmentally friendly and good in welding effect; through the adding of Sn and Ni, the melting point of brazing filler metal alloy is reduced, and the tensile strength and wettability of the brazing filler metal alloy are enhanced.

The invention relates to the field of co-extrusion production control, and particularly discloses an efficient film bag feeding control system, which is applied to a multi-raw-material synchronous conveying device of a co-extrusion process, and comprises a full-link data acquisition module, a full-link data processing module and a full-link data processing module, the raw material characteristic parameters comprise a melting point T, a stacking density rho and a magnetic sensitive particle loading amount M; the instantaneous load pressure P of each raw material conveying channel, the temperature Tm of a co-extrusion die head melting area, the real-time thickness H of a co-extrusion film layer, stock bin liquid level data and motor rotating speed data are collected and integrated to obtain a full-link original data set; the single-drive linkage conveying mechanism comprises a main servo motor, a plurality of sets of electromagnetic clutches and a plurality of sets of spiral conveying assemblies, and the main servo motor drives a transmission shaft through a synchronous belt. According to the technical scheme, for the co-extrusion process, the multi-raw-material synchronous conveying precision can be matched, and the problems that parameter adjustment lags behind, adaptability is poor and a downstream process feedback closed loop is lacked are solved.

The invention discloses a preparation method of a high-strength, high-hardness and ablation-resistant CuWTaTeAl gradient nano composite material. The method comprises the following steps: 1, mechanically mixing Cu80Al20 spherical coated powder, Cu90W10 spherical coated powder, WTe2 alloy powder, Ta powder and Cu powder, and then carrying out ball milling and mixing; 2, performing SPS (spark plasma sintering); thirdly, after soaking treatment, multi-pass hot rolling deformation is carried out, and then quenching treatment is carried out; and 4, annealing heat treatment. The binary spherical coating powder, the alloy powder and the elementary substance powder are subjected to ball milling and mixing to achieve uniform distribution of all elements, high-melting-point W and Ta are added to improve the ablation-resistant temperature of the composite material, large-scale copper dendrite powder is added to form gradient distribution nanocrystals, the proportion of all the elements is controlled, the lattice distortion degree is increased, and the ablation-resistant temperature of the composite material is improved. The high-strength, high-hardness and ablation-resistant CuWTaTeAl gradient nano composite material is suitable for the fields of contacts, switches, electrical connectors, resistance welding electrodes and the like.

The invention relates to the technical field of molten salt, in particular to nitro binary molten salt and a preparation method thereof. The preparation method comprises the following steps: mixing sodium carbonate and a potassium hydroxide solution, and then adding a starch-based grafted crystal inhibitor to inhibit crystallization; adding a nitric acid aqueous solution in two stages, and introducing eutectic seed crystals to guide nucleation at the end of the first stage; crystal distribution is optimized through falling film evaporation and concentration and setting of partial reflux; and after spraying granulation, carrying out short-time melting reforming and controlled cooling in an inert atmosphere. According to the method, the composition uniformity and the structural stability of the molten salt are remarkably improved, so that the product has a melting point close to a theoretical eutectic point, low supercooling degree, high melting latent heat and excellent thermal cycling stability and corrosion resistance, and is suitable for an industrial heat storage system running for a long time.

The invention discloses a multi-material plastic plate extrusion molding device which comprises a plurality of double-screw extruders, the output ends of the double-screw extruders are communicated with a conveying pipe, and the end, away from the double-screw extruders, of the conveying pipe is communicated with a conveying shell. The invention relates to the technical field of plastic plate production equipment, through cooperation of the double-screw extruder, the conveying pipe, the conveying shell, the mixing and conveying assembly and the extrusion shaping assembly, extrusion shaping of multi-material plastic plates is achieved, targeted temperature and rotating speed setting can be conducted according to the characteristics of different raw materials, and the production efficiency is improved. Different raw materials are mixed in an optimal molten state, the problems of layering, uneven mixing and the like caused by large differences of melting points and flowability in the mixing process of the different materials are avoided, the overall stability and reliability of the plastic plate are improved, the requirements of the market for the multi-material composite plastic plate are met, and the market prospect is wide. The large-scale application of the plastic plate in more fields is promoted.

The invention relates to the technical field of refractory materials, in particular to an antioxidant and application thereof in steel ladle slag line bricks, and the antioxidant comprises a Si / SiC multiphase material, modified nano Al2O3 and CaF2; the ladle slag line brick comprises an antioxidant, fused magnesite, crystalline flake graphite and phenolic resin. Si-SiC compound waste is subjected to magnetic separation and acid pickling, then a SiO2 passivation layer is formed through pre-oxidation, moisture and air in the storage period are isolated, and a titanate coupling agent is introduced to improve the wettability and compatibility with phenolic resin. P2O5 released by phosphate on the surface of the modified nano Al2O3 at a high temperature reacts with alkali (earth) metal migrated to a SiO2 oxide layer to prevent the alkali (earth) metal from forming a low-melting-point eutectic substance, CaF2 reacts with SiO2 along with temperature rise, a passivation layer is broken, internal Si and SiC are directly exposed, and boron oxide of the modified nano Al2O3 remarkably reduces activation energy and a temperature threshold value of the reaction of CaF2 and SiO2.

The present inventions concerns a copolymer of ethylene and an C3 to C8 alpha-olefin, wherein the copolymer has a density of 870 to 890 kg / m3 measured according to ISO 1183, a MFR2 of 0.5 to 8.0 g / 10 min measured according to ISO 1133, wherein the alpha-olefin is present in the copolymer in an amount of 20 to 35 wt.-%, wherein the copolymer has a first melting temperature Tm1 measured according to ISO 11357-3, characterized in that the first melt point Tm1 is between 90 and 115° C.

The invention provides a micron-scale high-melting-point oxide sheet layer enhanced ultra-high-temperature ceramic-based anti-ablation composite coating and a preparation method thereof.The preparation method comprises the steps that ultra-high-temperature carbide / boride ceramic powder, silicide powder and high-melting-point metal oxide powder are mechanically mixed, and spraying mixed powder with uniform components is obtained; the mixed powder is sprayed on the surface of a base body in a plasma spraying mode, and the ultra-high-temperature ceramic-based anti-ablation composite coating containing a micron-scale oxide lamellar structure is obtained; the lamellar high-melting-point oxide phase is introduced into the ultrahigh-temperature ceramic-based composite silicide coating, so that the problem that the silicon-containing glass phase is easy to lose and splash under high-heat-flow scouring is effectively solved. The high-melting-point oxide sheet layer serves as a physical barrier, can effectively limit flowing of a silicon-containing glass liquid phase in the ablation process and allows gaseous oxidation products to escape at the same time, so that a firmly-attached composite oxide layer is formed, and the oxidation resistance and the anti-scouring and anti-stripping capacity of the coating are greatly improved.

The application provides a refining slag and a preparation method and application thereof, and belongs to the technical field of non-ferrous metal smelting.The application provides a refining slag, which comprises the following components in percentage by mass: KCl 30%-40%, MgCl2 47.5%-60% and CaF2 10%-12.5%.The KCl, MgCl2 and CaF2 three components form a synergistic effect of complementary advantages in the aluminum alloy electroslag remelting slag system, the melting point is reduced, the aluminum liquid can be matched, the operation is safer and more stable, a good slag crust is formed, and finally a high-quality electroslag ingot with a clean surface and a pure interior is obtained.

This invention relates to the field of vacuum melting technology, and in particular to a vacuum melting furnace for copper alloys and its ultrasonic-assisted melting method, comprising the following steps: placing copper alloy raw materials into a crucible and drawing a vacuum, then filling with argon gas to a slightly positive pressure; performing induction heating to a temperature 50-120°C above the melting point to obtain a melt; lowering an ultrasonic probe into the melt for continuous ultrasonic treatment; reducing the induction heating temperature to 20-60°C above the melting point and continuing ultrasonic treatment; induction heating to the melt temperature being the pouring temperature, performing pulsed ultrasonic treatment, and pouring the melt into an ingot mold; allowing the melt in the ingot mold to continue cooling with the furnace, then removing the vacuum and opening the furnace to obtain a copper alloy ingot. This invention, using the above steps, reduces gas content, increases ingot density, effectively removes non-metallic impurities, improves copper alloy purity, refines grains, and reduces secondary oxidation and gas entrapment during pouring.

The application discloses a bismaleimide resin performance prediction model training method, a performance prediction method, a structure design method and related products, relates to the technical field of bismaleimide resin, and the performance prediction model training method comprises the following steps: taking a molecular structure as input, taking a test condition as a supplementary input feature, taking a dielectric constant as a label, taking a predicted value of the dielectric constant as output, training a supervised learning model to obtain a dielectric constant prediction model; taking the molecular structure as input, taking melting point data as a label, taking a predicted value of the melting point data as output, training the supervised learning model to obtain a melting point prediction model; and taking the molecular structure as input, taking a 5% thermal decomposition temperature as a label, taking a predicted value of the 5% thermal decomposition temperature as output, training the supervised learning model to obtain a thermal decomposition temperature prediction model. The three prediction models are obtained by training the supervised learning model, so that the performance prediction of the bismaleimide resin material can be realized based on the theoretical model.

The invention discloses a neodymium-iron-boron magnet and a preparation method thereof, and the neodymium-iron-boron magnet comprises the following components in percentage by mass: 29.0 to 33.0 percent of R, 0.89 to 1.1 percent of B, 0.1 to 5.0 percent of M, and the balance of T and inevitable impurities. Wherein R is at least one of Nd, Pr, Ho, Ce, Gd, La, Dy and Tb, M is at least one of Al, Cu, Ga, Zr, Ti, Nb, Zn and Mn, and T contains Fe and Co; the neodymium-iron-boron magnet further comprises exogenously-added nanometer second-phase particles, the nanometer second-phase particles are oxides of high-melting-point elements, and the average particle size of the surface area of the nanometer second-phase particles ranges from 80 nm to 300 nm. According to the neodymium-iron-boron magnet, through reasonable design of main components and multi-element addition, collaborative optimization of magnetic performance and mechanical performance is achieved.

This invention provides a highly conductive preformed solder sheet, comprising a core layer and a shell layer disposed around the core layer. By embedding the solid flux core layer within the solder alloy layer to form a sandwich-like shape, the flux can be effectively protected from oxidation. There is no need to apply flux before brazing or remove it after brazing, reducing manufacturing costs and the void rate on the welded surface, thus improving the reliability of the solder sheet. The solder alloy shell is composed of tin, silver, copper, indium, cerium, vanadium, lutetium, yttrium, and zinc. The addition of small amounts of rare earth elements lutetium, yttrium, and cerium improves the conductivity and heat transfer of the solder sheet. The addition of indium, vanadium, and zinc increases the melting point of the solder sheet and improves its solidification state. Since no magnetic materials such as lead, iron, cobalt, nickel, or niobium are added, signal interference caused by metals is avoided.

The invention discloses a high-efficiency preparation method of a high-volume-fraction particle reinforced metal matrix composite material, which is a multi-unit hot-pressing sintering molding preparation method, and is characterized by specifically comprising the following steps: (1) uniformly mixing reinforcement particles and metal matrix powder according to a certain volume ratio to form composite powder; (2) loading the composite powder into a mold; (3) hot pressed sintering is conducted, the sintering temperature is 1-50 DEG C below the melting point of the metal matrix, and a multi-unit sample piece of the high-volume-fraction particle reinforced metal matrix composite is obtained; and (4) processing the multi-unit sample piece into a plurality of small-size sample pieces. According to the method, multiple target small-size sample pieces (only one-dimensional size is larger than 10 mm) can be spliced and expanded into multi-unit sample pieces (the two-dimensional size is not smaller than 10 * 10 mm) according to the size and shape characteristics of the target sample pieces, the multi-unit sample pieces are prepared firstly through hot pressing sintering, and then the multiple small-size sample pieces are obtained through cutting. According to the technical scheme, high-efficiency and batch production of high-performance and high-precision hot-pressed sintered small-size samples is achieved, the preparation cost can be effectively controlled, and engineering is achieved.

The invention relates to the field of metal nano material preparation, and discloses a supersonic gas atomization preparation method of high-dispersity spherical nano aluminum powder, which comprises the following steps: establishing a constant-temperature aluminum melt flow, and constructing a supersonic gas-solid two-phase atomization jet flow; nitrogen with the temperature lower than the melting point of the particles is used for carrying flow, solid zinc stearate particles are carried and accelerated to supersonic speed, and the aluminum melt flow is impacted; solid rigid momentum of the particles penetrates through an aluminum liquid interface to enter liquid drops, thermal relaxation time difference is used for inducing the particles to generate phase change decomposition in the liquid drops, the liquid drops are broken from the inside through volume expansion, and a carbon-zinc composite isolation layer is formed in situ through decomposition products. And high-efficiency nanocrystallization crushing under low energy consumption is realized.

A method of preparing a mixture of a metal or metal alloy and (NbxTi1-x)C (where 0<x≤1) in which (NbxTi1-x)C in particulate form (either with or without metal powder) is formed into a preform and then if necessary added to the metal. The resulting (NbxTi1-x)C / metal mixture can then be heated to a temperature below the melting point of the (NbxTi1-x)C and optionally dispersed in liquid metal and / or casted and cooled to produce a solid product with improved physical properties.

A separator includes: a first layer having a melting point of 950° C. or more and 2715° C. or less; a second layer having a heat conductivity of 0.02 W / m·K or more and 0.15 W / m·K or less under an environment of a temperature of 700° C. and a pressure of 0.2 MPa; and a third layer for which a compressive load acting on a test piece having a rectangular shape and a dimension of 50 mm square when viewed in a first direction is 0.7 kN or more when a thickness of the test piece is 5 mm and is 8 kN or less when the thickness of the test piece is 2.5 mm, and the first layer, the second layer, and the third layer are provided side by side in the first direction.

The invention provides a preparation method of a shrinkage-resistant supercritical TPU foaming material, and relates to the technical field of foaming materials, and the preparation method comprises the following steps: selecting an unactivated inorganic filler, and activating the inorganic filler by using a coupling agent containing amino or hydroxyl; uniformly dispersing the activated powder into a TPU base material through a pre-dispersion-dispersion process, and extruding into a plate through an extruder; placing the extruded TPU plate in a two-way stretching instrument, setting the temperature to be higher than the Vicat softening point and lower than the melting point of the TPU, and enabling the material to deform in the transverse direction and the longitudinal direction through two-way stretching; by introducing the filler with groups such as amino or hydroxyl, the filler and TPU can generate hydrogen-bond interaction, so that the dimensional stability of the material is improved; by adding the inorganic filler, the effect of heterogeneous nucleation points is achieved in the supercritical foaming process, and by means of two-way stretching and molecular chain orientation, the strength of the material in the length-width direction is improved, and the post-curing speed is increased.

The present subject matter relates to a method of creating layers of interconnected or contiguous material using a heated powdered composition comprising base particles and a barrier material, and applying a reducing agent to the powdered composition. The heated powdered composition can be maintained at a temperature above its melting or softening point, and the barrier material prevents coalescence between the particles until the reducing agent is applied.

The present application relates to the technical field of steel metallurgy, and particularly relates to a low-reactivity continuous casting protective slag suitable for high-rare earth weathering steel. The protective slag is composed of the following components in percentage by mass: CaO 25%-40%, SiO2 20%-30%, Al2O3 5%-10%, Ce2O3 2%-10%, C 3%-10%, Na2O 5%-15%, CaF2 5%-10%, MgO 2%-10%, and the balance being inevitable impurities. The low-reactivity continuous casting protective slag is adapted to the characteristics of rare earth elements being easy to oxidize and easy to form high-melting-point substances, so that the defects such as cracks and adhesion of the cast slab are avoided.

Methods of three-dimensional printing can include iteratively applying a polymer build material as individual layers to a powder bed, where the polymer build material includes from about 80 wt % to 100 wt % polymer build particles, and based on a three-dimensional object model, selectively applying a binder agent including an aqueous liquid vehicle and polymer binder particles onto the individual layers of the polymer build material. The polymer binder particles have or are capable of having a melting temperature lower than a melting temperature of the polymer build particles. The methods can include exposing the powder bed to heat at a temperature less than a melting point of the polymer build particles but greater than a melting temperature of the polymer binder particles. The heat causes the polymer binder particles to melt to adhere the polymer build particles together to form a three-dimensional object.

A process and apparatus of producing a product having a wrought structure. The process comprises the step of: applying heat and a compressive load simultaneously to an application area of a cold spray deposition preform to transform the comprising consolidated particle structure into a wrought structure, the compressive load being applied laterally to the application area. The application of compressive load and heat to the application area raises the temperature of the material of the preform in the application area to between the recrystallisation temperature and the melting point of the material.

Provided are a method for measuring the wax concentration of a paint, a coating method, and a method for manufacturing a surface-treated steel sheet, which can measure the wax concentration contained in the paint at a point before applying the coating to the target material to be coated. 【Solution means】A solid content extraction step (step S101) of heating the paint to extract a solid containing wax, a wax extraction step (step S102) of immersing the solid in an organic solvent to obtain a wax extract, an analysis step (step S103) of analyzing the wax extract, and a calculation step (step S104) of calculating the wax concentration from the analysis results, and the heating conditions of the solid content extraction step satisfy the following. T W +20 ≦ T ≦ T W +70 90 ≦ t ≦ 150 T W +130 < T + t < T W +190 T is the heating temperature (°C), T W is the melting point of the wax (°C), and t is the heating time (minutes).

The application relates to the technical field of casting materials, and particularly discloses a rare earth alloyed inoculant. The rare earth alloyed inoculant adds rare earth elements to a traditional silicon-based inoculant, the rare earth elements can react with S, O and N in iron liquid to generate rare earth sulfide, oxide and nitride particles, and the particles can be used as nucleation substrates of graphite. Since the melting points of the particles are higher than the temperature of the iron liquid, the nucleation quantity of the rare earth inoculant is not only large but also has a long anti-degradation time, so that the inoculation effect can be ensured, the graphite is finer, and the strength of a casting is improved.

A method for making a homogeneous mixture of polyolefin solids and an organic peroxide without melting the polyolefin solids during preparation. The method comprises applying acoustic energy at a frequency of 20 to 100 hertz to a heterogeneous mixture comprising the polyolefin solids and the organic peroxide for a period of time sufficient to substantially intermix the polyolefin solids and the organic peroxide while maintaining the temperature of the heterogeneous mixture below the melting temperature of the polyolefin solids, thereby making the mixture homogeneous without melting the polyolefin solids.

A hot-pressing sintering method for an optical zinc sulfide rectifier includes the following steps: zinc sulfide powder pretreatment; loading: mixing the pretreated zinc sulfide powder with a sintering additive with a melting point lower than zinc sulfide and loading it into a mold with a thermal expansion coefficient smaller than that of polycrystalline zinc sulfide, placing it in a hot press furnace, closing the furnace, the weight of the mixed powder loaded into the mold exceeding the raw material weight required for the ideal product of the mold, the mold being pre-coated with a release agent; starting up, when the absolute pressure drops below 500 Pa, starting the heating, while continuing to evacuate to no more than 5 Pa; the first stage heating at 5-10℃ / min to the second stage heating at 300-400℃ / min. 00℃ and hold for 1-4 hours; S4, the vacuum pressure at the second stage target temperature of 300-400℃ should not exceed 5Pa; 10 minutes before the end of the second stage, pre-pressurize in a cold state to 40-60% of the process pressure; in the third stage, continue to raise the temperature to 900-1000℃ at 5-10℃ / min, hold for 30-60 minutes after reaching the temperature, raise the process pressure to 20-40MPa in 30 minutes, and finally hold for 60-120 minutes; after the holding and pressure holding are completed, release the pressure, turn off the heating, let it cool naturally, cool with the furnace to room temperature, and then remove from the furnace.

The invention discloses an OEA and PEA eutectic crystal and a preparation method and application thereof, the eutectic crystal comprises oleoyl ethanolamine and hexadecanamide ethanol according to a substance amount ratio of 1: 1-1: 1.2, and an X-ray powder diffraction pattern of the eutectic crystal has characteristic diffraction peaks when a 2 theta angle is 8.2 degrees + / -0.2 degrees, 12.5 degrees + / -0.2 degrees, 16.8 degrees + / -0.2 degrees, 21.3 degrees + / -0.2 degrees and 24.6 degrees + / -0.2 degrees. Compared with existing OEA, the eutectic crystal is higher in melting point and has more excellent stability. The preparation method of the OEA eutectic is simple, easy to control and good in reproducibility. According to the invention, the application convenience of the OEA is greatly improved, the cost in storage, transportation and use processes is saved, and the application range of the OEA is widened.

Provided is a formed article including polychlorotrifluoroethylene, wherein the polychlorotrifluoroethylene has a melting point of 211 to 216° C., and the formed article has a projected area of 1,000 mm2 or more, a thickness of 25 to 50 mm, and a degree of crystallinity of 65% or less.

A composite material comprises a dispersion material having a thermal conductivity of 100 W / K ⋅ m or above, and an insulator interposed between the dispersion materials. For example, the dispersion material is an aluminum-based metal powder. For example, the insulator is an oxide or a resin having a glass transition point equal to or lower than the melting point of the dispersion material. For example, the electrical conductivity of the composite material is 0.5 × 106 S / m or below.

A fusible link element (10; 15; 25; 35) comprising a metal composite material in which a first fusible metal (11; 21; 31) and a second fusible metal (12; 22; 32) are layered on top of each other, wherein the second fusible metal (12; 22; 32) has a lower melting temperature than the first fusible metal (11; 21; 31), characterized by the fact that the first fusible metal (11; 21; 31) is a Sn-Ag alloy and the Sn-Ag alloy contains at least 20 wt% and at most 30 wt% Ag, and the second fusible metal (12; 22; 32) is a Sn-Bi alloy and the Sn-Bi alloy contains at least 40 wt% and at most 70 wt% Bi, wherein at a common working temperature at least part of a component of the second fusible metal (12; 22; 32) is melted and part of a component of the first fusible metal (11; 21; 31) is melted, and where, at the common working temperature, the difference between a liquidus temperature and a solidus temperature of the first fusible metal (11; 21; 31) and the second fusible metal (12; 22; 32) is reduced by a shift in the equilibrium of Sn between the first fusible metal (11; 21; 31) and the second fusible metal (12; 22; 32) and by a mutual diffusion of Ag and Bi between the first fusible metal (11; 21; 31) and the second fusible metal (12; 22; 32).