34 results about "Directed crystallization" patented technology

The invention provides a method for preparing alpha semi-hydrated gypsum by utilizing desulfurized gypsum, comprising the technological steps of purification, crystal transforming reaction, oriented crystallization, washing and separation, and drying and pulverization. The method concretely comprises the following steps of: enhancing the taste of calcium sulfate dlhy in the desulfurized gypsum to be greater than 95% through a purification treatment; dissolving and recrystallizing the desulfurized gypsum at 70 to 98 DEG C under the normal pressure through adding prepared habit modifiers, transforming into the alpha semi-hydrated gypsum and then carrying out oriented crystallization on the alpha semi-hydrated gypsum to form a short column-shaped alpha semi-hydrated gypsum crystal under the function of an oriented crystal type stabilizer, wherein the length-diameter ratio of the short column-shaped alpha semi-hydrated gypsum crystal is less than 1:3, the 2h breaking strength is greater than 6.5 MPa, the compression strength is greater than 23 MPa, the dry breaking strength is greater than 25 MPa, and the dry compression strength is greater than 53 MPa. The method can be widely used in the fields of ceramics, automobiles, precise casting, heterogenic casting and the like.

A giant-magnetostrictive material is (Tb1-x-yDyxRy)(Fe1-z-pBe2Mp)g, where R is chosen from Ho, Er, Pr and Nd, M is chosen from Ti, V, Cr, Co, Ni, Mn, Si, Ga and Al, x=0.65-0.80, y=0-0.15, and g=1.75-2.55. Its preparing process includes smelting mother alloy in Ar atmosphere in vacuum furnace, growing oriented crystallizing material in vacuum or inert gas, and heat treating in vacuum furnace. Its advantages are high magnetostrictive strain ratio, good low-field performance, and low cost.

A monocrystal and orientational cylindrical crystal combined blade used for gas turbine features that its middle region is orientational cylindrical crystals and its gas inlet and outlet edges have monocrystal form. Its manufacture method includes such steps as installing a composite crystallizer to the crystallizer of orientational crystallizing furnace, smelting by 100-150 of overheat, regulating the temp of mould heater to 1500-1530 deg.C for upper region and 1550-1580 deg.C for lower region, casting, and moving mould downward at 5-7 mm/S.

The invention discloses a cartilage extracellular matrix and silk fibroin composite orientation cartilage support and a preparation method thereof and belongs to the biological tissue engineering technology. According to the cartilage extracellular matrix and silk fibroin composite orientation cartilage support and the preparation method of the cartilage support, cartilage extracellular matrixes are prepared through articular cartilage of people, pigs, cows or sheep, silk fibroin is prepared through mulberry silk, after the cartilage extracellular matrixes and the silk fibroin are evenly mixed according to a specific proportion, directed crystallization is performed under a certain temperature, ultraviolet cross linking is firstly performed after freezing and drying, and then cross linking of carbodiimide and N-hydroxysuccinimide or glutaraldehyde and genipin is performed so that the cartilage extracellular matrix and silk fibroin composite orientation cartilage support can be prepared. Due to the design, biocompatibility is good, and immunological rejective reaction is avoided; a composition structure and mechanical properties are similar to those of cartilage extracellular matrixes of people; material sources are wide, cost is low, the preparation technology is simple, the cartilage extracellular matrix and silk fibroin composite orientation cartilage support can be used for constructing tissue engineering cartilage and repairing cartilage degradation, and clinical application prospects are good.

The invention relates to a vertical Bridgman preparation method for large-size aluminum oxide-yttrium aluminum garnet eutectic ceramic. The process of the method is characterized in that aluminum oxide-yttrium aluminum garnet eutectic ceramic grows at an argon atmosphere through a VB method. The specific growth process comprises four major processes, including raw material preparation, process before heating, eutectic growth, and cooling and annealing. By combining the advantages of a directed crystallization method and a vertical zone-melting method for crystal growth, the prepared aluminum oxide-yttrium aluminum garnet eutectic ceramic is enabled to have the advantages of large size, few defect, high hardness, outstanding mechanical property at normal temperature and high temperature, strong thermal stability, easiness in processing and the like.

The invention discloses a pulse copper electroplating additive, an electroplating solution and application of the electroplating solution. The additive comprises sulfonate, organic amine modified glycidyl ether, a polyether compound and water, wherein the mass concentration of the sulfonate is 2-20 g/L, the mass concentration of the organic amine modified glycidyl ether is 10-100 g/L, and the mass concentration of the polyether compound is 10-100 g/L. When the additive is added into the electroplating solution for pulse electroplating of a circuit board, especially in the pulse electroplating process of a high-aspect-ratio circuit board, no columnar directional crystal is generated in a hole of the circuit board, no columnar crystal is generated at an orifice corner, the mechanical property of an electroplated copper layer in the hole is improved, the risk of fracture of the copper layer is reduced, and therefore, the stability of a terminal electronic product is improved.

The device for melting and purifying of a silicon feedstock comprises a crucible arranged inside a sealed chamber. A thermal gradient can be applied to the crucible by an arranged heat exchanger and a heating device. The device likewise comprises a device for reducing the pressure inside the chamber to a value lower than 10⁻² mbar and a device for stirring the silicon in the crucible. The silicon feedstock successively undergoes degassing and pre-heating to atmospheric temperature, and then melting and low pressure, high temperature purification. Once the low-pressure purification step has been completed, directed crystallization is carried out.

The invention belongs to the technical field of artificial single crystal preparation, and particularly relates to a preparation method of large-size lath-shaped artificial ruby crystal. The preparation method comprises the following steps: putting raw materials into a boat-shaped molybdenum crucible, and injecting hydrogen under the condition that the air pressure in a crystal furnace is lower than 2 * 10 <-4 > Pa to enable the air pressure in the crystal furnace to reach about 1.5 * 10 < 5 > Pa; raising the temperature in the crystal furnace to completely melt the raw materials; adjusting the position of the crucible to complete seeding, crystal shouldering growth and crystal equal-width growth; cooling the crystal furnace, and taking out the prepared ruby crystal. A horizontal directional crystallization method is utilized, the advantages of a directional crystallization method and a vertical zone melting method are achieved at the same time, and the method for preparing ruby has the advantages of being low in cost, short in period, large in size, high in crystal quality, good in product uniformity, adjustable in color size and the like.

The invention relates to the technical field of tunnel drainage, and particularly discloses a directional accelerated crystallization device for a tunnel drainage system and a use method.The directional accelerated crystallization device comprises a crystallization pond assembly, a felt layer and a medicine box assembly, the crystallization pond assembly comprises a crystallization pond, and a pond cover is arranged at the top of the crystallization pond; the crystallizing pond comprises a front wall, a rear wall, an outer wall and an inner wall; the medicine box assembly comprises a medicine storage box, a horizontal net-shaped medicine clamping box is arranged at the box bottom of the medicine storage box and is of a double-layer hollow net-shaped structure, the bottom of the medicine storage box is communicated with the net-shaped medicine clamping box, and reaction medicine is placed in the net-shaped medicine clamping box. Influences of temperature, flow velocity, chemicals, shape and surface morphology of the crystallizing pond on tunnel water body crystallization are considered, the assumption of directional crystallization of the tunnel drainage system can be realized, and the tunnel drainage system has the advantages of simple structure and easiness in chemical supplement, cleaning, maintenance and maintenance, can be applied to tunnels put into operation, and also can be applied to tunnel drainage systems. And the method can also be applied to tunnels in a design period.

The invention relates to the field of synthetic materials and is industrially applicable in the manufacture of wear-resistant construction parts for use under conditions of elevated temperatures, loads, and aggressive media, for cutting and machining tools, and in medical equipment. The technical problem of optimization of the performance parameters of the material, including crack resistance, hardness, and wear resistance, is solved. The objective is achieved by the fact that a material based on zirconium dioxide, containing yttrium and obtained by directed crystallization from batch mixture melted in a cold container, contains at least two tetragonal phases whose axes of tetragonality are 80-90°. The components of the batch mixture for obtaining the material are contained in the following ratio (in mol %): yttrium oxide, 2.8-3.7; zirconium dioxide, the remainder. To obtain the material, a thermal insulating layer 4 is formed by placing tamped residual pieces of the material and a powdery batch mixture on the bottom 2 of the container. Layer 9 consists of a powdery batch mixture containing metallic zirconium 8; layer 10, of residual pieces of the material; and layer 11, of powdery batch mixture and fine residual pieces of the material. During directed crystallization the rate of displacement of the container relative to inductor 12 is varied. 11 dependent claims, 2 illustrations.

The invention provides a method and device for nondestructive testing of crystal orientation difference and grain boundary defects in a single crystal or oriented crystal. The method comprises the following steps of: carrying out nondestructive testing of a crystal orientation angle (theta1, kappa1) of a crystal face in a certain direction (h1k1l1) in a sample by adopting transmission short-wavelength characteristic X-ray diffraction, and determining whether the orientation angle of the crystal face of the sample is out of tolerance or not; and in the (theta1, kappa1) direction of the crystal face, translating the sample, scanning and measuring the diffraction intensity and distribution of the (h1k1l1) crystal face of each part of the tested sample, and judging whether a grain boundary defect and a sub-grain boundary defect exist in the tested sample or not according to a measurement result. The device comprises a sample table, an X-ray irradiation system, an X-ray detection system, a rotating mechanism and the like, wherein the rotating mechanism is used for changing an included angle between an incident X-ray beam and a sample. With the method adopted, the problem that crystal defects such as crystal orientation difference, sub-grain boundary and grain boundary in the single crystal and the oriented crystal cannot be quickly, accurately and nondestructively measured is solved.

The invention provides a mold for preparing a tricrystal and a preparation method of the tricrystal, and relates to the field of metal materials. The preparation method specifically comprises the following steps of: cleaning trapezoidal columnar seed crystals with nitric acid, putting the cleaned trapezoidal columnar seed crystals into a specially designed mold in a Bridgman crystal growth furnace, putting a polycrystalline raw material into a raw material barrel, controlling the growth temperature and the heat preservation time of the tricrystal by using a temperature control system, enablingthe molten polycrystalline raw material to flow into the mold, controlling the growth speed of the tricrystal by moving a movable bracket, detecting the orientation of the tricrystal by using an X-ray Laue method, thus obtaining the result that the molten polycrystalline raw material is directionally crystallized along the direction of the seed crystals, and the tricrystal is formed according tothe relative orientation relationship among the seed crystals. The mold adopted by the invention is simple and can be repeatedly used, and the tricrystal body with a preset grain boundary structure can be easily obtained.

The invention discloses a vacuum melting furnace for purifying high-purity oxygen-free copper. The vacuum melting furnace comprises a feeding bin, a zone melting chamber and a control mechanism. The control mechanism comprises a console, a controller and an upper computer, the controller is arranged on the console, and the controller is connected with the upper computer; a vibration feeder is arranged in the feeding bin and connected with the controller. A zone smelting furnace is fixedly mounted in the zone smelting chamber, and an inlet of the zone smelting furnace is connected with an outlet of the feeding bin; a column crystal orientation crystallization cavity is formed in the pouring chamber, an inlet of the column crystal orientation crystallization cavity is communicated with an outlet of the zone melting furnace, a condensation pipe is embedded in the inner wall of the column crystal orientation crystallization cavity, and a water inlet pipe and a water outlet pipe are installed on the outer wall of the column crystal orientation crystallization cavity; and the other end of the condensation pipe is communicated with the water outlet pipe. By means of the method, metal impurities and gas in the copper rod can be effectively removed, the purity of oxygen-free copper is improved, and the melting loss of alloy components in the crystallization technological process can be small.

The invention discloses a growth device and a growth method of an iridium-free zone-melting gallium oxide crystal. The iridium-free zone-melting method provided by the invention belongs to a method for growing single crystals by a melt method, precious metal is not used as a heating source, an external heating body is used for heating, heat passes through an atmosphere isolation device made of a high-transmittance and high-heat-conduction material to heat and melt a solid gallium oxide polycrystal charge rod or a ceramic rod, then seed crystals are in contact with a melt, and the single crystals are grown by a single crystal growing method. By controlling process conditions such as temperature, rising and falling, rotating speed and the like, a melting region gradually moves upwards, so that a melt region far away from a thermal field is subjected to directional crystallization according to the crystal orientation of seed crystals, and finally, large-size and high-quality gallium oxide single crystals with determined crystal orientation are obtained.

The invention discloses a tray device for growing crystals by a horizontal directional crystallization method and a use method, the tray device comprises a guide rail and a tray placed on the guide rail, and a buffer plate is arranged between the guide rail and the tray; a plurality of transversely-arranged tungsten wires are evenly laid on the upper surface of the tray in the length direction at intervals so that a crucible to be placed can be placed on the tray through the tungsten wires, the guide rail is composed of two guide rail rods and a plurality of transverse plates evenly installed between the two guide rail rods, and a plurality of positioning columns are evenly and fixedly installed on the surfaces of the transverse plates located at the two ends at intervals respectively; Aand positioning holes through which the corresponding positioning columns penetrate are formed in the surfaces of the buffer plate and the tray in a one-to-one correspondence manner. The stability of the tray during guide rail moving is effectively improved, the tray is prevented from being bonded with the bottom of the crucible, meanwhile, deformation of the tray and the guide rail is reduced, the service life of the tray and the guide rail is prolonged, and the crystal growth quality is improved.

The present invention relates to the technical field of preparing artificial calcium fluoride (optical fluorite) single crystals by growing from a melt by the directed crystallization and by using a seed crystal. The aim of the invention is to obtain oriented single crystals with a small deviation from the given direction. The technical result is achieved by the selection of a concrete technological mode in which the leading role has a period for melting of seed crystal. The optical fluorite single crystals are grown by crystallization on the oriented seed inserted into the central part of a bottom of crucible. Before the beginning of crystallization the crucible with a melt is maintained in a melt zone for a time that is sufficient for the homogenization of the whole melt and in this time the bottom part of a seed crystal appears below a melt zone. Subsequently, the crucible with a melt and with a seed crystal is moved from the melt zone into the annealing zone with the given speed. The method differs from the prior art in that the crucible with a melt is kept in a melt zone for 24–48 hours, then the crucible is relocated upwards into the melt zone at a speed of 5–50 mm/hr to a level making 10–40% of the height of the seed crystal within the melt zone. The crucible is kept in such condition from 10 about 20 minutes, and then the crucible is moving downwards out of the melt zone in accordance to the given mode of crystallization.