2064 results about "Molding sand" patented technology

The invention belongs to the technical field of casting, and discloses a rapid mold-free casting manufacturing method. The method comprises the steps that the temperature of molding sand is decreased to range from minus 40 DEG C to minus 10 DEG C, a computer controls a working platform to move downwards by a certain distance and lays a layer of frozen bottom sand at the low-temperature environment, then, the working platform moves downwards by one layer thickness, a layer of low-temperature molding sand is laid, the computer controls sprayers to spray water or a water solution according to the cross-section shape of the current layer cast mold, and the sand mold is solidified; and printing is performed layer by layer, and a casting mold is obtained. The invention further provides a 3D printing ice-mold casting sand mold device. The device comprises a low-temperature molding chamber, the liftable working platform, a powder spreading device and a two-dimensional motion system. Array nozzles connected with a liquid supply system are installed on the two-dimensional motion system and spray water or the water solution. A feeding system is used for providing low-temperature molding sand. The casting mold manufactured by adopting the method has the beneficial effects of being environment friendly, high in manufacturing speed, low in cost, low in gas generating amount, free of deformation and the like and has the popularization and usage value.

The invention discloses a casting manufacturing method for general sand casting, which pertains to a digital-driven rapid manufacturing casting technology. The steps of the process are: the establishment of a model, the establishment of a casting system, the simulation of the casting process, the evaluation and the optimization; a molding sand with a certain proportion is mixed for preparation according to the requirements of the performance of a cast, thus preparing a sand billet; a procedure code is compiled according to the shape of a processing cavity, and the procedure code is input to a sand numerical control machine tool; the cast and a core are processed; the cast is cleared and detected; the core setting and the assembly of the cast are carried out; and the casting is carried out to form the cast. The casting manufacturing method adopts the casting and the cutting machining technologies for organic combination, which is a new cast production method. The numerical control cutting technology is adopted for processing the complicated large cast directly, which can not only eliminate the chain for manufacturing the mold, but can also improve the processing precision of the cast, reduce the thickness of the cast, improve the rigidity and reduce the weight; furthermore, the method has the green advantages of saving materials and reducing energy consumption.

The invention discloses a preparation method of molding sand for gray iron casting, comprising the following three steps: preparing raw materials, preparing the molding sand, and mixing the molding sand. The preparation method has the advantages of simple process steps, easy operation, no use of coal dust, clean workshop, little pollution, and low cost and environmental protection by using straw powder, modified starch and other renewable raw materials. The prepared molding sand has small gas content, short drying time, good permeability and high baked tensile strength in casting, and can improve the releasability of the sand mold, further improving the fineness of casts.

A phenol-formaldehyde novolac resin having a low concentration of free phenol prepared by distilling residual phenol from a molten novolac resin and replacing at least a portion of the phenol with a solvent having a volatility equal to or less than phenol. Such modified novolac resins are suitable for the production of resin coated molding sands for shell molding and sand cores, as well as for the production of resin coated proppants for use in oil and gas recovery operations.

The invention discloses a rapid manufacturing method for sprayed and cured molding sand. The rapid manufacturing method is characterized by comprising the following steps: molding sand is mixed with a curing agent in advance, and diluted resin is sprayed onto the molding sand mixed with the curing agent through a spray; through powder layering and resin spraying, the molding sand with sprayed resin is cured, and then adhesive forming is realized; the formed layers are heated for drying; the entity of a casting mold is formed through layer-by-layer printing, stacking and curing, and then the strength of the casting mold is improved through further drying. Through adoption of the rapid manufacturing method, the problem that the amount of gas evolution of the casting mold is overlarge can be solved through reduction of the resin consumption, the spray is protected from blockage, the curing speed is increased, the assembly quality of the casting mold and a mold core is improved, and finally the casting mold with relatively high strength is obtained.

The invention discloses clay molding sand for cast steel and a preparation method thereof. The clay molding sand is prepared from the following raw materials in parts by weight: 60-80 parts of quartz sand, 20-30 parts of forsterite sand, 8-12 parts of bentonite, 5-8 parts of composite powder, 4-6 parts of talcum powder, 2-3 parts of nanometer aluminum oxide, 3-5 parts of pine sawdust, 2-4 parts of alpha-starch, 1-2 parts of dextrin, 3-6 parts of calcium phosphate, 1.5-2.5 parts of sulfite lye and 4-8 parts of water. The molding sand is high-temperature resistant, high in strength and high in impact resistance, can be used for overcoming the defects on hot spot parts and avoiding sand adhesion, and a phenomenon that the sand mold is broken due to impact force of liquid steel casting is avoided. Moreover, the clay molding sand is low in air release amount, good in air permeability effect and high in liquidity, the defects of air holes, cold shut and shrinkage porosity in the casting can be effectively overcome, and the yield of the casting is improved.

The invention discloses a lost wax shell-based negative pressure dry sand and iron shot chilling vibrational composite casting process method. The method is characterized by comprising the following steps of: feeding a shell manufactured by a lost wax process into a chilling sand box; loading steel shots in the gap between the shell and the chilling sand box; feeding the chilling sand box into a sand box with a vacuumized negative pressure model; fully filling dry sand between the chilling sand box and the sand box with the vacuumized negative pressure model; paving a plastic film; placing a pouring cup; and pouring under the simultaneous vacuumizing and vibrating condition. By the method, the strength of molding sand is high, a chilling effect is good, the process characteristics of lost foam casting and hot investment casting are combined, the defect of foam-gasified carbon special for the lost foam casting is overcome, the chilling effect of the iron shots is fully exerted, the pouring is performed under the vibration condition, and alloy grains are refined, so that wear-resisting castings have higher density, hardness and wear resistance.

This invention relates to compositions and methods for improving the performance of organophilic organic-clay complexes, which are dispersible in organic liquids to form a gel therein. Depending on the composition of the gel, such gels may be useful as lubricating greases, oil-based muds, oil base packer fluids, paint-varnish-lacquer removers, paints, foundry molding sand binders, adhesives and sealants, inks, polyester laminating resins, polyester gel coats, cosmetics, detergents, and the like.

High-temperature-resisting easy collapse molding sand is made from, by weight, 240-280 parts of quartz sand, 50-55 parts of lightweight calcium carbonate powder, 20-30 parts of hollow ceramic microspheres, 10-15 parts of hollow glass microspheres, 40-55 parts of aluminum silicate powder, 25-30 parts of titanium dioxide, 35-40 parts of fluorite nano-powder, 30-40 parts of gypsum whisker, 60-70 parts of expanded perlite, 10-15 parts of talcum powder, 2-4 parts of sodium metasilicate, 1-2 parts of glucose powder, 1-2 parts of urea, 1-2 parts of chlorinated paraffin, and a proper amount of water. The materials such as the hollow ceramic microspheres and the hollow glass microspheres are used, so that the molding sand is fine in breathability and fluidity; meanwhile, the lightweight calcium carbonate, the glucose, the urea and the like are used, so that the molding sand is fine in high temperature collapsibility, high dry strength of sand molds, high in wet bonding power, excellent in sticking resistance and applicable to various hardening manners; drying time after CO2 hardening is shortened, and reuse rate of used sand can be increased significantly.

The invention discloses a mixed casting molding sand and a preparation method thereof. The preparation method mainly comprises: performing dry mixing of component raw materials including quartz sand, attapulgite, wax, asbestos, a furan resin, a phenolic resin, bentonite and potassium dichromate by certain weight parts; and adding water, mixing, placing sand, molding, casting, cooling and separating to obtain finished product. The preparation method of the invention is simple, the formula is reasonable, the cost is low, the production efficiency is high, the surface of an aluminum sand piece is made smooth by strictly controlling the particle size of quartz sand, and the breathability is high.

The invention belongs to the field of foundry industry, in particular relates to molding sand for aluminum casting and a preparation technology thereof. The molding sand for the aluminum casting comprises the following constituents: old sand, new sand, bentonite and water. The preparation technology of the molding sand for the aluminum casting comprises a sand-mixing method: weighting the old sand, the new sand and the bentonite according to a proportion, firstly mixing the same for 10 to 20 seconds, adding water to mix for 80 to 100 seconds and standing the mixed material for 20 seconds after the mixed material is well mixed. The invention has the advantages that the particle sizes of the sand are strictly controlled, the sand with the particle size of 200 / 100 meshes is selected, and the proportion of the sand failing to pass 200 meshes is larger than 50 percent so that both the surface smoothness of aloxite parts and the air permeability of the molding sand are favorable.

The invention discloses resin casting molding sand and a preparation method thereof. The method mainly comprises: performing dry mixing of component raw materials including quartz sand, straw ash, tung oil, asbestos, a furan resin, a phenolic resin, kaoline and potassium dichromate by certain weight parts; and adding water, mixing, placing sand after mixing, molding, casting, cooling and separating to obtain a finished product. The preparation method is simple, the formula is reasonable, the cost is low, the production efficiency is high, the surface of the aluminum sand is made smooth by strictly controlling the particle size of the quartz sand, and the breathability is high.

The invention discloses a modified phosphate casting binder and a preparation method and application thereof. The modified phosphate casting binder is synthesized and prepared by a chemical reaction from the following components in percentage by weight: 9-15% of aluminum hydroxide, 60-65% of phosphoric acid, 1-5% of boric acid, 1-3% of borax, 1-5% of citric acid, 10-20% of water and 4-15% of ethanol. The obtained binder has good chemical stability, strong moisture absorption resistance and high bonding strength. The binder disclosed by the invention is suitable for preparing a self-hardening sand mould and has the characteristics of high bonding strength, long service time of a sand mould, good performance stability of the sand mould, easy collapse of the sand mould, normal-temperature regeneration of old sand and easy sand clearing of castings, and has broad application prospects in the casting industry.

The invention discloses a method for eliminating carbon defects by adopting a high-performance coating, negative-pressure firing, vacant shell pouring and quick airflow cooling in lost foam casting. The process comprises the following steps: placing a mould into a sand box; filling dry sand into the sand box; sealing the upper surface of a sand layer with a plastic thin film; starting a vacuum pump, igniting and gasifying the foam mould from a pouring gate under a negative pressure condition so as to form an intact vacant shell cavity, wherein over 95 percent of carbon is discharged out of the molding sand box; pouring molten iron and steel; lifting or cutting the sealing thin film on the top surface of the sand box when the molten iron and steel is in a temperature area where a liquid phase and a solid phase coexist, and then sucking cold airflow into the sand box so as to quickly cool a cast piece; and after stopping the pouring, continuing extracting air for 3 to 6 minutes, and then stopping the vacuum pump. The method can realize the elimination of the carbon defects of the cast piece, grain refinement, and easy falling-off of the coating by discharging and reducing carbon and pouring the vacant shell in the lost foam casting, makes the cast piece have bright and clean surface to comprehensively improve the quality of the cast piece, saves energy and reduce consumption, is high in efficiency and benefit and is applied to industrialized mass production.

The invention relates to a furan self-hardening resin sand mold for producing an integral casting axle case, which is characterized in that raw sand, furan resin, and curing agent are molded by weight part according to the following methods of: stirring the raw sand and the furan resin sufficiently in a sand mixer, wherein the furan resin is 1.0-1.5% of the weight part of the raw sand, and the furan resin is cementing agent; adding boric acid, and mixing equally, wherein the boric acid is 0.5-0.75% of the weight part of the raw sand, and the boric acid is curing agent; putting the mixed molding sand in a sand box during the molding; and curing and molding for about 20-30 minutes by utilizing a chemical method of the reaction between the resin and the curing agent. The furan self-hardening resin sand mold for producing the integral casting axle case can improve the quality and the service life of the casting, stably produce qualified castings, and reduce the cost of the axle case assembly.

The invention discloses a molding sand containing wood fiber and a production method thereof. The method comprises steps of: carrying out dry mixing on raw materials of 80-90 parts of mixed wood, 10-20 parts of recycling sand, 5-10 parts of quartz sand, 3-5 parts of glass fiber, 1-3 parts of cement, 3-5 parts of water glass, 1-3 parts of wood fiber, 5-10 parts of flour and a proper amount of water; then adding and mixing with water; and carrying out sand release, molding, casting aluminum water, and cooling and separation to obtain a finished product. The invention has advantages of simple production method, reasonable formula, low cost, high production efficiency; adoption of quartz sand and glass fiber as variant sand raw materials can change waste into treasure; and addition of wood fiber can increase the strength of the molding sand.

The invention relates to a casting process of all levels of large-scale hollow ingots below 250-ton level, in particular to a manufacturing method of composite core low-segregation large-scale hollow ingots. The manufacturing method is applicable to the preparation process of all large-scale hollow ingots which adopt the composite core pouring, comprising the casting of the hollow ingots with various shapes, specifications and materials. In addition to the usage of the computer simulation means to reasonably design an ingot mold and a pouring system, the invention mainly adopts the composite core hole forming technology, the large temperature difference cooling technology, the narrow gap molding sand technology, the bottom pouring dispersible gate drainage technology, the thick and large chassis mandatory cooling technology and a liquid nitrogen ejector device etc., and the invention further designs the corresponding mold and the equipment, pours the steel water with the different materials and prepares the low-segregation hollow ingots. The invention can ensure the serial solidification of the hollow ingots, reduce the defects of shrinkage, loose and inclusion, control the segregation position, lead the segregation band of the hollow ingots to be positioned at the middle position and improve the utilization rate and the using range of the hollow ingots.

The invention discloses molding sand. The molding sand is characterized by being prepared from the following materials in parts by weight: 200-240 parts of quartz sand, 30-35 parts of sericite, 60-70 parts of kaolin, 30-40 parts of calcium carbonate, 10-15 parts of coke powder, 10-15 parts of clays, 2-4 parts of titanium dioxide, 4-5 parts of aluminum oxide powder, 20-30 parts of argil, 3-4 parts of asphalt, 10-15 parts of bentonite, 3-4 parts of ammonium dihydrogen phosphate, 4-5 parts of sodium metasilicate, 2-3 parts of sodium dodecyl benzene sulfonate and an appropriate amount of water. According to the invention, the quartz sand, the sericite and the kaolin are used and roasted to achieve abundant pores and good gas permeability, moreover, mobility is good, and grinding of added calcium carbonate, clay, titanium dioxide, asphalt, and the like is combined, so that the molding sand has excellent cohesiveness, plasticity and heat stability, and also has high collapsibility. The molding sand material disclosed by the invention is fine and uniform; a casting piece produced by the molding sand has a smooth surface and a few flaws.

The invention provides a steel rail thermite welding system, which comprises a sand mould, a crucible and fluxes, wherein the crucible is arranged above the sand mould, the fluxes are filled in the crucible, and the sand mould comprises a polyhedral body cast with molding sand. The body comprises a bottom die, a left side die and a right side die, the bottom die is made of refractory materials, and the left side die and the right side die are the same in structure and respectively comprise three risers, wherein two risers are positioned on the outer side of a rail base angle of base metal of a steel rail so that liquid steel can flow through the rail base angle to promote welding, and the other riser is positioned at a position close to the rail base angle in a triangular rail base area and is communicated with the inside of a cavity at the position of a rail head, so that solidifying contraction of liquid steel in the rail base angle area and a rail head area is simultaneously compensated. By the aid of the system, the steel rail can be welded without rail matching under the condition of a wide rail gap exceeding 30mm. The invention further provides a method for welding the steel rail by using the steel rail thermite welding system.

The invention discloses easy-to-fill precoated sand and a preparation method thereof. Raw materials comprise roughing sand, phenolic resin, curing agents, lubricating agents and additives. The preparation method comprises the following steps that the roughing sand is heated to 130 to 170 DEG C, then, the phenolic rein, a half quantity of the lubricating agents, the curing agents and the rest half quantity of lubricating agents are sequentially added, finally, the discharging is carried out, and then, crushing, sieving and package are carried out. Through the improvement on the raw material ingredients and the preparation process, the forming intensity of the precoated sand is high, the high-temperature intensity is high, the deformation quantity is small, the flowability is good, complicated sand cores can be produced, the surface smoothness of the molding sand is good, the collapsibility performance is excellent, castings can be easily subjected to the vibration sand falling treatment, the precoated sand gas producing quantity is reduced, and the high-temperature performance and other casting performance of the precoated sand are improved.

The invention discloses casting molding sand and a preparation method thereof. Raw materials in part by weight, i.e. 70-80 parts of pulverized coal ash, 15-20 parts of returned sand, 20-25 parts of quartz sand, 2-4 parts of sepiolite, 5-15 parts of bentonite, 2-4 parts of mullite sand, 3-5 parts of water glass, 5-7 parts of resin and 2-4 parts of steel fiber, are weighed and mixed evenly, and then, the casting molding sand is obtained. The casting molding sand has the advantages that the cost can be reduced, the air permeability is good, and the improvement on the quality of castings is favored.

The invention discloses a manufacturing method of heating / heat-insulated washburn risers on inner / outer metal mold sand casting manganese steel crushing wall or rolling mortar wall, which comprises the following steps: (1) calculating the effective feeding distances of risers based on the fact that a crushing wall or a rolling mortar wall is the structural characteristic of a uniform-wall thickness annular closed casting and is the main thermal center, and determining the quantity, the shapes, the sizes and the positions of the risers; (2) respectively designing and manufacturing components of the heating / heat-insulated risers; (3) assembling components of heating / heat-insulated riser sleeves; assembling an outer metal mold with spread molding sand and an inner metal mold with spread molding sand and a tapered neck riser seat sleeve on a casting bottom plate, fastening the outer metal mold and the inner metal mold, covering a top box provided with the upper halves of the heating / heat-insulated riser sleeves, fastening with the outer metal mold and the inner metal mold into a whole casting mold, casting, and knocking off the risers after uncovering. By using the method to produce the manganese steel casting risers, the invention achieves obvious feeding effect, increases the production rate of the casting process, reduces the riser cutting cost and increases the economic benefits.

The invention discloses a casting technique for manufacturing a mold core by using resin sand, which sequentially comprises the following steps: 1) liquid iron is melted down: the measured raw materials are put into a line-frequency furnace and heated to be melted into the liquid iron; 2) molding sand is sent into a dry furnace to be dried, and then put into a sand mixer and simultaneously added with phenol resin and curing agent to be mixed with the dried molding sand, wherein, the curing agent comprises phenol-based polyisocyanate and triethylamine, and the weight of the phenol resin is 10-20 times as heavy as that of the triethylamine; the mixed sand is put into a casting model machine for manufacturing the mold core; 3) after being molded, the mold core is processed by spraying, water based paint is mainly applied in the spraying treatment, and then the sprayed mold core is dried in a dryer. As the curing agent in the technique is formed by the phenol-based polyisocyanate and the triethylamine, external heating is not needed in the technique for manufacturing the core; the resin sand can be rapidly cured under the catalysis of the triethylamine, thus improving the production efficiency.

The invention relates to a water glass modifying additive for casting and a production process and a using method thereof. The modifying additive consists of the following components in percentage by mass: 40 to 65 percent of styrene-acrylate emulsion, 0 to 10 percent of urea resin, 0.1 to 0.5 percent of quaternary ammonium salt and 25 to 55 percent of water. Used water glass sand is subjected to dry reclamation, the residual Na2O content of the used sand is controlled in a certain range and the water galls with ultra-low modulus is matched with the modifying additive so that the available time for preparing molding sand by mixing all or partial reclaimed sand can be prolonged and the molding sand has good process performance; and the reclamation rate of the used water glass sand can reach over 85 percent. The water glass modifying additive is directly added into the water glass at normal temperature and stirred uniformly without a fussy heating-cooling process so as to facilitate the operation on a molding site.

The invention discloses a preparation method for a precoated sand material applicable to the laser sintering of a magnesium alloy. The precoated sand material comprises evenly mixed crude sand, an organic binder, a coupling agent, a curing agent and a flame retardant, wherein the flame retardant is a mixture of any two or three of boric acid powder, carbon powder and pyrite powder. By adding the composite flame retardant, the defects of surface ablation and formed holes, micropores and the like when in pouring a magnesium alloy can be greatly reduced; in addition, the composite flame retardant added in the precoated sand solves the problem that a single flame retardant can greatly reduce the strength of an initial precoated sand laser-sintered part blank. According to the preparation method, not only can the magnesium alloy flame retardance problem of an SLS precoated sand mold sand core be solved, but also the strength of the initial laser-sintered molding part blanks can be guaranteed, the precoated sand material can be directly applied to pouring of a magnesium alloy, especially to high-temperature pouring of the magnesium alloy, and has great advantages on the fast integral precise forming aspects of especially complicated inner cavity, and integrated sand mold sand core.

The invention discloses a containerless casting molding method of a frozen sand mold, and belongs to the technical field of casting rapid molding. The method includes the steps that according to the characteristics of a casting, proper molding sand is selected and used and is evenly mixed with liquid, and a filling mold is placed in the frozen environment; after the molding sand is frozen and cured, a sand blank is obtained and placed on a machining platform to be fixed; the sand blank is directly cut and machined on machining equipment, and a casting mold is obtained; and finally, under the frozen environment, casting is carried out, and a final casting is obtained. According to the method, water or a solution is adopted to serve as a binding element, the source is wide, the price is low, organic resin and other binding elements are not used, and the problems that in the pouring process, the gas-forming amount is large, and waste sand is difficult to recycle are solved. The containerless casting molding method is an environment-friendly green casting method and is suitable for part rapid development trial production and small-batch production.

An ester solidifying mould sand binding agent for casting, its characteristics are: the mass percentage of main chemical component is: SiO2 24 ~ 32, K2O 0.5-28, Na2O 1-21, water 47-65. The binding agent of the invention has high solid content and low viscosity, and has proper work time when used in ester vulcanized water glass cold-setting sand, the stripping time can be adjusted according the requirements of art at will, the mould and core have characteristics of moisture-resistance, deformation, no crush, high strength, stable core size, good collapsibility of core after casting and easy sand shakeout. The old sands can be used for regenarate sand 100%. It can be used for single-piece and small-volume castings production, also be used for mechanized production line to achieve large-volume castings production.

The invention relates to a self-adaptive casting mould manufacture method for a casting, which belongs to the technical field of casting and numerical control machining. The method of the invention comprises the following steps of: constructing a three-dimensional solid model of a casting mould according to a casting drawing and reversely solving a cavity of the casting mould; carrying out sand block partitioning design according to the structural characteristics of the casting mould; manufacturing a sand mould (core) in blocks by selecting different mould sand materials, such as zircon powder, mullite powder, quartz sand, and the like; adding cold iron, a cooling pipeline, and the like into different parts of the casting mould according to a simulating result of pouring solidification; processing the sand mould (core) in blocks; and after forming the mould (core), post processing and forming a final poured casting mould. The type and the shrinking percentage of molding sand for each sand block are determined according to a simulating result of a stress field and a temperature field during mold filling and solidification processes. Finally, the size of sand blocks required to be mixed is determined so as to establish the casting mould of each sand block. The invention can singly design each casting mould (mould sand material can be different) according to the structural characteristics and local solidification characteristics of the casting and greatly improves the flexibility and the operability of casting mould design and the adaptability of the casting. The self-adaptive casting mould manufacture method is especially suitable for the manufacture of a single casting and small-mass castings.

The invention relates to a molding sand capable of quick air permeation and heat dissipation, which is prepared from the following raw materials in parts by weight: 100-120 parts of return sand, 140-150 parts of quartz sand, 30-40 parts of dry coal ash, 50-60 parts of vitrified microbead, 14-20 parts of hydroxyl-aluminum pillared bentonite, 1-2 parts of sodium carboxymethyl cellulose, 20-25 parts of starch, 2-3 parts of raw tung oil, 1-2 parts of lime powder, 4-5 parts of calcium fluoride, 4-5 parts of aluminum nitride, 40-45 parts of haydite, 4-5 parts of cement and a right amount of water. The return sand, quartz sand and the like are calcined, pulverized and subjected to high-temperature calcination, and the sodium carboxymethyl cellulose and other assistants are dispersed and ground, so that the molding sand has excellent smoothness, binding property, toughness and plasticity; the vitrified microbeads are utilized to greatly enhance the air permeability and reduce the subsurface porosity; the starch is utilized to enhance the collapsibility; and the aluminum nitride is utilized to increase the heat conductivity and enhance the production efficiency.