2051 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 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.

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 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 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 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 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.