361 results about "Shrinkage porosity" patented technology

The invention discloses an intelligent scheduling and collaborative operation system and method based on aluminum alloy part manufacturing and machining, and relates to the technical field of aluminum alloy part manufacturing and machining. The system comprises the following components: a data acquisition and transmission module, which is used for arranging a plurality of sensors in each link of aluminum alloy part casting to acquire material performance and processing parameter data, encrypting and transmitting the data to a processing center, and carrying out data cleaning, format conversion and normalization preprocessing; through cooperative operation of machine learning and a fluid dynamics simulation technology, real-time, accurate and intelligent regulation and control are carried out on the whole aluminum alloy casting process, the machine learning analysis module can monitor material performance in real time and pre-judge the future change trend of the material performance, the fluid dynamics simulation module can deeply analyze casting defect generation roots, and the casting defect generation quality is improved. And the defects of air holes and shrinkage porosity can be prevented in advance, stable product performance is ensured, and the strict requirements of automobile parts and the like for high-quality aluminum alloy products are met.

A bearing hub casting mold and casting method. The mold comprises part models, risers and a sprue bush, wherein each riser is connected to the top of the part model; the sprue bush is connected to each riser by means of a horizontal runner; and the part models, the risers and the sprue bush are sequentially distributed from bottom to top in a vertical direction. In the bearing hub casting mold, by means of the provision of the riser at the top of each part model, a bearing hub is cast-molded by means of a top-pouring process, and after pouring, there is no isolated liquid-phase region during a solidification process of a casting, and the casting has no shrinkage porosity defect, thereby improving the quality of a bearing hub part.

The invention discloses a manufacturing method of 925 silver jewelry, which comprises the following steps: S1, preparing alloy components, S2, designing a cast tree structure, S3, casting, and S4, densifying a casting, the alloy components comprise 92.5-93.0% of silver, 1.0-3.0% of platinum, 0.05-0.5% of copper, 1.5-3.5% of zinc, 1.5-3.5% of indium, 0.03-0.3% of tin, 0.05-0.5% of germanium, 0.03-0.3% of rare earth, and 0.003-0.02% of boron. According to the manufacturing method, alloy components are optimized, the casting performance of the alloy components is improved, the casting process is optimized, the feeding capacity of molten metal is improved, shrinkage porosity and air holes are reduced, the initial density of the casting is improved, and subsequent composite treatment is carried out, so that the density from the surface to the shallow surface of the casting is further improved, grains are refined, and the surface roughness is further reduced; and the requirement of high brightness of the jewelry surface is met.

The invention relates to the technical field of die-casting production and manufacturing of metal parts, in particular to a magnesium alloy die-casting die device. The mold comprises a mold mechanism, the mold mechanism comprises a first mold assembly, a second mold assembly and a feeding mechanism, a plurality of receding openings are formed in the peripheral sides of the first mold assembly and the second mold assembly, liquid pouring gates and cavities are formed in the first mold assembly and the second mold assembly, and the feeding mechanism comprises a feeding barrel and a sprue spreader; when the first mold assembly and the second mold assembly are closed, the mold core is located in the mold cavity; the core pulling assembly comprises a fixing frame connected with the mold core and a driving device connected with the fixing frame; the overflow discharging system comprises an overflow groove, an exhaust channel and an exhaust mechanism; and the pre-jacking mechanism is configured to act on the die-casting metal part during die opening. The technical problems of turbulence air entrapment, shrinkage cavity shrinkage porosity, demolding damage and the like are effectively solved, and the production quality and efficiency of magnesium alloy die-casting parts are improved.

The invention provides a method for on-line detection of spheroidization rate and shrinkage porosity index of nodular cast iron, which comprises the following steps: pouring molten iron subjected to spheroidization into a thermal analysis sample cup, recording the change rule of the temperature of the molten iron in the thermal analysis sample cup along with time, and drawing a cooling curve of solidification time-temperature; according to the shape of the cooling curve, determining which of a hypoeutectic solidification mode, a near-eutectic solidification mode and a hypereutectic solidification mode the solidification mode of the spheroidized iron liquid belongs to; different calculation formulas are adopted for predicting the nodularization rate and the shrinkage porosity index of the nodular cast iron according to the three different solidification modes. The method comprises the following steps: drawing a cooling curve between solidification time and temperature of molten iron, carrying out numerical differential treatment on the curve to obtain a temperature value of a feature point, and judging which solidification mode of the molten iron belongs to a hypoeutectic solidification mode, a near-eutectic solidification mode and a hypereutectic solidification mode according to the shape of the cooling curve. And further calculating the spheroidization rate and shrinkage index of the spheroidized molten iron through a formula.

The invention relates to the technical field of casting molds, and discloses an automobile planet carrier casting mold which comprises a mold plate arranged between an upper mold and a lower mold, an upper sand mold, a lower sand mold, a sand core and a sprue are installed on the mold plate, and the sand core is located between the upper sand mold and the lower sand mold and used for blocking cavity communication of the upper sand mold and the lower sand mold; guide columns corresponding to the upper and lower dies are mounted on the upper and lower end faces of the template, and are inserted into guide holes of the upper and lower dies, so that accurate die assembly is realized. Through combination of the upper sand mold, the lower sand mold and the sand core, the mold can mold an upper casting and a lower casting at the same time by using the sand core to block communication of the mold cavity, the production efficiency is greatly improved, the thickness of the sand core is set to be 0.8 times of the wall thickness of the casting, shrinkage porosity linearity caused by a hot spot in the casting can be avoided, and meanwhile, the production efficiency is improved. The pouring gate supplies liquid to the upper sand mold and the lower sand mold through the residue filter, impurities in molten metal are removed through the filtering assembly, the shrinkage porosity defect caused by the impurities is reduced, and therefore the qualification rate of castings is increased.

The invention discloses a casting cylinder body preparation method. The casting cylinder body preparation method comprises the following steps that 1, the bottom of a plunger hole in a cylinder body is sealed; 2, the copper alloy and the casting cylinder body are sintered; step 3, cooling the cast cylinder body; according to the method, through a segmented cooling mode, casting defects such as shrinkage porosity and shrinkage cavities are avoided, copper-steel bimetal metallurgy diffusion bonding is achieved, it is guaranteed that a copper alloy layer has good mechanical and tribological properties, and therefore the service life of the copper-steel bimetal cylinder body is prolonged.

The invention discloses a semi-true centrifugal casting method for a large barrel-shaped casting product, which comprises the following steps: designing an outer mold and a sand core, designing a positioning structure, manufacturing a casting channel in the middle of the sand core, manufacturing an expanded blind riser at the bottom of the casting channel, and manufacturing the sand core by using a water glass and carbon dioxide blowing hardening process. The method comprises the following steps: profiling the interior of a sand core to manufacture a net-shaped steel framework, designing an exhaust rope for casting, brushing paint on the surface of the sand core and in an outer mold, positioning and closing a box, centrifuging according to the process, casting, collecting flow and slowly pouring when the calculated process weight is observed, stopping until molten steel reaches a pouring cup, naturally cooling, and cleaning the sand core to obtain a complete casting. Compared with the prior art, suspension type design of the sand core is achieved, the overall structural strength of the sand core is high, the sand core has good air permeability, shrinkage porosity or shrinkage cavity of the bottom of a product in the centrifugal process is avoided through the blind riser, and integrated centrifugal casting forming of a bottom plate and a barrel body of a casting product is achieved.

The invention relates to a secondary aluminum alloy homogenizing heat treatment process which comprises the following steps: putting a secondary aluminum alloy ingot into a heat treatment furnace, and heating to the homogenizing temperature of 550-590 DEG C; after the regenerated aluminum alloy cast ingot is heated to the homogenization temperature, homogenization heat preservation is conducted, and the homogenization heat preservation time is 6-10 h; and after homogenization and heat preservation, the regenerated aluminum alloy cast ingot is taken out of the heat treatment furnace for water quenching, and the homogenized regenerated aluminum cast ingot is obtained. By means of the homogenizing process, inclusions, air holes and shrinkage porosity are effectively eliminated, the morphology of an iron-rich phase is improved, the MgSi phase is promoted to be redissolved into a matrix, the plasticity of the aluminum alloy is remarkably improved, an optimal structure is provided for subsequent extrusion forming production of a high-performance regenerated wrought aluminum alloy profile, and important industrial application value is achieved.

According to the industrial valve body forming method, through optimal design of a parting surface, optimal design of a pouring system, optimal design of a dead head, optimal design of chiller arrangement and optimal design of reduced scale and smelting process parameters in sequence, the size precision of a casting can be guaranteed, and meanwhile the quality of a flange face and the internal quality can be guaranteed; oxidation slag inclusion defects caused by turbulent flow are effectively reduced, the solidification speed of thick and large parts is increased, the shrinkage cavity and shrinkage porosity defects of key positions of castings are eliminated, the size precision and the internal quality of the valve body castings both meet the requirements of design drawings, and the product percent of pass is increased.

The invention belongs to the technical field of casting, and provides a method for improving shrinkage porosity of a reversing frame casting and the reversing frame casting, and the method comprises the following steps: obtaining a reversing frame by adopting the process steps of molten iron smelting, spheroidizing treatment, inoculation treatment and casting molding; wherein the carbon content in the casting is 3.8%, and the silicon content in the casting is 2.6%; the casting temperature is 1400 DEG C; a chilling block is arranged in the mold; the casting contains 0.0041%-0.0062% of bismuth, and the bismuth is added after spheroidizing and before inoculation. According to the method, by optimizing the technological conditions in the casting technology, the optimal technological conditions for casting are determined, the carbon content is 3.8%, the silicon content is 2.6%, the casting temperature is 1400 DEG C, and the chilling block is arranged, so that the shrinkage porosity and cavity defects of the casting are remarkably improved; and meanwhile, by further optimizing the components and the content relation of the casting, the strength performance of the casting is further improved on the premise that the shrinkage porosity and cavity defect improvement state is guaranteed, and the casting is made to be more suitable for the high-strength application scene requirement.

The invention provides a centrifugal casting method, device and equipment for a nodular cast iron pipe and a medium, and relates to the technical field of centrifugal casting. The method comprises the steps that analog simulation is conducted on the solidification structure in the centrifugal casting process of the nodular cast iron pipe, and a simulation result of the solidification structure is obtained; aiming at the simulation result of the solidification structure, fitting a mapping relation between each casting process parameter and the grain size of the solidification structure in a plurality of casting process parameters influencing the solidification structure; based on the mapping relation between each casting process parameter and the grain size of the solidification structure, casting process values corresponding to the multiple casting process parameters are determined; and performing centrifugal casting on the nodular cast iron pipe based on the casting process value. By the adoption of the scheme, the problems that due to improper selection of relevant casting process parameters, the solidification structure of the nodular cast iron pipe has the defects of air holes, impurities, shrinkage porosity, shrinkage cavities, hot cracks and the like can be solved, and therefore the quality of the produced nodular cast iron pipe is improved.

The invention discloses a GH625 forged rod and a preparation method thereof, and belongs to the technical field of metallurgy. The preparation method of the GH625 forged rod comprises the following steps that a consumable ingot is subjected to homogenization treatment; the consumable ingot obtained after homogenization treatment is forged; and the homogenization treatment comprises the following steps: preserving heat for 10-30 hours at the temperature of 1100-1150 DEG C and preserving heat for 10-80 hours at the temperature of 1150-1220 DEG C. According to the preparation method of the GH625 forged rod, through the combination of the homogenization treatment and the forging deformation process, segregation and shrinkage porosity formed in the preparation process of the oversized GH625 forged rod can be efficiently reduced, and the product yield and the qualified rate are increased.

The GDC casting mold comprises a left mold body and a right mold body, corresponding forming cavities are formed in the left mold body and the right mold body, sand cores are arranged in the forming cavities, riser cavities are communicated beside the forming cavities, vent holes are formed in the riser cavities, ejector pin rods are movably inserted in the vent holes, the ejector pin rods are of a hollow rod structure, and the ejector pin rods are of a hollow rod structure. One side of the ejector pin rod is fixed on an ejector plate, one side of the ejector plate is connected with an ejector driving piece, a vacuum generator is arranged on the ejector plate, one end of the ejector pin rod is communicated with a vacuum port of the vacuum generator, and an air supply port of the vacuum generator is communicated with an external compressed air supply source. According to the GDC casting mold, the dead head cavity communicates with the side of the forming cavity, waste gas left in the mold filling process of molten metal is gathered in the dead head cavity and is efficiently discharged along the vent hole, the ejector pin rod and a discharge outlet of the vacuum generator under the assistance of vacuum negative pressure, and the defects of air holes, shrinkage cavities or shrinkage porosity of castings are avoided; the compactness and the surface quality of the casting are influenced.

The invention relates to the field of polycrystalline high-temperature alloy blade investment casting simulation, in particular to a polycrystalline high-temperature alloy blade large-module casting simulation method. The method comprises the following steps: constructing a blade model, a pouring cup model, an upper cross gate model, a lower cross gate model and a middle connecting part model, assembling the models into a large-module casting, importing the large-module casting into analogue simulation software, and performing grid division; setting physical property parameters and heat transfer coefficients of the large-module casting and nucleation parameters of the blade at the research part; a temperature field distribution diagram, a temperature gradient distribution diagram, a shrinkage porosity and cavity defect diagram and a grain morphology diagram of the blade are obtained through simulation. According to the method, the integral casting process of the large-module process can be effectively simulated, the experiment time and cost are greatly saved, the large-module process parameters are optimized and designed in advance, and the method has important significance on batch application of the large-module casting technology.

The utility model discloses a device for eliminating shrinkage porosity and sand pores in a casting, which relates to the technical field of casting processing and comprises a bottom plate and a vertical rod, limiting shells are rotatably arranged on two sides of the upper surface of the bottom plate, two molds are inserted into the limiting shells, casting ports are arranged on the upper sides of the two molds, and the vertical rod is arranged on the vertical rod. The two vertical rods are fixedly arranged on the two sides of the upper surface of the bottom plate, transverse plates are fixedly arranged between the two sides of the two vertical rods, a movable ring is arranged between the two transverse plates, sliding blocks are fixedly arranged at the two ends of the movable ring, and strip-shaped openings are formed in the surfaces of the two transverse plates; the two sliding blocks are slidably connected with the corresponding strip-shaped openings, knocking rods are fixedly arranged on the two sides of the movable ring, a rotating rod is rotationally arranged on the upper surface of the bottom plate, and a rotating disc fixedly sleeves the upper end of the rotating rod. According to the utility model, shrinkage porosity and sand pore elimination work can be carried out on a plurality of castings at the same time, and the working efficiency can be greatly improved.

The utility model relates to the field of transfer tools, in particular to a transfer tool for investment casting of complex structural parts, which comprises a bottom plate, a plurality of through holes are arranged on the bottom plate, a support part is arranged on the bottom surface of the bottom plate, and the bottom plate and the support part are integrally cast by high-temperature alloy. An exhaust assembly is arranged on the upper surface of the bottom plate; the through holes are formed in the bottom plate, the weight of the transfer tool can be reduced, high-temperature alloy casting is adopted, the service life is prolonged, the arranged exhaust assembly is matched with the through holes in the bottom plate, the air convection speed of the bottom of a casting is increased, heat dissipation of the casting is facilitated, sequential solidification of the casting is facilitated, and the defects of shrinkage porosity and shrinkage cavities are overcome.

The invention belongs to the technical field of casting, and provides an optimization design method and an optimization design system for casting an exhaust pipe. The method comprises the following steps: S10, establishing a three-dimensional digital model designed by an exhaust pipe casting, a riser, a pouring system and an initial internal chill, and performing casting solidification process simulation on the three-dimensional digital model based on an interference signal set to obtain a shrinkage defect prediction result and an internal chill interface thermodynamic analysis result; s20, according to the shrinkage porosity defect prediction result, the geometrical shape and the structural layout of a specific area of the internal chill are adjusted; s30, adjusting design parameters and pouring process parameters of the contact interface of the internal chill and the exhaust pipe casting according to the thermodynamic analysis result of the interface of the internal chill; and S40, the steps are repeated, iterative simulation and optimization are carried out until the simulation result meets the preset shrinkage inhibition standard and the internal chill fusion standard at the same time, and the target internal chill design is obtained and output. According to the invention, the occurrence probability of black skin processing can be reduced on the premise of effectively inhibiting shrinkage porosity.

The invention discloses a loose piece type chilling block for aluminum alloy metal mold casting, and particularly relates to the technical field of metal casting, the loose piece type chilling block comprises a chilling block body, the chilling block body is made of a material with the thermal conductivity coefficient larger than or equal to 200 W / (m.K), one end of the chilling block body is provided with a transverse vent hole and two threaded holes, and the other end of the chilling block body is provided with a through hole; one end of the chilling block body is provided with a shell core inclined plane, the other end of the chilling block body is provided with a working inclined plane flush with the shell core inclined plane, a plurality of rib grooves are formed in the working inclined plane, exhaust grooves are formed in the upper side and the lower side of the chilling block body, and a positioning hole and a longitudinal vent hole are formed in the upper side of the chilling block body. The rib grooves and the exhaust grooves are additionally designed, so that the cooling efficiency and the exhaust effect are improved, shrinkage porosity, shrinkage cavities and gas shrinkage cavities are avoided, the longitudinal ventilation and exhaust holes and the transverse ventilation and exhaust holes are formed, the gas diffusion capacity is enhanced, meanwhile, heat dissipation is assisted, local cooling is accelerated, local thermal stress can be relieved, and the crack risk is reduced.

The invention relates to a narrow-breadth double-layer solid-liquid composite material based on molten aluminum and a preparation method and application thereof.The preparation method comprises the following steps that roughening treatment is conducted on the bonding surface of a plastic processing material, solid-phase particles are formed on the bonding surface of the plastic processing material through a spray drying method, and the solid-phase particles comprise metal with the melting point not higher than 650 DEG C; and liquid aluminum is prepared, the liquid aluminum is continuously cast on the bonding surface of the strip through a cast rolling technology, the solid particles and the liquid aluminum move along with the plastic processing material so as to pass through a roller and be subjected to aftertreatment to form the narrow-breadth double-layer solid-liquid composite material, the roughness of the bonding surface is 1-5 microns, and the average particle size of the solid particles is 1-5 microns. According to the scheme, the influence of direct introduction of solid-phase particles into the molten aluminum on the liquidity of the molten aluminum is avoided, shrinkage cavities and shrinkage porosity in the aluminum layer of the composite material can be reduced, meanwhile, a mechanical embedding structure can be formed with the combination surface of the molten aluminum and the strip in the cast rolling process, and the interface combination effect is improved.

The invention relates to a box type sand core type pouring system which comprises a sand box, a pouring system and a sand core box, and the pouring system comprises a first mold, a plurality of second molds, a cavity and a sprue; after sand is put into the sand core box to be solidified, the sand box is opened, and the first mold and the second mold are pulled out, so that channels, left on the sand box and the sand core box, of the first mold and the second mold form a transverse pouring gate and an inner pouring gate respectively; enabling the molten iron to sequentially pass through a straight pouring gate, an inner pouring gate and a transverse pouring gate to enter a cavity, and completing the molding of a casting; by optimizing the design of the pouring channel, uniform distribution of molten metal is achieved, the defects, such as air holes and shrinkage porosity, in a casting are reduced, and the overall quality of the casting is improved. By optimizing the design of the pouring channel, the hardness deviation of the plate surface is obviously reduced to be at least HB10, the sand inclusion and falling defects of the plate surface are eliminated, the use of consumables such as a ceramic tube, a rubber bottom and tube sticking glue is reduced, the production cost is greatly reduced, and the production efficiency is improved.

The utility model discloses an oblique outlet shell sand mold low-pressure casting mold which comprises an upper box, a lower box, a built-in sand core and an external sand core which are used for casting forming, the upper box and the lower box are detachably spliced into a box body, the built-in sand core and the external sand core are arranged in the box body, the external sand core is located between the upper box and the lower box, and the upper box and the lower box are detachably spliced into the box body. The external sand core is connected with the internal sand core in a clamped mode, sand collecting grooves are formed in the positioning and matching positions of the internal sand core and the external sand core and the lower box, a flange movable block is arranged on the oblique wire outlet position of the external sand core in a sleeved mode, and a chilling block is arranged on one side of the flange movable block. By pre-embedding the chiller, the defects such as shrinkage cavities and shrinkage porosity of important parts of the sealing groove of the casting flange are effectively avoided, so that the defect grade of the important parts reaches the standard; the external sand core can effectively solve the problem of difficulty in parting; smooth parting of the casting is ensured by adopting a flange loose piece to realize a flange segmentation mode; and shakeout in the casting is reduced by adding the sand collecting groove, and the casting quality of the casting is improved.

The invention discloses a pouring process and a pouring system of a disc casting and a product prepared by the pouring process and the pouring system, and belongs to the technical field of scroll plate processes. According to the method, a horizontal top riser process is adopted, molten iron containing a vermicular iron material enters a cavity through an inner pouring gate and a top riser, the pouring temperature is 1410-1430 DEG C, and the pouring time of a single ladle of molten iron is controlled within 10 min. And in the pouring process, the tangential speed of molten iron mold filling is controlled to be smaller than 1.2 m / s. According to the pouring technology, a horizontal top riser technology is adopted, the feeding pressure of a top riser is large, the feeding effect is good, the higher error-tolerant rate is achieved in the production process, and the interior of a casting is compact and free of the defects of shrinkage porosity, shrinkage cavities and the like. The mechanical properties of the prepared casting meet the conditions that the tensile strength is larger than or equal to 450 MPa, and the yield strength is larger than or equal to 315 MPa; the disc end face vermicularizing rate of the disc casting is larger than or equal to 60%, the center thin wall vermicularizing rate is larger than or equal to 40%, and the disc casting has high mechanical performance.

The invention discloses a die-casting forming method for an integrated die-casting automobile rear floor, and relates to a forming method for a die-casting automobile rear floor. The technical problems that the wall thickness of eight symmetrically-arranged boss structures in an existing integrated die-casting automobile rear floor exceeds 10 cm, cooling lag exists in the position during solidification, an isolated liquid phase area is easily formed, and shrinkage porosity and shrinkage cavities are formed are solved. According to the method, firstly, the optimal technological parameters are determined through simulation, then die-casting automobile rear bottom plate forming is conducted, eight local loading feeding openings are formed in total, the local extrusion specific pressure reaches 120-150 MPa, local extrusion can be achieved on all hot spot areas of a casting and the thick and large part of a product, the product density is improved, and defects are avoided. According to the method, local forced feeding can be effectively achieved by conducting local pressure supplementing on the boss position, the effect of eliminating serious shrinkage porosity and shrinkage cavity defects of the hot spot position through forced feeding is quite remarkable, and the method is quite beneficial to improving the overall mechanical property of the floor after integrated die casting.

The invention discloses a mold for aluminum alloy casting and an aluminum alloy casting feeding method.The mold comprises a left mold body and a right mold body, casting cavities are formed in the left mold body and the right mold body, sand cores are arranged in the casting cavities, the casting cavities are arranged in the vertical direction, the top ends of the casting cavities penetrate to the top of the mold, cap cavities are formed in the two sides of the casting cavities, and the cap cavities communicate with the casting cavities; the casting mold cavity is provided with a main pouring gate penetrating to the top end of the mold, a plurality of transverse pouring gates are arranged beside the main pouring gate, one end of each transverse pouring gate is communicated with the main pouring gate, the other end of each transverse pouring gate is communicated with the cap cavity, and the mold for aluminum alloy casting is used for feeding. The casting mold cavity of the mold for aluminum alloy casting is vertically arranged, the top end of the casting mold cavity is open, aluminum alloy liquid is stably filled from bottom to top, heat can be concentrated to the top, sequential solidification from bottom to top is formed, shrinkage cavities and shrinkage porosity are effectively reduced, an opening in the top provides a direct exhaust channel for gas in the mold and gas generated by a sand core, and the casting mold cavity is more stable. And the risk that the casting generates air holes is greatly reduced.

The utility model discloses a circuit breaker shell low-voltage mould internal non-metal riser sleeve assembly which comprises a circuit breaker shell body, a circuit breaker mould core is movably installed on the inner surface of the circuit breaker shell body, a first overflow piece is arranged on the top of the circuit breaker mould core, a second overflow piece is arranged on the right side of the first overflow piece, and the second overflow piece is arranged on the right side of the second overflow piece. A first riser bush is arranged on the right side of the second overflow piece, and a second riser bush is arranged on the right side of the first riser bush. According to the device, the first riser sleeve and the second riser sleeve are arranged, and in the shrinkage process of a casting, the first riser sleeve and the second riser sleeve are both made of non-metal heat preservation materials, and meanwhile, a first cover plate and a second cover plate can prevent heat of an injection molding solution in the first riser sleeve and the second riser sleeve from being rapidly diffused; and shrinkage porosity and shrinkage cavities caused by the fact that closed solidified hard skins are formed on the surfaces of injection molding solutions in the first riser sleeve and the second riser sleeve too early are avoided.

The invention provides a preparation method of a cobalt-based alloy casting, which comprises the following steps: S1, raw material preparation: selecting the following raw materials in percentage by mass: 50-65% of cobalt, 20-30% of chromium, 5-15% of tungsten, 3-8% of nickel, 0.2-0.8% of carbon and the balance of inevitable impurities, pretreating the raw materials to remove impurities such as surface oil stains and oxides; s2, smelting: adding the pretreated raw materials into a vacuum induction smelting furnace; according to the preparation method of the cobalt-based alloy casting, the raw material ratio and pretreatment are accurately controlled, smelting is conducted under the vacuum condition, and electromagnetic stirring is combined, so that the uniformity of alloy components is effectively guaranteed, and the stability of the performance of the casting is improved; the reasonable casting process comprises proper casting temperature, casting mold preheating and a bottom pouring type casting mode, so that the defects of air holes, shrinkage porosity and the like are reduced, and the casting quality is improved.

The invention relates to a numerical simulation and machine learning combined casting process optimization method and device.The method comprises the steps that during numerical simulation low-pressure casting, a mechanism model based on momentum conservation and energy conservation is adopted to solve a flow field and a temperature field, a volume function method is adopted to process a flowing free surface in the mold filling process, and the flow field and the temperature field are calculated; the microscopic segregation degree in the solidification process is determined according to the relation between the solidification solid phase fraction and the temperature, and a solidification temperature field simulation result is obtained; and according to the simulation result, adopting a Xinshan criterion representing the permeation feeding capacity of the solidified interdendritic liquid to predict the shrinkage cavity porosity so as to obtain the shrinkage cavity porosity volume, and adopting a machine learning method based on Gaussian process regression and heredity to predict the shrinkage cavity porosity under different low-pressure casting process conditions. Therefore, the problems that the design cost is high, the period is long, and the adaptability and robustness of the technological parameters are poor due to the fact that the selection of the casting technological parameters mostly depends on experience or repeated tests and a large number of simulation and actual trial casting tests are needed are solved.

The invention relates to the technical field of brake drum casting, and discloses a prediction method and system for brake drum casting process parameters, and the prediction method comprises the steps: obtaining a training data set, the training data set comprises characteristic variables and a shrinkage defect volume y, and the characteristic variables comprise brake drum size variables and process parameter variables; training the constructed feed-forward neural network by using a training data set to obtain parameter values of the feed-forward neural network, and obtaining a prediction model of the brake drum casting process parameters; measuring each numerical value of the brake drum size variable of the brake drum workpiece, selecting a plurality of groups of process parameter variables, substituting the brake drum size variable and each group of process parameter variables into the prediction model, and obtaining the shrinkage porosity defect volume y corresponding to each group of process parameter variables, and the technological parameter variable corresponding to the minimum shrinkage defect volume y is selected as the optimal technological parameter of the brake drum workpiece. And more suitable casting process parameters of brake drums with different sizes can be quickly obtained, and the time and economic cost is lower.

In order to improve the metallurgical quality of a thin-wall casting in the investment casting process, the invention provides a novel control method based on machine learning and a sequential solidification principle. The method comprises the steps that firstly, geometric structure parameters related to the solidification process are calculated on discretization representation of a casting model, and the geometric structure parameters comprise the distance from a local position to a casting head, the geometric modulus and the mold shell thickness; secondly, in combination with a numerical simulation result, a random forest algorithm is used for establishing a mapping model of geometric structure parameters and solidification time of the casting, and R2 on a verification set is 0.9974; based on the model, the gradient of a solidification curve on a geodesic path is quantitatively adjusted in combination with measures of local formwork thickness reduction and heat preservation cotton coating, and sequential solidification is achieved. And after optimization, the total shrinkage porosity volume of the casting is reduced to 24.78 mm < 3 > from 71.69 mm < 3 >, and is reduced by 65%. The effectiveness of the method is further verified through a pouring experiment, an efficient and quantitative solution is provided for shrinkage porosity control of the thin-wall complex casting, and a new thought is provided for intelligent control over investment casting defects.