597 results about "Investment casting" patented technology

The invention provides systems for integrated haptic design and fabrication of dental restorations that provide significant advantages over traditional practice and existing computer-based systems. The systems feature technical advances that result in significantly more streamlined, versatile, and efficient design and fabrication of dental restorations. Among these technical advances are the introduction of voxel-based models; the use of a combination of geometric representations such as voxels and NURBS representations; the automatic identification of an initial preparation (prep) line and an initial path of insertion; the ability of a user to intuitively, haptically adjust the initial prep line and/or the initial path of insertion; the automatic identification of occlusions and draft angle conflicts (e.g., undercuts); the haptic simulation and/or marking of occlusions and draft angle conflicts; and coordination between design output and rapid prototyping/milling and/or investment casting.

<heading lvl="0">Abstract of Disclosure</heading> A dental prosthesis is made by first forming a model of a patient's dentition. A three dimensional digital data corresponding to the surfaces of the model is then created. Based on this data, a three dimensional digital data file is then created substantially corresponding to the dental prosthesis to be manufactured. The three dimensional digital data of the dental prosthesis to be manufactured is next transmitted to automated prototyping equipment, and using the automated prototyping equipment, a wax pattern of the dental prosthesis is manufactured based upon this three dimensional digital data of the dental prosthesis. Finally, using this wax pattern in the lost wax investment casting process, the dental prosthesis is made. Prior to investment casting, marginal edges of the wax pattern are adjusted manually.

A castable high temperature aluminum alloy is cast by controlled solidification that combines composition design and solidification rate control to synergistically enhance the performance and versatility of the castable aluminum alloy for a wide range of elevated temperature applications. In one example, the aluminum alloy contains by weight approximately 1.0-20.0% of rare earth elements that contribute to the elevated temperature strength by forming a dispersion of insoluble particles via a eutectic microstructure. The aluminum alloy also includes approximately 0.1 to 15% by weight of minor alloy elements. Controlled solidification improves microstructural uniformity and refinement and provides the optimum structure and properties for the specific casting condition. The molten aluminum alloy is poured into an investment casing shell and lowered into a quenchant at a controlled rate. The molten aluminum alloy cools from the bottom of the investment casting shell upwardly to uniformly and quickly cool the aluminum alloy.

The invention discloses a wax injection mold for investment casting of hollow turbine blades and a method for rapidly and accurately manufacturing the wax injection mold. The mold consists of a cavity mold, a mold core and an accessory structure, wherein the cavity mold comprises an upper mold and a lower mold of a combined structure; each mold block forming the cavity mold consists of an external aluminum mold frame, an internal cast zinc alloy inlay and a conformal cooling copper pipe embedded into the inlay; a mold core positioning piece which can be decomposed at a high temperature is arranged on a longitudinal rib of the mold core; and water-soluble core blocks used for forming exhaust openings in the rear edges of the turbine blades are arranged on rear edge ribs of the mold core. The matching precision of the mold core positioning piece and the cavity mold is guaranteed by adopting a cavity mold interior running-in method, and the matching precision of the water-soluble core blocks and the cavity mold is guaranteed by adopting a cavity mold interior adhesion method. The wax injection mold disclosed by the invention is low in manufacturing cost and short in period, and the high wax pattern precision and core positioning precision can be obtained.

A method for combining three different means of constructing the concentric layers of the outer collecting wall for industrial size centrifuges, whereby treating the inward-facing elements of easily cast or stamped materials using processes such as Physical Vapor Deposition, Chemical Vapor Deposition or metal plating, transforms them into an innermost member with superior hardness and durability, and whereby said wear surface member or deposited layer is physically supported by a middle composite layer made up of one or more investment castings designed to optimally transfer centrifugally-induced compression loads from the innermost wear surface toward the outer surface of the composite wall, such castings being of ceramic, metals or other materials, and whereby the outer surface of said composite wall is comprised of a filament-wound hoop strength reinforcement layer, using aramid, graphic, carbon or such fibers mixed and embedded in resin, such that all highly desirable characteristics for a centrifuge outer, heavies-collecting wall are provided, including interior hardness and wear abrasion, incompressibility and intrinsic dynamic balance, and substantially higher hoop or bursting strength, than can be attained through any metal-crafted centrifuge outer wall, and, model for model, for substantially lower design and fabrication costs.

A method for making an article by an investment casting process is presented, along with a method for making casting cores, the casting cores made by this method, and dies for making such cores. The method for making a component comprises providing a single-piece sacrificial die, the die comprising at least one internal cavity; introducing a ceramic slurry into the at least one cavity of the die, the slurry comprising a ceramic and a carrier fluid; curing the slurry to form a ceramic casting core; removing the sacrificial die by exposing the die to an environment adapted to destroy the die while leaving the ceramic casting core intact; and performing an investment casting process using the ceramic casting core as part of a mold-core assembly to form the component.

A green product for use in fabricating a ceramic article comprises a ceramic powder immobilized within a silicone matrix, wherein the silicone matrix comprises one or more cross linked or polymerized silicone monomers and/or oligomers, wherein the one or more cross linked or polymerized silicone monomers and/or oligomers have a alkenyl reactive functional group and a hydride reactive functional group. Processes for forming a green product and a ceramic core with the silicone monomers and/or oligomers are also disclosed.

The invention discloses an aluminum-based dot matrix material based on 3D printing technology. In the dot matrix material, industrial pure aluminum or any aluminum alloy is employed as a base body. Unit cell configuration and a periodic structure thereof are modeled and designed with CATIA software and the model is produced from high-molecular materials through the 3D printing technology. An investment casting shell mould is prepared from soluble gypsum and the aluminum-based dot matrix material is prepared through an air-pressure seepage process. The aluminum-based dot matrix material can be in a pyramid type, a Kagome type and a grating type in the unit cell configuration. The invention also provides a sandwiched plate composite structure composed of the dot matrix material and a compact surface plate. The diameter of a unit cell bar is 0.5-5.0 mm, the length of the unit cell bar is 0.5-15.0 mm, and an included angle between the unit cell bar and a protective surface is 30-70 degrees. The compact surface plate is made from industrial pure aluminum, aluminum alloy, iron alloy or high-molecular materials. The dot matrix material with the industrial pure aluminum as the base body can reach higher than 5 MPa/g*cm<-3> in specific compressive strength.

The present invention provides a low viscosity photocurable composition including (i) a cationically curable component (ii) a free radically active component (iii) an antimony-free cationic photoinitiator (v) a free radical photoinitiator, and (vi) a toughening agent. The photocurable composition can be cured using rapid prototyping techniques to form three-dimensional articles which can be used in various aerospace and investment casting applications.

The present disclosure generally relates to integrated core-shell investment casting molds that provide filament structures corresponding to cooling hole patterns on the surface of the turbine blade or stator vane, which provide a leaching pathway for the core portion after metal casting. The invention also relates to core filaments that can be used to supplement the leaching pathway, for example in a core tip portion of the mold.

The present disclosure generally relates to integrated core-shell investment casting molds that provide filament structures corresponding to cooling hole patterns in the surface of the turbine blade or stator vane, which provide a leaching pathway for the core portion after metal casting. These filament structures may be linear or non-linear. The invention also relates to core filaments that can be used to supplement the leaching pathway, for example in a core tip portion of the mold.

The present disclosure generally relates to partial integrated core-shell investment casting molds that can be assembled into complete molds. Each section of the partial mold may contain both a portion of a core and portion of a shell. Each section can then be assembled into a mold for casting of a metal part. The partial integrated core-shell investment casting molds and the complete molds may be provided with filament structures corresponding to cooling hole patterns on the surface of the turbine blade or the stator vane, which provides a leaching pathway for the core portion after metal casting. The invention also relates to core filaments that can be used to supplement the leaching pathway, for example in a core tip portion of the mold.

A method of making pairs of thread splits inserts used to injection mold bottle preforms. Machining a hollow outer part of the pair of thread split inserts with an opening therethrough and outer portions of two cooling conduits extending from the opening therethrough to respective inlets and outlets. Making an inner part of the pair of thread split inserts by injection molding a ceramic core with the required shape and investment casting the inner part around the ceramic core. The outer surface of the inner part having grooves to partially form inner portions of the two cooling fluid conduits. Then machining the cast inner part to fit in the opening through the outer part. Mounting the outer part around the inner part with the inner and outer portions of the two cooling fluid conduits aligned. Applying brazing material between the inner and outer parts and heating them in a vacuum furnace to integrally braze them together. Finally, cutting the integral inner and outer parts in half to form the pair of thread split inserts with each of the thread split inserts having one of the cooling fluid conduits therein.

The present disclosure generally relates to integrated core-shell investment casting molds that provide a filament structure corresponding to a cooling hole pattern in the surface of the turbine blade or stator vane, which provide a leaching pathway for the core portion after metal casting. The invention also relates to core filaments that can be used to supplement the leaching pathway, for example in a core tip portion of the mold.

The invention discloses a method for preparing a shuttering for a precision investment casting TiAl-based alloy, and relates to a method for preparing an oxide ceramic shuttering. The method solves the problems of slow drying for making the shuttering, longer production period for cast and high cost during production of a TiAl-based alloy precise cast. The preparation method comprises: firstly, adopting SLS technology to prepare a fusible pattern; secondly, coating polyvinyl alcohol on the surface of bauxite and grinding the bauxite into granules; thirdly, smearing a shuttering surface layer; fourthly, smearing a shuttering back layer; fifthly, removing wax from the shuttering, and roasting the shuttering; and sixthly, casting the TiAl-based alloy in vacuum to obtain the TiAl-based alloy cast. The method only needs 13 to 15 days to obtain the TiAl-based alloy precise cast from CAD design, but the prior method at least needs 45 to 60 days, so the method saves nearly two thirds of production period, and the manufacturing cost is correspondingly lowered.

The present disclosure generally relates to partial integrated core-shell investment casting molds that can be assembled into complete molds. Each section of the partial mold may contain both a portion of a core and portion of a shell. Each section can then be assembled into a mold for casting of a metal part. The partial integrated core-shell investment casting molds and the complete molds may be provided with filament structures corresponding to cooling hole patterns on the surface of the turbine as or stator vane, which provide a leaching pathway for the core portion after metal casting. The invention also relates to core filaments that can be used to supplement the leaching pathway, for example in a core tip portion of the mold.

An article may be manufactured by providing a reticulate core element in a mold shell having a shape at least partially corresponding to a shape of the article. The molten metallic material is introduced to the shell so as to at least partially infiltrate into the reticulate core element. The molten metallic material is permitted to solidify. The shell and the reticulate core element are destructively removed. The removal leaves the article with one or more gas-permeable porous regions.

The present disclosure generally relates to integrated core-shell investment casting molds that provide an indentation structure corresponding to a thin root component of the turbine blade or vane (i.e. angel wing, skirt, damper lug).

A fugitive pattern for making a shell mold for investment casting a metal or alloy comprises a substantially random interpolymer and a low molecular weight polymer in proportions to provide a fugitive pattern having a combination of properties suitable for use in making the shell molds.

The invention relates to a case making method of a silica sol investment casting with a slender hole structure, and the method is achieved through adopting the following steps of max mould preparation 1, doping 2, sanding 3, drying 4, in-hole grouting 5, continuous case making 6, demaxing 7 as well as roasting and casting 8, wherein the steps between the doping 2 and the drying 4 are adopted for 2-3 times; wherein in the step 5, the in-hole grouting is achieved through the following steps: soft white slime is used for plugging up the lower end and a lateral hole of a part, and a stainless steel wire used for ensuring that a mandril is not fractured at the end part is inserted into the end part of the hole, and the diameter of the stainless steel wire is about 2mm; and sizing agent is injected after the process of plugging up the hole and inserting the wire are ready, and the case making is continued after the sizing agent is solidified. The invention has the advantages that a mold core die is independently manufactured, the period is short, and the cost is low; in addition, the method is not limited by the sorts of the dies and is especially suitable for small amount of products or a single product, and the application is flexible.

This invention provides methods for forming stainless steel, single-piece, multi-chambered water faucets and fixtures with a single one-body construction. A variety of stainless steel products can be formed with a main body having an internal hollow region and a plurality of dividing chambers. The main body may be constructed using high temperature resistant ceramic cores in combination with a lost wax investment casting process. The stainless steel products formed from a single piece construction can eliminate the need for additional time-consuming manufacturing steps, such as parts welding, screw assembly, or precision press fitting. In addition, water faucets and fixtures can be provided that are substantially lead-free, non-verdigris, and non-toxic in compliance with environmental regulations and lead/toxic limits.

At least one feed core and at least one wall cooling core are assembled with a number of elements of a die for forming a cooled turbine engine element investment casting pattern. A sacrificial material is molded in the die. The sacrificial material is removed from the die. The removing includes extracting a first of the die elements from a compartment in a second of the die elements before disengaging the second die element from the sacrificial material. The first element includes a compartment receiving an outlet end portion of a first of the wall cooling cores in the assembly and disengages therefrom in the extraction.

The invention discloses a precision lost wax casting technology based on selective laser powder sintering 3D printing. The precision lost wax casting technology comprises the following steps that S101, a target part is subjected to optimal design of a CAD casting technology; S102, selective laser powder sintering 3D printing forming is carried out; and S103, silica sol/water glass precision investment casting is carried out. A wax mold of the part can be fast manufactured without molds, the metal part is fast manufactured, fast manufacturing of complex parts can be achieved, and integration, automation and fastness in the precision casting technology process can be achieved; and the development period of new products are greatly shortened, development cost is reduced, and the precision lost wax casting technology is especially suitable for production of single small-batch complex castings and trial-manufacturing of new products.

The invention provides a partial cooling technology of cold iron in investment casting. The partial cooling technology comprises the following steps of: 1, manufacturing a wax model by a general investment casting process; 2, designing the cold iron and a wax block which has the same shape and dimension as the cold iron, according to the shape of the outer surface of a hot spot of a casting, and then manufacturing the cold iron and the wax block, wherein the inner surfaces of the designed cold iron and the wax block are clung to the outer surface of the hot spot of the casting in shape, and the cold iron and the wax block are provided with positioning platforms; 3, fixing the wax block to a part requiring partial chilling on the wax model, and tightly clinging to the surface of the wax model; 4 manufacturing a housing at the surface of the wax model, and exposing part of the positioning platform of the wax block from a model housing; 5, dewaxing the model housing; 6, roasting the model housing at high temperature; 7, fixing the cold ion in an opening of the model housing, and positioning through the positioning platform; and 8, casting after preheating the model housing, wherein the partial chilling effect is realized in the cold iron. By carrying out the steps mentioned above, the heat exchange at the hot spot of the casting can be improved, the chilling effect can be realized, and as a result, the purpose of reducing the defect of dispersed shrinkage of a shrinkage cavity in the casting can be realized.

An investment casting thin-walled part casting method is disclosed, comprising the following steps of: (1) manufacturing the mould of a wax pattern; (2) manufacturing the wax pattern; (3) welding the wax pattern and a pouring wax rod group to a module; (4) shell making; (5) de-waxing; (6) roasting the shell; (7) pouring; (8) cleaning the shell; (9) heat treatment; (10) removing reinforcing ribs, implementing root polishing and ball blasting; the mould manufacturing of the wax pattern comprises that a mould is provided with two parallel cast cavities between which a plurality of channel holes are arranged; the wax manufacturing comprises that: the wax is injected into the mould of the wax pattern at first and then the wax pattern is de-moulded after being cooled, therefore, the shaped wax pattern is of a catamaran-type structure, and wax-made reinforcing ribs equal to the number of the channels in the step (1) are arranged between the catamaran-type structure. Compared with the prior art, the invention has the characteristics of being difficult of deformation, high rate of finished products and high benefit.

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 relates to a precise forming method for titanium-aluminum intermetallic compounds. According to the method, yttrium oxide powdery sand is selected as a surface-layer refractory to prepare a ceramic shell for investment casting, and in combination with processes such as a vacuum consumable skull furnace or a vacuum induction water-cooling copper crucible furnace and centrifugal casting, a titanium-aluminum intermetallic compound casting is prepared. The ceramic shell prepared according to the forming method is high in inertia, and good in matching between strength and deformability and collapsibility, and is suitable for investment casting of the titanium-aluminum intermetallic compounds; a prepared casting is complete in forming, the smallest wall thickness can reach 1mm, the dimension precision reaches lower than CT7, a surface pollution layer is thin, surface roughness is less than or equal to 6.3 micrometers, and more importantly, cracks cannot be formed, and therefore, the problems that titanium-aluminum alloy is low in room-temperature plasticity and easy to crack during forming are solved. The forming method is applicable to development and engineering production of various structural parts of the titanium-aluminum intermetallic compounds.

An investment casting pattern is formed by installing a first core to a first element of a molding die to leave a first portion of the first core protruding from the first element. After the installing, the first element is assembled with a feed core and a second element of the molding die so that the first portion contacts the feed core. A material is molded at least partially over the first core and the feed core. The first portion has one or more surface area enhancements.

The invention discloses a rapid investment casting method based on stereolithography (SL). A wax mould in investment casting is replaced with a resin prototype (1) produced by applying a 3D printing technology, the resin prototype (1) is of a thin-walled honeycomb structure, an ingate (2) is arranged on the resin prototype (1), a gating system adopts a conventional wax gating system (3), a groove (4) is formed in the wax gating system (3), the ingate (2) is inserted into the groove (4) to be bonded and fixed during tree casting, a wax rod (5) is arranged on the resin prototype (1), and vent holes are formed after shell making. The rapid investment casting method reduces the casting cost, reduces the production cycle, and avoids the cracking phenomenon of a shell in the process of roasting.

The present disclosure generally relates to integrated core-shell investment casting molds that provide an integrated ceramic filter. These integrated core-shell investment casting molds also provide filament structures corresponding to cooling hole patterns on the surface of the turbine blade or stator vane, which provide a leaching pathway for the core portion after metal casting. The invention also relates to core filaments that can be used to supplement the leaching pathway, for example in a core tip portion of the mold.