Directional hardening of metal teemed in mould. RU patent 2520282.
 Device to produce castings with directed and monocrystalline structure / 2492026Invention relates to metallurgy and may be used for making gas turbine blades, jet nozzle flaps and spacers, disc billets, etc. Proposed device comprises vacuum chamber with end covers, induction melting furnace, mould heating furnace, mould cooling container, heat isolation shield arranged between mould heating furnace and mould cooling container and mould suspension system. Mould heating furnace top zone comprises two electric heaters connected in parallel and equipped with separate power supplies. Vacuum chamber front end cover is mounted at monorail to displace perpendicular to the device lengthwise axis. Heat isolation shield is composed of at least two segments with individual drives and guides. Mould suspension system comprises mould support to prevent its deformation and destruction. Bottom zone heater height makes 1/3-1/4 of top zone heater height. Induction melting furnaces comprises crucible with capacity approximating to 60 kg. |
 Method of producing monocrystalline articles from refractory nickel alloys with preset crystal-lattice orientation / 2492025Invention relates to metallurgy. Proposed method comprises casting the monocrystal billet of arbitrary crystal-lattice orientation, its seeding to macrostructure, defining the billet orientation as the angle between its geometrical axis and the plane of selected crystal-lattice orientation, cutting the billet to seeds at obtained angle with cutting plate located parallel with selected crystal-lattice orientation plane. Seed end is seeded to macrostructure and marks are applied thereon that correspond to crystal-lattice orientations in the cutting plane. Said seed is placed in the mould seed seat so that seed end is located along article geometrical axis. Article crystal-lattice orientation is set by aligning the mark of definite orientation with the article geometrical axis. |
 Gas turbine engine blade made by investment casting and method of its production, gas turbine engine with said blade, and gas turbine engine / 2477196Invention relates to metallurgy. Gas turbine engine is produced by investment casing. Blade comprises root 4 with anvil 5 made integral with said root. Anvil comprises site 5a provided with first tray 12 with radial surfaces 13 and bottom 14. Said tray 12 serves to decrease anvil thickness. Second tray 16 is made in first tray 12, between root and anvil, to facilitate metal pouring in investment mould solely at one point. |
 Method of gravity casting of shaped casts / 2444415Invention relates to casting shaped casts (different-wall complex-shape casts) using casting moulds. Proposed method consists in feeding melt portions in the mould in definite time intervals. Melt portions are solidified solely from below by directed heat exchange between portion and mould and said heat exchange is controlled by temperature control instruments. Program of portion feed digital ACS control signals is developed to control portion volume and time intervals between portion feed with due allowance for computer simulation of melt solidification in mould. To determine portion volume, criterion of invariability of reduced portion R0 is used as relation of liquid melt portion volume V to area of portion chilled surface F, while time of feed next portion is defined from (60…80)%-th degree of previous portion solidification. |
 Method of producing articles from heat resistant monocrystalline nickel alloys / 2427446Invention relates to metallurgy and may be used in producing large-size long castings for gas turbine units and engines from monocrystalline heat resistant nickel alloys operated at 1500°C. Castings are produced in ceramic mould made up of starting cavity, moulding cavity and dozzle section. Starting cavity and moulding cavity are arranged at 90-120° to dozzle section. Ceramic mould is heated to preset temperature while heat resistant nickel alloy is heated in melting crucible to temperature exceeding liquidus temperature to fill melt into ceramic mould. Cast directed crystallisation is conducted by radiation method on displacing ceramic mould from heating zone into cooling zone at preset rate. Ceramic mould is displaced horizontally while crystallisation is performed at metallostatic pressure of 5-25 g/cm2. |
 Procedure for production of mono-crystal nuclei simultaneous with mono-crystal part casting / 2422564Here is disclosed procedure for production of at least one mono-crystal nucleus acceptable as seed at fabrication of high pressure mono-crystal guiding nozzle unit of turbo-machine with at least one blade between two platforms by metal casting. The procedure consists in making wax pattern 10 containing first element 11 forming a pattern of the guiding nozzle unit, second element 13 forming pattern of seed and containing a flat shear of localisation of crystal orientation, and at least third element 14 including pattern 14A of source nucleus with a flat shear of localisation of crystal orientation. There is formed a ceramic case casting mould on base of the said wax pattern 10 and there is introduced seed containing the said flat shear of localisation of crystal orientation into a casting mould. Metal is cast into a mould. Oriented crystallisation of metal in the cast mould on base of seed is carried out so, as to facilitate the same crystallographic structure of produced source nucleus as of the part. Produced source nucleus is separated from the part for further usage as seed. |
 Method of casting of ring-like ingots from refractory difficult-to-form nickel-based alloys / 2422244Invention relates to metallurgy, particularly, to produce and deform ingots from refractory difficult-to-form nickel alloys operated at above 600°C, particularly, gas turbine composite plates, rolled rings, etc. Proposed method comprises vacuum-induction casting of alloy to produce charge, making ceramic mould, melding charge of refractory alloy, casting melt into ceramic mould and performing directed crystallisation in ceramic mould. Ceramic mould is made up of outer and inner parts and baffle inserts. Mould inner part is fitted on outer part bottom. Space between outer part inner wall and inner part outer wall are divided in height by baffle inserts into two parts equal to ingot height. Said inserts have bores for filling and feeding bottom ingots in directed crystallisation of ingots. |
 Cooling component of mould casting material and use of said mould component / 2422243Invention is intended for sand mould for casting cylinder block 1 from casting material consisting of light metals. Mould cooling component is made from Ni- and/or Mn-alloyed foundry iron. Content of Ni and/or Mn in foundry iron is selected to make thermal expansion factors of component 2 complying with that of light metal material. |
 Method of producing casts with directed structure / 2411106Invention relates to casing and may be used for production of gas turbine engine vanes from heat-resistant alloys. Proposed method comprises producing shell mould, placing stub at mould bottom prior to heating, heating mould to above liquidus temperature of heat-resistant alloy, filling mould with melt, and performing directed crystallisation with the help heat-resistant stub. Stub is produced by casting in vacuum furnace in open-bottom mould arranged on uncooled copper crystalliser. Stub cooled down, its surface is ground that stays in contact with uncooled crystalliser to depth of amorphous frozen crystals zone. Then, deep etching of stub surface layer is performed to produce distinguished boundaries in relief structure between column grains of crystals. |
 Method of thermal control on injection moulding machine mould and device to this end / 2403125Invention relates to metallurgy. Proposed method consists in heating the mold prior to injecting melt and cooling the mould down to part withdrawal temperature. Melts represents thermosoftening plastic material. Mould is heated to melt temperature prior to injecting thermosoftening plastic material therein. Mould is heated by feeding heat carrier from high-temperature heat carrier tank. In cooling the mould with the part, mould temperature is regulated by feeding the controlled-temperature coolant. Said controlled temperature is obtained by mixing low-temperature heat carrier with high-temperature heat carrier fed from appropriate tanks. Proposed device comprises heat carrier heater, heat exchanger for cooling heat carrier, driven pump to feed heat carrier into mould, heat carrier temperature pickups, high-temperature heat carrier tank with heater, low-temperature heat carrier tank with heat exchanger, three-way valve communicating mould outlet branch pipe with heat carrier tanks inlet branch pipes, and three-way valve communicating tanks outlet branch pipes with the pump intake branch pipes. |
 Blade for aircraft compressors and turbines / 2243851Proposed blade includes vane with leading and trailing edges and platform. Vanes and platform are made in form of separate interconnected monocrystals. Each monocrystal has different direction of crystallization relative to longitudinal axis of blade. Deviation from direction of crystallization of vane and/or platform and direction of maximum working tension stresses does not exceed 15 deg. |
| Refrigerating fluid for casting with directional crystallization / 2243852 Claimed fluid contains (mass %): copper 24.9-27.1 and tempers: silicium 6.0-7.0; iron 0.4-0.6; aluminum 68.7-65.3. Copper and silicium decrease fluid viscosity, increase castability and improve convective cooling. Iron in limits of its solubility in aluminum affords the ability to except dissolution of crystallizer steel bath. |
| Cooling liquid for directed-crystallization casting / 2245758 Cooling liquid contains aluminum and alloying elements such silicon and manganese. Components are taken at next relation, mass. %: silicon, 11.5 - 12.5; manganese, 0.9 -1.3 ; aluminum, 87.6 - 86.2. Silicon provides enhanced fluidity and lowered viscosity of alloy. Silicon and manganese have high heat conductivity, heat capacity and density. It provides increased convection cooling. |
| Cooling liquid for directed-crystallization casting / 2245759 Cooling liquid contains aluminum and alloying elements such as copper and silicon. Components are taken at next relation, mass. %: copper, 25.6 - 27.8; silicon, 5.1 - 5.4; aluminum, 69.3 - 66.8. Presence of silicon provides enhanced fluidity and lowered viscosity of alloy. Silicon and copper have high heat conductivity, heat capacity and density providing increased convection cooling. |
| Cooling liquid for directed crystallization casting / 2247627 Cooling liquid includes aluminum and alloying elements, namely copper and zinc. Components are taken at next relation, mass. %: copper, 17 - 16; zinc, 1.9 - 3.6; aluminum, 81.1 - 80.4. Zinc and copper are characterized with high heat conduction, heat capacity and density. It enhances convection type cooling. Presence of zinc increases fluidity and decreases viscosity of alloy. |
 Method for casting hollow cooled articles and cast cooled hollow article / 2252109Method comprises steps of making article with use of composite ceramic core produced by two stages; placing preliminarily made and fired additional cores into pattern press-mold; making pattern and placing it into core press-mold; at temperature 90 - 110°C pressing-in ceramic mass for making main core to be joined in press-mold with additional cores as one piece; removing pattern and subjecting composite core to high-temperature annealing. Ready article features 3 - 5 accuracy class and surface of 3 - 5 purity class. |
 Method for producing nickel-alloy castings / 2254962Intermetallide nickel alloy is used as nickel alloy for casting. Method comprises steps of super heating melt before casting it by 250 - 290 C higher than liquidus temperature of alloy; soaking it no more than 3 min; then superheating alloy by 170 - 220°C higher than liquidus temperature of alloy and soaking it no more than 10 min; cooling alloy until temperature of pouring it at rate 10 - 50°C/min and pouring alloy into hot molds. Directed crystallization of alloy is realized due to moving mold from heating zone to zone for cooling at rate 40 - 240°C/min. After crystallization mold with casting is moved back from cooler to heater and it is soaked at temperature 1100 - 1150°C no less than for 15 -20 min. |
 Device for production of castings of directive and mono-crystal structure / 2258578Proposed device has heating zone with heater and cooling zone which are separated by heat-insulating shield. Heater with unit of ceramic casting molds is mounted in heating zone. Cooling zone is provided with movable water-cooled cooler. Device is additionally provided with fixed water-cooled cooler mounted under shield. Shield and fixed cooler have holes which are coaxial relative to one another and to each casting mold. Clearance between holes and casting molds are minimum. |
 Method for forming member of turbine nozzle apparatus and turbine nozzle apparatus / 2265496Method comprises steps of making model of member of nozzle apparatus having starting and blade portions; forming starting portion of model in the form of two plates being circle sectors; connecting centers of sectors in the same point; connecting arcs of sectors with blade portion of member; according to model making ceramic mold; heating it, pouring melt and realizing oriented crystallization of alloy; removing produced casting out of ceramic envelope and core; then extracting starting portion; mutually joining blade portions and forming impeller of turbine nozzle apparatus. Method provides possibility for making detachable nozzle apparatuses with blades having mono-crystalline structure and predetermined crystallographic orientation. |
 Method for forming member of turbine impeller and turbine impeller / 2265497Method comprises steps of forming model of member of turbine impeller having disc and blade portions; making disc portion of model of two plates in the form of circle sectors; connecting central angles of sectors in the same point and connecting arcs of sectors with blade portion of member; making ceramic mold according to prepared model; heating it and pouring melt into it; in order to form blade portion of member, pouring refractory nickel-base alloy and starting process of oriented crystallization; in order to form disc portion of member, pouring deformed refractory nickel-base alloy and terminating oriented crystallization process. Method allows produce built-up impellers of turbines whose discs with blades have mono-crystalline structure of predetermined crystallographic orientation and sufficient mechanical strength. |
FIELD: metallurgy.
SUBSTANCE: proposed method comprises application of different-composition protective-separation coatings on the mould surface before teeming of fused metal. Coating, 0.1-0.2 mm thick, consisting of ultrafine powder of magnesium oxide in amount of 20-25 wt % and industrial oil in amount of 78-80 wt %. Coating, 0.2-0.3 mm thick, consisting of ultrafine powder of zirconium oxide in amount of 20-25 wt % and industrial oil in amount of 75-80 wt %. Coating, 0.3-0.4 mm thick, consisting of ultrafine powder of zirconium oxide in amount of 20-25 wt % and industrial oil in amount of 75-80 wt %.
EFFECT: directed crystallisation of metal, higher strength of casts.
1 dwg, 1 ex
The invention relates to the field of foundry production, namely the method of directional solidification filled in form of the metal.
The known method of directional solidification filled in the form (metal Buildover. Metallurgy is the same yesterday, today, tomorrow. Kiev: Naukova Dumka, 1990, str, RIS).
Its disadvantage is the difficulty of play of the results obtained from ingot to the bullion due to the lack of backward linkages, providing an opportunity of correction operational parameters of ingot solidification.
The known method of casting the disk and the ring blanks of heat-resistant hard alloys on a Nickel basis. The method includes the vacuum-induction smelting alloy with obtaining raw materials procurement, manufacturing ceramic forms, melting raw materials procurement heat-resistant alloy, fill melt in ceramic form and conduct directed crystallization in ceramic form. Ceramic mold made from the outer, the inner parts and the insertion of partitions. The inner part of the ceramic form installed at the bottom of the outer part. The space between the inner wall of the outer part and the outer wall of the internal parts in height inserts-partitions into parts, equal to the height of blanks. In boxes with holes, through which carry out the filling and feeding downstream blanks in the process of directional crystallization casting. Reduced complexity of manufacturing of details, increase the utilization of metal.
The disadvantages of this method are the limitations of using only a Nickel-based alloys, as well as complex and costly mold. The method may not be used without the need to readjust the equipment in standard conditions.
The known method of directional solidification filled in the form of metal (RF patent №2392092 from 02.07.2008). The method includes control of the process of crystallization in uniform, equipped with means of ensuring temperature difference in the direction crystallization of metal. Use a circular shape with a tapered inner surface. The temperature difference in the direction crystallization of metal is carried out by means of simultaneous cooling of annular shape from the bottom and its internal surface and heating metal in its upper part. Improved quality of castings.
The disadvantage of this method is complicated and expensive mold, as well as the inability to apply without readjustment of the equipment under standard conditions.
Closest to the claimed method is a method that is described in the patent №1680441 from 30.09.1991. The method consists in the fact that the pouring of molten metal produce in the mold coated with its internal surface coating thickness of 0.3-1.5 mm, short warmed up by means of an electric current with voltage 30-400 Century Floor consists of a mixture of graphite powder, alumina and gel SiO2 as a binder allocated from hydrolyzed solution of ethyl silicate, taken in the ratio,%: graphite 17-40, SiO 2 12-19, alumina else. The number of graphite coating changes within the specified limits, increasing from casting to supply parts of the Gating system. The electric current is led to the mold and poured the metal in the ladle.
The disadvantage of this method is the need for additional equipment and electric power for heating cover and chill mould, the need to prepare mixtures of different composition for different quantities of graphite in the floor in different parts of the mold.
The objective of the invention is a way to use without readjustment of the equipment under standard conditions.
The task is achieved by the fact that before pouring molten metal into the mold, on the part of its surfaces are applied protective-release covering various compositions. On the lower part of the walls of the mold coated, consisting of ultrafine powder of magnesium oxide 20-25% by weight and industrial oils 75-80% by weight the thickness of 0.1-0.2 mm In the middle part of the mold coated, consisting of ultrafine powder of zirconium oxide 20-25% by weight and industrial oils 75-80% by weight thickness of 0,2-0,3 mm On the top of the mold coated, consisting of ultrafine powder of zirconium oxide 20-25% by weight and industrial oils 75-80% by weight thickness of 0,3-0,4 mm
As a result, after pouring molten metal of the most intense heat goes through the bottom of the mold that is not coated. Less intense heat goes through the lower part of the walls of the mold coated, based on the powder of magnesium oxide. And the least intense heat goes through the middle and upper parts of the walls of the mold, where the coating based on zirconium oxide, as zirconium oxide has a lower thermal conductivity compared to magnesium oxide and thickness of coating layer Zirconia more. Thus, a directional heatsink on top of the casting to the bottom of the mold, this creates the necessary conditions for the directed crystallization of the melt.
The use of the proposed method of directional solidification of metal, ceteris paribus, can improve the quality alloyed and unalloyed metal, provides the possibility of reducing the consumption of alloying additives in metal for low-duty parts and high quality metal for the manufacture of critical parts.
Figure 1 shows: on the lower part surface of the mold 1 cause 2 floor, consisting of ultrafine powder of magnesium oxide 20-25% by weight and industrial oils 75-80% by weight the thickness of 0.1-0.2 mm In the middle part of the mold coated 3, consisting of ultrafine powder of zirconium oxide 20-25% by weight and industrial oils 75-80% by weight thickness of 0,2-0,3 mm On the top of the mold coated 4, consisting of ultrafine powder of zirconium oxide 20-25% by weight and industrial oils 75-80% by weight thickness of 0,3-0,4 mm
This ratio is explained by the fact that in a larger quantity of oil in the floor, it will not have sufficient strength and will run off with the coated surface, and with fewer oil coating is thicker in composition and will not ensure uniform application of the coating on the walls of the mold. Thickness of the applied coating is limited to the value of 0.5 mm, with a greater thickness of the coating will flow down from the walls of the form. Different coatings are necessary for the formation of directional crystallization front. The presence of three zones with different thickness of the coating is because fewer zones will be formed in front of directional crystallization and more areas will lead to the complication of technologies.
Summary of the invention consists in the following: applied to the surface of the mold protective separation layer prevents the direct contact of molten metal with metal form, reducing heat sink. The bottom of the mold is not covered with protective separation coated and will dissipate heat quickly. On the lower part of the mold coating on the basis of nanopowder magnesium oxide, it significantly reduces the heat sink. In the middle part of the mold is applied thicker layer coatings on the basis of nanopowder zirconium dioxide. Powder Zirconia has a much lower conductivity compared to powder magnesium oxide, it will lead to a significant reduction of the heat sink in the middle of the form. Minimum heat sink be at the top of the mold because of the presence of the coating on the basis of zirconium dioxide maximum thickness. Thus creates a directional heatsink from flooded metal to the bottom of the mold. This ensures directional crystallization of ingot and formation of high strength properties of castings.
Example.On the lower part surface of the mold coated, consisting of ultrafine powder of magnesium oxide 20 wt.% and industrial oils 80% thickness of 0,15 mm At the middle part of the mold coated, consisting of ultrafine powder of zirconium oxide 22% and industrial oils 78% by weight thickness of 0,25 mm On top of the mold coated, consisting of ultrafine powder of zirconium oxide 22% and industrial oils 78% by weight thickness 0,35 mm, Then the mold is filled with molten alloy. The melt solidifies, mold cools, casting is pulled.
The method of directional solidification of metal into the mold with on its surface protective-dividing coverings with different composition that includes a fill in the mold of molten metal, wherein use a mold, on the lower part of the walls which are coated consisting of ultrafine powder of magnesium oxide 20-25% by weight and industrial oils 75-80% by weight the thickness of 0.1-0.2 mm at the middle part of the walls - floor, consisting of ultrafine powder of zirconium oxide 20-25% by weight and industrial oils 75-80% by weight thickness of 0,2-0,3 mm, and on the upper part of the walls - floor, consisting of ultrafine powder of zirconium oxide 20-25% by weight and industrial oils 75-80% by weight thickness of 0,3-0,4 mm