CN114799047A - Multilayer module superposed wax mold structure and method for efficiently preparing single crystal blade by using same - Google Patents
Multilayer module superposed wax mold structure and method for efficiently preparing single crystal blade by using same Download PDFInfo
- Publication number
- CN114799047A CN114799047A CN202210530518.0A CN202210530518A CN114799047A CN 114799047 A CN114799047 A CN 114799047A CN 202210530518 A CN202210530518 A CN 202210530518A CN 114799047 A CN114799047 A CN 114799047A
- Authority
- CN
- China
- Prior art keywords
- wax
- blade
- layer
- pattern
- wax pattern
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000013078 crystal Substances 0.000 title claims abstract description 64
- 238000000034 method Methods 0.000 title claims abstract description 21
- 238000007711 solidification Methods 0.000 claims abstract description 29
- 230000008023 solidification Effects 0.000 claims abstract description 29
- 239000007788 liquid Substances 0.000 claims abstract description 20
- 238000005266 casting Methods 0.000 claims abstract description 19
- 238000000576 coating method Methods 0.000 claims description 36
- 239000011248 coating agent Substances 0.000 claims description 34
- 239000000956 alloy Substances 0.000 claims description 32
- 229910045601 alloy Inorganic materials 0.000 claims description 27
- 238000009415 formwork Methods 0.000 claims description 11
- 238000001816 cooling Methods 0.000 claims description 9
- 238000010899 nucleation Methods 0.000 claims description 8
- 238000004519 manufacturing process Methods 0.000 abstract description 12
- 230000007547 defect Effects 0.000 abstract description 9
- 230000008569 process Effects 0.000 abstract description 8
- 238000005452 bending Methods 0.000 abstract description 6
- 238000009826 distribution Methods 0.000 abstract description 5
- 238000005495 investment casting Methods 0.000 abstract description 3
- 238000012797 qualification Methods 0.000 abstract description 3
- 230000009467 reduction Effects 0.000 abstract description 3
- 230000007704 transition Effects 0.000 abstract description 3
- 239000010410 layer Substances 0.000 description 89
- 239000002356 single layer Substances 0.000 description 16
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 13
- 239000004576 sand Substances 0.000 description 9
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 8
- 239000002002 slurry Substances 0.000 description 8
- 238000001035 drying Methods 0.000 description 7
- 238000010438 heat treatment Methods 0.000 description 7
- 238000004088 simulation Methods 0.000 description 7
- 239000000843 powder Substances 0.000 description 6
- 238000003825 pressing Methods 0.000 description 6
- 238000004781 supercooling Methods 0.000 description 6
- 238000005238 degreasing Methods 0.000 description 5
- 229910000601 superalloy Inorganic materials 0.000 description 5
- 238000007605 air drying Methods 0.000 description 4
- 238000013461 design Methods 0.000 description 4
- 238000002360 preparation method Methods 0.000 description 4
- 238000005086 pumping Methods 0.000 description 4
- 238000003892 spreading Methods 0.000 description 4
- 238000004140 cleaning Methods 0.000 description 3
- 238000009792 diffusion process Methods 0.000 description 3
- 239000011159 matrix material Substances 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 238000005070 sampling Methods 0.000 description 3
- 239000002344 surface layer Substances 0.000 description 3
- 238000009423 ventilation Methods 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 238000009825 accumulation Methods 0.000 description 2
- 230000003044 adaptive effect Effects 0.000 description 2
- 238000005034 decoration Methods 0.000 description 2
- 238000003618 dip coating Methods 0.000 description 2
- 238000007667 floating Methods 0.000 description 2
- 239000004519 grease Substances 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000006911 nucleation Effects 0.000 description 2
- 238000013021 overheating Methods 0.000 description 2
- 239000003973 paint Substances 0.000 description 2
- 230000003014 reinforcing effect Effects 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 230000007480 spreading Effects 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 238000003723 Smelting Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 238000000844 transformation Methods 0.000 description 1
- 238000009966 trimming Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C7/00—Patterns; Manufacture thereof so far as not provided for in other classes
- B22C7/02—Lost patterns
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/02—Sand moulds or like moulds for shaped castings
- B22C9/04—Use of lost patterns
- B22C9/043—Removing the consumable pattern
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/22—Moulds for peculiarly-shaped castings
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D27/00—Treating the metal in the mould while it is molten or ductile ; Pressure or vacuum casting
- B22D27/04—Influencing the temperature of the metal, e.g. by heating or cooling the mould
- B22D27/045—Directionally solidified castings
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
Abstract
The invention provides a multi-layer module superposed wax mold structure and a method for efficiently preparing a single crystal blade by using the same, and relates to the technical field of precision casting of aero-engine blades. The multilayer module superposed wax pattern structure provided by the invention comprises a casting system wax pattern, a blade wax pattern, a crystal selector wax pattern and a chilling plate wax pattern which are sequentially connected from top to bottom; the blade wax pattern comprises a plurality of layers of blade wax patterns which are sequentially connected from top to bottom. The invention effectively reduces the diameter of the die set and reduces the size requirements on the chilling plate and the die cavity of the directional solidification furnace under the condition of ensuring the same production capacity of the blades; the reduction of the diameter of the module obviously improves the temperature field distribution in the directional solidification process, improves the uniformity of a transverse temperature field, reduces the bending degree of an isotherm and improves the temperature gradient at the front edge of a solid-liquid interface; the defects of the single crystal blade are obviously reduced, including the reduction of the generation tendency of mixed crystals at the transition section and the platform, and the qualification rate of the mass production of the single crystal blade is effectively improved.
Description
Technical Field
The invention relates to the technical field of precision casting of blades of aero-engines, in particular to a multi-layer module overlapping wax mold structure and a method for efficiently preparing single crystal blades by using the same.
Background
The single crystal blade is an important part of an aeroengine, and is generally prepared by adopting an investment casting method. Firstly, carrying out structural design of a module, pressing and combining wax molds, preparing a mould shell by degreasing the wax mold module, then coating, sanding, dewaxing, roasting and the like, finally pouring molten alloy liquid into the mould shell fixed in a high-vacuum degree directional solidification furnace, drawing a casting mould to a cooling area, and breaking vacuum for sampling after solidification is finished.
Wherein the structural design of the mould set as an initial step in the production of the single crystal blade directly affects the quality of the single crystal blade. At present, the module structure for mass production of single crystal blades in the industry is generally a single-layer module, namely the blades are arranged in a single layer; under the condition of ensuring that the production capacity of the single crystal blade is not changed, the diameter of the single-layer module is large, on one hand, the size of a chilling plate and a cavity of the directional solidification furnace is required to be large, on the other hand, the transverse temperature field distribution in the directional solidification process is not uniform, an isotherm is bent, the temperature gradient at the front edge of a solid-liquid interface is small, the solidification defects of a transition section, a platform mixed crystal and the like are easy to occur, and the production qualification rate of the single crystal blade is limited.
The wax module trees disclosed in chinese patents CN107931523A and CN210730902U are both single-layer module structures commonly used in the industry at present, i.e. the blades are arranged around the center of the module in a single layer; when the structure is used for the production task of large-batch single crystal blades, the diameter of the die set is increased when the number of the blades in the die set is increased for improving the production capacity, and the requirements on the sizes of the chilling plate and the cavity of the directional solidification furnace are further improved.
Xu et al, 2014, "Multiscale Modeling and Simulation of direct purification Process of Turbine Blade Casting with MCA Method", published in metallic and Materials transformations B, indicate that the temperature field inside the Blade during Directional Solidification will tilt and bend when the number of blades in the module is large.
The doctrine of Liyafeng, "study of mixed crystal defects of nickel-based single crystal superalloy turbine blade platforms", indicates that a bent isotherm can cause preferential supercooling at the corners of the platforms, mixed crystals are nucleated after the supercooling degree is reached, and the mixed crystal forming tendency is increased along with the increase of the bending degree of the isotherm.
In summary, the single-layer module is commonly used when the single crystal blades are prepared in large batch in the prior art, and the diameter of the single-layer module is larger, so that the chilling plate and the directional solidification furnace cavity are required to have large sizes; on the other hand, the deterioration of the temperature field distribution in the directional solidification process, including the non-uniform transverse temperature field, the bending of isotherms and the small temperature gradient at the front edge of a solid-liquid interface, is caused, so that the formation tendency of mixed crystals is increased, and the qualification rate of the mass production of the single crystal blades is seriously reduced.
Disclosure of Invention
The multilayer module superposed wax pattern structure provided by the invention can effectively reduce the module diameter, the size of a chilling plate and a cavity of a directional solidification furnace, improve the temperature field distribution in the directional solidification process, reduce the generation of solidification defects and realize the efficient preparation of the single crystal blade under the condition of ensuring that the production capacity of the blade is not changed.
In order to achieve the above object, the present invention provides the following technical solutions:
the invention provides a multi-layer module superposed wax mold structure for preparing a single crystal blade, which comprises a casting system wax mold, a blade wax mold, a crystal selector wax mold and a chilling plate wax mold which are sequentially connected from top to bottom;
the blade wax pattern comprises a plurality of layers of blade wax patterns which are sequentially connected from top to bottom.
Preferably, the pouring system wax mold consists of a pouring cup wax mold and a plurality of inclined pouring channel wax molds which are distributed around the pouring cup wax mold in a circle; the bottom of the oblique pouring channel wax mold is connected with the top end of the top layer blade wax mold, the bottom end of the top layer blade wax mold is connected with the top end of the next layer of blade wax mold, and the rest is done in this way, and the multiple layers of blade wax molds are connected end to end in the vertical direction.
Preferably, the device further comprises a center pillar wax mold; the sprue cup wax mold, the center column wax mold and the chilling plate wax mold are sequentially connected with the same axle center from top to bottom.
Preferably, the crystal selector wax mold comprises an upper spiral section wax mold and a lower seeding section wax mold.
Preferably, the number of layers of the blade wax pattern is two.
The invention provides a preparation method of a single crystal blade, which comprises the following steps:
providing a multi-layer module overlapping wax mold structure in the technical scheme;
sequentially coating, sanding, dewaxing and roasting the multi-layer module superposed wax mold structure to obtain a mold shell;
and pouring the molten alloy liquid into the mold shell, so that the molten alloy liquid is directionally solidified from bottom to top, and removing the shell to obtain the single crystal blade.
Preferably, the casting and the solidification are both carried out in a directional solidification furnace; the step of directionally solidifying the molten alloy liquid from bottom to top comprises the following steps: during solidification, the formwork is drawn downwards to a cooling zone.
Preferably, the drawing speed is 50-150 mu m/s.
Preferably, the dewaxing is steam dewaxing.
Preferably, the method further comprises preheating the mold shell before pouring the molten alloy into the mold shell.
The invention provides a multi-layer module superposed wax mold structure for preparing a single crystal blade, which comprises a casting system wax mold, a blade wax mold, a crystal selector wax mold and a chilling plate wax mold which are sequentially connected from top to bottom; the blade wax pattern comprises a plurality of layers of blade wax patterns which are sequentially connected from top to bottom. The multilayer module superposed wax pattern structure provided by the invention is constructed in a mode of superposing the blade wax patterns up and down under the condition of ensuring the same blade production capacity, and the diameter of the module can be reduced to half of that of a single-layer module by taking the two-layer module superposed wax pattern structure as an example, so that the diameter of the module is effectively reduced, and the size requirements on a chilling plate and a directional solidification furnace cavity are reduced; the reduction of the diameter of the module obviously improves the temperature field distribution in the directional solidification process, improves the uniformity of a transverse temperature field, reduces the bending degree of an isotherm and improves the temperature gradient at the front edge of a solid-liquid interface; the defects of the single crystal blade are obviously reduced, the generation tendency of mixed crystals at the transition section and the platform can be reduced, and the yield of the mass production of the single crystal blade is effectively improved.
Drawings
FIG. 1 is a schematic view of a multi-layer pattern assembly of an embodiment 1; in FIG. 1, 1 is a wax mold of a casting system; 1-1 is a sprue cup wax mould; 1-2 is an inclined pouring channel wax mould; 2, a blade wax mould; 3 is a crystal selector wax mould; 3-1 is a spiral section wax mould; 3-2 is a seeding section wax mould; 4 is a chilling plate wax mould; 5 is a central column wax mould;
FIG. 2 is a top view of FIG. 1;
FIG. 3 is a detail illustration of a double-layered stacked blade in the multi-layered modular wax pattern structure of FIG. 1;
FIG. 4 is a comparison graph of the simulation results of the temperature fields of the single-layer module blade (a) and the double-layer module superposed blade, the lower-layer blade (b) and the upper-layer blade (c) when the molten superalloy solidifies to the blade body, wherein the upper and lower limit temperatures of a scale are the liquid-phase line temperature and the solidus line temperature of the alloy respectively;
FIG. 5 is a comparison graph of the simulation results of the temperature fields of the single-layer module blade (a) and the double-layer module superposed blade lower-layer blade (b) and upper-layer blade (c) when the molten superalloy solidifies to the blade platform, wherein the upper and lower limit temperatures of the scale are the liquid and solidus temperatures of the alloy;
fig. 6 is a comparison of the simulation results of the solidified grains of the single-layer module blade (a) and the double-layer module superimposed blade (b).
Detailed Description
The invention provides a multi-layer module superposed wax mold structure for preparing a single crystal blade, which comprises a casting system wax mold, a blade wax mold, a crystal selector wax mold and a chilling plate wax mold which are sequentially connected from top to bottom;
the blade wax pattern comprises a plurality of layers of blade wax patterns which are sequentially connected from top to bottom.
The multi-layer module superposed wax pattern structure provided by the invention comprises a casting system wax pattern and a blade wax pattern connected with the bottom end of the casting system wax pattern. As an embodiment of the invention, the pouring system wax pattern is composed of a pouring cup wax pattern and a plurality of inclined pouring channel wax patterns distributed around the pouring cup wax pattern. As an embodiment of the invention, the inclined pouring channel wax mold is a radial structure which is uniformly distributed along the circumferential direction of the pouring cup wax mold. In the present invention, the inclined angle of the inclined runner is preferably 20 ° to 70 °. In the invention, the inclined pouring channel wax molds are multiple.
As an embodiment of the invention, the bottom end of the inclined pouring channel wax mould is connected with the top end of the top layer blade wax mould, the bottom end of the top layer blade wax mould is connected with the top end of the next layer of blade wax mould, and so on, and the multiple layers of blade wax moulds are connected end to end in the vertical direction. As an embodiment of the invention, the bottom end of a slant gate wax pattern is connected with two vertically adjacent blade wax patterns, as shown in FIG. 3.
In the present invention, the number of layers of the blade wax pattern is preferably two.
The multilayer module overlapping wax mold structure provided by the invention comprises a crystal selector wax mold connected with the bottom end of the blade wax mold. As an embodiment of the invention, the crystal selector wax mold comprises an upper spiral segment wax mold and a lower seeding segment wax mold. In the invention, the spiral section wax pattern is connected with the bottom end of the bottommost layer blade wax pattern.
The multilayer module superposed wax mold structure provided by the invention comprises a chilling plate wax mold connected with the bottom end of the crystal selector wax mold.
As an embodiment of the present invention, the multi-layer pattern-stacked wax pattern structure further includes a center pillar wax pattern; the sprue cup wax mold, the center column wax mold and the chilling plate wax mold are sequentially connected with the same axle center from top to bottom.
As an embodiment of the present invention, when the number of the layers of the blade wax pattern is two, the multi-layer pattern assembly overlapping wax pattern structure is: the pouring system wax pattern consists of a pouring cup wax pattern and a plurality of inclined pouring gate wax patterns which are distributed around the pouring cup wax pattern in a circle; the bottom end of the inclined pouring channel wax mold is connected with the top end of the upper layer blade wax mold, and the bottom end of the upper layer blade wax mold is connected with the top end of the lower layer blade wax mold; the bottom end of the lower layer blade wax mould is connected with the top end of the spiral section wax mould, and the bottom end of the spiral section wax mould is connected with the top end of the seeding section wax mould; the bottom end of the seeding section wax mould is connected with the chilling plate wax mould; and the sprue cup wax mold, the center column wax mold and the chilling plate wax mold of the casting system wax mold are sequentially connected with the same axle center from top to bottom.
The invention also provides a preparation method of the single crystal blade, which comprises the following steps:
providing a multi-layer module overlapping wax mold structure in the technical scheme;
sequentially coating, sanding, dewaxing and roasting the multi-layer module superposed wax mold structure to obtain a mold shell;
and pouring the molten alloy liquid into the mold shell, so that the molten alloy liquid is directionally solidified from bottom to top, and removing the shell to obtain the single crystal blade.
The invention provides a multilayer module superposition wax mould structure in the technical scheme. The multi-layer module superposed wax mold structure in the technical scheme is obtained by preferably adopting a pneumatic wax pressing machine for pressing. In the invention, the temperature of the wax cylinder during pressing is preferably 70-75 ℃, the nozzle temperature is preferably 60-65 ℃, and the injection pressure is preferably 0.1-0.6 MPa.
After the multilayer module overlapping wax pattern structure is obtained, the multilayer module overlapping wax pattern structure is sequentially coated, sanded, dewaxed and roasted to obtain the formwork. In the invention, the multi-layer module overlapping wax mold structure preferably further comprises oil removal and degreasing treatment before coating and sanding. The invention can remove grease on the surface of the module by adopting oil removal and degreasing treatment, and improves the capability of the coating for wetting the surface of the wax mould.
The invention preferably adopts a dip-coating method to coat and hang the multi-layer module superposed wax mould structure. In the specific coating and hanging process, the surface of the multi-layer module superposed wax mould structure is kept to be uniformly coated with the coating, so that blank and local accumulation are avoided; the edges, the grooves and the joints are uniformly brushed by using a brush pen or a special tool to avoid generating bubbles. According to the invention, floating sand on the previous layer is preferably cleaned before each layer of coating is coated: stirring is carried out at regular time in the coating process so as to master and adjust the viscosity of the coating. In the present invention, the sanding is preferably fluidized sanding or shower sanding. According to the invention, after the multilayer die set superposed wax pattern structure is taken out from the coating groove, the sand can be scattered when the residual coating flows uniformly and does not continuously drop; the sand-spreading granularity is selected according to the coating level and is adaptive to the viscosity of the coating, the surface layer sand granularity is fine, and the reinforcing layer sand granularity is coarse. In the present invention, drying and hardening are performed after each coating and sanding of one layer. In the specific embodiment of the invention, the multilayer module superposed wax pattern structure is coated and sanded for 7 layers, the 1 st layer is a surface layer, 70# EC95 powder, silica sol and slurry are mixed and then coated, and the mixture is dried for more than 8 hours; 2, coating 2 layers of mixed 35# EC95 powder, silica sol and slurry, and drying for more than 6 hours; coating and hanging the mixed 22# EC95 powder, silica sol and slurry on the 5 th to 6 th layers, and drying for more than 6 hours; the 7 th layer is a sealing layer, only slurry is coated and hung, and the slurry is dried by air after the coating and hanging are finished; after drying 1-3 layers, before coating the lower layer, the lower layer is reinforced by silica sol and requires good ventilation, and the proper temperature (21 +/-1.5 ℃) and humidity (40 +/-10%) are ensured.
In the present invention, the dewaxing is preferably steam dewaxing. In the invention, during steam dewaxing, the steam pressure of the outer container is preferably 0.7-0.75 MPa, the dewaxing time is preferably 12-14 min, and the dewaxing temperature is preferably 160-170 min. Preferably, according to the present invention, after said dewaxing, a through-air drying is carried out.
In the present invention, the calcination is preferably performed in a heating furnace; the roasting temperature is preferably 850 ℃; the holding time is preferably 1.5 h. After the roasting, the mold shell is preferably taken out after being cooled to 500 ℃ along with the furnace, and is cooled to room temperature in air to obtain the mold shell.
After obtaining the mould shell, the invention pours the molten alloy liquid into the mould shell, so that the molten alloy liquid is directionally solidified from bottom to top, and the single crystal blade is obtained after shelling. According to the invention, before the molten alloy is poured into the mold shell, the mold shell is preferably preheated. In the invention, the preheating temperature is preferably 1530-1560 ℃. In the present invention, the time of said pouring is preferably less than 5 s; the casting temperature is preferably 1520-1540 ℃.
In the present invention, the casting and the solidification are preferably both carried out in a directional solidification furnace; the directionally solidifying the molten alloy liquid from bottom to top preferably comprises: during solidification, the formwork is drawn down to a cooling zone. In the invention, the drawing speed is preferably 50-150 μm/s, and more preferably 100 μm/s.
In the present invention, the casting and solidification are preferably performed under vacuum conditions.
The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
Firstly, the structural design and preparation of a wax mould:
the double-layer module overlapping wax mold structure adopted by the embodiment is shown in figures 1-2.
a. The design and the wax matrix suppression of double-deck module stack wax matrix structure: the double-layer module superposed wax pattern structure consists of five parts, namely a casting system wax pattern 1, a blade wax pattern 2, a crystal selector wax pattern 3, a chilling plate wax pattern 4 and a center column wax pattern 5; the casting system wax mold 1 consists of a sprue cup wax mold 1-1 and a plurality of inclined sprue wax molds 1-2 uniformly distributed around one circle of the sprue cup wax mold, and the crystal selector wax mold 3 consists of an upper spiral section wax mold 3-1 and a lower crystal guiding section wax mold 3-2; pressing the wax mould with the structure by using an air wax pressing machine; when the wax mould is pressed, the temperature of a wax cylinder is 75 ℃, the temperature of a nozzle is 65 ℃, and the injection pressure is 0.5MPa, and the pressed wax mould is subjected to burr removal and model trimming operation;
b. the combination of double-deck module stack wax matrix structure: combining the wax patterns according to the following sequence: the bottom end of the oblique pouring channel wax mold 1-2 is connected with the top end of the upper layer blade wax mold, and the bottom end of the upper layer blade wax mold is connected with the top end of the lower layer blade wax mold; the bottom end of the lower layer blade wax mould is connected with the top end of the crystal selector wax mould 3; the bottom end of the crystal selector wax mold 3 is connected with a chilling plate wax mold 4; a pouring cup wax mold 1-2, a center pillar wax mold 5 and a chill plate wax mold 4 of the wax mold of the pouring system are sequentially connected with the same axle center from top to bottom;
c. oil removal and degreasing: and removing grease on the surface of the double-layer module superposed wax mold structure.
Step two, preparing a mould shell:
a. coating and sanding: coating and hanging the double-layer module superposed wax pattern subjected to degreasing treatment by adopting a dip-coating method, keeping the surface of the wax pattern uniformly coated with paint, and avoiding blank and local accumulation; the edges, the grooves and the joints are uniformly brushed by using a brush pen or a special tool to avoid bubbles; cleaning floating sand on the previous layer before coating each layer of paint: stirring is carried out at regular time in the coating process so as to master and adjust the viscosity of the coating. The sand spreading adopts rain type sand spreading; taking the double-layer die set superposed wax pattern out of the coating groove, and sanding when the residual coating on the double-layer die set superposed wax pattern flows uniformly and does not continuously drop; the sand-spreading granularity is selected according to the coating level and is adaptive to the viscosity of the coating, the surface layer sand granularity is fine, and the reinforcing layer sand granularity is coarse; fully drying and hardening after coating and sanding one layer; double-deck module stack mould shell carries out 7 layers and coats and hangs the sanding, (1) surface course, and 70# EC95 powder + silica sol + ground paste are according to 1: 2: 2, coating and hanging after mixing, and air drying for more than 8 hours; (2) 2-4 layers, 35# EC95 powder + silica sol + slurry according to the weight ratio of 1: 2: 2, coating 2 layers after mixing, and air-drying for more than 6 hours; (3) 5-6 layers, wherein the proportion of 22# EC95 powder, silica sol and slurry is 1: 2: 2, coating and hanging after mixing, and air drying for more than 6 hours; (4) sealing the layer, only coating the slurry, and drying by air after coating; after 1-3 layers are dried, the lower layer is strengthened by silica sol before coating and requires good ventilation, and the proper temperature (21 +/-1.5 ℃) and humidity (40 +/-10%) are ensured;
b. dewaxing: opening the mould shell on the end face of the sprue cup to facilitate wax removal and air exhaust, and dewaxing by adopting a steam method, wherein the steam pressure of an outer container is 0.7MPa, the dewaxing time is 13min, and the dewaxing temperature is 165 min; fully drying for 12 hours under ventilation condition after dewaxing;
c. roasting: cooling the double-layer module superposed formwork to 300 ℃, then placing the double-layer module superposed formwork into a heating furnace to roast at 850 ℃ for 1.5h, cooling the double-layer module superposed formwork to 500 ℃ along with the furnace, then taking out the double-layer module superposed formwork, and cooling the double-layer module superposed formwork to room temperature;
d. inspecting and casing repairing: checking whether the mould shell has the defects of deformation, cracks, damage and the like; repairing the crack, damage and other defects, and removing the redundant edge of the mold shell at the pouring gate.
Thirdly, preparing the blade in a directional solidification furnace:
a. an inspection device: checking whether each valve of the equipment can normally operate or not, whether the water supply device, the power supply device and the gas supply device are normal or not, reasonably adjusting the relative positions of the temperature measuring device and the bottom of the crucible according to the amount of alloy materials, cleaning dust in the furnace chamber and wiping each observation window;
b. loading a master alloy: punching a large-size shrinkage cavity on the cut alloy material, polishing the alloy material by using abrasive paper, cleaning the alloy material by using alcohol, and placing the alloy material into a crucible;
c. fixing a formwork: fixing a chill plate mould shell of a double-layer mould set superposed mould shell on a chill plate of the directional solidification furnace by using a special clamp or an iron wire, and enabling the central position of a mould shell pouring gate to be coaxial with the central position of a liquid guide funnel, ensuring that alloy liquid is smoothly poured into the mould shell, and closing a furnace door;
d. vacuumizing: firstly opening a mechanical pump to perform rough vacuum pumping to within 1000Pa, opening a roots pump to continue vacuum pumping to within 20Pa, preheating a diffusion pump, opening a valve of the diffusion pump to perform high vacuum pumping until the temperature of diffusion pump oil is raised to 300 ℃, and performing high vacuum pumping until the temperature is 6.67 multiplied by 10 - 3 Pa；
e. Heating up and heating: heating the heating body according to a set temperature curve, and heating the double-layer module superposed formwork;
f. alloy smelting: melting and refining the single crystal superalloy: slowly adding electricity until the alloy is melted, and then overheating the alloy melt until only a small amount of scum exists on the free surface of the alloy liquid in the edge area; then, carrying out furnace shaking operation, and preheating the edge of the crucible to prevent splashing in the pouring process; overheating to a set temperature, and keeping the temperature for 2 min;
g. pouring and drawing: rapidly cooling the overheated melt to a temperature slightly higher than the pouring temperature, raising a temperature thermocouple, pouring alloy liquid into a double-layer module superposition mould shell, and drawing the casting mould into a cooling area according to the drawing rate of 100 mu m/s;
h. sampling: after solidification, vacuum breaking and sampling are carried out when the temperature of the whole furnace body is reduced to be below 100 ℃, and then shelling and finishing are carried out to obtain a large batch of single crystal blades.
The single-layer module for preparing single crystal blades in large batch by using the same process is taken as a comparative example, and fig. 4 is a comparison graph of the temperature field simulation results of the single-layer module blade and the double-layer module superposed blade when the molten high-temperature alloy is solidified to the bottom of the blade body. As can be seen from FIG. 4, the double-layer module overlapped blade has low isotherm bending degree, the supercooling degree of the corner part at the bottom of the blade body is small, the critical nucleation supercooling degree of the alloy is difficult to achieve, and the single crystal blade has small tendency of forming mixed crystal defects.
FIG. 5 is a comparison graph of temperature field simulation results for a single layer module blade and a double layer module stacked blade when molten superalloy solidifies to the blade platform. As can be seen from FIG. 5, the double-layer module superposed blade has low isotherm bending degree, small supercooling degree at the corner of the platform, difficult achievement of critical nucleation supercooling degree of the alloy and small tendency of forming mixed crystal defects of the single crystal blade.
FIG. 6 is a comparison of the simulation results of solidified grains for a single layer module blade and a double layer module stacked blade. As can be seen from FIG. 6, the single-layer module blade has mixed crystals formed therein, so that it is difficult to produce a qualified single-crystal blade, and the double-layer module stacked blade has no mixed crystals formed therein, so that the single-crystal blade is successfully produced.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (10)
1. A multi-layer module superposed wax mould structure for preparing a single crystal blade comprises a casting system wax mould, a blade wax mould, a crystal selector wax mould and a chilling plate wax mould which are sequentially connected from top to bottom;
the blade wax pattern comprises a plurality of layers of blade wax patterns which are sequentially connected from top to bottom.
2. The multi-layer pattern assembly superimposed wax pattern structure according to claim 1, wherein the gating system wax pattern is composed of a sprue cup wax pattern and a plurality of inclined runner wax patterns distributed around the sprue cup wax pattern in a circle; the bottom of the inclined pouring channel wax mould is connected with the top end of the top layer blade wax mould, the bottom of the top layer blade wax mould is connected with the top end of the next layer of blade wax mould, and the like, and the multiple layers of blade wax moulds are connected end to end in the vertical direction.
3. The multi-layer pattern assembly superimposed wax pattern structure of claim 2, further comprising a king post wax pattern; the sprue cup wax mold, the center column wax mold and the chilling plate wax mold are sequentially connected with the same axle center from top to bottom.
4. The multi-layer pattern assembly superimposed wax pattern structure as claimed in claim 1, wherein the crystal selector wax pattern comprises an upper spiral segment wax pattern and a lower seeding segment wax pattern.
5. The multi-layer pattern assembly superimposed wax pattern structure of claim 1, wherein the number of layers of the blade wax pattern is two.
6. A method for preparing a single crystal blade, comprising the steps of:
providing a multi-layer module superimposed wax pattern structure as defined in any one of claims 1 to 5;
sequentially coating, sanding, dewaxing and roasting the multi-layer module superposed wax mold structure to obtain a mold shell;
and pouring the molten alloy liquid into the mold shell, so that the molten alloy liquid is directionally solidified from bottom to top, and removing the shell to obtain the single crystal blade.
7. The method according to claim 6, wherein the casting and the solidification are both performed in a directional solidification furnace; the step of directionally solidifying the molten alloy from bottom to top comprises the following steps: during solidification, the formwork is drawn down to a cooling zone.
8. The method according to claim 7, wherein the drawing rate is 50 to 150 μm/s.
9. The method of claim 6, wherein the dewaxing is steam dewaxing.
10. The method of claim 6, further comprising preheating the mold shell prior to pouring the molten alloy in the mold shell.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210530518.0A CN114799047A (en) | 2022-05-16 | 2022-05-16 | Multilayer module superposed wax mold structure and method for efficiently preparing single crystal blade by using same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210530518.0A CN114799047A (en) | 2022-05-16 | 2022-05-16 | Multilayer module superposed wax mold structure and method for efficiently preparing single crystal blade by using same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114799047A true CN114799047A (en) | 2022-07-29 |
Family
ID=82516158
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210530518.0A Pending CN114799047A (en) | 2022-05-16 | 2022-05-16 | Multilayer module superposed wax mold structure and method for efficiently preparing single crystal blade by using same |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114799047A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI850117B (en) * | 2023-09-21 | 2024-07-21 | 復盛應用科技股份有限公司 | A club head assembly tree cleaning method |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103894539A (en) * | 2014-03-31 | 2014-07-02 | 东方电气集团东方汽轮机有限公司 | Method for preparing wax mold of monocrystal spiral crystal selector |
| CN105268916A (en) * | 2014-06-11 | 2016-01-27 | 中国科学院金属研究所 | Preparation technology for monocrystal turbine guide vane |
| CN106270392A (en) * | 2015-05-25 | 2017-01-04 | 西安航空动力股份有限公司 | A kind of manufacture method of single crystal super alloy working-blade |
| CN109351951A (en) * | 2018-11-29 | 2019-02-19 | 中国科学院金属研究所 | A kind of process reducing single crystal blade platform rarefaction defect |
| CN110405146A (en) * | 2019-08-30 | 2019-11-05 | 中国航发动力股份有限公司 | A kind of device and method for reinforcing crystal selector formwork |
| CN111618279A (en) * | 2020-06-24 | 2020-09-04 | 中国航发北京航空材料研究院 | Precision casting method for quintuplet directional columnar crystal blade |
| CN112045169A (en) * | 2018-11-27 | 2020-12-08 | 安徽应流航源动力科技有限公司 | Casting method of monocrystalline high-temperature alloy blade capable of precisely controlling three-dimensional crystal orientation |
| CN215315501U (en) * | 2021-06-26 | 2021-12-28 | 深圳市万泽航空科技有限责任公司 | Wax tree structure for forming single crystal blade |
| CN114309474A (en) * | 2022-03-14 | 2022-04-12 | 成都航宇超合金技术有限公司 | Investment casting process of small and medium-sized single crystal turbine blades |
-
2022
- 2022-05-16 CN CN202210530518.0A patent/CN114799047A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103894539A (en) * | 2014-03-31 | 2014-07-02 | 东方电气集团东方汽轮机有限公司 | Method for preparing wax mold of monocrystal spiral crystal selector |
| CN105268916A (en) * | 2014-06-11 | 2016-01-27 | 中国科学院金属研究所 | Preparation technology for monocrystal turbine guide vane |
| CN106270392A (en) * | 2015-05-25 | 2017-01-04 | 西安航空动力股份有限公司 | A kind of manufacture method of single crystal super alloy working-blade |
| CN112045169A (en) * | 2018-11-27 | 2020-12-08 | 安徽应流航源动力科技有限公司 | Casting method of monocrystalline high-temperature alloy blade capable of precisely controlling three-dimensional crystal orientation |
| CN109351951A (en) * | 2018-11-29 | 2019-02-19 | 中国科学院金属研究所 | A kind of process reducing single crystal blade platform rarefaction defect |
| CN110405146A (en) * | 2019-08-30 | 2019-11-05 | 中国航发动力股份有限公司 | A kind of device and method for reinforcing crystal selector formwork |
| CN111618279A (en) * | 2020-06-24 | 2020-09-04 | 中国航发北京航空材料研究院 | Precision casting method for quintuplet directional columnar crystal blade |
| CN215315501U (en) * | 2021-06-26 | 2021-12-28 | 深圳市万泽航空科技有限责任公司 | Wax tree structure for forming single crystal blade |
| CN114309474A (en) * | 2022-03-14 | 2022-04-12 | 成都航宇超合金技术有限公司 | Investment casting process of small and medium-sized single crystal turbine blades |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI850117B (en) * | 2023-09-21 | 2024-07-21 | 復盛應用科技股份有限公司 | A club head assembly tree cleaning method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105458182B (en) | A kind of casting method of volute | |
| JP5567331B2 (en) | Continuous mold filling method, mold assembly and casting | |
| CN111451447B (en) | Precision casting method of solid duplex single crystal guide blade | |
| CN105057593B (en) | A kind of copper-alloy casting full form casting process | |
| CN102228955B (en) | Treatment method for deformation of massive lost foam | |
| CN102836963B (en) | Support casting process | |
| CN104661775A (en) | Shell mould having a heat shield | |
| CN105057594A (en) | Precise investment casting technology | |
| JP2013136097A (en) | Method for making article having fine equiaxed grain structure | |
| CN109986025A (en) | Stainless steel water pump vane wheel full form casting process | |
| CN113089078B (en) | Casting method for preparing hollow large-size duplex block casting single crystal guide blade by seed crystal method | |
| CN110976769A (en) | Method for manufacturing mould shell of alloy precision casting | |
| CN114799047A (en) | Multilayer module superposed wax mold structure and method for efficiently preparing single crystal blade by using same | |
| CN105945227A (en) | Precise casting technology for fusion mold | |
| CN111203514A (en) | Precision casting method for high-temperature alloy complex thin-wall casting | |
| CN108927493A (en) | A kind of aluminium alloy electric automobile inner-cooled machine shell cast shaping process | |
| CN111136258B (en) | Heat treatment method of high-temperature Ti-based alloy casting | |
| CN109317613B (en) | Shell preparation method for preventing bending deformation of directional test bar | |
| CN109351951A (en) | A kind of process reducing single crystal blade platform rarefaction defect | |
| CN109986029A (en) | Pump body full form casting process | |
| CN201442085U (en) | Directional solidification casting device for titanium alloy missile cabins | |
| RU2314891C1 (en) | Mold making method for casting with use of investment patterns | |
| CN115625292A (en) | Investment casting method for producing nickel-based superalloy rocker arm | |
| CN110976843A (en) | Casting production process flow of turbine blade of gas turbine | |
| CN110976773A (en) | Method for improving performance of nickel-based alloy casting |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20220729 |
|
| RJ01 | Rejection of invention patent application after publication |