Wax pattern for controlling the looseness of multi-directional / single crystal guide blade edge plate and preparation method thereof

Abstract

The present invention discloses a wax mold and a preparation method for controlling the looseness of a multi-joint directional / single crystal guide blade edge plate. The guide blade wax mold includes an upper edge plate, a lower edge plate, a blade body and a shrinkage compensation structure. At least one shrinkage compensation structure is arranged between two adjacent blade bodies. The two end faces of the shrinkage compensation structure are respectively connected to the corresponding blade bodies, and the bottom surface of the shrinkage compensation structure is connected to the lower edge plate. The method comprises the following steps: pressing a guide blade wax mold, and assembling a plurality of guide blade wax molds into a module group; assembling the module group with other components to form a casting system, and preparing a mold shell of the casting system by a precision investment casting method; casting and forming by a directional solidification method, and obtaining a guide blade casting after shelling; heat-treating the guide blade casting and then cutting off the shrinkage compensation structure, so as to obtain a guide blade capable of controlling the looseness of the edge plate. The present invention avoids the looseness of the area between two adjacent blade bodies on the lower edge plate by arranging a shrinkage compensation structure.

Description

Technical Field

[0001] The invention belongs to the technical field of precision casting of high-temperature alloy turbine blades, and in particular relates to a wax mold for controlling the loosening of edge plates of multi-linked directional / single crystal guide blades and a preparation method thereof. Background Art

[0002] As we all know, single crystal / directional high temperature alloys (i.e. single crystal high temperature alloys and directional high temperature alloys) are widely used in the preparation of aircraft engine turbine blades due to their excellent high temperature performance. For the lower edge plate of single crystal / directional multi-joint guide blades (i.e. multi-joint guide blades made of single crystal high temperature alloys or directional high temperature alloys, with at least two guide blades), due to the large area of ​​the lower edge plate area and the shielding of multiple blade bodies, the heat dissipation conditions are poor during the directional solidification process, the temperature field fluctuations during the solidification process are large, and shrinkage compensation is more difficult, resulting in a large area of ​​looseness in the lower edge plate area. These looseness will become the location of stress concentration, resulting in the performance of the blades being reduced and affecting the service safety of the blades. It can be seen that the control technology of looseness is the key technology in the current manufacturing process of aircraft engine turbine blades.

[0003] For the lower edge plate of the multi-joint guide blades, looseness may occur at the edge of the lower edge plate and in the edge plate area between two adjacent blade bodies. The edge plate area between two adjacent blade bodies is large and is hindered by the blade body during directional solidification, resulting in poor heat dissipation conditions. Therefore, looseness is more likely to occur in this area. Therefore, it is urgent to develop a wax mold and preparation method for controlling the looseness of the edge plate of multi-joint directional / single crystal guide blades to avoid looseness in the edge plate area between two adjacent blades, and at the same time, new looseness will not occur in other non-loose areas due to the setting of the shrinkage-feeding structure.

[0004] The invention patent with application publication number CN113492197A discloses a wax mold method for avoiding recrystallization and micro-porosity of single crystal hollow blades, comprising the following steps: installing M pieces of single crystal hollow blade wax molds on a wax mold assembly device, configuring N groups of anti-recrystallization ribs for each single crystal hollow blade wax mold, and obtaining a single crystal hollow blade casting mold; preparing a single crystal hollow blade shell mold, and dewaxing, pouring, and shelling it to obtain a single crystal hollow blade blank; heat treating and machining the blank to obtain a single crystal hollow blade without recrystallization defects. The anti-recrystallization ribs include a first block-shaped anti-recrystallization rib, a strip-shaped anti-recrystallization rib and a second block-shaped anti-recrystallization rib, wherein the upper end of the strip-shaped anti-recrystallization rib is connected to the bottom end of the first block-shaped anti-recrystallization rib, and the lower end is connected to the top end of the second block-shaped anti-recrystallization rib; the anti-recrystallization ribs are connected between the upper edge plate and the lower edge plate of the single crystal hollow blade wax mold, wherein the first block-shaped anti-recrystallization rib is connected to the upper edge plate, and the second block-shaped anti-recrystallization rib is connected to the lower edge plate. This technical solution is mainly used to prevent the single crystal hollow blade from recrystallizing and prevent the edge position of the lower edge plate from being loose, but it cannot prevent the edge plate area between the blades on both sides of the lower edge plate from being loose.

[0005] The invention patent with application publication number CN111618279A discloses a method for precision casting of a quintuple directional columnar crystal blade, comprising the following steps: pressing a quintuple blade wax mold, and combining it with a seeding section and a pouring system to form a blade module, setting a heat-insulating baffle between the center column tube of the pouring system and the blade wax mold, and welding shrinkage-feeding blocks at the edges of the upper and lower edge plates of the blade; using the blade module to prepare a shell mold with a multi-layer structure, wherein the number of shell mold layers below the lower edge plate is greater than the number of shell mold layers above the blade body; after melting, pouring, shelling, and cutting, a quintuple directional columnar crystal blade casting is obtained. This technical solution helps directional sequential solidification by setting a heat-insulating baffle, and controls the looseness of the edge plate by welding the shrinkage-feeding block, that is, solving different problems by adding different components, so this technical solution cannot achieve both controlling the looseness of the edge plate and facilitating directional solidification through one component, and the welding position of the shrinkage-feeding block can only prevent the looseness of the edge plate, but cannot prevent the looseness of the edge plate area between adjacent blades. Summary of the invention

[0006] In order to solve the problems existing in the prior art, the present invention provides a wax mold for controlling the looseness of the edge plates of multi-linked directional / single crystal guide blades, the guide blade wax mold comprising an upper edge plate, a lower edge plate, a blade body and a shrinkage compensation structure, the number of the blade bodies is at least two, at least one of the shrinkage compensation structures is arranged between two adjacent blade bodies, the two end surfaces of the shrinkage compensation structure are respectively connected to the corresponding blade bodies, and the bottom surface of the shrinkage compensation structure is connected to the lower edge plate; the upper edge plate, the lower edge plate, the blade body and the shrinkage compensation structure are integrally formed, or after the upper edge plate, the lower edge plate and the blade body are integrally formed, the shrinkage compensation structure is bonded to the area between the two adjacent blade bodies.

[0007] Preferably, the shape of the feeding structure is U-shaped or elongated, the center point of the U-shaped surface of the U-shaped feeding structure is located in the area 1 / 4-3 / 4 between the leading edge and the trailing edge of the two blades, and the center point of the elongated feeding structure is located in the area 1 / 4-3 / 4 between the leading edge and the trailing edge of the two blades.

[0008] In any of the above schemes, it is preferred that the U-shaped shrinkage structure is located in an area rotated ±45° with the center point of the U-shaped surface as the rotation point and the straight line passing through the center point of the U-shaped surface and parallel to the long side of the lower edge plate as the reference; the long strip shrinkage structure is located in an area rotated ±45° with the center point as the rotation point and the straight line passing through the center point and parallel to the long side of the lower edge plate as the reference.

[0009] In any of the above solutions, preferably, the length of the feeding structure is the distance between the center points of the two end surfaces of the feeding structure when the two end surfaces of the feeding structure are respectively connected to the corresponding blade body.

[0010] In any of the above solutions, preferably, the thickness of the two ends of the feeding structure is respectively 0.5-1 times the thickness of the blade body connected to the two end surfaces of the feeding structure.

[0011] In any of the above solutions, preferably, the thickness in the middle of the feeding structure is 0.2-0.7 times the thickness of the relatively thinner end of the two ends of the feeding structure; and the two ends of the feeding structure are smoothly transitionally connected to the middle.

[0012] In any of the above solutions, preferably, the height of the long strip feeding structure is 0.2-0.5 times the height of the blade body.

[0013] In any of the above schemes, preferably, the heights at both ends of the U-shaped feeding structure are 0.2-0.5 times the height of the blade body, and the height in the middle of the U-shaped feeding structure is not less than 0.25 times the heights at both ends of the U-shaped feeding structure.

[0014] In any of the above schemes, preferably, the portion where the feeding structure is connected to the blade body and the lower edge plate is smoothly transitioned in a rounded form, and the radius of the rounding is 0.5-2 mm.

[0015] The present invention also provides a method for preparing a multi-joint directional / single crystal guide blade with controlled edge plate looseness, which is prepared by using any of the wax molds for controlling the looseness of the edge plates of the multi-joint directional / single crystal guide blades described above, and comprises the following steps in order:

[0016] Step 1: according to the designed guide blade wax mold structure, a guide blade wax mold is pressed by a hot injection molding method, and a plurality of guide blade wax molds are combined into a module set; or, a structural wax mold and a feeding structural wax mold formed integrally of an upper edge plate, a lower edge plate, and a blade body are respectively pressed by a hot injection molding method, and then the feeding structural wax mold is bonded to the structural wax mold formed integrally of an upper edge plate, a lower edge plate, and a blade body according to the designed positional relationship to form a guide blade wax mold, and a plurality of guide blade wax molds are combined into a module set;

[0017] Step 2: Assembling a mold group consisting of a plurality of guide vane wax molds with other components to form a gating system, and preparing a mold shell of the gating system by using an investment casting method;

[0018] Step 3: After the shell of the gating system is prepared, it is placed in a vacuum induction melting device and cast by a directional solidification method, and the guide blade casting is obtained after shelling;

[0019] Step 4: Heat-treat the guide vane casting. After the heat treatment is completed, the shrinkage compensation structure is removed by mechanical processing to obtain a guide vane capable of controlling the looseness of the edge plate.

[0020] The pouring system includes a pouring cup, a pouring plate, a support column, a lower base plate, a plurality of inclined runners, a plurality of seeding structures, and a plurality of guide vane wax molds; the pouring cup, the pouring plate, the support column and the lower base plate are connected in sequence from top to bottom, and a plurality of guide vane wax molds are located between the lower base plate and the pouring plate and are evenly arranged along the edge of the lower base plate; the bottom of the guide vane wax mold is connected to the lower base plate through the seeding structure, and the top is connected to the pouring plate through the inclined runner.

[0021] The directional solidification method is adopted for casting. The casting material is single crystal high-temperature alloy or directional high-temperature alloy. The directional solidification sequence from bottom to top is the seeding structure of the same height, the lower edge plate of the same height, the blade body and the shrinkage-feeding structure of the same height, the upper edge plate of the same height, and the inclined runner of the same height. The casting material solidifies from bottom to top in each component in the casting system shell.

[0022] In the present invention, the hot injection molding method, investment casting method, directional solidification method, heat treatment, machining method, etc. adopted are all traditional processes, and there are no special requirements for the process flow, process parameters, equipment used, etc., as long as the shape, size, setting position of the shrinkage-feeding structure in the guide vane wax mold and the connection relationship with the blade body and the lower edge plate meet the requirements of the present invention, the size of the shrinkage-feeding structure mainly changes with the change of the blade body size and the edge plate size in the guide vane wax mold.

[0023] The wax pattern and preparation method for controlling the looseness of the edge plate of a multi-directional / single crystal guide blade of the present invention have the following beneficial effects:

[0024] (1) The present invention designs a special feeding structure, and sets the feeding structure in the area between two adjacent blades in the guide vane wax mold, and the two end surfaces of the feeding structure are respectively connected to the corresponding blades, and the bottom surface of the feeding structure is connected to the lower edge plate. This design allows the molten metal to flow from the blade to the lower edge plate through the feeding structure (that is, this design allows the lower edge plate to have sufficient feeding channels during the directional solidification process). During the directional solidification process, the molten metal is sufficiently fed in the area between two adjacent blades on the lower edge plate (that is, the lower edge plate is fed by the feeding structure), thereby avoiding a large amount of looseness in this area.

[0025] (2) The present invention optimizes the directional solidification sequence of the guide vane by specially designing and strictly limiting the shape and size (including length, thickness, height, etc.) of the feeding structure, making the directional solidification sequence closer to the theoretical state, thereby avoiding the loosening of the area between two adjacent blades on the lower edge plate, and at the same time, the setting of the feeding structure will not cause new loosening in other non-loose parts. (3) The feeding structure and wax mold pressing, mold assembly, casting, etc. of the present invention are simple and reliable, low-cost, and easy to operate. They can effectively eliminate the loosening of the area between two adjacent blades on the lower edge plate of the single crystal / directional multi-link guide vane, and at the same time, the setting of the feeding structure will not cause new loosening in other non-loose parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic structural diagram of a guide vane wax model in a preferred embodiment of a wax model and a preparation method for controlling the looseness of a multi-linked directional / single crystal guide vane edge plate according to the present invention;

[0027] Figure 2 for Figure 1 A schematic diagram of the structure of the gating system in the illustrated embodiment (only one guide vane wax model is shown);

[0028] Figure 3 for Figure 1 A photograph of the internal structure of the area between two adjacent blades on the lower edge plate of the guide blade prepared using the feeding structure in the embodiment shown;

[0029] Figure 4 for Figure 1 A photograph of the internal structure of the area between two adjacent blades on the lower edge plate of the guide blade prepared without the feeding structure in the embodiment shown;

[0030] Figure 5A photograph of the internal structure of the area between two adjacent blades on the lower edge plate of a guide blade prepared by using a feeding structure in another preferred embodiment of the wax pattern and preparation method for controlling the looseness of the edge plate of a multi-linked directional / single crystal guide blade according to the present invention;

[0031] Figure 6 for Figure 5 A photograph of the internal structure of the area between two adjacent blades on the lower edge plate of the guide blade prepared without using a feeding structure in the embodiment shown.

[0032] Notes in the figure:

[0033] 1-guide vane wax mold, 101-upper edge plate, 102-lower edge plate, 103-blade body, 104-leading edge, 105-trailing edge, 106-shrinkage feeding structure; Casting system, 201-pouring cup, 202-pouring plate, 203-support column, 204-lower base plate, 205-inclined runner, 206-seedling structure. DETAILED DESCRIPTION

[0034] In order to further understand the content of the present invention, the present invention will be described in detail below in conjunction with specific embodiments.

[0035] Embodiment 1:

[0036] like Figure 1-2 As shown, according to a preferred embodiment of the wax mold for controlling the looseness of the edge plates of multi-linked directional / single crystal guide blades of the present invention, the guide blade wax mold 1 includes an upper edge plate 101, a lower edge plate 102, a blade body 103 and a feeding structure 106, the number of the blade body 103 is two, and one feeding structure 106 is arranged between two adjacent blade bodies 103, the two end surfaces of the feeding structure 106 are respectively connected to the corresponding blade bodies 103, and the bottom surface of the feeding structure 106 is connected to the lower edge plate 102; the upper edge plate 101, the lower edge plate 102, the blade body 103 and the feeding structure 106 are integrally formed, or after the upper edge plate 101, the lower edge plate 102 and the blade body 103 are integrally formed, the feeding structure 106 is bonded to the area between the two adjacent blade bodies 103.

[0037] The feeding structure 106 is U-shaped, and the center point of the U-shaped surface of the U-shaped feeding structure 106 is located at a position 1 / 4 between the leading edge 104 and the trailing edge 105 of the two blade bodies 103. The straight line passing through the center point of the U-shaped surface of the U-shaped feeding structure 106 is parallel to the long side of the lower edge plate 102.

[0038] The length of the feeding structure 106 is the distance between the center points of the two end surfaces of the feeding structure 106 when the two end surfaces of the feeding structure 106 are respectively connected to the corresponding blade airfoil 103 .

[0039] The thickness of the two ends of the feeding structure 106 is 0.8 times the thickness of the blade 103 connected to the two end surfaces of the feeding structure 106. The thickness of the middle of the feeding structure 106 is 0.4 times the thickness of the relatively thinner end of the two ends of the feeding structure 106; the two ends of the feeding structure 106 are smoothly connected to the middle.

[0040] The height of the two ends of the U-shaped feeding structure 106 is 0.2 times the height of the blade body 103, and the height of the middle of the U-shaped feeding structure 106 is not less than 0.25 times the height of the two ends of the U-shaped feeding structure 106. The portion where the feeding structure 106 is connected to the blade body 103 and the lower edge plate 102 is smoothly transitioned in a rounded form, and the radius of the rounding is 2 mm.

[0041] This embodiment also provides a method for preparing a multi-joint directional / single crystal guide blade with controlled edge plate looseness, which is prepared using the wax mold for controlling the looseness of the edge plate of the multi-joint directional / single crystal guide blade, and includes the following steps in order:

[0042] Step 1: According to the designed guide blade wax mold structure, a guide blade wax mold is pressed by a hot injection molding method, and ten guide blade wax molds are combined into a module set; or, a structural wax mold and a feeding structure wax mold formed integrally of an upper edge plate, a lower edge plate, and a blade body are pressed by a hot injection molding method respectively, and then the feeding structure wax mold is bonded to the structural wax mold formed integrally of an upper edge plate, a lower edge plate, and a blade body according to the designed positional relationship to form a guide blade wax mold, and ten guide blade wax molds are combined into a module set;

[0043] Step 2: Assemble a mold group consisting of ten guide vane wax molds and other components together to form a gating system, and prepare a mold shell of the gating system by using an investment casting method;

[0044] Step 3: After the shell of the gating system is prepared, it is placed in a vacuum induction melting device and cast by a directional solidification method, and the guide blade casting is obtained after shelling;

[0045] Step 4: Heat-treat the guide vane casting. After the heat treatment is completed, the shrinkage compensation structure is removed by mechanical processing to obtain a guide vane capable of controlling the looseness of the edge plate.

[0046] The pouring system 2 includes a pouring cup 201, a runner plate 202, a support column 203, a lower base plate 204, twenty inclined runners 205, twenty seeding structures 206, and ten guide blade wax molds 1; the pouring cup 201, the runner plate 202, the support column 203 and the lower base plate 204 are connected in sequence from top to bottom, and the ten guide blade wax molds 1 are located between the lower base plate 204 and the runner plate 202, and are evenly arranged along the edge of the lower base plate 204; the bottom of the guide blade wax mold 1 is connected to the lower base plate 204 through the seeding structure 206, and the top is connected to the runner plate 202 through the inclined runner 205.

[0047] The directional solidification method is adopted for casting. The casting material is a single crystal high-temperature alloy. The directional solidification sequence from bottom to top is the seeding structure of the same height, the lower edge plate of the same height, the blade body and the shrinkage-feeding structure of the same height, the upper edge plate of the same height, and the inclined runner of the same height. The casting material solidifies from bottom to top in each component in the casting system shell.

[0048] In this embodiment, the internal structure of the area between two adjacent blades on the lower edge plate of the guide blade prepared by the feeding structure is as follows: Figure 3 As shown in the figure, the internal structure of the area between two adjacent blades on the lower edge plate of the guide blade prepared without the shrinkage structure is as follows Figure 4 As shown, compared Figure 3 and Figure 4 It can be seen that the middle area of ​​the upper edge plate of the blade prepared with the shrinkage-feeding structure is not loose, and the tissue is dense and uniform.

[0049] In this embodiment, the hot injection molding method, investment casting method, directional solidification method, heat treatment, machining method, etc. adopted are all traditional processes, and there are no special requirements for the process flow, process parameters, equipment used, etc., as long as the shape, size, setting position of the shrinkage-compensating structure in the guide vane wax mold and the connection relationship with the blade body and lower edge plate meet the requirements of this embodiment, the size of the shrinkage-compensating structure mainly changes with the change of the blade body size and the edge plate size in the guide vane wax mold.

[0050] The wax pattern and preparation method for controlling the looseness of the edge plate of the multi-directional / single crystal guide blade in this embodiment have the following beneficial effects:

[0051] (1) A special feeding structure is designed and set in the area between two adjacent blades in the guide vane wax mold, and the two end faces of the feeding structure are connected to the corresponding blades, and the bottom face is connected to the lower edge plate. This design allows the molten metal to flow from the blade to the lower edge plate through the feeding structure (that is, this design allows the lower edge plate to have sufficient feeding channels during the directional solidification process). During the directional solidification process, the molten metal is sufficiently fed in the area between two adjacent blades on the lower edge plate (that is, the lower edge plate is fed by the feeding structure), thereby avoiding a large amount of looseness in this area. (2) By specially designing and strictly limiting the shape and size (including length, thickness, height, etc.) of the feeding structure, the directional solidification sequence of the guide vane is optimized, making the directional solidification sequence closer to the theoretical state, thereby avoiding the generation of looseness in the area between two adjacent blades on the lower edge plate, and at the same time, the setting of the feeding structure will not cause new looseness in other non-loose parts. (3) The feeding structure and wax mold pressing, mold assembly, casting, etc. are simple, reliable, low-cost, and easy to operate. They can effectively eliminate the looseness in the area between two adjacent blades on the lower edge plate of the single crystal / directional guide blade. At the same time, the setting of the feeding structure will not cause new looseness in other non-loose areas.

[0052] Embodiment 2:

[0053] According to another preferred embodiment of the wax pattern and preparation method for controlling the looseness of the edge plate of a multi-directional / single crystal guide blade of the present invention, its shrinkage feeding structure, wax pattern structure, gating system structure, preparation process, technical principle, beneficial effects, etc. are basically the same as those of the first embodiment, except that:

[0054] The shape of the feeding structure is U-shaped, and the center point of the U-shaped surface of the U-shaped feeding structure is located at a position 3 / 4 between the leading edge and the trailing edge of the two blades. The U-shaped feeding structure is located at a position rotated 45° clockwise with the center point of the U-shaped surface as the rotation point and a straight line passing through the center point of the U-shaped surface and parallel to the long side of the lower edge plate as the reference.

[0055] The length of the feeding structure is the distance between the center points of the two end faces of the feeding structure when the two end faces of the feeding structure are connected to the corresponding blade body. The thickness of the two ends of the feeding structure is 0.5 times the thickness of the blade body connected to the two end faces of the feeding structure, and the thickness of the middle of the feeding structure is 0.2 times the thickness of the relatively thinner end of the two ends of the feeding structure. The two ends of the feeding structure are smoothly connected to the middle.

[0056] The height of the two ends of the U-shaped feeding structure is 0.5 times the height of the blade body, and the height of the middle of the U-shaped feeding structure is not less than 0.25 times the height of the two ends of the U-shaped feeding structure. The portion where the feeding structure is connected to the blade body and the lower edge plate is smoothly transitioned in the form of a fillet, and the radius of the fillet is 2mm. The directional solidification method is used for casting, and the casting material is a directional high-temperature alloy.

[0057] In this embodiment, the internal structure of the area between two adjacent blades on the lower edge plate of the guide blade prepared by the feeding structure is as follows: Figure 5 As shown in the figure, the internal structure of the area between two adjacent blades on the lower edge plate of the guide blade prepared without the shrinkage structure is as follows Figure 6 As shown, compared Figure 5 and Figure 6 It can be seen that the middle area of ​​the upper edge plate of the blade prepared with the shrinkage-feeding structure is not loose, and the tissue is dense and uniform.

[0058] Embodiment three:

[0059] According to another preferred embodiment of the wax pattern and preparation method for controlling the looseness of the edge plate of a multi-directional / single crystal guide blade of the present invention, its shrinkage feeding structure, wax pattern structure, gating system structure, preparation process, technical principle, beneficial effects, etc. are basically the same as those of the first embodiment, except that:

[0060] The shape of the feeding structure is a long strip, the center point of the long strip feeding structure is located at a position 1 / 2 between the leading edge and the trailing edge of the two blades, and the long strip feeding structure is located at a position rotated 45° counterclockwise with the center point as the rotation point and a straight line passing through the center point and parallel to the long side of the lower edge plate as the reference.

[0061] The length of the feeding structure is the distance between the center points of the two end faces of the feeding structure when the two end faces of the feeding structure are connected to the corresponding blade body. The thickness of the two ends of the feeding structure is 1 times the thickness of the blade body connected to the two end faces of the feeding structure, and the thickness of the middle of the feeding structure is 0.7 times the thickness of the relatively thinner end of the two ends of the feeding structure. The two ends of the feeding structure are smoothly connected to the middle.

[0062] The height of the long strip feeding structure is 0.5 times the height of the blade body. The portion where the feeding structure is connected to the blade body and the lower edge plate is smoothly transitioned in a rounded form, and the radius of the rounded shape is 2 mm. The directional solidification method is used for casting, and the casting material is a single crystal high-temperature alloy.

[0063] Embodiment 4:

[0064] According to another preferred embodiment of the wax pattern and preparation method for controlling the looseness of the edge plate of a multi-directional / single crystal guide blade of the present invention, its shrinkage feeding structure, wax pattern structure, gating system structure, preparation process, technical principle, beneficial effects, etc. are basically the same as those of the first embodiment, except that:

[0065] The feeding structure is in the shape of an elongated strip, the center point of which is located at a position 1 / 4 between the leading edge and the trailing edge of the two blades, and the straight line passing through the center point of the elongated strip feeding structure is parallel to the long side of the lower edge plate.

[0066] The length of the feeding structure is the distance between the center points of the two end faces of the feeding structure when the two end faces of the feeding structure are connected to the corresponding blade body. The thickness of the two ends of the feeding structure is 0.8 times the thickness of the blade body connected to the two end faces of the feeding structure, and the thickness of the middle of the feeding structure is 0.5 times the thickness of the relatively thinner end of the two ends of the feeding structure. The two ends of the feeding structure are smoothly connected to the middle.

[0067] The height of the long strip-shaped feeding structure is 0.2 times the height of the blade body. The portion where the feeding structure is connected to the blade body and the lower edge plate is smoothly transitioned in a rounded form, and the radius of the rounded shape is 2 mm. The directional solidification method is used for casting, and the casting material is a directional high-temperature alloy.

[0068] Special note: The technical solution of the present invention involves many parameters, and the synergistic effects between the various parameters need to be comprehensively considered to obtain the beneficial effects and significant progress of the present invention. Moreover, the value ranges of the various parameters in the technical solution are obtained after a large number of experiments. For each parameter and the combination of each parameter, the inventor has recorded a large amount of experimental data. Due to space limitations, the specific experimental data will not be disclosed here.

[0069] It is not difficult for a person skilled in the art to understand that the wax pattern and preparation method for controlling the looseness of the edge plate of a multi-directional / single crystal guide blade of the present invention include any combination of the invention content and the specific implementation method of the above-mentioned invention specification and the various parts shown in the drawings. Due to the limited space and to make the specification concise, the various schemes composed of these combinations are not described one by one. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A wax model for controlling the looseness of multi-directional / single crystal guide blade edge plates, characterized in that: The guide blade wax mold comprises an upper edge plate, a lower edge plate, a blade body and a feeding structure, the number of the blade bodies is at least two, at least one feeding structure is arranged between two adjacent blade bodies, two end surfaces of the feeding structure are respectively connected to the corresponding blade bodies, and the bottom surface of the feeding structure is connected to the lower edge plate; the upper edge plate, the lower edge plate, the blade body and the feeding structure are integrally formed, or the feeding structure is bonded to the area between the two adjacent blade bodies after the upper edge plate, the lower edge plate and the blade body are integrally formed; The length of the feeding structure is the distance between the center points of the two end surfaces of the feeding structure when the two end surfaces of the feeding structure are respectively connected to the corresponding blade body; The thickness of the two ends of the feeding structure is 0.5-1 times the thickness of the blade body connected to the two end surfaces of the feeding structure; the thickness of the middle of the feeding structure is 0.2-0.7 times the thickness of the relatively thinner end of the two ends of the feeding structure; the two ends of the feeding structure are smoothly connected to the middle; The feeding structure is in a U-shape, and the center point of the U-shaped surface of the U-shaped feeding structure is located in the region of 1 / 4-3 / 4 between the leading edge and the trailing edge of the two blades; the U-shaped feeding structure is located in the region rotated ±45° with the center point of the U-shaped surface as the rotation point and with the straight line passing through the center point of the U-shaped surface and parallel to the long side of the lower edge plate as the reference; The heights of the two ends of the U-shaped feeding structure are 0.2-0.5 times the height of the blade body, and the height in the middle of the U-shaped feeding structure is not less than 0.25 times the heights of the two ends of the U-shaped feeding structure.

2. The wax pattern for controlling the looseness of the edge plate of multi-directional / single crystal guide blades according to claim 1, characterized in that: The shape of the feeding structure is replaced by a long strip, and the center point of the long strip feeding structure is located in the 1 / 4-3 / 4 area between the leading edge and the trailing edge of the two blades; the long strip feeding structure is located in an area rotated ±45° with the center point as the rotation point and a straight line passing through the center point and parallel to the long side of the lower edge plate as the reference; the height of the long strip feeding structure is 0.2-0.5 times the height of the blade.

3. The wax pattern for controlling the looseness of the edge plate of multi-directional / single crystal guide blades according to claim 1 or 2, characterized in that: The portion where the feeding structure is connected to the blade body and the lower edge plate is smoothly transitioned in a rounded form, and the radius of the rounded portion is 0.5-2 mm.

4. A method for preparing multi-jointed directional / single crystal guide blades with controlled edge plate looseness, characterized in that: The method is prepared by using a wax pattern for controlling the looseness of the edge plate of a multi-directional / single crystal guide blade according to any one of claims 1 to 3, and comprises the following steps in chronological order: Step 1: according to the designed guide blade wax mold structure, a guide blade wax mold integrally formed by an upper edge plate, a lower edge plate, a blade body and a feeding structure is pressed by a hot injection molding method, and a plurality of guide blade wax molds are combined into a module set; or, a structural wax mold integrally formed by an upper edge plate, a lower edge plate and a blade body and a feeding structure wax mold are pressed by a hot injection molding method respectively, and then the feeding structure wax mold is bonded to the structural wax mold integrally formed by an upper edge plate, a lower edge plate and a blade body according to the designed positional relationship to form a guide blade wax mold, and a plurality of guide blade wax molds are combined into a module set; Step 2: Assembling a mold group consisting of a plurality of guide vane wax molds with other components to form a gating system, and preparing a mold shell of the gating system by using an investment casting method; Step 3: After the shell of the gating system is prepared, it is placed in a vacuum induction melting device and cast by a directional solidification method, and the guide blade casting is obtained after shelling; Step 4: Heat-treat the guide vane casting. After the heat treatment is completed, the shrinkage compensation structure is removed by mechanical processing to obtain a guide vane capable of controlling the looseness of the edge plate.

5. The method for preparing multi-jointed directional / single crystal guide blades for controlling the looseness of edge plates according to claim 4, characterized in that: The pouring system includes a pouring cup, a pouring plate, a support column, a lower base plate, a plurality of inclined runners, a plurality of seeding structures, and a plurality of guide vane wax molds; the pouring cup, the pouring plate, the support column and the lower base plate are connected in sequence from top to bottom, and a plurality of guide vane wax molds are located between the lower base plate and the pouring plate, and are evenly arranged along the edge of the lower base plate; the bottom of the guide vane wax mold is connected to the lower base plate through the seeding structure, and the top is connected to the pouring plate through the inclined runner; The directional solidification method is adopted for casting. The casting material is single crystal high-temperature alloy or directional high-temperature alloy. The directional solidification sequence from bottom to top is the seeding structure of the same height, the lower edge plate of the same height, the blade body and the shrinkage-feeding structure of the same height, the upper edge plate of the same height, and the inclined runner of the same height. The casting material solidifies from bottom to top in each component in the casting system shell.

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