Wax model for controlling the looseness of the crown of a directional / single crystal working blade and its preparation method

Abstract

The present invention discloses a wax mold and a preparation method for controlling the looseness of a directional / single crystal shrouded working blade. The working blade wax mold includes a tenon, an edge plate, a blade body, a blade shroud and a shrinkage-compensating structure. At least one shrinkage-compensating structure is arranged on both sides of the blade body. One side of the shrinkage-compensating structure is connected to the blade body, and the other side is connected to the blade shroud. The preparation method includes the following steps: pressing the working blade wax mold and assembling a plurality of wax molds into a module group; assembling the module group with other components to form a casting system, and preparing the mold shell of the casting system by a precision investment casting method; casting and forming by a directional solidification method, and obtaining a working blade casting after shelling; heat-treating the casting and removing the shrinkage-compensating structure to obtain a working blade capable of controlling the looseness of the blade shroud. The present invention optimizes the directional solidification sequence of the blade by arranging a shrinkage-compensating structure to avoid looseness in the blade shroud area.

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 a shroud of a directional / single crystal working blade with a shroud and a preparation method thereof. Background Art

[0002] As we all know, the working blades of low-pressure turbines of advanced aircraft engines and the working blades of power turbines of turboshaft and turboprop engines usually have a shroud structure to reduce air leakage at the tip of the blade, thereby reducing gas loss, improving turbine efficiency, and increasing power output. However, the appearance of the shroud structure will cause a sudden change in the cross-sectional area of ​​the turbine working blades, making the temperature field change more complex during the directional solidification process, the mushy zone wider, and the interdendritic space at the shroud position difficult to be effectively compensated, resulting in a large amount of looseness on the shroud.

[0003] Porosity can easily cause stress concentration during the service of the blade, becoming a source of cracks, leading to premature failure of the blade, and thus endangering the service safety of the engine. Therefore, it is urgent to develop a shrouded turbine working blade that avoids looseness of the blade shroud and a preparation method thereof, so as to effectively control the looseness on the blade shroud. This is also a technical problem that urgently needs to be solved in the current manufacturing process of aircraft engine turbine working blades.

[0004] The invention patent with application publication number CN108176817A discloses a method for controlling the looseness of a slender, thin-walled, crowned equiaxed crystal casting turbine blade. The wax mold module includes a pouring cup, a runner connected to the pouring cup, and a center column tube. The runner includes a tenon end runner and a blade crown end runner. The tenon end runner is welded to the tenon inner gate of the blade. The blade crown end runner is welded to the blade crown inner gate. The wax mold module is combined in a circular module or a straight plate module. The wax mold module is coated with refractory material, dewaxed after drying, and a mold shell is obtained after pre-baking. Insulation cotton is wrapped on the mold shell except for the middle section of the blade body. The length of the middle section of the blade body is 1 / 3 of the length of the blade body. The mold shell wrapped with insulation cotton is baked and remelted and poured to obtain a blade casting. This technical solution is mainly used to control the looseness of the blade body of the turbine blade, but it cannot avoid the looseness of the blade crown of the turbine blade.

[0005] The invention patent with application publication number CN101934366A discloses a solidified material, casting mold and shrinkage compensation method for a turbine blade with crown directionally crystallized. In the shrinkage compensation method, by setting a side subsidy next to the highest point of the lower crown of the blade, and setting a crown shrinkage compensation riser on the side subsidy and the top of the lower crown, the lower crown of the blade can be compensated during the precision casting process; by setting the sprue of the blade on the upper crown, and connecting the top of the sprue to the upper circular plate, the upper crown can be compensated. For the lower crown, this technical solution only sets a side subsidy next to the highest point of the lower crown, which makes it difficult to achieve complete or sufficient shrinkage compensation; for the upper crown, the sprue is directly set on the upper crown, which is easily impacted by molten metal during casting, affecting the shrinkage compensation effect. 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 a blade crown of a oriented / single crystal shrouded working blade, the working blade wax mold comprising a tenon, an edge plate, a blade body, a blade crown and a shrinkage-compensating structure, the blade body and the blade crown being perpendicular to each other, and the bottom of the blade body and the upper surface of the blade crown being smoothly transitionally connected by chamfering, at least one shrinkage-compensating structure is arranged on both sides of the blade body, one side of the shrinkage-compensating structure is connected to the blade body, and the other side is connected to the blade crown; the tenon, the edge plate, the blade body, the blade crown and the shrinkage-compensating structure are integrally formed, or the shrinkage-compensating structure is bonded to both sides of the blade body after the tenon, the edge plate, the blade body and the blade crown are integrally formed.

[0007] Preferably, the feeding structure is located in the region 1 / 5-4 / 5 between the leading edge and the trailing edge of the blade body; on the same side of the blade body, the arc distance between two adjacent feeding structures is not less than 1 / 5 of the arc length between the leading edge and the trailing edge of the blade body.

[0008] In any of the above schemes, preferably, the feeding structure is located in a region rotated by ±40° with the side connected to the blade body as the rotation axis and with the plane perpendicular to the blade body section as the reference.

[0009] In any of the above schemes, it is preferred that the shape of the feeding structure is a right-angled triangle flat plate shape or a trapezoidal flat plate shape; the two right-angled sides of the right-angled triangle flat plate-shaped feeding structure are respectively connected to the blade body and the blade crown, the two right-angled sides are smoothly connected by chamfering, and the hypotenuse is a straight line or an arc; the two right-angled sides of the trapezoidal flat plate-shaped feeding structure are respectively connected to the blade body and the blade crown, the two right-angled sides are smoothly connected by chamfering, the hypotenuse is a straight line or an arc, and the short side is parallel to the right-angled side connected to the blade body.

[0010] In any of the above schemes, it is preferred that the height of the right-angled triangle flat plate-shaped feeding structure is 0.2-0.6 times the height of the blade body, that is, the length of the right-angled side connected to the blade body is 0.2-0.6 times the height of the blade body; the width of the right-angled triangle flat plate-shaped feeding structure is, by extending the right-angled side connected to the blade crown to the edge of the blade crown, 0.25-1 times the straight-line distance between the blade body and the edge of the blade crown, that is, the length of the right-angled side connected to the blade crown is 0.25-1 times the straight-line distance between the blade body and the edge of the blade crown.

[0011] In any of the above schemes, preferably, the thickness of the right-angled triangle flat plate-shaped feeding structure near one end of the blade body is 0.5-1.2 times the thickness of the blade body connected thereto, and the thickness of the right-angled triangle flat plate-shaped feeding structure near one end of the blade crown is 0.2-0.8 times the thickness of the blade body connected thereto; and the overall thickness of the right-angled triangle flat plate-shaped feeding structure smoothly transitions from the thickness near one end of the blade body to the thickness near one end of the blade crown.

[0012] In any of the above schemes, it is preferred that the height of the trapezoidal flat plate shaped feeding structure near one end of the blade body is 0.2-0.6 times the height of the blade body, and the height of the trapezoidal flat plate shaped feeding structure near one end of the blade crown is 0.2-0.8 times the height near one end of the blade body, that is, the length of the right-angled side connected to the blade body is 0.2-0.6 times the height of the blade body, and the length of the short side near one end of the blade crown is 0.2-0.8 times the length of the right-angled side connected to the blade body; the width of the trapezoidal flat plate shaped feeding structure is, by extending the right-angled side connected to the blade crown to the edge of the blade crown, 0.25-1 times the straight-line distance between the blade body and the edge of the blade crown, that is, the length of the right-angled side connected to the blade crown is 0.25-1 times the straight-line distance between the blade body and the edge of the blade crown.

[0013] In any of the above schemes, preferably, the thickness of the trapezoidal flat plate shaped feeding structure close to one end of the blade body is 0.5-1.2 times the thickness of the blade body connected thereto, and the thickness of the trapezoidal flat plate shaped feeding structure close to one end of the blade crown is 0.2-0.8 times the thickness of the blade body connected thereto; and the overall thickness of the trapezoidal flat plate shaped feeding structure smoothly transitions from the thickness close to one end of the blade body to the thickness close to one end of the blade crown.

[0014] The present invention also provides a method for preparing a directional / single crystal shrouded working blade with controlled shroud looseness, which is prepared using any of the above-mentioned wax molds for controlling directional / single crystal shrouded working blade shroud looseness, and comprises the following steps in order:

[0015] Step 1: According to the designed working blade wax mold structure, a working blade wax mold is pressed by a hot injection molding method, and a plurality of working blade wax molds are combined into a module set; or, a structural wax mold and a feeding structural wax mold formed integrally of a tenon, an edge plate, a blade body, and a blade crown are pressed by a hot injection molding method respectively, and then the feeding structural wax mold is bonded to the structural wax mold formed integrally of a tenon, an edge plate, a blade body, and a blade crown according to the designed positional relationship to form a working blade wax mold, and a plurality of working blade wax molds are combined into a module set;

[0016] Step 2: Assemble a mold group consisting of several working blade 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;

[0017] 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 working blade casting is obtained after shelling;

[0018] Step 4: heat-treat the working blade casting. After the heat treatment is completed, the shrinkage-feeding structure is removed by mechanical processing to obtain a working blade capable of controlling the looseness of the blade crown.

[0019] Preferably, the pouring system includes a pouring cup, a runner plate, a support column, a lower base plate, a plurality of inclined runners, a plurality of seeding structures, and a plurality of working blade wax molds; the pouring cup, the runner plate, the support column and the lower base plate are connected in sequence from top to bottom, and a plurality of the working blade wax molds are located between the lower base plate and the runner plate, and are evenly arranged along the edge of the lower base plate; the bottom of the working blade wax mold is connected to the lower base plate through the seeding structure, and the top is connected to the runner plate through the inclined runner.

[0020] 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 blade crown of the same height, the blade body and the shrinkage-feeding structure of the same height, the edge plate of the same height, the tenon 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.

[0021] 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 working blade wax mold and the connection relationship with the blade body and blade crown 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 blade crown size in the working blade wax mold.

[0022] The wax mold and preparation method for controlling the looseness of the shroud of a directional / single crystal working blade with shroud of the present invention have the following beneficial effects:

[0023] (1) The present invention designs a special feeding structure and sets a certain number of feeding structures in the area between the blade body and the blade crown of the working blade wax model to optimize the directional solidification sequence of the blade and ensure that the blade crown is adequately fed with molten metal, thereby solving the problem of loose blade crown in the working blade and avoiding looseness in the blade body and other positions.

[0024] (2) The present invention optimizes the directional solidification sequence of the working blade by specially designing and strictly limiting the shape and size (including height, width, thickness, etc.) of the feeding structure, making the directional solidification sequence closer to the theoretical state, so that the blade crown can be fully fed, and while eliminating the looseness of the blade crown, it will not cause looseness in other positions.

[0025] (3) The shrinkage compensation structure and wax mold pressing, mold assembly, casting, etc. of the present invention are simple, reliable, low-cost, and easy to operate. The prepared blades have excellent performance. The present invention has played a great application and economic value in the field of manufacturing aircraft engine turbine working blades. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic structural diagram of a wax model of a working blade in a preferred embodiment of a wax model and a preparation method for controlling the looseness of a shroud of a directional / single crystal working blade with a shroud according to the present invention;

[0027] Figure 2 for Figure 1 A schematic diagram of the position of the feeding structure on the back side of the blade in the embodiment shown;

[0028] Figure 3 Bit Figure 1 A schematic diagram of the position of the feeding structure on one side of the blade basin in the embodiment shown;

[0029] Figure 4 for Figure 1 A schematic diagram of a right-angled triangle flat plate-shaped feeding structure in the illustrated embodiment;

[0030] Figure 5 for Figure 1 A schematic diagram of the structure of the pouring system in the illustrated embodiment (only one working blade wax model is shown);

[0031] Figure 6 for Figure 1 Microstructure photos of the crown of the working blade prepared in the embodiment shown;

[0032] Figure 7A schematic diagram of a trapezoidal flat plate-shaped feeding structure in another preferred embodiment of a wax mold and a preparation method for controlling the looseness of a shroud of a directional / single crystal working blade according to the present invention;

[0033] Figure 8 for Figure 7 The microstructure photograph of the blade crown area in the working blade prepared in the embodiment shown is shown.

[0034] Notes in the figure:

[0035] 1-working blade wax mold, 101-tenon, 102-edge plate, 103-blade body, 104-blade crown, 105-leading edge, 106-trailing edge, 107-feeding structure, 108-right-angle edge, 109-bevel edge, 110-short edge;

[0036] 2- pouring system, 201- pouring cup, 202- pouring plate, 203- support column, 204- lower base plate, 205- inclined pouring channel, 206- seeding structure. DETAILED DESCRIPTION

[0037] 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.

[0038] Embodiment 1:

[0039] like Figure 1-5 As shown, according to a preferred embodiment of the wax mold for controlling the looseness of the blade crown of a oriented / single crystal shroud working blade of the present invention, the working blade wax mold 1 includes a tenon 101, an edge plate 102, a blade body 103, a blade crown 104 and a feeding structure 107, the blade body 103 and the blade crown 104 are perpendicular to each other, and the bottom of the blade body 103 and the upper surface of the blade crown 104 are smoothly transitioned and connected by chamfering, two feeding structures 107 are respectively arranged on both sides of the blade body 103, one side of the feeding structure 107 is connected to the blade body 103, and the other side is connected to the blade crown 104; the tenon 101, the edge plate 102, the blade body 103, the blade crown 104 and the feeding structure 107 are integrally formed, or the feeding structure 107 is bonded to both sides of the blade body 103 after the tenon 101, the edge plate 102, the blade body 103 and the blade crown 104 are integrally formed.

[0040] The feeding structure 107 is located in the region of 1 / 5-4 / 5 between the leading edge 105 and the trailing edge 106 of the blade 103; on the same side of the blade 103, the arc distance between two adjacent feeding structures 107 is not less than 1 / 5 of the arc length between the leading edge 105 and the trailing edge 106 of the blade 103. The feeding structure 107 is located in the region rotated ±40° with the side connected to the blade 103 as the rotation axis and with the plane perpendicular to the section of the blade 103 as the reference.

[0041] The feeding structure 107 is in the shape of a right-angled triangular flat plate. The two right-angled sides 108 of the right-angled triangular flat plate feeding structure 107 are respectively connected to the blade body 103 and the blade crown 104, the two right-angled sides 108 are smoothly connected by chamfering, and the hypotenuse 109 is a straight line or an arc.

[0042] The height of the right-angled triangle flat plate-shaped feeding structure 107 is 0.4 times the height of the blade body 103, that is, the length of the right-angled side 108 connected to the blade body 103 is 0.4 times the height of the blade body 103; the width of the right-angled triangle flat plate-shaped feeding structure 107 is, by extending the right-angled side 108 connected to the blade crown 104 to the edge of the blade crown 104, 0.6 times the straight-line distance between the blade body 103 and the edge of the blade crown 104, that is, the length of the right-angled side 108 connected to the blade crown 104 is 0.6 times the straight-line distance between the blade body 103 and the edge of the blade crown 104.

[0043] The thickness of the right-angled triangle flat plate-shaped feeding structure 107 near one end of the blade body 103 is 0.85 times the thickness of the blade body 103 connected thereto, and the thickness of the right-angled triangle flat plate-shaped feeding structure 107 near one end of the blade crown 104 is 0.5 times the thickness of the blade body 103 connected thereto; the overall thickness of the right-angled triangle flat plate-shaped feeding structure 107 smoothly transitions from the thickness near one end of the blade body 103 to the thickness near one end of the blade crown 104.

[0044] This embodiment also provides a method for preparing a directional / single crystal shrouded working blade with controlled shroud looseness, which is prepared using the above-mentioned wax mold for controlling directional / single crystal shrouded working blade with controlled shroud looseness, and includes the following steps in order:

[0045] Step 1: According to the designed working blade wax mold structure, a working blade wax mold is pressed by a hot injection molding method, and ten working blade wax molds are combined into a module set; or, a structural wax mold and a feeding structural wax mold formed integrally of a tenon, an edge plate, a blade body, and a blade crown are pressed by a hot injection molding method respectively, and then the feeding structural wax mold is bonded to the structural wax mold formed integrally of a tenon, an edge plate, a blade body, and a blade crown according to the designed positional relationship to form a working blade wax mold, and ten working blade wax molds are combined into a module set;

[0046] Step 2: Assemble the mold group consisting of ten working blade wax molds and other components together to form a gating system, and prepare the mold shell of the gating system by using an investment casting method;

[0047] 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 working blade casting is obtained after shelling;

[0048] Step 4: heat-treat the working blade casting. After the heat treatment is completed, the shrinkage-feeding structure is removed by mechanical processing to obtain a working blade capable of controlling the looseness of the blade crown.

[0049] The pouring system 2 includes a pouring cup 201, a runner plate 202, a support column 203, a lower base plate 204, ten inclined runners 205, ten seeding structures 206, and ten working 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 working 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 working 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.

[0050] The casting is carried out by directional solidification method. 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 blade crown of the same height, the blade body and the shrinkage-feeding structure of the same height, the edge plate of the same height, the tenon of the same height, and the inclined runner of the same height. The casting material solidifies from bottom to top in each component of the casting system shell.

[0051] The working blade is prepared by using the feeding structure of this embodiment. The optical microstructure of the blade crown area is as follows: Figure 6 As shown in the figure, it can be seen that the leaf crown area is not loose and the tissue is dense and uniform.

[0052] 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-feeding structure in the working blade wax mold and the connection relationship with the blade body and blade crown meet the requirements of this embodiment, the size of the shrinkage-feeding structure mainly changes with the change of the blade body size and blade crown size in the working blade wax mold.

[0053] The wax mold and preparation method for controlling the looseness of the shroud of a directional / single crystal working blade with a shroud in this embodiment have the following beneficial effects: (1) A special shrinkage compensation structure is designed, and a certain number of shrinkage compensation structures are set in the area between the blade body and the shroud of the working blade wax mold to optimize the directional solidification sequence of the blade, and at the same time, the shroud area is sufficiently compensated by the molten metal, thereby solving the problem of loose shroud in the working blade. (2) By specially designing and strictly limiting the shape and size (including height, width, thickness, etc.) of the shrinkage compensation structure, the directional solidification sequence of the working blade is optimized, and the directional solidification sequence is closer to the theoretical state, so that the shroud is fully compensated, and while eliminating the looseness of the shroud, looseness will not occur in other positions. (3) The shrinkage compensation structure and the wax mold pressing, assembly, casting, etc. are simple, reliable, low-cost, and easy to operate, and the prepared blade has excellent performance.

[0054] Embodiment 2:

[0055] According to another preferred embodiment of the wax mold and preparation method for controlling the looseness of the shroud of a directional / single crystal working blade of the present invention, its feeding structure, wax mold structure, gating system structure, preparation process, technical principle, beneficial effects, etc. are basically the same as those of the first embodiment, except that:

[0056] The feeding structure is in the shape of a right-angled triangle flat plate. The two right-angled sides of the feeding structure are respectively connected to the blade body and the blade crown, the two right-angled sides are smoothly connected by rounding, and the hypotenuse is a straight line or an arc.

[0057] The height of the right-angled triangle flat plate-shaped feeding structure is 0.6 times the height of the blade body, that is, the length of the right-angled side connected to the blade body is 0.6 times the height of the blade body; the width of the right-angled triangle flat plate-shaped feeding structure is, by extending the right-angled side connected to the blade crown to the edge of the blade crown, 1 times the straight-line distance between the blade body and the edge of the blade crown, that is, the length of the right-angled side connected to the blade crown is 1 times the straight-line distance between the blade body and the edge of the blade crown.

[0058] The thickness of the right-angled triangle flat plate-shaped feeding structure near one end of the blade body is 1.2 times the thickness of the blade body connected thereto, and the thickness of the right-angled triangle flat plate-shaped feeding structure near one end of the blade crown is 0.8 times the thickness of the blade body connected thereto; the overall thickness of the right-angled triangle flat plate-shaped feeding structure smoothly transitions from the thickness near one end of the blade body to the thickness near one end of the blade crown.

[0059] Embodiment three:

[0060] According to another preferred embodiment of the wax mold and preparation method for controlling the looseness of the shroud of a directional / single crystal working blade of the present invention, its feeding structure, wax mold structure, gating system structure, preparation process, technical principle, beneficial effects, etc. are basically the same as those of the first embodiment, except that:

[0061] like Figure 7 As shown, the feeding structure is in the shape of a trapezoidal flat plate. The two right-angled sides 108 of the feeding structure in the trapezoidal flat plate shape are respectively connected to the blade body and the blade crown, the two right-angled sides 108 are smoothly connected by chamfering, the hypotenuse 109 is a straight line or an arc, and the short side 110 is parallel to the right-angled side 108 connected to the blade body.

[0062] The height of the trapezoidal flat plate-shaped feeding structure near one end of the blade body is 0.2 times the height of the blade body, and the height of the trapezoidal flat plate-shaped feeding structure near one end of the blade crown is 0.2 times the height near one end of the blade body, that is, the length of the right-angled side connected to the blade body is 0.2 times the height of the blade body, and the length of the short side near one end of the blade crown is 0.2 times the length of the right-angled side connected to the blade body; the width of the trapezoidal flat plate-shaped feeding structure is, extending the right-angled side connected to the blade crown to the edge of the blade crown, 0.25 times the straight-line distance between the blade body and the edge of the blade crown, that is, the length of the right-angled side connected to the blade crown is 0.25 times the straight-line distance between the blade body and the edge of the blade crown.

[0063] The thickness of the trapezoidal flat plate-shaped feeding structure near one end of the blade body is 0.5 times the thickness of the blade body connected thereto, and the thickness of the trapezoidal flat plate-shaped feeding structure near one end of the blade crown is 0.2 times the thickness of the blade body connected thereto; the overall thickness of the trapezoidal flat plate-shaped feeding structure smoothly transitions from the thickness near one end of the blade body to the thickness near one end of the blade crown.

[0064] The working blade is prepared by using the feeding structure of this embodiment. The optical microstructure of the blade crown area is as follows: Figure 8 As shown in the figure, it can be seen that the leaf crown area is not loose and the tissue is dense and uniform.

[0065] Embodiment 4:

[0066] According to another preferred embodiment of the wax mold and preparation method for controlling the looseness of the shroud of a directional / single crystal working blade of the present invention, its feeding structure, wax mold structure, gating system structure, preparation process, technical principle, beneficial effects, etc. are basically the same as those of the first embodiment, except that:

[0067] The feeding structure is in the shape of a trapezoidal flat plate. The two right-angled sides of the feeding structure are respectively connected to the blade body and the blade crown, the two right-angled sides are smoothly connected by rounding, the hypotenuse is a straight line or an arc, and the short side is parallel to the right-angled side connected to the blade body.

[0068] The height of the trapezoidal flat plate-shaped feeding structure near one end of the blade body is 0.6 times the height of the blade body, and the height of the trapezoidal flat plate-shaped feeding structure near one end of the blade crown is 0.8 times the height near one end of the blade body, that is, the length of the right-angled side connected to the blade body is 0.6 times the height of the blade body, and the length of the short side near one end of the blade crown is 0.8 times the length of the right-angled side connected to the blade body; the width of the trapezoidal flat plate-shaped feeding structure is, when the right-angled side connected to the blade crown is extended to the edge of the blade crown, 1 times the straight-line distance between the blade body and the edge of the blade crown, that is, the length of the right-angled side connected to the blade crown is 1 times the straight-line distance between the blade body and the edge of the blade crown.

[0069] The thickness of the trapezoidal flat plate-shaped feeding structure near one end of the blade body is 1.2 times the thickness of the blade body connected thereto, and the thickness of the trapezoidal flat plate-shaped feeding structure near one end of the blade crown is 0.8 times the thickness of the blade body connected thereto; the overall thickness of the trapezoidal flat plate-shaped feeding structure smoothly transitions from the thickness near one end of the blade body to the thickness near one end of the blade crown.

[0070] 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 each parameter in the technical solution are obtained after a large number of experiments. For each parameter and the combination of each parameter, the inventors have recorded a large amount of test data. Due to space limitations, the specific test data are not disclosed here. It is not difficult for those skilled in the art to understand that the wax mold and preparation method for controlling the looseness of the shroud of a oriented / single crystal working blade of the present invention include the invention content and specific implementation methods of the above-mentioned specification of the present invention and any combination of the parts shown in the accompanying drawings. Due to space limitations and to make the specification concise, the various schemes consisting of these combinations are not described one by one. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A wax mold for controlling the looseness of the shroud of a directional / single crystal working blade, characterized in that: The working blade wax mold comprises a tenon, an edge plate, a blade body, a blade crown and a feeding structure, wherein the blade body and the blade crown are perpendicular to each other, and the bottom of the blade body and the upper surface of the blade crown are smoothly transitionally connected by chamfering, and at least one feeding structure is arranged on both sides of the blade body, and one side of the feeding structure is connected to the blade body, and the other side is connected to the blade crown; the tenon, the edge plate, the blade body, the blade crown and the feeding structure are integrally formed, or the feeding structure is bonded to both sides of the blade body after the tenon, the edge plate, the blade body and the blade crown are integrally formed; The feeding structure is located in the region of 1 / 5-4 / 5 between the leading edge and the trailing edge of the blade, and the feeding structure is located in the region rotated ±40° with the side connected to the blade as the rotation axis and the plane perpendicular to the blade section as the reference; the feeding structure is in the shape of a right-angled triangular flat plate, and its two right-angled sides are respectively connected to the blade and the blade crown; The height of the right-angled triangle flat plate-shaped feeding structure is 0.2-0.6 times the height of the blade body, that is, the length of the right-angled side connected to the blade body is 0.2-0.6 times the height of the blade body; the width of the right-angled triangle flat plate-shaped feeding structure is, when the right-angled side connected to the blade crown is extended to the direction of the blade crown edge, 0.25-1 times the straight-line distance between the blade body and the blade crown edge, that is, the length of the right-angled side connected to the blade crown is 0.25-1 times the straight-line distance between the blade body and the blade crown edge; The thickness of the right-angled triangle flat plate-shaped feeding structure near one end of the blade body is 0.5-1.2 times the thickness of the blade body connected thereto, and the thickness of the right-angled triangle flat plate-shaped feeding structure near one end of the blade crown is 0.2-0.8 times the thickness of the blade body connected thereto; the overall thickness of the right-angled triangle flat plate-shaped feeding structure smoothly transitions from large to small from the thickness near one end of the blade body to the thickness near one end of the blade crown.

2. The wax model for controlling the looseness of the shroud of a directional / single crystal working blade according to claim 1, characterized in that: The shape of the feeding structure is replaced by a trapezoidal flat plate shape, and its two right-angled sides are respectively connected to the blade body and the blade crown; The height of the trapezoidal flat plate-shaped feeding structure near one end of the blade body is 0.2-0.6 times the height of the blade body, and the height of the trapezoidal flat plate-shaped feeding structure near one end of the blade crown is 0.2-0.8 times the height near one end of the blade body, that is, the length of the right-angle side connected to the blade body is 0.2-0.6 times the height of the blade body, and the length of the short side near one end of the blade crown is 0.2-0.8 times the length of the right-angle side connected to the blade body; the width of the trapezoidal flat plate-shaped feeding structure is, when the right-angle side connected to the blade crown is extended to the direction of the edge of the blade crown, 0.25-1 times the straight-line distance between the blade body and the edge of the blade crown, that is, the length of the right-angle side connected to the blade crown is 0.25-1 times the straight-line distance between the blade body and the edge of the blade crown; The thickness of the trapezoidal flat plate-shaped feeding structure near one end of the blade body is 0.5-1.2 times the thickness of the blade body connected thereto, and the thickness of the trapezoidal flat plate-shaped feeding structure near one end of the blade crown is 0.2-0.8 times the thickness of the blade body connected thereto; the overall thickness of the trapezoidal flat plate-shaped feeding structure smoothly transitions from large to small from the thickness near one end of the blade body to the thickness near one end of the blade crown.

3. The wax mold for controlling the looseness of the shroud of a directional / single crystal working blade according to claim 1 or 2, characterized in that: On the same side of the blade, the arc distance between two adjacent feeding structures is not less than 1 / 5 of the arc length between the leading edge and the trailing edge of the blade.

4. The wax model for controlling the looseness of the shroud of a directional / single crystal working blade according to claim 1, characterized in that: The two right-angled sides of the right-angled triangle flat plate-shaped shrinkage-compensation structure are smoothly connected by chamfering, and the hypotenuse is a straight line or an arc.

5. The wax model for controlling the looseness of the shroud of a directional / single crystal working blade according to claim 2, characterized in that: The two right-angled sides of the trapezoidal flat plate-shaped shrinkage-feeding structure are smoothly connected by chamfering, the hypotenuse is a straight line or an arc, and the short side is parallel to the right-angled side connected to the blade body.

6. A method for preparing a directional / single crystal shrouded working blade for controlling the looseness of the shroud, characterized in that: The method is prepared by using a wax model of a controlled oriented / single crystal shrouded working blade with loose shroud according to any one of claims 1 to 5, and comprises the following steps in chronological order: Step 1: according to the designed working blade wax mold structure, a working blade wax mold integrally formed by a tenon, an edge plate, a blade body, a blade crown and a feeding structure is pressed by a hot injection molding method, and a plurality of working blade wax molds are combined into a module set; or, a structural wax mold integrally formed by a tenon, an edge plate, a blade body and a blade crown 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 a tenon, an edge plate, a blade body and a blade crown according to the designed positional relationship to form a working blade wax mold, and a plurality of working blade wax molds are combined into a module set; Step 2: Assemble a mold group consisting of several working blade 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; 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 working blade casting is obtained after shelling; Step 4: heat-treat the working blade casting. After the heat treatment is completed, the shrinkage-feeding structure is removed by mechanical processing to obtain a working blade capable of controlling the looseness of the blade crown.

7. The method for preparing a directional / single crystal shrouded working blade for controlling shroud looseness according to claim 6, characterized in that: The pouring system includes a pouring cup, a pouring plate, a support column, a lower bottom plate, a plurality of inclined pouring channels, a plurality of seeding structures, and a plurality of working blade wax molds; the pouring cup, the pouring plate, the support column, and the lower bottom plate are sequentially connected from top to bottom, and a plurality of working blade wax molds are located between the lower bottom plate and the pouring plate, and are evenly arranged along the edge of the lower bottom plate; The bottom of the working blade 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 pouring channel; 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 blade crown of the same height, the blade body and the shrinkage-feeding structure of the same height, the edge plate of the same height, the tenon 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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