JP7259659B2 - Turbine blade and method for manufacturing turbine blade - Google Patents

Description

The present invention relates to a turbine blade and a method for manufacturing a turbine blade.

2. Description of the Related Art Conventionally, as a turbine blade, for example, as described in Japanese Unexamined Patent Application Publication No. 2013-015142, there is known a blade portion and a mounting portion. A plurality of turbine blades, for example, are attached to the outer circumference of a rotor and used, and have attachment portions for attaching the blade portions to the ends of the blade portions. As a method of manufacturing a turbine blade, a method of forming a turbine blade by shaving from a lump of material, a method of forming a turbine blade by forging or casting, and the like are known.

JP 2013-015142 A

It is difficult to manufacture a high-strength turbine blade with respect to the turbine blade and the manufacturing method of the turbine blade described above. That is, high-temperature strength (mainly creep strength) is required for the airfoil portion of the turbine blade, and fatigue strength is required for the attachment portion. Since the blades are used in high temperature conditions, they are required to have strength to withstand use in high temperature conditions. On the other hand, since the mounting portion receives repeated stress, it is desirable that the fatigue strength is high. However, it is difficult to increase the strength of different types of blades and attachments that are connected to each other.

Therefore, it is desirable to develop turbine blades and methods of manufacturing turbine blades with different types of enhanced strength for the airfoil portion and attachment portion.

A turbine blade according to an aspect of the present disclosure is a turbine blade formed by connecting a wing portion and a mounting portion, wherein the wing portion is formed of metal with a columnar structure along the longitudinal direction, and the mounting portion has an equiaxed structure. is formed of a metal. According to this turbine blade, the high-temperature strength of the blade portion can be increased by forming the blade portion from the columnar structure. In addition, the fatigue strength of the mounting portion can be increased by forming the mounting portion with an equiaxed structure.

Further, in the turbine blade according to one aspect of the present disclosure, the blade portion may be formed of a columnar structure having an average long side length of 200 μm or more, and the attachment portion may be formed of an equiaxed structure having an average grain size of 50 μm or less. good. In this case, the high-temperature strength of the blade can be increased by forming the blade with a columnar structure having an average long side length of 200 μm or more. Moreover, the fatigue strength of the mounting portion can be increased by forming the mounting portion with an equiaxed structure having an average grain size of 50 μm or less.

Further, in the turbine blade according to one aspect of the present disclosure, the transition distance between the columnar structure of the blade portion and the equiaxed structure of the mounting portion may be 5 mm or less. In this case, since the transition distance between the columnar structure of the wing portion and the equiaxed structure of the mounting portion is within 5 mm, the mixed region of the columnar structure and the equiaxed structure is formed short at the boundary between the wing portion and the mounting portion. Therefore, the high-temperature strength of the wing portion and the fatigue strength of the mounting portion can be properly exhibited.

A method for manufacturing a turbine blade according to an aspect of the present disclosure is a method for manufacturing a turbine blade formed by connecting an airfoil portion and a mounting portion, in which a powder material is irradiated with an energy beam to melt the powder material to form the airfoil portion and the mounting portion. A turbine blade is manufactured by sequentially forming the parts, and the blade part and the mounting part are formed under different energy beam irradiation conditions, the blade part is formed as a columnar structure, and the mounting part is equiaxed. Configured to shape as tissue. According to this turbine blade manufacturing method, by varying the irradiation conditions of the energy beam in the shaping of the blade portion and the shaping of the mounting portion, the blade portion can be formed into a columnar structure and the mounting portion into an equiaxed structure. Therefore, in the manufactured turbine blade, the high-temperature strength of the airfoil portion can be increased, and the fatigue strength of the mounting portion can be increased. Further, by irradiating the powder material with an energy beam to melt the powder material and successively form the wing portion and the attachment portion, the transition distance between the structure of the wing portion and the structure of the attachment portion can be shortened.

In addition, in the method for manufacturing a turbine blade according to an aspect of the present disclosure, the shaping of the blade section can be performed by lowering the scanning speed of the energy beam and widening the scanning interval of the energy beam as compared with the shaping of the mounting section. good. In this case, the wing is shaped as a columnar structure by making the scanning speed of the energy beam slower and the scanning interval of the energy beam wider than the shaping of the attachment, thereby shaping the wing as a columnar structure, The mounting portion can be shaped as an equiaxed structure. Therefore, in the turbine blade, the high-temperature strength of the airfoil portion can be increased, and the fatigue strength of the attachment portion can be increased.

According to the invention of the present disclosure, it is possible to provide a turbine blade and a method of manufacturing a turbine blade with different types of enhanced strength for the airfoil portion and the mounting portion.

1 is a schematic cross-sectional view of a turbine blade according to an embodiment of the present disclosure; FIG. FIG. 2 is a diagram showing an example of the state of use of the turbine blade of FIG. 1; FIG. 2 is a diagram showing the state of metal crystals in the turbine blade of FIG. 1; FIG. 2 is a schematic configuration diagram of the turbine blade manufacturing apparatus of FIG. 1 ; FIG. 4 is an explanatory diagram of a molding process in the method for manufacturing the turbine blade according to the embodiment; 4 is a flow chart showing a method for manufacturing a turbine blade according to an embodiment; FIG. 4 is an explanatory diagram of a preheating step in the method for manufacturing the turbine blade according to the embodiment; 4 is a cross-sectional image of a manufacturing example of the turbine blade according to the embodiment; It is a figure which shows the modification of the manufacturing method of the turbine blade which concerns on embodiment.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

FIG. 1 is a structural schematic diagram of a turbine blade according to an embodiment of the present disclosure. FIG. 2 is a diagram showing an example of how the turbine blade of FIG. 1 is used.

As shown in FIG. 1 , a turbine blade 1 is a component used in jet engines, gas turbines, and the like, and includes a blade portion 2 and a mounting portion 3 . The blade portion 2 is a blade member that constitutes a turbine. The blade portion 2 extends, for example, in the radial direction D of the turbine and has a curved shape in a cross section crossing the radial direction D. As shown in FIG. Specifically, a cross section of the blade portion 2 that traverses the radial direction D has the shape of a blade cross section. The attachment portion 3 is a portion for attaching the wing portion 2 . The mounting portion 3 has a shape corresponding to, for example, the structure and shape of the turbine.

For example, as shown in FIG. 2, the turbine blade 1 is used attached to a rotor 91 of a turbine. Specifically, a plurality of turbine blades 1 are arranged in the circumferential direction of the rotor 91 and used. In this case, the mounting portion 3 is joined to the outer periphery of the rotor 91, and assembled in a plurality arranged in the circumferential direction. The mounting portion 3 is, for example, dovetailed to the rotor 91 . By assembling the mounting portion 3 in this manner, a plurality of blade portions 2 are arranged and provided in the circumferential direction of the rotor 91 .

During operation of a turbine using this turbine blade 1, the blade portion 2 is exposed to high temperature gas. Therefore, the blade portion 2 is required to have high high-temperature strength. That is, the wings 2 are required to have high strength so that they are not easily deformed at high temperatures. On the other hand, during operation of the turbine, the mounting portion 3 is repeatedly stressed. Therefore, the mounting portion 3 is required to have high fatigue strength.

The wings 2 are made of metal with a columnar structure extending in the longitudinal direction. In other words, the wing portion 2 is made of a columnar metal whose crystalline state extends in the longitudinal direction. Here, the longitudinal direction is the direction from the proximal end to the distal end of the blade portion 2, and coincides with the radial direction D of the rotor 91 in FIG. The wing portion 2 is formed of a columnar structure, so that high-temperature strength is enhanced.

Moreover, the wing portion 2 is formed of a columnar structure having an average long side length of 200 μm or more. In other words, the wings 2 are made of metal with an average length of 200 μm or more in the long side direction of the crystal. For example, in the cross section of the blade portion 2, the average length of the crystal grains in the long side direction is 200 μm or more. Here, the length of the long side means the length of the long side when the crystal is rectangular. Also, when the crystal is not rectangular, it means the length of the longest part of the crystal. The length of the long side is measured, for example, using an EBSD (Electron BackScatterDiffraction) measurement method. Incidentally, if the long side length of the crystal can be measured, the average long side length may be measured using a technique other than the EBSD measurement method.

The mounting portion 3 is made of equiaxed metal. That is, the mounting portion 3 is made of a metal whose crystalline state is equiaxed. The mounting portion 3 is formed with an equiaxed structure, thereby increasing the fatigue strength.

Moreover, the mounting portion 3 is formed of an equiaxed structure having an average grain size of 50 μm or less. That is, the mounting portion 3 is made of a metal having an average crystal grain size of 50 μm or less. For example, in the cross section of the attachment portion 3, the average grain size of crystal grains is 50 μm or less. By setting the average grain size to 50 μm or less, the fatigue strength of the attachment portion 3 can be enhanced. The grain size of the crystals is measured, for example, using the EBSD measurement method. Note that, as long as the grain size of the crystal can be measured, the average grain size may be measured using a technique other than the EBSD measurement method.

The wing portion 2 and the mounting portion 3 are made of, for example, the same metal. The wing portion 2 and the mounting portion 3 are made of, for example, a nickel-based alloy. Moreover, the wing portion 2 and the attachment portion 3 may be formed of a titanium alloy.

FIG. 3 shows the state of metal crystals of the turbine blade 1 . In FIG. 3, the vertical axis indicates the position of the turbine blade 1 in the longitudinal direction (radial direction D). That is, the lower portion of the vertical axis is the position of the mounting portion 3 and the upper portion of the vertical axis is the position of the wing portion 2 . In FIG. 3, the horizontal axis indicates the state of the metal structure. The right side is a columnar structure, and the left side is an equiaxed structure. Between the columnar structure and the equiaxed structure is a structure in which the columnar state (columnar crystals) and the equiaxed structure (equiaxed crystals) are mixed. The distance of mixed tissue between the columnar and equiaxed textures is called the transition distance. In other words, the transition distance means the distance at which the columnar structure and the equiaxed structure are mixed at the boundary between the wing portion 2 and the attachment portion 3 .

At the boundary between the wing portion 2 and the mounting portion 3, it is preferable that the structure in which the columnar structure and the equiaxed structure are mixed is as short as possible. That is, it is desirable that the transition distance from one of the columnar structure and the equiaxed structure to the other is short. That is, the high-temperature strength of the wing portion 2 and the fatigue strength of the mounting portion 3 can be increased by forming the wing portion 2 with a columnar structure as much as possible and forming the mounting portion 3 with an equiaxed structure as much as possible.

However, it is difficult to shorten the transition distance between the columnar structure and the equiaxed structure to form a metal part such as a turbine blade. For example, when manufacturing a metal part by casting, it is conceivable to manufacture a metal part containing a columnar structure and an equiaxed structure by controlling the solidification state by adjusting the cooling. In this case, it is difficult to manufacture a metal part with a transition distance between the columnar structure and the equiaxed structure in units of millimeters (less than 1 cm).

In the turbine blade 1, the transition distance between the columnar structure of the blade portion 2 and the equiaxed structure of the mounting portion 3 is within 5 mm. Further, in the turbine blade 1, the transition distance between the columnar structure of the blade portion 2 and the equiaxed structure of the mounting portion 3 may be 1 mm or less. Furthermore, in the turbine blade 1, the transition distance between the columnar structure of the blade portion 2 and the equiaxed structure of the mounting portion 3 may be within 0.5 mm. By shortening the transition distance between the columnar structure of the blade portion 2 and the equiaxed structure of the attachment portion 3 in this manner, the high-temperature strength of the blade portion 2 and the fatigue strength of the attachment portion 3 can be enhanced.

Next, a method for manufacturing the turbine blade 1 according to this embodiment will be described.

First, the three-dimensional modeling apparatus 10 used for the manufacturing method of the turbine blade 1 will be described. FIG. 4 is a schematic configuration diagram of the three-dimensional modeling apparatus 10. As shown in FIG. The three-dimensional modeling apparatus 10 is an apparatus that irradiates the powder material A with an electron beam B to melt and solidify the powder material A, thereby modeling the turbine blade 1 . The three-dimensional modeling apparatus 10 includes, for example, a step of irradiating the powder material A with an electron beam B to preheat the powder material A, and a step of irradiating the powder material A with the electron beam B to melt the powder material A, thereby forming a turbine. The step of forming a part of the blade 1 is repeated, and the solidified powder material is laminated to form the turbine blade 1 . Preheating, also referred to as preheating, is the process of heating the powder material A to a temperature below its melting point prior to building an object. Additional heating may also be performed after building to adjust the average temperature of the build and the surrounding powder bed. Additional heating is also called post-heating.

The three-dimensional modeling apparatus 10 includes a beam emitting section 20 , a modeling section 30 and a control section 40 . The beam emission unit 20 emits an electron beam B to the powder material A of the modeling unit 30 to melt the powder material A. As shown in FIG. The electron beam B is a charged particle beam formed by linear motion of electrons, which are charged particles. In addition, the beam emitting unit 20 irradiates the powder material A with the electron beam B to preheat the powder material A, and then irradiates the powder material A with the electron beam B to melt the powder material A to create a three-dimensional shape. The modeling of the turbine blade 1, which is an object, is carried out.

The beam emission section 20 includes an electron gun section 21 , an aberration coil 22 , a focus coil 23 , a deflection coil 24 and a scattering detector 25 . The electron gun section 21 is electrically connected to the control section 40, operates upon receiving a control signal from the control section 40, and emits an electron beam B. As shown in FIG. The electron gun section 21 is provided, for example, so as to emit an electron beam B downward. The aberration coil 22 is electrically connected to the controller 40 and operates upon receiving a control signal from the controller 40 . The aberration coil 22 is installed around the electron beam B emitted from the electron gun section 21 and corrects the aberration of the electron beam B. FIG. The focus coil 23 is electrically connected to the controller 40 and operates upon receiving a control signal from the controller 40 . The focus coil 23 is installed around the electron beam B emitted from the electron gun part 21, converges the electron beam B, and adjusts the focus state at the irradiation position of the electron beam B. FIG. The deflection coil 24 is electrically connected to the controller 40 and operates upon receiving a control signal from the controller 40 . The deflection coil 24 is installed around the electron beam B emitted from the electron gun section 21, and adjusts the irradiation position of the electron beam B according to a control signal. Since the deflection coil 24 performs electromagnetic beam deflection, the scanning speed at the time of irradiation of the electron beam B can be increased compared to mechanical beam deflection. The electron gun section 21, the aberration coil 22, the focus coil 23, and the deflection coil 24 are installed, for example, in a column 26 having a cylindrical shape. Note that the installation of the aberration coil 22 may be omitted.

The scattering detector 25 is a device that detects scattering of the powder material A by irradiation of the electron beam B to the powder material A. As shown in FIG. In other words, the scattering detector 25 detects a smoke phenomenon in which the powder material A scatters and rises like a mist when the electron beam B is applied to the powder material A. FIG. As the scattering detector 25, for example, an X-ray detector is used. In this case, the scattering detector 25 detects X-rays generated when smoke is generated, and the scattering of the powder material A can be detected by detecting the X-rays. Scatter detector 25 is mounted, for example, on column 26 and positioned to face electron beam B. As shown in FIG. In addition, the scattering detector 25 may be provided in the vicinity of the irradiation area of the powder material A in some cases. Further, depending on the three-dimensional modeling apparatus 10, the scattering detector 25 may not be provided.

The shaping section 30 is a part for shaping the desired turbine blade 1, and the powder material A is arranged in the chamber 30a. The shaping section 30 is provided below the beam emitting section 20 . The modeling section 30 includes a box-shaped chamber 30a, and includes a plate 31, an elevator 32, a powder coating mechanism 33, and a hopper 34 inside the chamber 30a. The chamber 30a is coupled with the column 26, and the internal space of the chamber 30a communicates with the internal space of the column 26 in which the electron gun section 21 is arranged.

The plate 31 is a member that supports the turbine blade 1 to be shaped. An object is built on the plate 31 and the plate 31 supports the turbine blade 1 being built. A circular plate-like body is used as the plate 31, for example. The plate 31 is arranged on an extension line of the emission direction of the electron beam B, and is provided, for example, in the horizontal direction. The plate 31 is arranged to be supported by an elevating stage 35 installed below, and moves vertically together with the elevating stage 35 . The elevator 32 is a device that raises and lowers the elevation stage 35 and the plate 31 . The elevator 32 is electrically connected to the controller 40 and operates upon receiving a control signal from the controller 40 . For example, the elevator 32 moves the plate 31 upward together with the elevator stage 35 at the beginning of the modeling of the turbine blade 1, and lowers the plate 31 each time the powder material A is melted and solidified on the plate 31 and stacked. . Any mechanism may be used as the elevator 32 as long as it is a mechanism capable of lifting the plate 31 .

The plate 31 is arranged in a build tank 36 . The modeling tank 36 is installed in the lower part inside the chamber 30a. The modeling tank 36 is, for example, cylindrical and extends in the moving direction of the plate 31 . The modeling tank 36 is formed with a circular cross-section that is concentric with the plate 31 . A lift stage 35 is formed to match the inner shape of the modeling tank 36 . That is, when the inner shape of the modeling tank 36 is circular in horizontal cross section, the external shape of the elevating stage 35 is also circular. This makes it easier to prevent the powder material A supplied to the modeling tank 36 from leaking down the elevation stage 35 . In addition, in order to prevent the powder material A from leaking downward from the lifting stage 35, a sealing material may be provided at the outer edge of the lifting stage 35. FIG. In addition, the shape of the modeling tank 36 is not limited to a cylindrical shape, and may be a rectangular tubular shape having a rectangular cross section.

The powder coating mechanism 33 is a member that supplies the powder material A above the plate 31 and smoothes the surface of the powder material A, and functions as a recoater. For example, the powder coating mechanism 33 uses a bar-shaped or plate-shaped member, and moves horizontally to supply the powder material A to the irradiation area of the electron beam B and level the surface of the powder material A. The movement of the powder coating mechanism 33 is controlled by an actuator and mechanism (not shown). As a mechanism for leveling the powder material A, a mechanism other than the powder coating mechanism 33 can be used. The hopper 34 is a container for containing the powder material A. A discharge port 34a for discharging the powder material A is formed in the lower part of the hopper 34 . The powder material A discharged from the discharge port 34 a flows onto the plate 31 or is supplied onto the plate 31 by the powder coating mechanism 33 . Plate 31, elevator 32, powder coating mechanism 33 and hopper 34 are installed in chamber 30a. The inside of the chamber 30a is in a vacuum or almost vacuum state. As a mechanism for supplying the powder material A in layers onto the plate 31, a mechanism other than the powder coating mechanism 33 and the hopper 34 can be used.

Powder material A is composed of a large number of powder bodies. As the powder material A, metal powder is used, for example. As the powder material A, granules having a particle diameter larger than that of the powder may be used as long as they can be melted and solidified by irradiation with the electron beam B.

The control unit 40 is an electronic control unit that controls the entire apparatus of the three-dimensional modeling apparatus 10, and includes, for example, a computer including a CPU, a ROM, and a RAM. The control unit 40 controls the elevation of the plate 31, the operation control of the powder coating mechanism 33, the emission control of the electron beam B, the operation control of the deflection coil 24, the detection of scattering of the powder material A, and the detection of the scattering position of the powder material A. conduct. The control unit 40 controls the elevation of the plate 31 by outputting a control signal to the elevator 32 to operate the elevator 32 and adjust the vertical position of the plate 31 . The control unit 40 operates the powder coating mechanism 33 before the electron beam B is emitted to supply the powder material A onto the plate 31 for leveling. The control unit 40 outputs a control signal to the electron gun unit 21 to control the electron beam B to be emitted from the electron gun unit 21 .

The controller 40 controls the irradiation position of the electron beam B by outputting a control signal to the deflection coil 24 as operation control of the deflection coil 24 . For example, when preheating the powder material A, the control unit 40 outputs a control signal to the deflection coil 24 of the beam emission unit 20 to scan and irradiate the electron beam B on the plate 31 .

When modeling an object, the control unit 40 uses, for example, three-dimensional CAD (Computer-Aided Design) data of the turbine blade 1 to be modeled. The three-dimensional CAD data of the turbine blade 1 is shape data of the turbine blade 1 that is input in advance. The control unit 40 generates two-dimensional slice data based on the three-dimensional CAD data. The slice data is, for example, horizontal cross-sectional data of the turbine blade 1, and is a collection of a large number of data corresponding to vertical positions. The control unit 40 determines the area of the powder material A to be irradiated with the electron beam B based on this slice data.

FIG. 5 is a diagram showing scanning of the electron beam B when the turbine blade 1 is shaped. In addition, in FIG. 5, illustration of the powder material A is omitted for convenience of explanation. As shown in FIG. 5, the electron beam B is irradiated along the arrow direction according to the shape of the turbine blade 1 . The electron beam B is scanned at a preset interval G, and the entire molding region R is irradiated. The modeling region R is set according to the slice data of the turbine blade 1 to be shaped.

The control unit 40 causes the wing portion 2 and the attachment portion 3 to be shaped by varying the irradiation conditions of the electron beam B. FIG. For example, the controller 40 varies the scanning speed and scanning interval of the electron beam B in shaping the wing portion 2 and the mounting portion 3 . Specifically, the wing portion 2 is formed by lowering the scanning speed of the electron beam B and widening the scanning interval G of the electron beam B with respect to the forming of the mounting portion 3 . On the other hand, the mounting portion 3 is formed by increasing the scanning speed of the electron beam B and narrowing the scanning interval G of the electron beam B as compared with the forming of the wing portion 2 . Further, the output of the electron beam B may be made different in shaping the wing portion 2 and the mounting portion 3 . The irradiation conditions of the electron beam B are set by appropriately adjusting the scanning speed, the scanning interval, the beam output, etc. so that the wing portion 2 is modeled as a columnar structure and the mounting portion 3 is modeled as an equiaxed structure. .

FIG. 6 is a flow chart showing a method for manufacturing the turbine blade 1 according to this embodiment.

As shown in FIG. 6, the turbine blade 1 is manufactured by sequentially forming the mounting portion 3 and the blade portion 2 . First, as shown in S10 of FIG. 6, the mounting portion 3 is shaped. The mounting portion 3 is formed by repeating the step of supplying the powder material A onto the plate 31, the preheating step, and the forming step.

The step of supplying the powder material A is a step of supplying the powder material A to the irradiation area of the electron beam B and leveling the surface thereof. For example, in FIG. 1, the control unit 40 outputs a control signal to the elevator 32 to adjust the vertical position of the plate 31, and outputs a control signal to an actuator or mechanism (not shown) to operate the powder coating mechanism 33. As a result, the powder coating mechanism 33 operates horizontally to supply the powder material A onto the plate 31 and level the surface of the powder material A. As shown in FIG.

The preheating step is a step of heating the powder material A in advance before forming an object. The control unit 40 outputs a control signal to the beam emitting unit 20 to cause the electron gun unit 21 to emit the electron beam B and scan the electron beam B. FIG. As a result, as shown in FIG. 7, the powder material A on the plate 31 is uniformly irradiated with the electron beam B and heated.

The shaping process is a process of shaping the mounting portion 3 of the turbine blade 1 . For example, the control unit 40 generates two-dimensional slice data based on three-dimensional CAD data of the mounting portion 3 to be shaped. Based on this slice data, the control unit 40 determines a modeling region R to irradiate the powder material A with the electron beam B, and irradiates the electron beam B from the beam emitting unit 20 according to the modeling region R. . In the modeling process here, a part of the layers that constitute the attachment portion 3 is modeled. At this time, the irradiation of the electron beam B is performed at a higher scanning speed and a narrower interval G between scanning of the electron beam B than in the shaping of the wing portion 2 . The irradiation conditions of the electron beam B are set by appropriately adjusting the scanning speed, the scanning interval G, the output, etc. of the electron beam B so that the mounting portion 3 has an equiaxed structure. As a result, the crystal grain size of the metal in the attachment portion 3 becomes small, and the attachment portion 3 is shaped as an equiaxed structure.

In the molding of the mounting portion 3, the step of supplying the powder material A, the preheating step, and the molding step are repeated, whereby the mounting portion 3 is gradually formed in layers, and finally the desired mounting portion 3 is formed. be done.

When the shaping of the mounting portion 3 in S10 is completed, the shaping of the wing portion 2 is performed (S20). The wing portion 2 is formed by repeating the step of supplying the powder material A onto the plate 31, the preheating step, and the forming step. Further, if necessary, an additional heating step may be performed after the shaping step, and the step of supplying the powder material A, the preheating step, the shaping step, and the additional heating step may be repeated.

The step of supplying the powder material A is a step of supplying the powder material A to the irradiation area of the electron beam B and leveling the surface thereof. For example, in FIG. 4, the control unit 40 outputs a control signal to the elevator 32 to adjust the vertical position of the plate 31 and outputs a control signal to an actuator or mechanism (not shown) to operate the powder coating mechanism 33 . As a result, the powder coating mechanism 33 operates horizontally to supply the powder material A onto the plate 31 and level the surface of the powder material A. As shown in FIG.

The preheating step is a step of heating the powder material A in advance before forming an object. The control unit 40 outputs a control signal to the beam emitting unit 20 to cause the electron gun unit 21 to emit the electron beam B and scan the electron beam B. FIG. As a result, as shown in FIG. 7, the powder material A on the plate 31 is uniformly irradiated with the electron beam B and heated.

The shaping process is a process of shaping the airfoil portion 2 of the turbine blade 1 . For example, the control unit 40 generates two-dimensional slice data based on three-dimensional CAD data of the wing portion 2 to be modeled. Based on this slice data, the control unit 40 determines a modeling region R to irradiate the powder material A with the electron beam B, and irradiates the electron beam B from the beam emitting unit 20 according to the modeling region R. . In the modeling process here, a part of the layers forming the wing portion 2 is modeled. At this time, the irradiation conditions of the electron beam B are different from those of the mounting portion 3 . Irradiation of the electron beam B is performed with the scanning speed of the electron beam B being slower and the scanning interval G of the electron beam B being wider than those in the molding of the mounting portion 3 . The irradiation conditions of the electron beam B are set by appropriately adjusting the scanning speed, the scanning interval G, the output, etc. of the electron beam B so that the wing portion 2 has a columnar structure. As a result, the crystal grain size of the metal in the wing portion 2 is increased, and the wing portion 2 is shaped as a columnar structure.

The additional heating step is a step of heating the modeling region R and the powder material A in order to maintain and adjust the average temperature of the modeled object and surrounding powder after modeling. The control unit 40 outputs a control signal to the beam emitting unit 20 to cause the electron gun unit 21 to emit the electron beam B and scan the electron beam B. FIG. As a result, as shown in FIG. 7, the powder material A on the plate 31 is uniformly irradiated with the electron beam B and heated.

In the formation of the wing portion 2, the step of supplying the powder material A, the preheating step, the forming step, and the additional heating step are repeatedly performed, so that the wing portion 2 is gradually formed in layers, and finally the mounting portion 3 is formed. The wing portion 2 is formed by connecting to the .

After finishing the shaping of the wing portion 2 in S20, the series of control processing in FIG. 6 ends. Although the method of forming the mounting portion 3 and the wing portion 2 in this order has been described here, the wing portion 2 and the mounting portion 3 may be formed in this order.

FIG. 8 shows an actual manufacturing example. The image on the left side of FIG. 8 is a cross-sectional image of a shaped body in which a columnar structure and an equiaxed structure are separately produced, and the image on the right side of FIG. 8 is an analysis image in which the boundary portion is enlarged. This shaped body is manufactured by the manufacturing method described above, and is formed of a nickel-based alloy. Looking at the image on the right in FIG. 8, it can be seen that the transition distance between the columnar structure and the equiaxed structure is short. The transition distance between the columnar structure (columnar crystals) and the equiaxed structure (equiaxed crystals) is approximately 0.5 mm.

As described above, according to the turbine blade 1 according to the present embodiment, the high-temperature strength of the blade portion 2 can be increased by forming the blade portion 2 with a columnar structure. Moreover, the fatigue strength of the mounting portion 3 can be increased by forming the mounting portion 3 with an equiaxed structure.

Further, according to the turbine blade 1 according to the present embodiment, the high-temperature strength of the blade portion 2 can be increased by forming the blade portion 2 with a columnar structure having an average long side length of 200 μm or more. Moreover, the fatigue strength of the mounting portion 3 can be increased by forming the mounting portion 3 with an equiaxed structure having an average grain size of 50 μm or less.

Further, according to the turbine blade 1 according to the present embodiment, the transition distance between the columnar structure of the blade portion 2 and the equiaxed structure of the attachment portion 3 is set to 5 mm or less. Therefore, a short mixed region of the columnar structure and the equiaxed structure is formed at the boundary between the wing portion 2 and the mounting portion 3 . Therefore, the high-temperature strength of the blade portion 2 and the fatigue strength of the mounting portion 3 can be exhibited appropriately.

According to the manufacturing method of the turbine blade 1 according to the present embodiment, by making the irradiation conditions of the electron beam B different in the shaping of the blade part 2 and the shaping of the mounting part 3, the blade part 2 and the mounting part 3 are formed into different structures. can be molded. That is, the wing portion 2 can be formed as a columnar structure and the mounting portion 3 can be formed as an equiaxed structure. Therefore, the high-temperature strength of the blade portion 2 can be increased, and the fatigue strength of the mounting portion 3 can be increased. In addition, by irradiating the powder material A with the electron beam B to melt the powder material A and sequentially form the wing portion 2 and the mounting portion 3, the transition distance between the structure of the wing portion 2 and the structure of the mounting portion 3 is shortened. be able to. Therefore, the high-temperature strength of the blade portion 2 and the fatigue strength of the mounting portion 3 can be exhibited appropriately.

In addition, according to the method for manufacturing the turbine blade 1 according to the present embodiment, the blade portion 2 is formed by lowering the scanning speed of the electron beam B and the scanning interval of the electron beam B as compared with the forming of the mounting portion 3. is performed by widening the As a result, the wing portion 2 can be modeled as a columnar structure, and the mounting portion 3 can be modeled as an equiaxed structure. Therefore, in the turbine blade 1, the high-temperature strength of the blade portion 2 can be increased, and the fatigue strength of the attachment portion 3 can be increased.

In addition, this invention is not limited to embodiment mentioned above. The present invention can take various modifications without departing from the gist of the claims.

For example, in the above-described embodiment, the case of irradiating the powder material A with the electron beam B as the energy beam to shape the object has been described, but an energy beam other than the electron beam B may be radiated. For example, an object may be shaped by irradiating a laser beam or an ion beam.

In the above-described embodiment, the three-dimensional modeling apparatus 10 for the turbine blade 1 sequentially performs the powder material A supply process, the preheating process, the modeling process, and the additional heating process. It may be done. For example, as shown in FIG. 9, the beam emitting unit 20, the powder coating mechanism 33, and the heater 50 are arranged in the circumferential direction above the plate 31 so that the plate 31 can rotate around the central position C. As shown in FIG. Thereby, the supply of the powder material A onto the plate 31, the preheating and the shaping can be performed at the same time. By manufacturing the turbine blade 1 with such a turbine blade 1 manufacturing apparatus, the turbine blade 1 can be manufactured efficiently in a short time. In particular, it is effective when the turbine blade 1 is large.

1 Turbine blade 2 Wing part 3 Attachment part 10 Three-dimensional modeling device 20 Beam emission part 21 Electron gun part 22 Aberration coil 23 Focus coil 24 Deflection coil 30 Modeling part 31 Plate 32 Elevator 33 Powder application mechanism 34 Hopper 40 Control part A Powder material B electron beam D radial direction R modeling area

Claims (3)

In a turbine blade formed by connecting a blade portion and a mounting portion,
The wings are formed of metal with a columnar structure along the longitudinal direction,
The mounting portion is formed of a metal having an equiaxed structure ,
A transition distance between the columnar structure of the wing portion and the equiaxed structure of the mounting portion is within 5 mm.
turbine blades. The wing portion is formed of the columnar structure having an average long side length of 200 μm or more,
The mounting portion is formed of the equiaxed structure having an average grain size of 50 μm or less,
A turbine blade according to claim 1 . In a method for manufacturing a turbine blade formed by connecting a blade portion and a mounting portion,
manufacturing the turbine blade by irradiating a powder material with an energy beam to melt the powder material to sequentially form the blade portion and the mounting portion;
In the shaping of the wing portion and the shaping of the attachment portion, the wing portion is shaped as a columnar structure and the attachment portion is shaped as an equiaxed structure, and the wing portion is shaped as a columnar structure and the mounting portion is shaped as an equiaxed structure .
The shaping of the wing section is performed by slowing the scanning speed of the energy beam and widening the scanning interval of the energy beam with respect to the shaping of the mounting section.
A method of manufacturing a turbine blade.

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