System and method for enhanced cooling during directional solidification of cast parts

Abstract

A casting system for forming a directionally solidified cast part is provided. The casting system defines an axial direction, a radial direction, and a circumferential direction. The casting system includes a chamber and a deflector disposed within the chamber. The chamber and the deflector collectively define a heating zone and a cooling zone. And the heating area and the cooling area are separated by the guide plate. The casting system also includes a shaft and a cooling plate disposed on the shaft. The cooling plate is movable between the heating zone and the cooling zone. A mold housing is disposed on the cooling plate. The casting system also includes a cooling system for directing a coolant fluid toward the mold housing.

Description

Technical Field

[0001] The present invention relates generally to materials and methods for producing directionally solidified castings, and particularly to reducing defects in alloys cast as single crystal (SX) and directionally solidified (DS) articles suitable for use as components in gas turbines and other high temperature applications. Background Art

[0002] Components of gas turbines, such as blades, vanes, and combustor components, are typically formed of nickel, cobalt, or iron-based superalloys characterized by having desirable mechanical properties at turbine operating temperatures. Because the efficiency of a gas turbine depends on its operating temperature, components that can withstand higher temperatures are required, and in particular turbine blades, nozzles, combustor components, and other hot gas path components. As material requirements for gas turbine components increase, various processing methods and alloy compositions have been used to enhance the mechanical, physical, and environmental properties of components formed from superalloys. For example, blades, nozzles, and other components employed in demanding applications are typically cast by directional casting techniques to have DS or SX microstructures, which are characterized by crystal orientation or growth direction in a selected direction to produce columnar polycrystalline or single crystal products.

[0003] Directional casting techniques for producing SX and DS castings typically require pouring a melt of the desired alloy into an investment casting mold maintained at a temperature above the alloy liquidus temperature. Solidification of the molten alloy within the mold occurs by gradually withdrawing the mold from a heating zone and into a cooling zone, where cooling occurs by convection and / or radiation. Solidification begins at the base of the mold and the solidification front advances to the top of the mold. A high thermal gradient is required at the solidification front to prevent nucleation of new grains during the directional solidification process.

[0004] During the directional solidification process of geometrically complex parts, grain defects may occur because local hot spots do not cool at the same rate as the rest of the part. Therefore, an improved system and method for cooling a cast part during a directional solidification process is desired and would be understood in the art. Summary of the invention

[0005] Aspects and advantages of casting systems and methods according to the present disclosure will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the technology.

[0006] According to one embodiment, a casting system for forming a directionally solidified cast component is provided. The casting system defines an axial direction, a radial direction, and a circumferential direction. The casting system includes a chamber and a guide plate disposed in the chamber. The chamber and the guide plate together define a heating zone and a cooling zone. The heating zone and the cooling zone are separated by the guide plate. The casting system also includes an axis and a cooling plate disposed on the axis. The cooling plate is capable of moving between the heating zone and the cooling zone. A mold shell is disposed on the cooling plate. The casting system also includes a cooling system for directing a coolant fluid toward the mold shell.

[0007] According to another embodiment, a method of forming a directionally solidified cast component using a casting system is provided. The casting system includes a chamber having a heating zone and a cooling zone separated by a guide plate. The method includes pouring an alloy in a liquid state into a mold shell. The mold shell is positioned on a cooling plate within the heating zone. The mold shell is moved from the heating zone to the cooling zone. While the mold shell is moved from the heating zone to the cooling zone, the alloy is transformed from the liquid state to a solid state within the mold shell. The method also includes directing a coolant fluid toward the mold shell using a cooling system.

[0008] These and other features, aspects and advantages of the casting system and method of the present invention will become better understood with reference to the following description and appended claims.The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] This specification sets forth a complete and enabling disclosure of the casting system and method of the present invention, including the best mode of making and using the system and method of the present invention, to one of ordinary skill in the art, with reference to the accompanying drawings, wherein:

[0010] Figure 1 is a schematic diagram of a turbine according to an embodiment of the present disclosure;

[0011] Figure 2 showing a cross-sectional view of a casting system in a first position according to an embodiment of the present disclosure;

[0012] Figure 3 shows an embodiment of the present disclosure in a second position Figure 2 A cross-sectional view of the casting system shown;

[0013] Figure 4 A cross-sectional view taken along line 4-4 is shown. Figure 3 A cross-sectional view of the casting system shown;

[0014] Figure 5showing a cross-sectional view of a casting system in a first position according to an embodiment of the present disclosure;

[0015] Figure 6 shows an embodiment of the present disclosure in a second position Figure 5 A cross-sectional view of the casting system shown;

[0016] Figure 7 A cross-sectional view taken along line 7-7 is shown. Figure 3 A cross-sectional view of the casting system shown;

[0017] Figure 8 showing a cross-sectional view of a casting system in a first position according to an embodiment of the present disclosure;

[0018] Fig. 9 The embodiment according to the present disclosure is shown Figure 8 a cross-sectional view of the casting system shown in a second position; and

[0019] Fig.10 is a flow chart of one embodiment of a method of forming a directionally solidified cast component using a casting system according to embodiments of the present disclosure. DETAILED DESCRIPTION

[0020] Reference will now be made in detail to embodiments of the casting system and method of the present invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the present invention, rather than limitation of the present invention. In fact, it will be apparent to those skilled in the art that changes and modifications may be made in the present invention without departing from the scope or spirit of the present invention as protected by the claims. For example, a feature illustrated or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, the present disclosure is intended to cover these changes and modifications that fall within the scope of the appended claims and their equivalents.

[0021] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations. In addition, unless otherwise specifically stated, all embodiments described herein should be considered exemplary.

[0022] The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar parts of the present invention. As used herein, the terms "first," "second," and "third" are used interchangeably to distinguish one component from another and are not intended to indicate the location or importance of the various components.

[0023] The term "fluid" may be a gas or a liquid. The term "fluid communication" means that a fluid is able to connect between designated areas.

[0024] As used herein, the terms "upstream" (or "upward") and "downstream" (or "downward") refer to relative directions relative to the flow of a fluid in a fluid pathway. For example, "upstream" refers to the direction from which the fluid is flowing, and "downstream" refers to the direction toward which the fluid is flowing. However, the terms "upstream" and "downstream" as used herein may also refer to current flow. The term "radially" refers to a relative direction that is substantially perpendicular to an axial centerline of a particular component, the term "axially" refers to a relative direction that is substantially parallel and / or coaxially aligned with an axial centerline of a particular component, and the term "circumferentially" refers to a relative direction extending around the axial centerline of a particular component.

[0025] Terms with approximate meanings (such as "about", "approximately", "substantially" and "substantially") are not limited to the exact values ​​specified. In at least some cases, approximate language may correspond to the accuracy of an instrument used to measure a value, or the accuracy of a method or machine used to construct or manufacture a component and / or system. In at least some cases, approximate language may correspond to the accuracy of an instrument used to measure a value, or the accuracy of a method or machine used to construct or manufacture a component and / or system. For example, approximate language may refer to a tolerance of 1%, 2%, 4%, 5%, 10%, 15% or 20% in an individual value, a range of values, and / or an end value of a range of defined values. When used in the context of an angle or direction, such terms are included within ten degrees greater than or less than the angle or direction. For example, "substantially vertical" includes directions within ten degrees of vertical in any direction (e.g., clockwise or counterclockwise).

[0026] Unless otherwise stated herein, the terms "coupled," "fixed," "attached to," and the like refer to direct coupling, fixing, or attachment, as well as indirect coupling, fixing, or attachment through one or more intermediate components or features. As used herein, the terms "include," "comprises," "includes," "has," or any other variation thereof, are intended to cover non-exclusive inclusions. For example, a process, method, article, or device that includes a list of features is not necessarily limited to only those features, but may include other features that are not expressly listed or that are inherent to such process, method, article, or device. In addition, unless expressly stated to the contrary, "or" refers to an inclusive or and not an exclusive or. For example, condition A or B is satisfied by any one of the following: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); and both A and B are true (or exist).

[0027] Here and throughout the specification and claims, unless context or language indicates otherwise, range limitations are combined and interchanged, such ranges are identified and include all sub-ranges contained therein. For example, all ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other.

[0028] Now referring to the accompanying drawings, Figure 1 A schematic diagram of one embodiment of a turbine is shown, which in the illustrated embodiment is a gas turbine 10. Although an industrial or land-based gas turbine is shown and described herein, the present disclosure is not limited to land-based and / or industrial gas turbines unless otherwise indicated in the claims. For example, the present invention as described herein can be used for any type of turbine, including but not limited to a steam turbine, an aircraft gas turbine, or a marine gas turbine.

[0029] As shown, the gas turbine 10 generally includes an inlet section 12, a compressor section 14 disposed downstream of the inlet section 12, a plurality of combustors (not shown) within a combustor section 16 disposed downstream of the compressor section 14, a turbine section 18 disposed downstream of the combustor section 16, and an exhaust section 20 disposed downstream of the turbine section 18. In addition, the gas turbine 10 may include one or more shafts 22 coupled between the compressor section 14 and the turbine section 18.

[0030] The compressor section 14 may generally include a plurality of rotor disks 24 (one of which is shown) and a plurality of rotor blades 26 extending radially outward from and connected to each rotor disk 24. Each rotor disk 24, in turn, may be coupled to or form part of a shaft 22 extending through the compressor section 14.

[0031] The turbine section 18 may generally include a plurality of rotor disks 28 (one of which is shown) and a plurality of rotor blades 30 extending radially outward from and interconnected to each rotor disk 28. Each rotor disk 28, in turn, may be coupled to or form a portion of a shaft 22 extending through the turbine section 18. The turbine section 18 also includes an outer casing 31 that circumferentially surrounds a portion of the shaft 22 and the rotor blades 30, thereby at least partially defining a hot gas path 32 through the turbine section 18.

[0032] During operation, a working fluid, such as air, flows through the inlet section 12 and into the compressor section 14, where the air is gradually compressed, thereby providing pressurized air to the combustors of the compressor section 16. The pressurized air is mixed with fuel and combusted within each combustor to produce combustion gases 34. The combustion gases 34 flow from the combustor section 16 through a hot gas path 32 into the turbine section 18, where energy (kinetic energy and / or thermal energy) is transferred from the combustion gases 34 to the rotor blades 30, causing the shaft 22 to rotate. The mechanical rotational energy can then be used to power the compressor section 14 and / or generate electricity. The combustion gases 34 leaving the turbine section 18 can then be discharged from the gas turbine 10 via the exhaust section 20.

[0033] Reference now Figures 2 to 9 , various views of a casting system 100 for forming a directionally solidified cast component are shown according to an embodiment of the present disclosure. As will be explained in more detail below, the directionally solidified cast component can be formed from a molten alloy solidified in a mold shell 122. In an exemplary embodiment, the directionally solidified cast component can be a turbine component (such as a rotor blade, a stator vane, a fuel nozzle, etc.). For example, the directionally solidified cast component can be a rotor blade, such that the cast component includes a shank and an airfoil extending from the shank. In this way, the mold shell 122 can define a shank portion 102 and an airfoil portion 104 corresponding to the shape of the shank and airfoil of a turbine rotor blade. The casting system 100 can define a cylindrical coordinate system having an axial direction A, a radial direction R extending substantially perpendicular to the axial direction A, and a circumferential direction C extending around the axial direction A.

[0034] As shown, the casting system 100 includes a chamber 108 and a baffle 110 disposed within the chamber 108. In many embodiments, the chamber 108 may include a bottom 140, a top 142, and a sidewall 144 extending between the bottom 140 and the top 142. In addition, the chamber 108 may define an axial centerline 150. For example, the chamber 108 may be a solid structure that defines an interior volume 112 (i.e., as used herein, the term "chamber" refers to a solid wall that defines an interior volume). The baffle 110 may separate the interior volume 112 into a heating zone 114 and a cooling zone 116. For example, the chamber 108 and the baffle 110 may jointly define the heating zone 114 and the cooling zone 116. The heating zone 114 and the cooling zone 116 may be separated by the baffle 110 so that a first side of the baffle 110 defines the heating zone 114 and a second side of the baffle 110 defines the cooling zone 116. The bottom portion 140 may partially define the cooling zone 116 , and the top portion 142 may partially define the heating zone 114 .

[0035] The casting system 100 may also include a cooling plate 118 that is movable (e.g., axially movable) between the heating zone 114 and the cooling zone 116. For example, the cooling plate 118 may be coupled to the shaft 120, and the shaft 120 may be actuated in the axial direction A (e.g., via one or more linear actuators 301, which are represented by a circled "A"). In various embodiments (not shown), the cooling plate 118 may be a water-cooled cooling plate 118. For example, the cooling plate 118 may have one or more water cooling circuits defined therein that circulate water through the cooling plate 118. Additionally, in many embodiments, the cooling plate 118 may be constructed of a highly thermally conductive material, such as copper or a copper alloy.

[0036] The casting system 100 may also include a mold shell 122 disposed on the cooling plate 118 (e.g., disposed on a top surface 119 of the cooling plate 118). For example, the mold shell 122 may extend axially from a base 125 disposed on the cooling plate 118 to a top end 126. The mold shell 122 may define a cavity 128 into which an alloy 162 in a liquid state (i.e., liquid alloy 164) may be poured in the heating zone 114 (e.g., from the crucible 124). Subsequently, the mold shell 122 may be moved (e.g., by actuating the shaft 120 to move the cooling plate 118 and the mold shell 122 along the axial centerline 150 from the heating zone 114 to the cooling zone 116). As the mold shell 122 moves into the cooling zone 116, the alloy can solidify into a solid state (i.e., solid alloy 166) from the base 125 to the top 126 of the mold shell 122 in the axial direction A (i.e., directional solidification) within the mold shell 122, thereby forming a directionally solidified cast component. For example, as the mold shell 122 moves from the heating zone 114 and the cooling zone 116, the alloy 162 can transform from a liquid state to a solid state. As shown, the horizontal dashed lines within the mold shell 122 can represent the alloy 162 in a liquid state (e.g., liquid alloy 164), and the cross-hatched lines within the mold shell 122 can represent the alloy 162 in a solid state (e.g., solid alloy 166).

[0037] When the mold shell 122 moves from the heating zone 114 to the cooling zone 116, a solidification front 130 may be formed within the mold shell 122 between the alloy 162 in the liquid state and the alloy 162 in the solid state. Although the solidification front 130 is shown as a line, it should be understood that the solidification front 130 may be a range (e.g., an axial range) within the mold shell 122. More specifically, the solidification front 130 may be a portion of the alloy 162 within the solidification temperature range. The solidification temperature range may be a temperature range in which the alloy 162 may transition from a liquid state to a solid state. In addition, the alloy 162 at (and above) the solidification front 130 may be higher than the solidus temperature for the alloy 162. That is, the solidus temperature is the highest temperature at which the alloy 162 becomes completely solid, and the temperature at the solidification line (and above relative to the axial direction A) may be higher than the solidus temperature.

[0038] In many embodiments, the chamber 108 can be a vacuum chamber that can be evacuated by the vacuum system 132. The electric heating element 134 can be disposed in the heating zone 114 to maintain the alloy 162 within the mold shell 122 above the solidus temperature (e.g., to maintain the liquid alloy 164) while in the heating zone 114. For example, when the electric heating element 134 is positioned within the heating zone 114, the electric heating element can surround the mold shell 122. The guide plate 110 can define an opening 111 through which the cooling plate 118, the shaft 120, and the mold shell 122 move between the heating zone 114 and the cooling zone 116.

[0039] To produce a directionally solidified cast component, the mold shell 122 is inserted into the heating zone 114 by moving the shaft 120 axially upward. Liquid alloy 164 is poured into the mold shell 122 through the crucible 124, and then the shaft is moved axially downward so that the mold shell 122 passes through the opening 111 from the heating zone 114 to the cooling zone 116. As a result, the alloy 162 is transformed from a liquid state to a solid state in the axial direction from the base 125 to the top end 126. For example, the alloy 162 first solidifies at the base 125 of the mold shell 122, and the solidification front moves axially upward to the top end 126 of the mold shell 122.

[0040] Due to the geometric complexity of the directionally solidified cast component, various portions of the alloy 162 within the mold shell 122 may not solidify at the same rate (e.g., some portions may solidify slower than other portions), which may result in one or more component defects. Therefore, the exemplary casting system 100 described herein includes a cooling system 200 for directing a coolant fluid 201 toward the mold shell 122 (e.g., within the cooling zone 116) to increase the solidification rate of the alloy to prevent the formation of defects.

[0041] The cooling system 200 may include a coolant fluid supply 202 and a coolant fluid supply line 204. The coolant fluid supply 202 may be a container, tank, or other coolant fluid reservoir. The coolant fluid supply line 204 may transport the coolant fluid 201 from the coolant fluid supply 202 into the cooling zone 116 to be directed toward the mold shell 122. In an exemplary implementation, the coolant fluid 201 may be a fluid that does not react with the alloy 162. For example, in an exemplary embodiment, the coolant fluid 201 may be an inert or rare gas, such as helium or argon. The coolant fluid 201 introduced into the chamber (e.g., into the cooling zone of the chamber 108) may be subsequently discharged by the vacuum system 132. For example, when the coolant fluid 201 is introduced into the cooling zone 116, the vacuum system 132 may continuously remove (or discharge) the coolant fluid to maintain the vacuum in the chamber 108.

[0042] In many embodiments, such as Figures 2 to 7 As shown, the cooling system 200 may include a plurality of ejection devices 206 axially spaced apart from each other. The plurality of ejection devices 206 may be disposed in the cooling zone 116 (e.g., axially between the guide plate 110 and the bottom 140). Each ejection device 206 may be in fluid communication with the coolant fluid supplier 202 via a coolant fluid supply line 204 (i.e., the coolant fluid supply line 204 may fluidly couple each ejection device 206 to the coolant fluid supplier 202). The plurality of ejection devices 206 may eject (or inject) the coolant fluid 201 toward the mold shell 122. For example, in some embodiments, as Figures 2 to 4 As shown, the ejection device 206 may include a plurality of nozzles 208, each nozzle extending radially to an outlet 210. Alternatively or additionally, as Figures 5 to 7 As shown, the ejection devices 206 can each include a ring 212 surrounding the mold shell 122 and defining a plurality of outlets 214. In both embodiments, the ejection devices 206 can define outlets that are sized and oriented to direct the coolant fluid 201 to project onto the mold shell 122 (e.g., the outer surface 123 of the mold shell) as decentralized jets. The decentralized jets of the coolant fluid 201 can project (or hit) the outer surface 123 of the mold shell 122, which allows heat transfer from the alloy 162 to the coolant fluid 201. Once the decentralized jets of the coolant fluid 201 have been projected onto the mold shell 122, they can be referred to as "post-projection fluid" and / or "spent cooling fluid" because the coolant fluid 201 has undergone energy transfer and therefore has different properties (e.g., a higher temperature and lower pressure than before projection). The spent cooling fluid can be discharged from the cooling zone 116 via the vacuum system 132.

[0043] Reference now Figures 2 to 4, various views of a casting system 100 according to an exemplary embodiment of the present disclosure are shown. For example, Figure 2 A cross-sectional view of the casting system 100 is shown in a first position (eg, a heating position), Figure 3 The casting system 100 is shown in a second position (e.g., during a withdrawal phase), and Figure 4 A cross-sectional view taken along line 4-4 is shown. Figure 3 A cross-sectional view of the casting system 100 is shown.

[0044] like Figures 2 to 4 As shown, the cooling system 200 may include a coolant fluid supply 202, a plurality of axially spaced ejection devices 206, and a coolant fluid supply line 204 extending between the coolant fluid supply 202 and the plurality of ejection devices 206. Each ejection device 206 may include a plurality of nozzles 208 extending toward the mold shell 122. For example, each nozzle 208 of the plurality of nozzles 208 may extend generally radially from the coolant fluid supply line 204, through the chamber 108, to an outlet 210 within the cooling zone 116.

[0045] In an exemplary embodiment, as compared to Figure 2 and Figure 3 As shown, each nozzle 208 in the plurality of nozzles 208 can be moved in a radial direction R to adjust a radial gap 218 between an outlet 210 of the nozzle 208 and an outer surface 123 of the mold shell 122. For example, each nozzle 208 can be at least partially formed by a flexible conduit or hose so that the nozzle 208 can be radially extended and / or retracted. For example, in many embodiments, each nozzle 208 in the plurality of nozzles 208 can include an actuator 301 that is operably connected to the controller 300. The actuator 301 is operable to adjust the radial position of the nozzle 208, for example, the actuator can extend and / or retract the nozzle 208 so that the radial position of the outlet 210 is changed. The outlet 210 of each nozzle 208 can be radially moved between the sidewall 144 of the chamber 108 and the axial centerline 150 of the chamber 108. As should be appreciated, the radial gap 218 can affect the effectiveness of projected cooling because when the coolant fluid 201 travels a shorter distance, the coolant fluid 201 will have a higher velocity and thereby remove more heat from the mold shell 122. Therefore, in an exemplary embodiment, each nozzle 208 can be selectively actuated so that the radial gap 218 is changed based on the cooling needs. For example, if more cooling is needed at a particular axial position of the mold shell 122, the nozzle 208 at the axial position can be actuated to shorten the radial gap 218, thereby increasing the effectiveness of projected cooling due to the increased velocity of the coolant fluid 201 striking the surface of the mold shell 122.

[0046] In addition, in many embodiments, each of the plurality of nozzles may include a valve 305 that is operably connected to the controller 300. Each valve 305 may be fluidly coupled to a corresponding nozzle 208 in the plurality of nozzles 208. The valve 305 may be actuated between an open position and a closed position. In the open position, the coolant fluid may be allowed to pass through the valve 305, while in the closed position, the coolant fluid may be blocked or otherwise restricted from flowing through the valve 305. Thus, in many embodiments, the controller 300 may selectively open / close one or more valves 305 based on the cooling needs of the alloy 162 within the mold shell 122. For example, when the mold shell 122 moves from the heating zone 114 to the cooling zone 116, the one or more valves 305 may be in a closed position until at least a portion of the mold shell 122 moves into the axial-circumferential plane of the nozzle 208 to which the one or more valves 305 are fluidly coupled. At this point, when the mold housing 122 moves into the axial-circumferential plane of the nozzle 208 to which the one or more valves 305 are fluidly coupled, the one or more valves 305 may be switched (or actuated) from a closed position to an open position.

[0047] like Figure 4 As shown, the coolant fluid supply line 204 may also include a ring portion 205 surrounding the chamber 108. For example, each of the plurality of nozzles 208 may extend generally radially from the ring portion 205 to a corresponding outlet 210. Figure 4 As shown, the plurality of nozzles 208 may be circumferentially spaced apart from one another (eg, circumferentially spaced equally apart).

[0048] The plurality of ejection devices 206 may be axially spaced apart from each other. For example, the cooling system 200 may include an initial ejection device 220 proximate (or near) the guide plate 110, a final ejection device 224 proximate (or near) the bottom 140, and a plurality of intermediate ejection devices 222 positioned between the initial ejection device 220 and the final ejection device 224. Figure 2 and Figure 3 In the illustrated embodiment, the plurality of ejection devices 206 may be configured as a plurality of radially movable nozzles 208 extending through the chamber 108 .

[0049] In other embodiments, Figures 5 to 7 As shown, the plurality of injection devices 206 may each be configured to function as a ring 212 that is axially movable and positioned within the cooling zone 116. In operation, when the mold shell 122 is axially moved from the heating zone 114 to the cooling zone 116, the mold shell 122 may axially travel through the opening 111, the initial injection device 220, the plurality of intermediate injection devices 222, and the final injection device 224 in this order until the cooling plate 118 reaches the bottom 140.

[0050] The ring 212 of each ejection device 206 is movable in the axial direction A within the cooling zone 116 between the guide plate 110 and the bottom 140. For example, Figure 5 The casting system 100 is shown in a first position, such as before the mold shell 122 is moved into a cooling zone. Figure 6 The casting system 100 is shown in a second position, for example, when the mold shell 122 is moved into the cooling zone 116. For example, the shaft 120 can move the mold shell 122 through the opening 111 and into the cooling zone 116 so that the ring 212 surrounds the mold shell 122 in the cooling zone 116. The ring 212 can be moved from the first position ( Figure 5 ) moves to the second position ( Figure 6 ), in the first position, the rings 212 are positioned a first axial distance 228 away from each other and close to the guide plate 110, and in the second position, the rings 212 are positioned a second axial distance 230 away from each other. The second axial distance 230 may be greater than the first axial distance 228. In addition, in the first position ( Figure 5 ), all of the rings 212 may be positioned closer to the baffle 110 than the bottom 140, which advantageously provides increased cooling to the mold shell 122 immediately upon traveling through the opening 111 and entering the cooling zone 116. Once the base 125 of the mold shell 122 is axially withdrawn (or moved) beyond the final ring 212 (i.e., the bottom-most ring 212), the rings 212 may begin to move axially with the mold shell 122 until the mold shell 122 is fully disposed within the cooling zone 116.

[0051] Each ring 212 can be in fluid communication with the coolant fluid supply line 204 via a branch 240. For example, each branch 240 can extend between the coolant fluid supply line 204 and the ring 212. A valve 305 can be fluidly coupled to each branch 240. In various embodiments, each ring 212 can be coupled to an actuator 303 that can change the axial position of the ring 212. For example, the actuator 303 can be disposed on each branch 240 (e.g., at a junction between the branch 240 and the coolant fluid supply line 204). In many embodiments, each actuator 303 can be operably connected to the controller 300. For example, each actuator can be operated to adjust the axial position of the ring 212, for example, the actuator can be extended and / or retracted to adjust the axial position of each ring 212 within the cooling zone 116. Each ring 212 can be axially movable between the guide plate 110 and the bottom 140.

[0052] like Figure 7As shown, each ring 212 may surround the mold housing 122 and define a plurality of outlets 214. The plurality of outlets 214 may be defined on the inner portion of the ring 212 and may be circumferentially spaced apart from each other. In some embodiments, as shown, the ring 212 may be shaped as a circular ring. In other embodiments, the ring 212 may have other shapes, such as an ellipse or other shapes. In particular, in many embodiments, each ring 212 may correspond to the mold housing 122 in the shape of the cross section, so that the ring 212 may define a uniform radial gap between the outlet 214 and the portion of the mold housing 122 to be cooled by the coolant fluid 201. In addition, the plurality of outlets 214 may be oriented toward the mold housing 122.

[0053] In many embodiments, the ring 212 of each ejection device 206 can define a diameter 250, and the diameter 250 of each ring 212 can be different (particularly, the inner diameter of each ring 212 can be different). For example, the ring 212 of a first ejection device 206 in the plurality of ejection devices 206 can define a first diameter, and the ring 212 of a second ejection device 206 in the plurality of ejection devices 206 can define a second diameter. The first diameter and the second diameter can be different. Particularly, as Figure 5 and Figure 6 As shown, the diameter of the ring 212 of each shooting device 206 can be different. For example, the diameter of the ring of the initial shooting device 220, the diameter of the ring of each intermediate shooting device 222, and the diameter of the ring of the final shooting device 224 can be different, which advantageously maintains a desired radial gap between the mold housing 122 and the outlet 214 of the ring 212.

[0054] Reference now Figure 8 and Fig. 9 , shows a casting system 100 according to another embodiment of the present disclosure. For example, Figure 8 shows a cross-sectional view of a casting system 100 in a first position according to an embodiment of the present disclosure, and Fig. 9 Showing an embodiment of the present disclosure in a second position Figure 8 A cross-sectional view of the casting system is shown.

[0055] like Figure 8 and Fig. 9As shown, the mold housing 122 may define a cooling circuit 252. For example, the cooling circuit 252 may be defined between the outer surface 123 and the inner surface 121 of the mold housing 122. The cooling circuit 252 may be in fluid communication with the cooling system 200. For example, the cooling system 200 may include a channel 254 defined in the shaft 120 and the cooling plate 118. For example, the channel 254 may extend from an inlet provided in the shaft 120 to an outlet provided in the top surface 119 of the cooling plate 118. The coolant fluid supply line 204 may be fluidly coupled to the inlet of the channel 254 (for example, the coolant fluid supply line 204 may extend between the coolant fluid supply source 202 and the inlet of the channel 254). The channel 254 may be fluidly coupled to the cooling circuit 252 of the mold housing 122. For example, the base 125 of the mold housing 122 may define an inlet to the cooling circuit 252, which is fluidly coupled to the outlet of the channel 254.

[0056] like Figures 2 to 9 As shown, the casting system 100 may also include a controller 300, which is shown as a block diagram to illustrate suitable components that may be included in the controller 300. As shown, the controller 300 may include: one or more processors 302 and associated one or more memory devices 304, which are configured to perform various computer-implemented functions (e.g., perform methods, steps, calculations, etc. and store relevant data as disclosed herein). In addition, the controller 300 may also include a communication module 306 to facilitate communication between the controller 300 and various components of the casting system 100 (such as the crucible 124, the shaft 120, the vacuum system 132, the electric heating element 134, the actuators 301, 303 and / or the valve 305). For example, the communication module 306 may communicate with the actuators 301, 303 to allow the processor 302 to selectively move the plurality of nozzles 208 ( Figures 2 to 4 ) or Ring 212( Figures 5 to 7 ). It should be understood that the crucible 124, shaft 120, vacuum system 132, electrical heating element 134, actuators 301, 303 and valve 305 can be communicatively coupled to the communication module 306 using any suitable means (e.g., a wired connection or a wireless connection using any suitable wireless communication protocol known in the art).

[0057] As used herein, the term "processor" refers not only to what is known in the art as an integrated circuit included in a computer, but also to controllers, microcontrollers, microcomputers, programmable logic controllers (PLCs), application specific integrated circuits, and other programmable circuits. In addition, the one or more memory devices 304 may generally include one or more memory elements, including but not limited to computer-readable media (e.g., random access memory (RAM)), computer-readable non-volatile media (e.g., flash memory), floppy disks, compact disk-read only memory (CD-ROM), magneto-optical disks (MOD), digital versatile disks (DVD), and / or other suitable memory elements. Such memory devices 304 may generally be configured to store suitable computer-readable instructions that, when implemented by the processor 302, configure the system 100 to perform various functions and / or operations, including (but not limited to) pouring the alloy 162 in a liquid state into the mold shell 122 using the crucible 124; moving the mold shell 122 from the heating zone 114 to the cooling zone 116 using the shaft 120; and directing the coolant fluid 201 toward the mold shell 122 using the cooling system 200.

[0058] Reference now Fig.10 , a flow chart of one embodiment of a method 1000 of forming a directionally solidified cast component using a casting system 100 according to aspects of the present subject matter. Figures 1 to 9 The method 1000 is described with reference to the casting system 100 and the gas turbine 10 described herein. However, it should be understood by one of ordinary skill in the art that the disclosed method 1000 can generally be used in conjunction with any casting system having any other suitable system configuration. Fig.10 The steps performed in a particular order are depicted for purposes of illustration and discussion, but the methods discussed herein are not limited to any particular order or arrangement unless otherwise specified in the claims. Those skilled in the art will understand using the disclosure provided herein that the various steps of the methods disclosed herein may be omitted, rearranged, combined and / or adjusted in various ways without departing from the scope of the present disclosure.

[0059] like Fig.10As shown, the method 1000 may include pouring an alloy 162 in a liquid state into a mold shell 122 at (1002). The mold shell 122 may be positioned on a cooling plate 118 within the heating zone 114. Prior to pouring at (1002), the alloy 162 may be heated to a molten or liquid state in a crucible 124, and once the alloy 162 is in a liquid state, the alloy 162 may be poured into the mold shell 122 through the crucible 124. For example, the alloy 162 may be poured into a cavity 128 defined by the mold shell 122 through an opening at a top end 126 of the mold shell 122, such that the alloy 162 fills the cavity 128 defined by the mold shell 122. The cavity 128 may correspond in shape to a directionally solidified cast component, such that the cavity 128 may have a rotor blade shape having a shank portion 102 and an airfoil portion 104.

[0060] In many implementations, prior to the pouring step or after the pouring step, the method 1000 can also include evacuating the chamber 108 using the vacuum system 132. The vacuum system 132 can remove all air from the chamber 108, thereby creating a vacuum. Additionally, in some implementations, when the mold housing 122 is within the heating zone 114 (e.g., during the pouring step and / or after the pouring step), the electric heating element 134 can heat the alloy 162 within the mold housing 122 to maintain or keep the alloy 162 in a liquid state.

[0061] In various implementations, the method 1000 may further include, at (1004), moving the mold shell 122 from the heating zone 114 to the cooling zone 116. Thus, while the mold shell 122 is being moved from the heating zone 114 to the cooling zone 116, the alloy 162 is transformed from a liquid state to a solid state within the mold shell 122. The movement at (1004) may include actuating the shaft 120 (e.g., by sending a signal using the controller 300) to translate the shaft 120 in the axial direction A, thereby moving the mold shell 122 from the heating zone 114 through the opening 111 in the guide plate 110 to the cooling zone 116.

[0062] In an exemplary implementation, the method 1000 may also include directing the coolant fluid 201 toward the mold shell 122 using the cooling system 100 at (1006). For example, the directing at (1006) may include emitting (or injecting) the coolant fluid 201 from an ejection device 206 positioned within the cooling zone 116 toward the outer surface 123 of the mold shell 122 in a scattered stream. Additionally or alternatively, the directing at (1006) may be performed during the moving step 1004. For example, the coolant fluid 201 may be directed toward the mold shell 122 while axially moving the mold shell 122 from the heating zone 114 to the cooling zone 116. In many embodiments, the cooling system 100 may include a plurality of ejection devices 206 that are axially spaced apart from each other and are movable within the cooling zone 116 (e.g., movable in the axial direction A and / or the radial direction R).

[0063] In an optional embodiment, if Fig.10 As shown, the method 1000 may include adjusting the position of the plurality of ejection devices 206 within the cooling zone 116 at (1008). For example, the plurality of ejection devices 206 may be moved axially and / or radially within the cooling zone 116 while the mold shell 122 is moved from the heating zone 114 to the cooling zone 116.

[0064] In various embodiments, the adjustment at (1008) may also include maintaining a constant radial gap between each of the plurality of ejection devices 206 and the outer surface 123 of the mold shell 122 while the mold shell 122 is axially moved from the heating zone 114 to the cooling zone 116 by adjusting the position of the plurality of ejection devices 206 at (1010). For example, each ejection device 206 may be moved axially and / or radially while the mold shell 122 is axially moved to maintain the constant radial gap. In various specific implementations, the constant radial gap may be located at the outlet of the ejection device 206 (e.g., Figures 2 to 4 Exit 210 or Figure 7 The ejection device 206 may be disposed between an outlet 214 in the mold and an outer surface 123 of the mold shell 122. When the mold shell 122 is withdrawn from the heating zone 114, the ejection device 206 may move axially at the same speed as the mold shell 122, a speed greater than the mold shell 122, or a speed slower than the mold shell.

[0065] In many embodiments, as described above, the plurality of ejection devices may include a plurality of nozzles 208 extending radially toward the mold shell 122. In such embodiments, the method may further include radially moving at least one nozzle 208 of the plurality of nozzles 208 to change a radial gap 218 between an outlet 210 of the at least one nozzle 208 and the outer surface 123 of the mold shell 122. The outlet 210 of each nozzle 210 may be radially moved within an envelope corresponding to the outer shape of the mold shell 122 while the mold shell 122 is withdrawn to maintain a constant radial gap between the outlet 210 and the outer surface 123 of the mold shell 122.

[0066] In other embodiments, each of the plurality of ejection devices 206 may include a ring 212 surrounding the mold shell 122 and defining a plurality of outlets 214. In such embodiments, the method may further include axially moving the ring 212 of at least one of the plurality of ejection devices 206 within the cooling zone 116. The ring 212 may be moved from a first position ( Figure 5 ) moves to the second position ( Figure 6 ), in the first position, the rings 212 are positioned a first axial distance 228 away from each other and close to the guide plate 110, and in the second position, the rings 212 are positioned a second axial distance 230 away from each other. The second axial distance 230 may be greater than the first axial distance 228. In addition, in the first position ( Figure 5 ), all of the rings 212 may be positioned closer to the baffle 110 than the bottom 140, which advantageously provides increased cooling to the mold shell 122 immediately upon traveling through the opening 111 and entering the cooling zone 116. Once the base 125 of the mold shell 122 is axially withdrawn (or moved) beyond the final ring 212 (i.e., the bottom-most ring 212), the rings 212 may begin to move axially with the mold shell 122 until the mold shell 122 is fully disposed within the cooling zone 116.

[0067] In many embodiments, the mold shell 122 can define a cooling circuit 252 (e.g., between an outer surface and an inner surface of the mold shell 122). In such embodiments, the method 1000 can also include directing the coolant fluid 201 through a channel 254 defined in the cooling plate 118 and a shaft 120 attached to the cooling plate 118 to the cooling circuit 252 defined in the mold shell 122.

[0068] This written description uses examples to disclose the invention, including the best mode, and also enables any person skilled in the art to practice the invention, including making and using any device or system and performing any combined method. The patentable scope of the invention is defined by the claims and may include other examples that occur to those skilled in the art. If these other examples include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ substantially from the literal language of the claims, these other examples are intended to be within the scope of the claims.

[0069] Further aspects of the invention are provided by the subject matter of the following clauses:

[0070] A casting system for forming a directionally solidified cast component, the casting system defining an axial direction, a radial direction, and a circumferential direction, the casting system comprising: a chamber; a guide plate, the guide plate being disposed in the chamber, the chamber and the guide plate together defining a heating zone and a cooling zone, the heating zone and the cooling zone being separated by the guide plate; a shaft; a cooling plate, the cooling plate being disposed on the shaft and being movable between the heating zone and the cooling zone; a mold shell, the mold shell being disposed on the cooling plate; and a cooling system for directing a coolant fluid toward the mold shell.

[0071] A casting system according to any of the preceding clauses, wherein the cooling system comprises a plurality of ejection devices axially spaced from one another.

[0072] A casting system according to any of the preceding clauses, wherein each of the plurality of injection devices comprises a plurality of nozzles extending towards the mould housing.

[0073] A casting system according to any of the preceding clauses, wherein each nozzle of the plurality of nozzles is movable in the radial direction to adjust a radial gap between an outlet of the nozzle and an outer surface of the mould shell.

[0074] A casting system according to any of the preceding clauses, wherein each nozzle of the plurality of nozzles comprises an actuator and a valve in operative communication with a controller.

[0075] A casting system according to any of the preceding clauses, wherein each of the plurality of ejection devices comprises a ring surrounding the mould housing and defining a plurality of outlets.

[0076] Casting system according to any of the preceding clauses, wherein the ring of each ejection device is movable in the axial direction within the cooling zone.

[0077] A casting system according to any of the preceding clauses, wherein the ring of a first one of the plurality of shooting devices defines a first diameter, wherein the ring of a second one of the plurality of shooting devices defines a second diameter, and wherein the first diameter and the second diameter are different.

[0078] A casting system according to any of the preceding clauses, wherein the mould housing defines a cooling circuit, the cooling circuit being in fluid communication with the cooling system.

[0079] A casting system according to any of the preceding clauses, wherein the cooling system comprises channels defined in the shaft and the cooling plate, the channels being fluidly coupled to the cooling circuit of the mold shell.

[0080] A casting system according to any of the preceding clauses, wherein the cooling system further comprises a coolant supply and a coolant fluid supply line.

[0081] A method of forming a directionally solidified cast component using a casting system, the casting system including a chamber having a heating zone and a cooling zone separated by a guide plate, the method comprising: pouring an alloy in a liquid state into a mold shell, the mold shell being positioned on a cooling plate in the heating zone; moving the mold shell from the heating zone to the cooling zone, whereby the alloy transforms from the liquid state to a solid state in the mold shell while moving the mold shell from the heating zone to the cooling zone; and directing a coolant fluid toward the mold shell using a cooling system.

[0082] A method according to any of the preceding clauses, wherein the casting system defines an axial direction, a radial direction and a circumferential direction, wherein the cooling system further comprises a plurality of injection devices axially spaced apart from each other, and wherein the method further comprises: adjusting the position of the plurality of injection devices within the cooling zone.

[0083] A method according to any one of the preceding clauses, wherein adjusting the position of the injection device further comprises: by adjusting the positions of the plurality of injection devices, maintaining a constant radial gap between each of the plurality of injection devices and the outer surface of the mold shell while axially moving the mold shell from the heating zone to the cooling zone.

[0084] A method according to any of the preceding clauses, wherein the plurality of injection devices comprises a plurality of nozzles extending radially toward the mold shell, and wherein adjusting the position of the injection devices further comprises: radially moving at least one of the plurality of nozzles to change a radial gap between an outlet of the at least one nozzle and an outer surface of the mold shell.

[0085] A method according to any of the preceding clauses, wherein each of the plurality of injection devices comprises a ring surrounding the mold shell and defining a plurality of outlets, and wherein adjusting the position of the cooling system further comprises: axially moving the ring of at least one of the plurality of injection devices within the cooling zone.

[0086] A method according to any of the preceding clauses, wherein the ring of a first one of the plurality of ejection devices defines a first diameter, wherein the ring of a second one of the plurality of ejection devices defines a second diameter, and wherein the first diameter and the second diameter are different.

[0087] A method according to any of the preceding clauses, wherein the mold shell defines a cooling circuit, and wherein the method further comprises: directing the coolant fluid through channels defined in the cooling plate and a shaft attached to the cooling plate to the cooling circuit defined in the mold shell.

Claims

1. A casting system for forming a directionally solidified cast component, the casting system defining an axial direction, a radial direction, and a circumferential direction, the casting system comprising: room; a guide plate, the guide plate being disposed in the chamber, the chamber and the guide plate jointly defining a heating zone and a cooling zone, the heating zone and the cooling zone being separated by the guide plate; axis; a cooling plate disposed on the shaft and movable between the heating zone and the cooling zone; A mold shell, wherein the mold shell is disposed on the cooling plate; as well as A cooling system is provided for directing a coolant fluid toward the mold shell.

2. The casting system of claim 1, wherein the cooling system comprises a plurality of ejection devices axially spaced apart from one another. 3 . The casting system of claim 2 , wherein each of the plurality of injection devices comprises a plurality of nozzles extending toward the mold housing. 4 . The casting system of claim 3 , wherein each of the plurality of nozzles is movable in the radial direction to adjust a radial gap between an outlet of the nozzle and an outer surface of the mold shell.

5. The casting system of claim 3, wherein each nozzle of the plurality of nozzles comprises an actuator and a valve in operable communication with a controller.

6. The casting system of claim 2, wherein each of the plurality of ejection devices comprises a ring surrounding the mold housing and defining a plurality of outlets.

7. The casting system of claim 6, wherein the ring of each ejection device is movable in the axial direction within the cooling zone.

8. The casting system of claim 6, wherein the ring of a first one of the plurality of shooters defines a first diameter, wherein the ring of a second one of the plurality of shooters defines a second diameter, and wherein the first diameter and the second diameter are different.

9. The casting system of claim 1, wherein the mold housing defines a cooling circuit in fluid communication with the cooling system.

10. The casting system of claim 9, wherein the cooling system includes channels defined in the shaft and the cooling plate, the channels fluidly coupled to the cooling circuit of the mold housing.

11. The casting system of claim 1 , wherein the cooling system further comprises a coolant supply and a coolant fluid supply line.

12. A method of forming a directionally solidified cast component using a casting system comprising a chamber having a heating zone and a cooling zone separated by a baffle, the method comprising: pouring the alloy in a liquid state into a mold shell positioned on a cooling plate within the heating zone; moving the mold shell from the heating zone to the cooling zone, whereby the alloy transforms from the liquid state to a solid state within the mold shell while moving the mold shell from the heating zone to the cooling zone; as well as A coolant fluid is directed toward the mold shell using a cooling system.

13. The method of claim 12, wherein the casting system defines an axial direction, a radial direction, and a circumferential direction, wherein the cooling system further comprises a plurality of ejection devices axially spaced apart from one another, and wherein the method further comprises: The positions of the plurality of ejection devices within the cooling zone are adjusted.

14. The method of claim 13, wherein adjusting the position of the ejection device further comprises: By adjusting the positions of the plurality of injection devices, a constant radial gap is maintained between each of the plurality of injection devices and the outer surface of the mold shell while the mold shell is axially moved from the heating zone to the cooling zone.

15. The method of claim 13, wherein the plurality of ejection devices comprises a plurality of nozzles extending radially toward the mold housing, and wherein adjusting the position of the ejection devices further comprises: At least one nozzle of the plurality of nozzles is radially moved to vary a radial gap between an outlet of the at least one nozzle and an outer surface of the mold shell.

16. The method of claim 13, wherein each of the plurality of ejection devices comprises a ring surrounding the mold shell and defining a plurality of outlets, and wherein adjusting the position of the cooling system further comprises: The ring of at least one ejection device of the plurality of ejection devices is axially moved within the cooling zone.

17. The method of claim 16, wherein the ring of a first one of the plurality of ejection devices defines a first diameter, wherein the ring of a second one of the plurality of ejection devices defines a second diameter, and wherein the first diameter and the second diameter are different.

18. The method of claim 12, wherein the mold shell defines a cooling circuit, and wherein the method further comprises: The coolant fluid is directed through channels defined in the cooling plate and a shaft attached to the cooling plate to the cooling circuit defined in the mold shell.

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