System and method for manufacturing ceramic molds that maintain the dimensions of the resulting cast parts.

Abstract

The present invention provides a method for manufacturing a ceramic mold that gives the resulting cast parts the intended dimensions, and also provides a ceramic mold. [Solution] The method includes the step of additively manufacturing a first portion of a ceramic mold (100). The body (162) of the core structure (104) defines a plurality of body openings (166). The method further includes the step of additively manufacturing a second portion of the ceramic mold (100) which is equipped with a tip cap (164) of the core structure (104). The tip cap (164) of the core structure (104) defines a plurality of tip cap openings (168). The method further includes the step of firing the first and second portions of the ceramic mold (100).

Description

Technical Field

[0001] The present disclosure generally relates to systems and methods for restricting movement between a shell structure and a core structure of an additively manufactured ceramic mold during and after firing of the additively manufactured ceramic mold.

Background Art

[0002] Turbine buckets or turbine blades, such as those used in gas turbine engines, aircraft engines, and / or steam turbines, can be formed using, for example, casting processes and forging processes. Conventionally, a mold is formed of a ceramic material and includes an outer ceramic shell having an inner surface that defines a cavity, and one or more ceramic cores disposed within the cavity to form internal cooling passages within a casting bucket. The ceramic mold can also be formed using a lost wax casting process, and the core is first formed by ceramic injection molding into a machined core die. The formed core can then be fired at a high temperature to strengthen the core, and thereafter, the fired core is placed in another machined wax die to form a shell surrounding the core.

[0003] More recently, the manufacturing process can also simultaneously form the core and the shell using an additive manufacturing process (i.e., a 3D printing process). Thereafter, the core and the shell can be fired simultaneously. During firing, the additively manufactured ceramic mold may be placed in an oven where the mold is significantly heated to sinter and fuse the ceramic particles to form a dense and durable structure. However, exposure of the additively manufactured mold to high temperatures during firing can cause movement or deflection of the core relative to the shell. As a result, distortion of the cooling passages may occur, there may be a constriction between the inner wall of the shell and the core, and / or in some cases, a core kissout, which is the condition when the core contacts the inner surface of the shell, may occur.

[0004] Therefore, improved systems and methods for manufacturing ceramic molds in which the shell and core structures are dimensionally stable relative to each other during firing are desired and will be recognized in the art. Specifically, systems and methods for manufacturing ceramic molds that give the resulting cast parts the intended dimensions will be highly valued by those skilled in the art. [Overview of the project]

[0005] The aspects and advantages of the ceramic molds and methods described herein are partially described in the following description, may become apparent from this description, or may be acquired through the practice of the art.

[0006] According to one embodiment, a method for manufacturing a ceramic mold is provided. The method includes the step of additively manufacturing a first part of a ceramic mold. The first part of the ceramic mold comprises a body of a core structure and a shell structure. The body of the core structure defines a plurality of body openings. The method further includes the step of additively manufacturing a second part of the ceramic mold, which comprises a tip cap of the core structure. The tip cap of the core structure defines a plurality of tip cap openings. The method further includes the step of firing the first and second parts of the ceramic mold to sinter and fuse the ceramic particles of the ceramic mold. After firing the first and second parts of the ceramic mold, the method further includes the step of connecting the first part and the second part by inserting each pin of a plurality of pins into the corresponding body openings of the plurality of body openings and the corresponding tip cap openings of the plurality of tip cap openings.

[0007] According to another embodiment, a method for manufacturing a ceramic mold is provided. The method includes the step of additively manufacturing a first portion of a ceramic mold. The first portion of the ceramic mold comprises a body of a core structure and a shell structure. The body of the core structure defines a plurality of body openings. The method further includes the step of additively manufacturing a second portion of the ceramic mold, which comprises a tip cap of a core structure. The tip cap of the core structure defines a plurality of tip cap openings. The method further includes the step of firing the first and second portions of the ceramic mold to sinter and fuse the ceramic particles of the ceramic mold. The method further includes the step of joining the tip cap and the body after firing the first and second portions of the ceramic mold.

[0008] In another embodiment, a ceramic mold is provided. This ceramic mold comprises a shell structure and a core structure disposed within the shell structure. A cavity is defined between the core structure and the shell structure. The cavity is adapted to define the shape of the cast part during casting and removal of the ceramic mold. The core structure comprises a body and an end cap. The body defines a plurality of body openings. The end cap defines a plurality of end cap openings. This ceramic mold further comprises a plurality of pins, each extending between a corresponding body opening in the plurality of body openings and a corresponding end cap opening in the plurality of end cap openings.

[0009] The features, aspects, and advantages of the ceramic mold and the method will be better understood by referring to the following description and the appended claims. The appended drawings, which are incorporated herein and constitute part of this specification, illustrate embodiments of the art and, together with the description in the specification, help to illustrate the principles of the art.

[0010] A complete and effective disclosure of the ceramic mold and the method, including the best mode for fabricating and using the system and method, is provided herein with reference to the accompanying drawings, intended for those skilled in the art. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram of a turbomachinery according to an embodiment of the present disclosure. [Figure 2] This is a partially fractured perspective view of a cast part (such as a turbine part) according to an embodiment of the present disclosure. [Figure 3] This figure shows a ceramic mold for producing cast parts (such as the cast parts shown in Figure 2) according to embodiments of the present disclosure. [Figure 4] This is a perspective view of an additive manufacturing system, such as a device for performing a series of steps in a method sequence in the additive manufacturing of ceramic molds, including direct photopolymerization (DLP), according to various aspects of the present disclosure. [Figure 5] This is a partially exploded cross-sectional view of a ceramic mold according to an embodiment of the present disclosure. [Figure 6] This is a cross-sectional view of the assembled state of a ceramic mold according to an embodiment of the present disclosure. [Figure 7A] This figure shows portions of a ceramic mold in three different stages of the process of joining a tip cap to a body using a pin, according to embodiments of the present disclosure. [Figure 7B] This figure shows portions of a ceramic mold in three different stages of the process of joining a tip cap to a body using a pin, according to embodiments of the present disclosure. [Figure 7C] This figure shows portions of a ceramic mold in three different stages of the process of joining a tip cap to a body using a pin, according to embodiments of the present disclosure. [Figure 8] This is an enlarged exploded view of a portion of a ceramic mold according to the embodiments of this disclosure. [Figure 9] This is an enlarged exploded view of a portion of a ceramic mold according to the embodiments of this disclosure. [Figure 10] This figure shows a method for manufacturing a ceramic mold according to an embodiment of the present disclosure. [Figure 11] This figure shows a method for manufacturing a ceramic mold according to an embodiment of the present disclosure. [Modes for carrying out the invention]

[0012] Hereinafter, embodiments of the ceramic mold and the method are given in detail, one or more of which are shown in the drawings. Each example is provided for illustrative purposes of the art and is not intended to limit the art. Indeed, it will be apparent to those skilled in the art that modifications and changes can be made in the art without departing from the scope or spirit of the claimed art. For example, features illustrated or described as part of one embodiment can also be used in conjunction with another embodiment to bring about further embodiments. For this reason, this disclosure is intended to include modifications and changes that fall within the scope of the appended claims and their equivalents.

[0013] The term “exemplary” is used herein to mean “serving as an example, case, or illustration.” Not all implementations described herein as “exemplary” should be construed as necessarily preferable or advantageous to other implementations. Furthermore, unless specifically identified, all embodiments described herein should be considered illustrative.

[0014] In the detailed description, numerals and letters are used to refer to features of the drawings. Similar or identical reference numerals in the drawings and description are used to refer to similar or identical parts of the invention. As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to indicate the location or importance of any individual component.

[0015] The term "fluid" can be a gas or a liquid. The term "fluid communication" means that a fluid can connect between specified regions.

[0016] As used herein, the terms “upstream” (or “forward”) and “downstream” (or “backward”) refer to the relative direction of fluid flow in a fluid path. For example, “upstream” refers to the direction from which the fluid has flowed, and “downstream” refers to the direction in which the fluid has flowed. However, as used herein, the terms “upstream” and “downstream” may also refer to the flow of electricity. The term “radially” refers to a relative direction that is substantially perpendicular to the axial centerline of a particular component; the term “axially” refers to a relative direction that is substantially parallel and / or coaxial with the axial centerline of a particular component; and the term “circumferentially” refers to a relative direction that extends around the axial centerline of a particular component.

[0017] Approximate terms such as “about,” “approximately,” “generally,” and “substantially” are not limited to the exact value specified. In at least some cases, the approximation may also refer to the precision of the instrument used to measure the value, or the precision of the method or machine used to construct or manufacture the components and / or system. For example, the approximation may also refer to being within a margin of 1, 2, 4, 5, 10, 15, or 20 percent at any of the endpoints defining the individual value, range of value, and / or range of value. When used in the context of angles or directions, such terms include a range of plus or minus 10 degrees from the stated angle or direction. For example, “nearly perpendicular” includes any direction within 10 degrees from perpendicular, such as clockwise or counterclockwise.

[0018] Terms such as "coupled", "fixed", "attached", etc., unless otherwise specified herein, refer to both direct coupling, fixing, or attachment and indirect coupling, fixing, or attachment through one or more intermediate components or features. As used herein, the terms "comprises", "comprising", "includes", "including", "has", "having", or any other variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, article, or apparatus that includes a listing of features is not necessarily limited to only those features, and may include other features not explicitly listed or other features inherent to such a process, method, article, or apparatus. Further, unless explicitly stated to the contrary, "or" refers to an inclusive logical disjunction, not an exclusive logical disjunction. 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).

[0019] Here, and throughout the specification and claims, limitations of ranges are combined and replaced, and such ranges are identified and include all sub-ranges subsumed therein, unless the context and language specifically dictate otherwise. For example, all ranges disclosed herein include endpoints, and the endpoints are combinable independently of each other.

[0020] Referring now to the drawings, FIG. 1 shows a schematic view of one embodiment of a turbomachine, which in the illustrated embodiment is a gas turbine 10. Although industrial or land-based gas turbine engines are shown and described herein, the present disclosure is not limited to industrial or land-based gas turbine engines unless specifically recited in the claims. For example, the inventions described herein may be used in any type of turbomachine, including but not limited to steam turbines, aircraft gas turbines, or marine gas turbines.

[0021] As shown in FIG. 1, the gas turbine engine 10 generally includes a compressor section 12. The compressor section 12 includes a compressor 14. The compressor section 12 includes an inlet 16 disposed at the upstream end of the gas turbine 10. The gas turbine 10 further includes a combustion section 18 in which one or more combustors 20 are disposed downstream of the compressor section 12. The gas turbine 10 further includes a turbine section 22 (i.e., an expansion turbine) downstream of the combustion section 18. A shaft 24 extends generally axially through the gas turbine engine 10 and couples the compressor section 12 and the turbine section 22.

[0022] The compressor section 12 can generally include a plurality of rotor disks 21 and a plurality of rotor blades 23 extending radially outward from each rotor disk and connected to each rotor disk. Each rotor disk 21 can be coupled to or form a front portion of the shaft 24 extending through the compressor section 12. The rotor blades 23 of the compressor section 12 can include turbomachine airfoils defining an airfoil shape (e.g., having a leading edge, a trailing edge, and sidewalls extending between the leading edge and the trailing edge). Further, the compressor section 12 includes stator vanes 19 disposed between the rotor blades 23. The stator vanes 19 can extend from and be coupled to the compressor casing 11.

[0023] The turbine section 22 may generally comprise a plurality of rotor disks 27 and a plurality of rotor blades 28 extending radially outward from each rotor disk 27 and interconnected to each rotor disk. Each rotor disk 27 may be coupled to or form part of the rear portion of a shaft 24 extending through the turbine section 22. The turbine section 22 further comprises an outer casing 32 that circumferentially surrounds the rear portion of the shaft 24 and the rotor blades 28. The turbine section 22 may comprise stator vanes or fixed nozzles 26 extending radially inward from the outer casing 32. The rotor blades 28 and stator vanes 26 may be arranged alternately in a stepped manner along the axial centerline 30 of the gas turbine 10. Both the rotor blades 28 and stator vanes 26 may comprise turbomachine airfoils that define the airfoil shape (e.g., having a leading edge, a trailing edge, and sidewalls extending between the leading and trailing edges).

[0024] During operation, ambient air or other working fluid is drawn into the inlet 16 of the compressor 14, gradually compressed, and supplied to the combustion section 18 as compressed air 35. The compressed air 35 flows into the combustion section 18 and mixes with the fuel to form a combustible mixture. The combustible mixture is burned in the combustion chamber 25 of the combustor 20, thereby producing combustion gases 41 that flow from the combustion chamber 25 to the turbine section 22. Energy (kinetic and / or heat) is transferred from the combustion gases 41 to the rotor blades 28, causing the shaft 24 to rotate and generate mechanical work. The spent combustion gases 41 (also called "exhaust gases") exit the turbine section 22 and flow through the exhaust diffuser 34, passing over several struts or main airfoil sections 43 located within the exhaust diffuser 34.

[0025] The gas turbine engine 10 can define a cylindrical coordinate system having an axial direction A extending along the axial centerline 30, a radial direction R perpendicular to the axial centerline 30, and a circumferential direction C extending around the axial centerline 30.

[0026] Figure 2 shows a partial fractured perspective view of an exemplary cast part 45, such as a turbine component (e.g., a rotor blade 50 or stator vane). The rotor blade 50 may be a rotor blade 23 located in the compressor section 12, or a rotor blade 28 located in the turbine section 22, as described above with reference to Figure 1. As shown in Figure 2, the rotor blade 50 generally comprises a shank 37 and an airfoil 40 extending outward from the shank 37. For example, the shank 37 may comprise a mounting section 38 and a platform 42, and the airfoil 40 may extend radially R from the platform 42. The platform 42 generally functions as a radially inward boundary to the gas flowing through the gas turbine engine 10 (e.g., air flowing through the compressor section 12, as shown in Figure 1, or hot gas 41 flowing through the hot gas path of the turbine section 22). The platform 42 extends along the axial direction A from a front surface 84 to a rear surface 82. As shown in Figure 2, the mounting portion 38 of the shank 37 may extend radially inward from the platform 42 and may have a root structure such as a dovetail joint configured to interconnect or fix the rotor blade 50 to the rotor disks 21, 27 (Figure 1). In exemplary embodiments, the rotor blade 50 may be a turbine rotor blade (such as the rotor blade 28 described above with reference to Figure 1) that can benefit from this cooling circuit.

[0027] The airfoil section 40 comprises a positive pressure sidewall 44 and an opposing negative pressure sidewall 46. The positive pressure sidewall 44 and the negative pressure sidewall 46 extend substantially radially outward from the platform 42, from the root 48, which can be defined at the intersection between the airfoil section 40 and the platform 42, to the tip 51 of the airfoil section 40. The positive pressure sidewall 44 connects to the negative pressure sidewall 46 at the leading edge 52 of the airfoil section 40 and the trailing edge 54 downstream of the leading edge 52, so that the airfoil section 40 extends between the leading edge 52 and the trailing edge 54. The positive pressure sidewall 44 generally includes the aerodynamically concave outer surface of the airfoil section 40. Similarly, the negative pressure sidewall 46 generally can define the aerodynamically convex outer surface of the airfoil section 40. The tip 51 is located radially opposite the root 48. Therefore, the tip 51 can generally define the radially outermost portion of the rotor blade 50 and may thus be configured to be located adjacent to a stationary shroud or seal (not shown) of the gas turbine 10. The tip 51 may include a tip cavity 66 or a tip shroud (not shown).

[0028] As shown in Figure 2, the rotor blade 50 may be at least partially hollow, and for example, the rotor blade 50 may include a defined cooling circuit 72 inside. The cooling circuit 72 may include a forward circuit 73 and a rear circuit 75. In some embodiments, the forward circuit 73 and the rear circuit 75 may be fluid-separated from each other. In other embodiments, the forward circuit 73 and the rear circuit 75 may be fluid-coupled from each other. The forward circuit 73 can be used to cool the front portion (or forward portion) of the rotor blade 50, and the rear circuit 75 can be used to cool the rear portion (or rear portion) of the rotor blade 50. The forward circuit 73 may be located between the leading edge 52 and the segmented rib 79, and the rear circuit 75 may be located between the segmented rib 79 and the trailing edge 54. Each forward circuit 73 may extend into the shank 37 and include a forward inlet passage 56A between an inlet 60 and a forward passage 90 of a plurality of forward passages 90 defined in the airfoil portion 40 in front of the segmented rib 79. Similarly, each rear circuit 75 may extend into the shank 37 and include a rear inlet passage 56B between the inlet 60 and one of the rear passages 96 defined in the airfoil portion 40 behind the segmented rib 79.

[0029] The front passage 90 and the rear passage 96 can be defined at least partially by and between a plurality of ribs 74. The ribs 74 extend partially through the cooling circuit 72 substantially along the radial direction R, as shown, for example, in Figure 2. The ribs 74 can extend entirely through the cooling circuit 72 between the positive pressure sidewall 44 and the negative pressure sidewall 46. For example, each rib 74 can terminate radially near either the root turnout or the tip turnout. The root turnout can be partially defined by a floor that defines the most radially inward boundary of the root turnout.

[0030] The coolant 58 may include a portion of the compressed air from the compressor section 12 (Figure 1) and / or steam, any other suitable gas, or other fluid for cooling the airfoil section 40. The inlet 60 may be located along the mounting section 38 of the rotor blade 50. The inlet 60 is in fluid communication with at least one of the forward circuit 73 via the forward inlet passage 56A or the rear circuit 75 via the rear inlet passage 56B.

[0031] In many embodiments, as shown in the illustration, the forward passage 90 may comprise a first forward passage 90 defined between the leading edge 52 and the rib 74, a second forward passage 90 defined between the two ribs 74, and a third forward passage 90 defined between the rib 74 and the split rib 79 (which separates the forward circuit 73 from the rear circuit 75). The third forward passage 90 extends directly from the forward inlet passage 56A. Multiple leading edge outlets 91 are defined on the leading edge 52, which can be in fluid communication with the first forward passage 90.

[0032] Similarly, the rear passage 96 may comprise a first rear passage 96 defined between the rib 74 and the split rib 79 (which separates the front circuit 73 from the rear circuit 75), a second rear passage 96 defined between the first pair of ribs 74, and a third rear passage defined between the second pair of ribs 74. The first rear passage 96 may extend directly from the rear inlet passage 56B. Furthermore, the rear circuit 75 may comprise a rear edge passage 92 defined between the rib 74 and the rear edge 54, which can be fluidly coupled to the third rear passage 96 via a plurality of holes 62 defined in the rib 74. In many embodiments, a plurality of rear edge outlets 93 are defined in the rear edge 54, thereby enabling fluid communication with the rear edge passage 92. In some embodiments (not shown), the rotor blade 50 may include a pin bank having a plurality of pins extending between a positive pressure side wall 44 and a negative pressure side wall 46 and located within a trailing edge passage 92.

[0033] Referring here to Figure 3, a ceramic mold 100 for producing cast parts (such as the cast parts 45 described above with reference to Figure 2) is shown according to various aspects of this disclosure. The ceramic mold 100 can be produced by utilizing additive manufacturing techniques. Additive manufacturing techniques may include, but are not limited to, several steps, including mold design by a CAD process, printing of the mold with ceramic slurry or ceramic powder, mold preparation by exhaust, cleaning, and firing of the mold. However, these steps may cause stress concentration and other defects in the ceramic mold 100. This is especially true during the firing step, which may apply a considerable amount of stress to the ceramic part and may cause cracking and dimensional inconsistencies. Figure 3 shows a ceramic mold 100 for cast parts (such as rotor blades) formed from a ceramic slurry in an additive manufacturing process.

[0034] The ceramic mold 100 may comprise a shell structure 102 and a core structure 104 disposed within the shell structure 102. The ceramic mold 100 may comprise an airfoil portion 140, a shank portion 160, and a base portion 170 (or pouring cup region). The airfoil portion may comprise a leading edge segment 142, a trailing edge segment 144, a positive pressure side segment 146 extending between the leading edge segment 142 and the trailing edge segment 144, and a negative pressure side segment 148 located on the opposite side of the positive pressure side segment 146 and extending between the leading edge segment 142 and the trailing edge segment 144.

[0035] In exemplary embodiments, the core structure 104 may comprise a body 162 and a tip cap 164 that can form part of the airfoil portion 140 of the ceramic mold 100. The tip cap may comprise part of a shell structure 102 and part of the core structure 104. Specifically, the tip cap 164 may comprise a tip shell 165 and a tip core 167. Furthermore, the core structure 104 may comprise a body 162 that can define a plurality of body openings 166, and the tip core 167 of the tip cap 164 can define a plurality of tip cap openings 168 (shown as dashed or dashed lines in Figure 3). The tip cap 164 and the body 162 can be manufactured separately (for example, using an additive manufacturing system), then joined together, and then the metal can be poured into the ceramic mold 100 to form a cast part. For example, multiple pins 108 can be inserted into openings 166, 168 such that each pin 108 extends from the tip cap opening 168 of the tip core 167 of the tip cap 164 to the body opening 166 of the body 162. In other words, each pin 108 of the multiple pins 108 can extend between the corresponding body opening 166 of the multiple body openings 166 and the corresponding tip cap opening 168 of the multiple tip cap openings 168.

[0036] Each tip cap opening 168 can be aligned (for example, radially and axially) with the corresponding body opening 166 so that each pin 108 (which may be substantially cylindrical) can extend between the openings 166 and 168 to connect the tip cap 164 to the body 162. The openings 166, 168 can each be sized and oriented to accept one of a plurality of pins 108. Specifically, the openings 166, 168 can extend substantially radially such that the openings 166, 168 are longest along the radial direction R.

[0037] As shown in Figure 3, at least one pin 108 may be substantially cylindrical in various embodiments. However, in other embodiments, one or more pins 108 may be molded to correspond to the part design, as shown. Such shapes may include a conical shape 109 or other shapes (such as a rectangular parallelepiped). In embodiments with a pin 108 having a conical shape 109, the tip cap opening 168 may be sized, molded, and / or oriented differently from the body opening 166 such that the tip cap opening 168 receives a first portion of the pin 108 (e.g., the conical base) and the body opening 166 receives a second portion of the pin 108 (e.g., the conical tip). Other shapes of pins, such as rectangles or other polygonal prisms, and correspondingly molded, sized, and oriented openings are possible.

[0038] Referring here to Figure 4, an additive manufacturing system 400 that may be used to produce the ceramic mold 100 discussed above with reference to Figure 3 is shown according to various aspects of this disclosure. In particular, the additive manufacturing system 400 shown in Figure 4 may be a direct light-emitting photoprocessing (DLP) system. However, other similar additive manufacturing systems may be used to produce the ceramic mold 100, and it should be understood that the present invention should not be limited to any particular type of additive manufacturing system unless specifically described in the claims. For example, in some embodiments, the system 400 may be a stereolithography (SLA) system utilizing a top-down irradiation technique that may be used to produce a one-piece core-shell mold according to the present invention.

[0039] An additive manufacturing system for producing ceramic molds comprises an optical imaging system 200 for providing a light source 205, a photosensitive medium 300 (such as a liquid ceramic photopolymer) adapted to change its state, and a control system 400 for continuously moving the optical imaging system over the photosensitive medium 300. The optical imaging system 200 can scan and / or cure a portion of the surface of the photosensitive medium 300 contained in a container 500 using an array of spatial light modulators (SLMs) 225. In an exemplary embodiment, the medium is a liquid ceramic photopolymer. As the optical imaging system 200 scans the photosensitive medium, the light source 205 illuminates a portion of the surface of the medium, causing a change in the properties of the medium (i.e., the liquid ceramic photopolymer cures, thereby transitioning from a liquid or aqueous state to a solid state). Next, the material construction platform 502 housed within the container 500 can be lowered (for example, in the Z direction), and the material recoating system 600 (shown as a wound-type drawdown bar for illustrative purposes) sweeps a uniform thickness layer of the photosensitive medium across the material construction platform 502 at high speed without interfering with previously constructed layers. Once the new photosensitive medium layer is formed, the focusing and aligning optical systems ensure that the surface of the medium is at the focal plane of the projection lens and can be fine-tuned in the Z direction as needed. Once this step is complete, the process repeats the cycle of curing the next layer and delivering new photosensitive material until the entire construction is complete.

[0040] Specifically, in an exemplary embodiment, light from a light source 205 of the optical imaging system 200, such as an ultraviolet (UV) light source, is tuned and delivered via the transmission optical system 215 and / or via the reflection optical system 220 (e.g., mirrors). The UV light source 205 is tuned and delivered onto the array of SLM 225 via the transmission optical system 215 and the reflection optical system 220.

[0041] The SLM225 array can receive a real-time video stream of CAD data slice bitmap images from the control system 400. The process control computer 405 of the control system 400 can turn on or off the corresponding pixels in the array. As described, light from the on pixels can be reflected downward and transmitted to the projection lens system 230. The projection lens 230 can transport a highly focused image corresponding to the on pixels, at a speed of several kilohertz (kHz), onto the surface 300 of the photosensitive medium in the material construction platform 502. The optical imaging system 200, comprising the light source 205, the optical system 215, the SLM array 225, and the projection lens 230, can be scanned at high speed along the X and Y axes to continuously expose and cure new areas of the photosensitive material in synchronization with the image continuously refreshed on the SLM array. Once the entire surface area of ​​the resin 300 has been scanned and exposed, the construction platform 502 can be moved downward along the negative Z-axis by the thickness of the slice layer, allowing a new photocurable material layer to be swept by the material recoating system 600. This process is repeated until the entire construction is complete.

[0042] The integrated core-shell ceramic mold of the present invention may be prepared using other alternative methods of DLP.

[0043] Referring here to Figures 5 and 6, two cross-sectional views of a ceramic mold 100 that can be manufactured using the additive manufacturing system 400 described above, with reference to Figures 4 to 8, are shown according to embodiments of this disclosure. Specifically, Figure 5 shows a partially exploded cross-sectional view of the ceramic mold 100, and Figure 6 shows a cross-sectional view of the assembled ceramic mold 100.

[0044] As shown in Figures 5 and 6, the ceramic mold 100 comprises a core structure 104 and a shell structure 102, each formed by an additive manufacturing system from a liquid ceramic photopolymer (a photosensitive resin that may contain powder, such as a photopolymer). The core structure 104 may be located within the shell structure 102. The core structure 104 of the ceramic mold 100 may correspond to the internal cavity of the cast part obtained when the ceramic mold is removed. For example, in an embodiment where the cast part is a rotor blade (such as the rotor blade 50 shown in Figure 2), the core structure 104 of the ceramic mold 100 may correspond to a cooling circuit 78 defined in the rotor blade 50. Similarly, the shell structure 102 of the ceramic mold 100 may correspond to the external structure of the cast part. For example, in an embodiment where the cast part is a rotor blade (such as the rotor blade 50 shown in Figure 2), the shell structure 102 of the ceramic mold 100 may correspond to the airfoil portion 40 and / or shank 37. For example, the ceramic mold 100 may further include an airfoil portion 140 and a shank portion 160. The airfoil portion 140 may correspond to the airfoil portion 40 (Figure 2) of the cast part 45, and the shank portion 160 may correspond to the shank 37 (Figure 2) of the cast part 45.

[0045] As shown in Figures 5 and 6, a cavity 110 is defined between the core structure 104 and the shell structure 102. The cavity 110 is adapted to define the shape of the cast parts 45, such as the rotor blade 50 (Figure 2), during casting and removal of the ceramic mold 100. The shell structure 102 defines a radially outer end 103 that defines a radially outer opening 105. Furthermore, in exemplary embodiments, the ceramic mold 100 may include a tip cap 164 comprising a portion of the shell structure 102 and a portion of the core structure 104. Specifically, the tip cap 164 may include a tip shell 165 and a tip core 167. Furthermore, the core structure 104 may include a body 162. The main body 162 of the core structure 104 defines a plurality of main body openings 166, and the tip core 167 of the tip cap 164 can define a plurality of tip cap openings 168 (shown by dashed or dashed lines in Figure 3).

[0046] Multiple body openings 166 can be spaced apart from each other in the axial direction. Furthermore, multiple body openings 166 can extend radially inward from an open end 176 defined on the radially outermost surface 173 of the body 162 to a closed end 178. Similarly, multiple tip cap openings 168 can be spaced apart from each other in the axial direction. Furthermore, multiple tip cap openings 168 can extend radially outward from an open end 172 defined on the radially innermost surface 175 of the tip core 167 to a closed end 174.

[0047] The tip cap 164 and the body 162 can be manufactured separately (for example, using an additive manufacturing system), then joined together, and finally the metal poured into the ceramic mold 100 to form a cast part (for example, the tip cap 164 and the body 162 can be joined together before or after firing of the ceramic mold 100). Multiple pins 108 can be inserted into openings 166, 168 such that each pin 108 extends from the tip cap opening 168 of the tip core 167 to the body opening 166 of the body 162. In other words, each pin 108 of the multiple pins 108 can extend between the corresponding body opening 166 of the multiple body openings 166 and the corresponding tip cap opening 168 of the multiple tip cap openings 168.

[0048] Each tip cap opening 168 can be aligned (for example, radially and axially) with the corresponding body opening 166 so that each pin 108 (which may be substantially cylindrical) can extend between the openings 166 and 168 to connect the tip cap 164 to the body 162. The openings 166, 168 can each be sized and oriented to accept one of a plurality of pins 108. Specifically, the openings 166, 168 can extend substantially radially such that the openings 166, 168 are longest along the radial direction R.

[0049] To assemble the tip cap 164 and connect it to the body 162, each of the multiple pins 108 can be inserted into one of the following: (1) a corresponding body opening 166 of the multiple body openings 166 such that the first exposed portion 182 of the pin 108 extends from the corresponding body opening 166 (for example, radially outward) (for example, radially outward from the radially outermost surface 173 of the body 162); or (2) a corresponding tip cap opening 168 of the multiple tip cap openings 168 such that the second exposed portion 184 of the pin extends from the corresponding tip cap opening 168 (for example, radially inward) (for example, radially inward from the radially innermost surface 175 of the tip cap 164). One or more pins 108 can be inserted through the open end 172 of the tip cap opening 168 until the upper surface of the pin 108 contacts the closed end 174. Alternatively or additionally, one or more pins may be inserted through the open end 176 of the body opening 166 until the bottom surface of pin 108 contacts the closed end 178 of the body opening 166. Subsequently, once pin 108 is inserted into one of the openings 166, 168, connecting the tip cap 164 to the body 166 may involve inserting the first exposed portion 182 into one of the tip cap openings 168, and / or inserting the second exposed portion 184 into one of the body openings 166. As shown in Figure 6, after assembly, the innermost surface 175 of the tip cap 164 may contact the outermost surface 173 of the body 162 (e.g., making flush contact).

[0050] Each pin 108 may be an elongated structure extending from a first end and a second end. Each pin may define a cross-sectional shape corresponding to the shape of the corresponding openings 166, 168 into which the pin 108 is inserted. For example, the cross-sectional shape of at least one of the multiple pins 108 may be a polygonal cross-sectional shape (such as a rectangle, square, triangle, hexagon, or any other polygon). In some embodiments, the cross-sectional shape of at least one of the multiple pins 108 may be a circular cross-sectional shape (such as a circle, ellipse, oblong, or another round cross-sectional shape).

[0051] As shown in Figures 5 and 6, the main body 162 of the core structure 104 comprises a front portion 122 and a rear portion 124, which can be separated from each other (until the tip cap 164 is coupled to the front portion 122 and the rear portion 124, respectively). The front portion 122 may correspond to the front circuit 73 of the casting part 45 described above with reference to Figure 2, for example, during casting and removal of the casting part 45 from the ceramic mold 100. Similarly, the rear portion 124 may correspond to the rear circuit 75 of the casting part 45 described above with reference to Figure 2, for example, during casting and removal of the casting part 45 from the ceramic mold 100. The front portion 122 of the main body 162 may include a front inlet portion 126 corresponding to the front inlet passage 56A (Figure 2) of the casting part 45. The rear portion 124 of the main body 162 may include a rear inlet portion 128 corresponding to the rear inlet passage 56B (Figure 2) of the casting part 45.

[0052] The core structure may further comprise a plurality of elongated connecting portions 118, 119 extending to the end portion (e.g., the radial end portion) at the radial outermost surface 173 of the core structure 104. Specifically, a first plurality of connecting portions 118 of the front portion 122 of the core structure 104 may extend radially to the corresponding end portion at the radial outermost surface 173 of the core structure 104, and a second plurality of connecting portions 119 of the rear portion 124 of the core structure 104 may extend radially to the corresponding end portion at the radial outermost surface 173 of the core structure 104. The plurality of elongated connecting portions 118, 119 may correspond to cooling passages 90, 96 (Figure 2) of the cast part 45. In particular, the front portion 122 may comprise a first plurality of elongated connecting portions 118 extending to the radial outermost surface 173 of the core structure 104 (and / or to the tip cap 164 if the core structure 104 is fully assembled). At least one of the first elongated connecting portions 118 may extend between the front inlet portion 126 and the radially outermost surface 173. Similarly, the rear portion 124 may comprise a second set of elongated connecting portions 119 extending to the radially outermost surface 173 of the core structure 104 (and / or to the tip cap 164 if the core structure 104 is fully assembled). At least one of the second elongated connecting portions 119 may extend between the rear inlet portion 128 and the radially outermost surface 173.

[0053] The first set of elongated connecting portions 118 may correspond to the front passage 90 (Figure 2) of the cast part 45 during casting and removal from the ceramic mold 100, for example. The second set of elongated connecting portions 119 may correspond to the rear passage 96 (Figure 2) of the cast part 45 during casting and removal from the ceramic mold 100, for example. The elongated connecting portions 118 and 119 may be elongated along the radial direction R (i.e., they may be the longest).

[0054] In many embodiments, at least two of the multiple pins 108 can contact each of the multiple elongated connecting portions 118, 119. At least two of the multiple pins 108 that are in contact with each of the elongated connecting portions 118, 119 can be aligned approximately in the radial direction R (for example, aligned within ±10% of the radial direction, or within ±25% of the radial direction).

[0055] In an exemplary embodiment, at least one of the multiple connecting portions 118, 119 defines one of the multiple body openings 166. Specifically, each of the multiple body openings 166 may be defined at its end by corresponding elongated connecting portions 118, 119. This configuration is advantageous because it provides additional support to the elongated connecting portions during the casting and / or firing process (e.g., when the core structure 104 is assembled and the pins 108 are inserted), resulting in higher dimensional accuracy of the cast part.

[0056] Referring here to Figures 7A, 7B, and 7C, portions of the ceramic mold 100 at three different stages of the process of joining the tip cap 164 to the body 162 using pins 108 are shown according to embodiments of this disclosure. Specifically, Figure 7A shows an exploded view of the ceramic mold 100. Figure 7B shows another exploded view of the ceramic mold 100 with the bonding material 156 applied to the tip cap 164 and / or body 162. Figure 7C shows a complete assembled view of the core body 104.

[0057] As shown in Figure 7B, before inserting the pin 108, the bonding material 156 can be applied to the tip cap 164 (specifically, the tip core 167 of the tip cap 164) and / or the body 162. Specifically, the bonding material 156 can be applied to the radially innermost surface 175 of the tip core 167 and / or applied (e.g., injected) into the tip cap opening 168. Similarly, before inserting the pin 108, the bonding material 156 can be applied to the radially outermost surface 173 of the body 162 and / or applied (e.g., injected) into the body opening 166. In some embodiments, the bonding material 156 may be a printed slurry (e.g., liquid ceramic photopolymer) that can be applied to the tip cap 164 and / or the body 162. Subsequently, as shown in Figure 7C, the tip cap 164 and the body 162 can be connected by inserting the pin 108 into the body opening 166 and the tip cap opening 168. After connecting the tip cap 164 and the body 162 to the pin 108, the printing slurry (e.g., liquid ceramic photopolymer) can be cured to solidify the printing slurry and fix the tip cap 164, the body 162, and the pin 108 in place. In other embodiments, the bonding material 156 may be mold repair cement or another bonding material.

[0058] Referring here to Figures 8 and 9, two different enlarged exploded views of a portion of the ceramic mold 100 are shown according to embodiments of the present disclosure. As shown in Figure 8, in some embodiments, one of the body 162 or the tip cap 164 (e.g., tip core 167) may be additively manufactured to have a pin projection 180. In such embodiments, the other of the body 162 or the tip cap 164 may define a corresponding opening that is sized, oriented, and molded to receive the pin projection 180. For example, in the illustrated embodiment, the pin projection 180 may be integrally formed with the body 162 such that the tip cap opening 168 receives the pin projection. As shown in Figure 9, the pin 108 may have a non-uniform geometric shape 182 such that the corresponding body opening 166 and tip cap opening 168 define openings of different sizes and shapes to receive different portions of a non-uniformly shaped pin. In the illustrated embodiment, the pin 108 may comprise a base portion 184, a platform portion 186 extending outward from the base portion 184, and a pin portion 188 extending from the platform portion 186.

[0059] Referring here to Figures 10 and 11, two flowcharts of methods 1200 and 1300 for manufacturing ceramic molds are shown according to embodiments of the subject matter. Methods 1200 and 1300 can be carried out using an additive manufacturing system such as the additive manufacturing system 400 described herein or another preferred system. Overall, methods 1200 and 1300 are described herein with reference to the additive manufacturing system 400, ceramic mold 100, and cast part 45 described above with reference to Figures 1 to 9. However, it will be understood by those skilled in the art that the disclosed methods 1200 and 1300 may generally be used in any other preferred system configuration. In addition, although Figures 10 and 11 show steps performed in a particular order for illustrative and explanatory purposes, the methods discussed herein are not limited to any particular order or configuration unless specifically specified in the claims. Those skilled in the art will understand that by using the disclosures provided herein, various steps of the methods disclosed herein can be omitted, rearranged, combined, and / or adapted in various ways without departing from the scope of this disclosure. The dashed boxes indicate optional steps of Methods 1200 and 1300.

[0060] As shown in Figure 10, Method 1200 may include, in (1202), the step of additively manufacturing a first part of a ceramic mold comprising a body and a shell structure. The body of the core structure may define a plurality of body openings. Furthermore, Method 1200 may include, in (1204), the step of additively manufacturing a second part of a ceramic mold comprising a tip cap of the core structure. The tip cap of the core structure may define a plurality of tip cap openings. The ceramic mold may be formed from a ceramic material, which may include, but is not limited to, silica, alumina, zirconia, or carbides.

[0061] The additive manufacturing of the ceramic mold in (1202) may include repeated steps of (a) bringing the cured portion of the workpiece into contact with the liquid ceramic photopolymer, (b) irradiating a portion of the liquid ceramic photopolymer adjacent to the cured portion, and (c) removing the workpiece from the uncured liquid ceramic photopolymer. Steps (a) to (c) are repeated until the ceramic mold shown in Figure 3 is formed.

[0062] In exemplary embodiments, method 1200 may further include, in (1206), a step of firing the first and second portions of the ceramic mold to sinter and fuse the ceramic particles of the ceramic mold. Firing the first and second portions of the ceramic mold may include controlled heating (e.g., in an oven or kiln) to strengthen the ceramic mold so that it can withstand the high temperatures and pressures used in metal casting. Prior to firing, the ceramic mold may be dried to remove any residual moisture. Firing may include a low-temperature firing period in which the first and second portions of the ceramic mold are gradually heated to remove any residual moisture and process additives from the mold material. Subsequently, firing may include a high-temperature firing period in which the ceramic particles are sintered and / or fused, thereby providing a dense and durable mold. The ceramic mold may then undergo a controlled cooling process.

[0063] In many implementations, method 1200 may include, in (1208), a step of connecting the tip cap to the body after firing the first and second parts of the ceramic mold. The connection in (1208) may further include, in (1210), inserting each pin of the plurality of pins into a corresponding body opening of a plurality of body openings and a corresponding tip cap opening of a plurality of tip cap openings. That is, each pin of the plurality of pins may be inserted into one of the following: (1) a corresponding body opening of a plurality of body openings such that a first exposed portion of the pin extends from the corresponding body opening (e.g., radially outward) (e.g., radially outward from the radially outermost surface of the body), or (2) a corresponding tip cap opening of a plurality of tip cap openings such that a second exposed portion of the pin extends from the corresponding tip cap opening (e.g., radially inward) (e.g., radially inward from the radially innermost surface of the tip cap). One or more pins may be inserted through the open end of a tip cap opening until the top surface of the pin contacts the closed end. Alternatively or additionally, one or more pins may be inserted through the open end of a body opening until the bottom surface of the pin contacts the closed end of the body opening. Subsequently, once the pins are inserted into one of the openings, connecting the tip cap to the body may involve inserting the first exposed portion into one of the tip cap openings, and / or inserting the second exposed portion into one of the body openings.

[0064] As shown in Figure 11, Method 1300 may include, in (1302), the step of additively manufacturing a first portion of a ceramic mold comprising a body and a shell structure. The body of the core structure may define a plurality of body openings. Furthermore, Method 1300 may include, in (1304), the step of additively manufacturing a second portion of a ceramic mold comprising a tip cap of the core structure. The tip cap of the core structure may define a plurality of tip cap openings.

[0065] The additive manufacturing of the ceramic mold in (1302) may include repeated steps of (a) bringing the hardened portion of the workpiece into contact with a liquid ceramic photopolymer, (b) irradiating a portion of the liquid ceramic photopolymer adjacent to the hardened portion through a window in contact with the liquid ceramic photopolymer, and (c) removing the workpiece from the unhardened liquid ceramic photopolymer. Steps (a) to (c) are repeated until the ceramic mold shown in Figure 3 is formed.

[0066] In exemplary embodiments, method 1300 may further include, in (1306), a step of firing the first and second portions of the ceramic mold to sinter and fuse the ceramic particles of the ceramic mold. Firing the first and second portions of the ceramic mold may include controlled heating (e.g., in an oven or kiln) to strengthen the ceramic mold so that it can withstand the high temperatures and pressures used in metal casting. Prior to firing, the ceramic mold may be dried to remove any residual moisture. Firing may include a low-temperature firing period in which the first and second portions of the ceramic mold are gradually heated to remove any residual moisture and any organic binders in the mold material. Subsequently, firing may include a high-temperature firing period in which the ceramic particles are sintered and / or fused, thereby providing a dense and durable mold. The ceramic mold may then undergo a controlled cooling process.

[0067] In many implementations, method 1300 may include, in (1308), a step of joining the tip cap to the body of the core structure after firing the first and second parts of the ceramic mold. In an exemplary implementation, the joining in (1308) may include, in (1310), applying a printed slurry inside at least one of a plurality of body openings or a plurality of tip cap openings. Subsequently, method 1300 may include, in (1312), a step of connecting the tip cap to the body by inserting each pin of a plurality of pins into the corresponding body openings of the plurality of body openings and the corresponding tip cap openings of the plurality of tip cap openings. Finally, the joining in (1308) may include, in (1314), curing the printed slurry to fix and bond the plurality of pins, tip cap, and body to each other.

[0068] In some embodiments, the bonding material may be a printed slurry (e.g., liquid ceramic photopolymer) that can be applied to the tip cap and / or body. The printed slurry may be the same material used to form ceramic parts using an additive manufacturing system, or it may be a different printed slurry. After connecting the tip cap and body with the pin, the printed slurry (e.g., liquid ceramic photopolymer) can be cured to solidify the slurry and fix the tip cap, body, and pin together. In other embodiments, the bonding material may be mold repair cement or another bonding material.

[0069] Methods 1200 and / or 1300 may further include the step of pouring liquid metal into a ceramic mold for solidifying the liquid metal to form a cast part. That is, after the mold is formed, a cast part can be formed by pouring liquid metal into the casting mold and allowing it to solidify. The ceramic mold may be filled with a metal such as nickel, aluminum, cobalt, or an iron-based alloy, for example, INCONEL®.

[0070] Finally, methods 1200 and / or 1300 may include the step of removing the ceramic mold from the cast part. The ceramic mold is then removed from the cast part by a combination of, for example, mechanical removal of the outer shell and leaching of the inner ceramic core. That is, after the ceramic mold is formed, the cast part can be formed by pouring liquid metal into the casting mold and allowing it to solidify. The ceramic mold is then removed from the cast part by a combination of, for example, mechanical removal of the shell structure and leaching of the core structure. After leaching of the ceramic core-shell, the resulting casting is a turbine blade or stator vane.

[0071] This specification discloses the present invention in its best mode and uses examples to enable those skilled in the art to carry out the invention, including the fabrication and use of any device or system, and the execution of any incorporated method. The patentable scope of the present invention is defined by the claims and may include other examples that those skilled in the art may conceive. Such other examples are within the scope of the claims if they include structural elements that are not different from the language of the claims, or equivalent structural elements that do not substantially differ from the language of the claims.

[0072] Further aspects of the present invention are provided by the subject matter of the following clauses.

[0073] A method for manufacturing a ceramic mold, the method comprising: adding a first part of the ceramic mold, the first part of the ceramic mold comprising a body of a core structure and a shell structure, the body of the core structure defining a plurality of body openings; adding a second part of the ceramic mold comprising a tip cap of a core structure, the tip cap of the core structure defining a plurality of tip cap openings; firing the first and second parts of the ceramic mold to sinter and fuse the ceramic particles of the ceramic mold; and, after firing the first and second parts of the ceramic mold, connecting the tip cap to the body by inserting each pin of a plurality of pins into the corresponding body openings of a plurality of body openings and the corresponding tip cap openings of a plurality of tip cap openings.

[0074] The method according to any of the above clauses, wherein the step of connecting the tip cap to the body includes inserting each pin of a plurality of pins into a corresponding body opening such that a first exposed portion of the pin extends from a corresponding body opening of a plurality of body openings, or into one of a plurality of corresponding tip cap openings such that a second exposed portion of the pin extends from a corresponding tip cap opening of a plurality of tip cap openings.

[0075] The method according to any of the above clauses, wherein the step of connecting the tip cap to the body further includes at least one of inserting the first exposed portion into one of a plurality of tip cap openings and inserting the second exposed portion into one of a plurality of body openings.

[0076] The method according to any of the above clauses, wherein the body of the core structure comprises a plurality of elongated connectors, each extending to an end, the plurality of elongated connectors corresponding to cooling channels within the cast part during casting and removal of the ceramic mold, and at least one of the plurality of elongated connectors defines one of the plurality of body openings.

[0077] The method according to any of the above clauses, wherein the ceramic mold defines the axial, radial, and circumferential directions, and the plurality of elongated connecting parts and the plurality of pins are longest along the radial direction.

[0078] The method according to any of the above provisions, wherein the cast parts include turbine parts.

[0079] The method according to any of the above clauses, wherein the method includes the steps of pouring liquid metal into a ceramic mold after the tip cap and the body of the core structure have been connected, and solidifying the liquid metal to form a cast part.

[0080] The method according to any of the above provisions, further comprising the step of removing a ceramic mold from a cast part.

[0081] The method according to any of the above provisions, wherein the step of removing the ceramic mold from the cast part includes a combination of mechanical force and chemical leaching.

[0082] A method for manufacturing a ceramic mold, the method comprising: a step of additively manufacturing a first portion of a ceramic mold, wherein the first portion of the ceramic mold comprises a body of a core structure and a shell structure, the body of the core structure defining a plurality of body openings; a step of additively manufacturing a second portion of the ceramic mold, comprising a tip cap of a core structure, wherein the tip cap of the core structure defining a plurality of tip cap openings; a step of firing the first portion and the second portion of the ceramic mold to sinter and fuse the ceramic particles of the ceramic mold; and a step of joining the tip cap and the body after firing the first portion and the second portion of the ceramic mold.

[0083] The method according to any of the above clauses, wherein the step of joining the tip cap to the body includes applying a printed slurry inside at least one of a plurality of body openings or a plurality of tip cap openings; connecting the tip cap to the body by inserting each pin of a plurality of pins into the corresponding body opening of the plurality of body openings and the corresponding tip cap opening of the plurality of tip cap openings; and fixing and joining the plurality of pins, tip cap and body to each other by curing the printed slurry.

[0084] The method according to any of the above clauses, wherein the body of the core structure comprises a plurality of elongated connectors, each extending to an end, the plurality of elongated connectors corresponding to cooling channels within the cast part during casting and removal of the ceramic mold, and at least one of the plurality of elongated connectors defines one of the plurality of body openings.

[0085] The method according to any of the above clauses, wherein the ceramic mold defines the axial, radial, and circumferential directions, and the plurality of elongated connecting parts and the plurality of pins are longest along the radial direction.

[0086] The method described in any of the above provisions, wherein the cast component includes a turbine rotor blade or a stator vane.

[0087] A ceramic mold comprising a shell structure and a core structure disposed within the shell structure, wherein a cavity is defined between the core structure and the shell structure, the cavity is adapted to define the shape of a cast part during casting and removal of the ceramic mold, the core structure comprising a body and an end cap, the body defining a plurality of body openings, and the end cap defining a plurality of end cap openings, and a plurality of pins, each extending between corresponding body openings of the plurality of body openings and corresponding end cap openings of the plurality of end cap openings.

[0088] A ceramic mold according to any of the above clauses, wherein the body of the core structure comprises a plurality of elongated connectors, each extending to its end, the plurality of elongated connectors corresponding to cooling channels within the cast part during casting and removal of the ceramic mold, and at least one of the plurality of elongated connectors defines one of the plurality of body openings.

[0089] A ceramic mold as described in any of the above clauses, wherein the ceramic mold defines the axial, radial, and circumferential directions, and the multiple elongated connecting parts and multiple pins are longest along the radial direction.

[0090] A ceramic mold as described in any of the above clauses, wherein the cast component is either a turbine rotor blade or a stator vane. [Explanation of Symbols]

[0091] 10. Gas turbine, gas turbine engine 11. Compressor casing 12 Compressor section 14 Compressor 16 Entrance 18 Combustion section 19. State vanes 20 Combustors 21 Rotor Disc 22 Turbine section 23 Rotor Blades 24 shafts 25 Combustion chamber 26 Fixed nozzle, stator vane 27 Rotor Disc 28 rotor blades 30 Axial center line 32 Outer casing 34 Exhaust Diffuser 35 Compressed air 37 Shank 38 Mounting part 40 Airfoil 41. Combustion gases, high-temperature gases 42 platforms 43 Main wing section 44 Positive pressure sidewall 45 Cast parts 46 Negative pressure sidewall 48 Root 50 rotor blades 51 Tip 52 Leading edge 54 Trailing edge 56A Front entrance passage 56B Rear entrance passage 58 Coolant 60 Entrance 62 holes 66 Tip Cavity 72 Cooling circuit 73 Forward circuit 74 Ribs 75 Rear circuit 78 Cooling circuit 79-piece rib 82 Rear 84 Front 90 Front passage, cooling passage 91 Front edge exit 92 Trailing edge passage 93 Trailing edge exit 96 Rear passage, cooling passage 100 ceramic molds 102 Shell Structures 103 Radial outer end 104 Core structure, core body 105 Radial outer opening 108 pins 109 Conical shape 110 Cavity 118 Long, slender connecting section 119 Long, slender connecting section 122 Front part 124 Rear part 126 Front entrance section 128 Rear entrance section 140 Airfoil section 142 Leading edge segment 144 trailing edge segment 146 Positive pressure side segment 148 Negative pressure side segment 156 Bonding materials 160 Shank portion 162 Main Unit 164 Tip cap 165 Tip Shell 166 Main body opening 167 Advanced Core 168 Tip cap opening 170 Base part 172 Open end 173 Radial outermost surface, outermost surface 174 Closed end 175 Radial innermost surface, innermost surface 176 Open end 178 Closed end 180 Pin protrusions 182 First exposed portion 184 Second exposed section, base section 186 Platform section 188 Pin section 200 Optical Imaging Systems 205 Light source 215 Transmission optical system, optical system 220 Reflective optical system 225 Spatial Light Modulators, SLMs, SLM Arrays 230 Projection Lens System, Projection Lens 300 Photosensitive media, surface (of photosensitive media), resin 400 Additive manufacturing systems, systems, and control systems 405 Process control computer 500 containers 502 Material Construction Platform 600 Material Recoating System 1200 methods 1300 methods

Claims

1. A method for manufacturing a ceramic mold (100), wherein the method is A step of manufacturing a first portion of the ceramic mold (100), wherein the first portion of the ceramic mold (100) comprises a body (162) of a core structure (104) and a shell structure (102), and the body (162) of the core structure (104) defines a plurality of body openings (166), A step of adding a second portion of the ceramic mold (100) having a tip cap (164) of the core structure (104), wherein the tip cap (164) of the core structure (104) defines a plurality of tip cap openings (168), The steps include firing the first and second portions of the ceramic mold (100) to sinter and fuse the ceramic particles of the ceramic mold (100), After firing the first and second portions of the ceramic mold (100), Insert each pin (108) of the plurality of pins (108) into the corresponding body opening (166) of the plurality of body openings (166) and the corresponding tip cap opening (168) of the plurality of tip cap openings (168). The steps involve connecting the tip cap (164) and the main body (162), and Methods that include...

2. The step of connecting the tip cap (164) and the main body (162) is, Each of the aforementioned plurality of pins (108) is, The first exposed portion of the pin (108) extends from the corresponding body opening (166) of the plurality of body openings (166), or The second exposed portion of the pin (108) extends from the corresponding tip cap opening (168) of the plurality of tip cap openings (168) Insert into one of them The method according to claim 1, including the method described in claim 1.

3. The step of connecting the tip cap (164) and the main body (162) is, Inserting the first exposed portion into one of the multiple tip cap openings (168), and Insert the second exposed portion into one of the multiple body openings (166) at least one of the following The method according to claim 2, further comprising:

4. The method according to any one of claims 1 to 3, wherein the main body (162) of the core structure (104) comprises a plurality of elongated connecting portions (118, 119), each extending to its end, the plurality of elongated connecting portions (118, 119) correspond to cooling channels in the cast part (45) during casting and removal of the ceramic mold (100), and at least one of the plurality of elongated connecting portions (118, 119) defines one of the plurality of main body openings (166).

5. The method according to claim 4, wherein the ceramic mold (100) defines an axial direction, a radial direction, and a circumferential direction, and the plurality of elongated connecting portions (118, 119) and the plurality of pins (108) are longest along the radial direction.

6. The method according to any one of claims 1 to 5, wherein the cast part (45) includes a turbine part.

7. The above method is performed after the tip cap (164) and the main body (162) of the core structure (104) are connected, The steps include pouring liquid metal into the ceramic mold (100), The steps include solidifying the liquid metal to form the cast part (45) and The method according to any one of claims 1 to 6, including the method described in any one of claims 1 to 6.

8. The method according to claim 7, further comprising the step of removing the ceramic mold (100) from the cast part (45).

9. The method according to claim 8, wherein the step of removing the ceramic mold (100) from the cast part (45) includes a combination of mechanical force and chemical leaching.

10. A ceramic mold (100), Shell structure (102), A core structure (104) disposed within the shell structure (102), wherein a cavity (110) is defined between the core structure (104) and the shell structure (102), the cavity (110) is adapted to define the shape of the cast part (45) during casting and removal of the ceramic mold (100), the core structure (104) includes a body (162) and a tip cap (164), the body (162) defines a plurality of body openings (166), and the tip cap (164) defines a plurality of tip cap openings (168), Each of the multiple pins (108) extends between the corresponding main body opening (166) of the multiple main body openings (166) and the corresponding tip cap opening (168) of the multiple tip cap openings (168) A ceramic mold (100) including the ceramic mold.

11. The ceramic mold (100) according to claim 10, wherein the main body (162) of the core structure (104) comprises a plurality of elongated connecting portions (118, 119), each extending to its end, the plurality of elongated connecting portions (118, 119) correspond to cooling channels in the cast part (45) during casting and removal of the ceramic mold (100), and at least one of the plurality of elongated connecting portions (118, 119) defines one of the plurality of main body openings (166).

12. The ceramic mold (100) according to claim 11, wherein the ceramic mold (100) defines an axial direction, a radial direction, and a circumferential direction, and the plurality of elongated connecting portions (118, 119) and the plurality of pins (108) are longest along the radial direction.

13. The ceramic mold (100) according to any one of claims 10 to 12, wherein the cast part (45) is one of a turbine rotor blade or a stator vane.

Images