Integrated Core-Shell Ceramic Mold for Turbine Blade Cooling Holes
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Solution Overview
Problem
Conventional methods for manufacturing turbine blades with intricate internal geometries and cooling passages are limited by the inability to produce fine filaments for effusion cooling holes, especially in locations inaccessible due to protrusion patterns, and require additional steps like ball chutes and tip pins for leaching pathways.
Innovation Solution
The use of direct light processing (DLP) to create integrated core-shell ceramic molds with thin filaments connecting the core and shell, enabling the formation of fine effusion cooling holes and eliminating the need for ball chutes and tip pins by supporting a floating tip plenum.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional investment casting methods are used to manufacture turbine blades with intricate internal geometries, then the manufacturing process can produce complex shapes, but the ability to create fine filaments for effusion cooling holes in inaccessible locations is limited
Solution Approach 1:
The mold is segmented into two distinct components: a core mold defining the internal cooling passages and a shell mold defining the external blade geometry. This segmentation allows independent optimization of each component, enabling the core to include complex internal features like fine filaments for effusion cooling holes while the shell provides the outer blade shape. The segmentation resolves the contradiction by separating the functions of internal passage formation and external geometry definition.
Solution Approach 2:
The invention introduces a new dimensional approach by incorporating three-dimensional printed ceramic filaments within the core mold structure. These filaments create internal pathways and support structures that extend into inaccessible locations of the blade, enabling cooling holes to be formed in regions that would be unreachable by conventional two-dimensional mold surfaces. This dimensional addition resolves the contradiction by providing access to previously inaccessible cooling hole locations.
2Productivity
If conventional methods are used to create leaching pathways with ball chutes and tip pins, then cooling passages can be formed, but additional post-casting modification steps are required
Solution Approach 1:
The invention merges the leaching pathway function directly into the core mold structure by designing the core itself to define the internal cooling passages. The core mold includes integrated features that provide leaching pathways during casting, eliminating the need for separate ball chutes and tip pins. This merging of functions reduces the number of components and post-casting modification steps, thereby improving productivity while maintaining ease of manufacture.
Solution Approach 2:
The leaching pathways and cooling passage geometries are predetermined and built into the core mold structure before casting. The core mold is designed with internal channels and features that automatically create the desired cooling passage network as the metal solidifies. This preliminary action eliminates the need for subsequent drilling, brazing, or other post-casting modifications, thereby improving manufacturing efficiency while keeping the process simple.
3Reliability
If traditional tip pins are used to support the tip plenum, then the plenum can be positioned, but the pins require subsequent closure by brazing
Solution Approach 1:
The invention extracts the tip pins and brazing operation from the manufacturing process entirely. Instead of using traditional tip pins to support the tip plenum, the core mold structure itself provides support and positioning features for the plenum. The core includes integrated support elements that hold the plenum in the correct position during casting without requiring removable pins or subsequent brazing operations. This extraction eliminates the complexity of pin closure while maintaining reliable plenum positioning.
Solution Approach 2:
The core mold structure provides self-supporting features that automatically position and support the tip plenum during casting. The core includes built-in support elements, such as ledges or engagement features, that hold the plenum in the correct position without requiring external pins or fasteners. This self-service approach eliminates the need for additional components and operations, thereby reducing device complexity while ensuring reliable plenum positioning through the core's inherent structural features.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for the precise creation of cooling holes in complex geometries, improving the manufacturing of turbine blades with enhanced cooling efficiency and reducing post-casting modifications, enabling the production of turbine blades with intricate internal voids and overhangs.
Implementation Method 1
A method for direct light processing (DLP) to create integrated core-shell ceramic molds
Data Source
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AI summary
The present disclosure generally relates to integrated core-shell investment casting molds that provide filament structures corresponding to cooling hole patterns in the surface of the turbine blade or stator vane, including in locations that are inaccessible due to the presence of protrusion patterns. The filament structures also provide a leaching pathway for the core portion after metal casting. The invention also relates to core filaments that can be used to supplement the leaching pathway, for example in a core tip portion of the mold.