Ceramic Core-Shell Mold with Floating Tip Plenum
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Solution Overview
Problem
Conventional methods for manufacturing complex turbine blades with intricate internal geometries, such as investment casting, face limitations in achieving fine detail and precise internal voids due to the resolution capabilities of existing ceramic core-shell mold production techniques like powder bed and selective laser activation.
Innovation Solution
The use of direct light processing (DLP) to create ceramic core-shell molds with integrated ceramic filaments that span between the core and shell portions, enabling the formation of effusion cooling holes and eliminating the need for ball chutes and tip pins, by producing thin filaments that define cooling hole patterns and support the tip plenum during casting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional powder bed or selective laser activation techniques are used to create ceramic core-shell molds, then the manufacturing process is relatively simple, but the resolution and precision of internal geometries and cooling hole patterns are insufficient
Solution Approach 1:
The mold is divided into separate core and shell portions that are manufactured independently using DLP technology, then assembled together. This segmentation allows each component to be optimized for high precision internal geometries while maintaining manufacturing feasibility.
Solution Approach 2:
The patent transitions from conventional 2D layer-by-layer powder bed or laser activation methods to 3D DLP volumetric printing, enabling simultaneous formation of complex internal cooling hole patterns and external geometries in a single manufacturing step, achieving superior resolution in multiple dimensions.
2Ease of manufacture
If traditional tip pins and ball chutes are used to support the tip plenum during casting, then the casting process is simpler, but additional post-casting modifications such as brazing are required
Solution Approach 1:
The patent removes the traditional tip pins and ball chutes from the mold assembly, replacing them with a floating tip plenum design supported by ceramic filaments integrated into the core structure. This extraction eliminates the need for post-casting brazing operations while maintaining structural support during casting.
Solution Approach 2:
The tip plenum is merged with the core structure through integrated ceramic filaments that provide support during casting. This combination eliminates the need for separate tip pins and ball chutes, reducing the number of components and post-casting assembly steps.
3Productivity
If ceramic filaments are integrated between core and shell to form cooling holes, then the number of post-casting modifications is reduced, but the manufacturing process becomes more complex
Solution Approach 1:
The ceramic filaments are pre-formed and integrated into the core structure before the casting process. This preliminary action creates the cooling hole pathways in advance, eliminating the need for post-casting drilling or modification operations and improving overall production efficiency.
Solution Approach 2:
The ceramic filaments serve dual functions: they provide structural support during casting and simultaneously define the cooling hole geometry. This self-service approach eliminates the need for separate operations to create cooling passages, reducing manufacturing steps and improving productivity.
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 production of turbine blades with intricate cooling hole patterns and reduced post-casting modifications, enhancing the precision and complexity of internal geometries achievable in cast components, particularly in jet aircraft engines and power generation turbines.
Implementation Method 1
contacting a cured portion of a workpiece with a liquid ceramic photopolymer; irradiating a portion of the liquid ceramic photopolymer adjacent to the cured portion through a window contacting the liquid ceramic photopolymer
Data Source
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AI summary
The present disclosure generally relates to integrated core-shell investment casting molds including a main core portion, a core tip portion, and a shell portion with at least one cavity between the core portion and the shell portion. The cavity defines the shape of a cast component upon casting and removal of the ceramic mold. These molds also provide filament structures corresponding to cooling hole patterns in the surface of the turbine blade or the stator vane, which provide a leaching pathway for the core portion after metal casting. At least two ceramic tip filaments connect the core tip portion and the shell portion and eliminate the need for tip pins or a shell lock to hold the tip plenum core in place during 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.