Ceramic Core-Shell Mold Fabrication via DLP
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Solution Overview
Problem
Conventional methods for manufacturing turbine blades and stator vanes face challenges in producing intricate internal geometries and fine detail features due to limitations in printing resolution, leading to inefficiencies in cooling hole formation and increased manufacturing time and expense.
Innovation Solution
The use of Direct Light Processing (DLP) for creating ceramic core-shell molds with high-temperature structural supports during the liquid metal pouring phase, allowing for the production of thin filaments and efficient cooling hole patterns, and incorporating support features like spheres, metal sheets, and external supports to enhance cooling rates and reduce additive material and print time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional investment casting methods are used to manufacture turbine blades with intricate internal cooling passages, then the manufacturing process can produce complex geometries, but the process requires numerous sequential steps including machining dies, molding ceramic cores, wax assembly, dipping in ceramic slurry, drying, dewaxing, casting, and drilling cooling holes, leading to increased manufacturing time and expense
Solution Approach 1:
The patent combines multiple conventional manufacturing steps into a single integrated process. Specifically, it merges the ceramic core molding, wax assembly, ceramic shell formation, and cooling passage creation into one additive manufacturing process that deposits ceramic material layer-by-layer to directly form the final mold with embedded cooling passages, eliminating the need for separate drilling operations and reducing the total number of process steps from over ten to a unified additive manufacturing operation
Solution Approach 2:
The patent replaces traditional mechanical subtractive manufacturing methods (drilling, machining) with an additive manufacturing approach. Instead of drilling cooling holes through solid ceramic cores after mold formation, the system uses additive deposition to directly create the cooling passages within the ceramic structure during the molding process itself, substituting mechanical removal of material with additive construction of the desired geometry
2Manufacturing precision
If additive manufacturing is used to create ceramic molds with thin filaments for cooling holes, then printing resolution and fine detail features are improved, but the structural integrity of the ceramic mold during liquid metal pouring may be compromised
Solution Approach 1:
The patent applies local quality by differentiating the structural properties of different regions within the ceramic mold. The mold contains both thin-walled regions (for achieving fine detail features and cooling passages) and thick-walled regions (for providing structural strength). This spatial variation in wall thickness and material density allows the mold to simultaneously achieve high printing resolution in critical areas while maintaining overall structural integrity to withstand liquid metal pouring temperatures and pressures
Solution Approach 2:
The patent employs composite material strategies by creating a ceramic mold structure with heterogeneous properties. The additive manufacturing process enables the formation of a composite ceramic structure where different regions have different material densities and thermal properties - with denser, stronger material in load-bearing areas and more porous, thinner material in regions requiring fine detail reproduction. This composite approach allows the mold to satisfy both resolution and strength requirements that would be contradictory in a homogeneous structure
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 enables the production of cast components with complex cooling hole patterns and improved thermal management, reducing manufacturing time and material usage while enhancing the precision and efficiency of the casting process.
Implementation Method 1
A direct light processing (DLP) system may then be used to form a ceramic core-shell mold 700/701
Data Source
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AI summary
A method for fabricating a ceramic mold is provided. The method includes the steps of 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, removing the workpiece from the uncured liquid ceramic photopolymer, and repeating the steps until a ceramic mold is formed. The ceramic mold includes a first opening for creating a cast article and a second opening for receiving a support member.