Hybrid Core Additive Manufacturing for Fine Cooling Passages
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Solution Overview
Problem
Current ceramic cores used in investment casting for gas turbine engine components are fragile and unable to produce fine cooling features, limiting the efficiency of air cooling and the manufacturing of components with dimensions smaller than 0.012-0.015 inches, which hampers the achievement of higher operating temperatures.
Innovation Solution
A hybrid core is created using additive manufacturing, combining a non-refractory metal portion and a refractory metal portion, where both are manufactured using powder during the additive process, allowing for precise formation of intricate cooling passages and enhanced structural integrity by fusing refractory metal and ceramic materials layer by layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional ceramic cores are used in investment casting, then the manufacturing process can produce turbine components, but the cores are fragile and cannot produce fine cooling features smaller than 0.012-0.015 inches
Solution Approach 1:
The patent applies composite materials by combining refractory metal (such as molybdenum or niobium) with ceramic materials to create a hybrid core assembly. The refractory metal portion provides the strength and ductility needed to prevent core breakage, while the ceramic portion enables the formation of fine cooling features. This composite approach resolves the contradiction between core strength and manufacturing precision by allowing the production of cooling passages smaller than 0.012-0.015 inches without compromising core integrity.
2Manufacturing precision
If fine cooling features are manufactured using conventional ceramic cores, then cooling precision is improved, but the cores become too fragile to handle and manufacture
Solution Approach 1:
The patent segments the core into two distinct portions: a refractory metal portion that provides structural strength and handling capability, and a ceramic portion that forms the fine cooling features. This segmentation allows each material to perform its optimal function—the metal portion withstands mechanical stresses while the ceramic portion enables precise cooling passage formation—thereby resolving the contradiction between cooling feature fineness and core strength.
Solution Approach 2:
By creating a composite core assembly with refractory metal and ceramic portions, the patent achieves both fine cooling features and adequate core strength. The refractory metal portion (such as molybdenum or niobium) provides the necessary mechanical properties for handling and manufacturing, while the ceramic portion enables the formation of cooling passages with dimensions smaller than 0.012-0.015 inches.
3Productivity
If operating temperature is increased to improve gas turbine engine efficiency, then efficiency is improved, but the temperature exceeds the melting points of super alloy materials
Solution Approach 1:
The patent changes the material parameters of the core by using refractory metals (such as molybdenum or niobium) that can withstand higher temperatures than conventional ceramic materials. This parameter change in material composition allows the core to maintain structural integrity at operating temperatures that exceed the melting points of super alloy materials, thereby enabling improved engine efficiency without material failure.
4Reliability
If air cooling is provided through turbine components, then cooling benefit is obtained, but engine efficiency is reduced due to the associated cost
Solution Approach 1:
The patent utilizes pneumatic cooling by flowing relatively cool air from the compressor section through passages in the turbine components. The hybrid core assembly enables more effective pneumatic cooling through finer, precisely located cooling passageway sections, which maximize the cooling benefit obtained from a given amount of cooling air, thereby reducing the efficiency penalty associated with air cooling.
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 high-temperature parts with finer cooling features and improved structural integrity, enhancing the efficiency of gas turbine engine components by allowing for smaller diameter cooling passages and increased cooling effectiveness without compromising the strength of the core.
Implementation Method 1
additive manufacturing process... fusing refractory metal and ceramic materials layer by layer
Data Source
AI summary
A hybrid core for manufacturing high temperature parts includes a non-refractory metal portion and a refractory metal portion wherein at least a portion of the non-refractory metal portion and the refractory metal portion are manufactured by using an additive manufacturing process.