Self-Supporting Additive Ceramic Core for Gas Turbine Casting
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Solution Overview
Problem
Current additive manufacturing processes for gas turbine engine components face challenges in creating self-supportive green cores during the firing process, as traditional methods require secondary ceramic setters, leading to increased costs and complexity.
Innovation Solution
A method involving the local elimination of additive manufacturing binder using a directional energy source, such as a laser, to form a thin outer skin on the core body, allowing it to be pre-sintered and self-supportive during the firing process, eliminating the need for secondary setters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional investment casting with weak ceramic cores is used, then complex internal cooling channel geometries can be achieved, but the cores collapse or crush during the solidification process
Solution Approach 1:
The patent changes the physical and mechanical parameters of the core material by using binder jetting technology to create a core with significantly enhanced strength properties. The core transitions from a weak ceramic that collapses under traditional casting to a high-strength green ceramic that can support complex geometries during solidification.
Solution Approach 2:
The patent replaces the traditional mechanical support system (setters and props) with an inherently strong core structure created through binder jetting. The core's own mechanical properties are enhanced to the point where it becomes self-supporting, eliminating the need for additional mechanical support elements.
2Manufacturing precision
If secondary ceramic setters are used to support the core during firing, then the core shape is retained, but manufacturing costs and process complexity increase
Solution Approach 1:
The patent enables the core to support itself during the firing process through the pre-sintered outer skin that provides structural rigidity. The core becomes self-sufficient, eliminating the need for external setters or props that would otherwise be required to maintain shape during thermal processing.
Solution Approach 2:
The patent applies preliminary sintering to the outer skin of the core before the main firing process. This pre-sintering action creates a rigid shell that maintains the core's geometric integrity during subsequent burning out and sintering operations, preventing deformation without requiring external support structures.
3Strength
If the green additive core is heated in an oven for burning out binder and sintering, then the core becomes strong, but thermal strains cause sag or deflection of the part
Solution Approach 1:
The patent applies preliminary sintering to the outer skin of the core before the main firing process. This pre-sintering creates a rigid shell that maintains the core's geometric integrity during subsequent burning out and sintering operations, preventing deformation without requiring external support structures.
Solution Approach 2:
The patent applies sintering selectively to the outer skin of the core, creating a localized region of high strength and rigidity. This outer shell has different properties than the inner core material, providing structural support where it is most needed to prevent thermal deformation during heating.
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 reduces thermal strains, prevents core cracking, and decreases processing costs by enabling the core to maintain its shape and structural integrity without additional support, thus enhancing manufacturing efficiency and reducing development time.
Implementation Method 1
A method involving the local elimination of additive manufacturing binder using a directional energy source, such as a laser, to form a thin outer skin on the core body
Implementation Method 2
allowing it to be pre-sintered and self-supportive during the firing process
Data Source
AI summary
A core for use in casting an internal cooling circuit within a gas turbine engine component, the core including a core body with an outer skin in which a core body additively manufacturing binder is locally eliminated. A method of manufacturing a core for casting a component, including casting a core body for at least partially forming an internal passage architecture of a component; and forming an outer skin on the core body in which a core body binder is locally eliminated.