Ceramic Bead Joining CMC Turbine Blade Components
Solution Overview
Problem
Gas turbine components face challenges in operating efficiently at high temperatures due to material limitations and increased cooling flow requirements, which offset the benefits of higher inlet temperatures.
Innovation Solution
A method of joining ceramic matrix composite (CMC) components using a ceramic bead that melts and fixes adjacent CMC components together, forming a contiguous component, and applying an overlayer for enhanced adherence and structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If turbine inlet temperature is increased to improve efficiency, then power plant efficiency improves, but material operating limits are reached and cooling flow requirements increase
Solution Approach 1:
The patent uses ceramic matrix composite (CMC) materials to construct turbine blades and components. CMC materials combine ceramic matrices with reinforcing fibers, providing both high-temperature resistance and mechanical strength. This composite structure enables the turbine to operate at higher inlet temperatures (1600-1800°C) without exceeding material operating limits, thus improving power plant efficiency while maintaining material integrity.
2Use of energy by moving object
If turbine inlet temperature is increased to improve efficiency, then power plant efficiency improves, but cooling flow requirements increase
Solution Approach 1:
CMC materials have inherently lower thermal conductivity and higher temperature resistance compared to traditional metallic superalloys. This allows the turbine components to operate at higher temperatures with reduced cooling flow requirements, as the CMC material itself can withstand higher temperatures without excessive thermal stress, thereby reducing the amount of cooling air needed.
3Strength
If CMC components are joined together to form turbine blades, then structural integrity is improved, but sealing between layers becomes challenging
Solution Approach 1:
The patent introduces a ceramic deposit as an intermediary material applied to the bonding surfaces of CMC components. This ceramic deposit serves as a mediator that enhances both the bonding strength between CMC layers and the sealing effectiveness. The deposit fills micro-gaps and irregularities at the interface, creating a reliable seal that prevents combustion gas leakage while maintaining structural integrity.
Solution Approach 2:
The patent modifies the surface parameters of CMC components by applying a ceramic deposit coating. This changes the surface roughness, chemical composition, and thermal properties of the bonding interface. The deposit creates a transition zone that improves both mechanical bonding and sealing performance, resolving the contradiction between structural integrity and sealing reliability.
4Strength
If ceramic bead is formed by melting CMC components to join them, then bonding strength is improved, but manufacturing precision becomes challenging
Solution Approach 1:
The ceramic deposit acts as an intermediary bonding material that is applied between CMC components before the ceramic bead formation process. This intermediary layer provides a buffer zone that accommodates slight misalignments and facilitates more precise positioning of components during assembly, while still achieving strong bonding when the ceramic bead is formed and melted.
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
The solution provides improved structural integrity, sealing, and adherence of the overlayer, enabling gas turbine components to operate effectively at high temperatures while preventing combustion gases from passing between CMC layers.
Implementation Method 1
The formation of the bead melts a portion of the first CMC component and the second CMC component, such that the ceramic bead, the first CMC component, and the second CMC component become a single contiguous component
Data Source
AI summary
A turbine blade having an airfoil portion includes a first ceramic matrix composite (CMC) component having a first outer surface and a second ceramic matrix composite (CMC) component having a second outer surface. The second CMC component is positioned adjacent the first CMC component such that the first outer surface and the second outer surface align with one another and at least partially define the airfoil portion. A ceramic bead is at least partially formed at an interface between the first CMC component and the second CMC component. The formation of the bead melts a portion of the first CMC component and the second CMC component, such that the ceramic bead, the first CMC component, and the second CMC component become a single contiguous component and the bead fixedly attaches the first CMC component and the second CMC component. The bead includes a bead outer surface that extends outward beyond the first outer surface and the second outer surface and an overlayer is deposited onto the airfoil portion, the overlayer bonded to the first outer surface, the second outer surface, and the bead outer surface.