Protective Shielding for Turbine Cooling Hole TBC Coating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for applying thermal barrier coatings (TBCs) to turbine components with cooling holes result in poor performance due to partial filling of holes and unpredictable coating application, often requiring additional manufacturing steps that can leave critical regions unprotected.
Innovation Solution
A method involving the use of protective shields formed during additive manufacturing, which block coating deposition in cooling flow passages and are later removed to allow fluid flow, ensuring efficient coating application and reduced post-process machining.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If cooling holes are drilled in bare metal and then coated with TBC, then the component can be manufactured, but the cooling holes suffer from partial filling with TBC and changes to the desired shape of the hole
Solution Approach 1:
Protective shields are installed in the cooling holes before TBC application to prevent coating material from entering the holes. This preliminary protective action ensures that the cooling holes maintain their desired shape and are not partially filled with TBC, thereby preserving both manufacturing precision and cooling performance
Solution Approach 2:
The protective shields act as intermediary elements between the TBC coating process and the cooling holes. These shields temporarily occupy the cooling hole space during coating, preventing direct interaction between TBC material and the cooling holes, thus maintaining hole integrity while allowing comprehensive surface coating
2Reliability
If coating is applied first and then cooling holes are drilled, then the component surface is protected, but an additional manufacturing step is required to remove coating and critical regions may lack TBC protection
Solution Approach 1:
Protective shields are preliminarily positioned in cooling holes before TBC application, enabling the coating process to proceed without requiring subsequent removal steps. This preliminary arrangement ensures complete TBC protection on all surfaces while preventing coating material from entering cooling holes, eliminating the need for additional post-coating manufacturing steps
Solution Approach 2:
The protective shields serve a dual function: they protect cooling holes from TBC intrusion during coating application, and they automatically ensure that critical regions remain unprotected by coating material. This self-service mechanism eliminates the need for separate operations to remove coating from cooling holes or to protect critical areas
3Manufacturing precision
If cooling holes are masked before coating or coating is removed from cooling holes after application, then coating can be applied, but the process is complex and time-consuming
Solution Approach 1:
Protective shields serve as intermediary elements that remain in place during the entire TBC application process, providing continuous protection to cooling holes. This intermediary approach eliminates the need for repeated masking and unmasking operations, thereby maintaining coating precision while significantly improving process efficiency and reducing manufacturing time
Solution Approach 2:
The protective shields enable continuous TBC application without interruption for masking or removal operations. The shields remain in place throughout the coating process, allowing the coating operation to proceed continuously and efficiently while maintaining precise control over where the coating is applied, thereby improving productivity without sacrificing coating precision
Data Source
AI summary
A method of depositing a coating on a component of a turbine engine. The method includes forming a turbine component including at least one cooling flow passage in fluid communication with an aperture on a surface of the turbine component. A protective shield is formed on an inner surface of the at least one cooling flow passage and extending to an exterior of the turbine component via the aperture. During a coating process, the protective shield is configured to block the coating from being deposited in the at least one cooling flow passage via the aperture. Subsequent to coating, at least a portion of the protective shield is removed to provide for passage of a cooling fluid flow in the at least one cooling flow passage. The cooling fluid flow exits the turbine component through the aperture. A turbine component employing user of the protective shield is also disclosed.