Drilling of Cooling holes (Laser + EDM)
Laser Ablation and EDM Drill Holes in Thermal Barrier Coatings for Effective Cooling
The widespread use of thick TBC coatings on film cooled blades has made it necessary to develop systems for reinstating cooling holes in the blades after the coating has been applied.
We can also remove coating selectively as required, and reinstate cooling holes when necessary. And our probing technology means we can do all of these processes extremely accurately, and taking into account any variation from the casting process.
What is Cooling holes drilling?
The Combined Laser Ablation and EDM (Electrical Discharge Machining) System with probing and optical accessories is a cutting-edge technology designed for precision drilling and shaping of cooling holes on gas turbine blades and vanes. This advanced system offers unparalleled capabilities in the power generation industry, enabling efficient and high-quality manufacturing processes.This innovative system integrates two key processes:
1. Laser Ablation: The laser ablation component uses a high-intensity laser beam to drill through ceramic coatings on turbine blades and vanes. This contact-free, non-mechanical method ensures minimal material stress and precise hole placement, even through dense and thick ceramic coatings.
2. EDM Machining: Electrical Discharge Machining is employed to shape and refine cooling holes after the ceramic coating has been removed by the laser. This process delivers exceptional precision, creating complex hole geometries while maintaining the structural integrity of the components.
Additionally, the system includes probing and optical accessories for real-time monitoring and quality control. Probing technology ensures accurate hole depth and diameter measurements, while optical accessories enhance visibility and allow for in-process adjustments.
One standout feature of this system is its ability to re-open holes after the ceramic coating is applied, guaranteeing optimal cooling performance.
Cooling holes drilling is used in:
Advantages of Cooling holes drilling
For critical TBC coated components, laser ablation performs no-contact ceramic machining that minimizes the stress applied on the ceramic top coat, preserving the integrity of delicate microstructures and critical bond coat-top coat interfaces. EDM drilling guarantees the accurate execution of complex hole shapes as designed by fluid dynamic engineers.
The FSNA machines are supplied with a camera system that allows easy adaptive programming of IGT repair components where existing holes need to be reopened after coating or weld repair.
An integrated camera and lighting system identifies the location of the holes already drilled on the part. Accurate reopening can restore the original dimension of the hole avoiding damages, clogging, and imperfections introduced by mechanical operations.