TBC Dry Ice Stripping ITSC · B. Allegrini. Stripping applications on TBC systems - During MCrAlY...
9
International Thermal Spray Congress 2010 May 01 2010 – Singapore C. C. Giolli Giolli and and A. A. Scrivani Scrivani TBC Dry Ice Stripping L. L. Engl Engl and T. and T. Duda Duda B. Allegrini B. Allegrini
Transcript of TBC Dry Ice Stripping ITSC · B. Allegrini. Stripping applications on TBC systems - During MCrAlY...
International Thermal Spray Congress 2010May 01 2010 – Singapore
C.C. GiolliGiolli and and A. A. ScrivaniScrivani
TBC Dry Ice Stripping
L.L. Engl Engl and T.and T. DudaDuda
B. AllegriniB. Allegrini
Stripping applications on TBC systems
- During MCrAlY or TBC manufacturing: Stripping offers thepossibility to correct problems of coating quality(thickness, porosity, roughness, adhesion, etc.)
- During repair operations on serviced coated componen ts:The first operation on a component to repair after theincoming is the used coating stripping
Main characteristic of the stripping processes is to re movethe coating without damaging the base material of thecomponent (avoiding corrosion, geometrical variations , etc.)
Masking
Stripping
Sand Blasting
LPPS (BC) coating
APS (TBC) Coating
Dry Ice Stripping
APS (TBC) Coating
State-of-the-art Dry Ice Stripping
Heat Treatment
NEW
TBC Stripping and Rework Process Comparison
base material
bond coatingTBC
1)TBC as-coated
2)TBC stripping
3)TBC removed
Dry Ice Stripping Process: The mechanism
TBC
MCrAlY
Base Material
TBC
MCrAlY
Base Material
MCrAlY
Base Material
The Cryo-blasting is a sand-blasting method that uses i ce dry CO 2pellets and it is based on:
- Thermal Shock (In the case of TBC it needs component pre-heating)
- Cracking
- Mechanical cleaning (Kinetic energy from speed and sublim ation)
► No remaining TBC visual
Dry Ice Stripping Process: Visual results
Measured Ra (µm): 12
Measured Ra (µm): 10
► Roughness Ra ≥ 10
Dry Ice Blasting Equipment
Gun andNozzles
NozzlesGun
Industrialization and Validation
- Stripping of a real component, re-coating and TCF
- Fast Heating of the surface to be stripped on real
components
- Final validation from OEMs
Conclusion
- The new stripping process is able to remove TBC system without damaging the main characteristics of the MCrAlY bond coat as thickness and roughness.
- It was possible to re-coat the bond coat with TBC obtai ninghigh adhesion and capability to pass cycling oxydation.
Next Steps
- First Pilot Lot in Progress
- Tests on EB-PVD TBC
- Optimization of the process costs
Thank you for your kind attention
PhD, Carlo Giolli - R&D and Process Engineering - Turboco ating SpAVia Mistrali 7 - Rubbiano di Solignano - 43040 - Italy [email protected] - www.turbocoating.com
