•Customer
MQTD, Avaiation
•Project Objective: process
High quality & cost effective coating
•Operating condition:
Stage 1 Turbine Blades (HPT)
•Substrate:
Ni-base Superalloy/SX (N5)
EB-PVD
Advantages •Strong adherence, wear resistance •Dense, atom/ion evaporation •Columnar grain
Drawbacks •High temp •Vacuum •High cost
Applications •Topcoat/MCrAlY •Tool coating •Functional film
•Centrifugal force, airflow impact and vibration
•Oxidation and erosion
•Thermal Mechanical Cycling
HPT blade lifetime: •Currently: 16,000 hours (2~3years) •Expected: 30,000+ hours
homogeneity, Cost estimation
5/ Confidentialmperature vs. Lifetime
6/ Confidential/
8/19/2020
TBC Structure & Failure
Layer
TBC top coat
Technologies Applications • Key Players • Our Approaches • Appendix
4/ Confidential/
8/19/2020
Project Background
Develop cost-effective aluminide and TBC coating on Ni based alloys
Applications •Topcoat APS •Bond coat LPPS •Corrosion/Wear resistance
9/ Confidential/
8/19/2020
Front Runners
Academic
USA USA USA Germany Ukraine USA
Tech Benchmark Turbine Blades Coating
High Temp Protective Coating tech for SX Turbine Blades
1/ Confidential/
8/19/2020
Operating Condition of Turbine Blades
-
Bond Coat
Aluminide, Solid
adhesion, transition
Gradient layer, Phase stability
<50100
NiAl PtAl MCrAlY
CVD,PackCem Plating, CVD VPS,HVOF,EB
• Rupture: CTE mismatch, sharp thermal gradient, thermomechanical cycling
TGO
Function
Thermally insulating
Oxidation resistance
Requirement
Low k, high CTE, porous morphology
t/µm
100~ 400
Dense alumina <1-10
Material YSZ Al2O3
Technique APS, EBPVD
8/ Confidential/
8/19/2020
Plasma Spraying
Advantages •Lamellar strip •Low k •Composition control •Thickness capability
Drawbacks •Partially melted particle •Cracks •Porosities
• Delamination: TGO, degradation of bond coating,
• Incipient crack nucleate&grow: thermomechanical fatigue
• Inclusion: Processing method derived
• FOD(foreign object damage), CMAS(Calcia, Magnesia, Alumina and Silica) 7/ Confidential/ 8/19/2020
Rough estimate of cost: •A set of blades for HPT: 1.5M gbp •Refurbishment: 0.3M to 1M gbp
3/ Confidential/
8/19/2020
Outline
• Project Charter (N Blocker) • TBC System • Current Tech
•Coating: (Al2O3)
Bond Coat (NiAl, MCrAlY, PtAl) & TGO TBC (8YSZ)
•Evaluation Criteria:
Thermal cycling test
Microstructure
* Adhesive strength, Oxidation resistance, Phase stability, Thickness
Fan LPC HPC HPT LPT
Journey through a jet engine
2/ Confidential/
8/19/2020
Data for Turbine Blades
•High Temperature: ~1400oC
•High Pressure: ~40atm
•High Rotating Speed: ~11,000rpm