Modelling of Microstructural EvolutionModelling of ... · Modelling of Microstructural...
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Modelling of Microstructural Evolution Modelling of Microstructural Evolution in Coated Superalloy Systems M. Karunaratne and R. C. Thomson The model can be used to design coatings with specific features such as high β phase fraction for long term oxidation resistance. Fig 5 shows New Coatings Design Fig 3 shows how the model can accurately predict the experimentally determined concentration profiles in an Amdry997 coated Concentration Predictions High temperature components used in gas- turbine engines are commonly made from nickel- based superalloys with MCrAlY (M=Ni, Co) Introduction model predictions for the retained β wt.% as a function of Cr and Co in hypothetical coatings containing 12.5 wt.% Al which have been deposited on IN738 substrate and after service at 900 o C for 1000 h. CMSX4 superalloy sample. surface coatings. Shown in Fig 1 are some of the changes found in a typical coated superalloy substrate during service. Figure 5 Figure 3 The capability of the model to simulate microstructure evolution precisely is demonstrated in Fig 4 where model predicted Microstructure Prediction Figure 1 This model can also be used to simulate modern concepts such as multi-layer coatings. Such systems consist of different layers performing specific functions and are predicted to outperform conventional coatings. Comparison in Fig 6 shows that the concentration profiles from an experimental Future Work phase profiles are compared to experimentally observed features in an Amdry997 coated CMSX-4 superalloy sample aged at 950 o C for 190h. These features include β phase recession near oxidation and interdiffusion zone boundaries, the presence of γ′ rich bands near oxidation and coating/substrate interfaces and the occurrence of TCP/carbide phases at various The 1-D diffusion model described here* is based on a finite-difference diffusion calculation which also combines aspects of equilibrium thermodynamics and oxidation modelling. The simulation model is capable of predicting evolution of the chemistry of the The Model Al-rich zone For enhanced oxidation & type I protection Cr enriche d zone For enhanced type II hot corrosion protection MCrAlY coating Standard oxidation and hot corrosion protection Alloy substrate 50 60 70 Al Cr Co lement concentration profiles from an experimental multilayer coating system can be predicted accurately by the simulation model. β depleted zone 70 80 Coating Substrate γ′ layer Coating-Substrate interface region Surface region Oxide scale γ β γ′ γ′ γ′ γ+γ′ γ′ rich layer locations. coating-substrate system and the associated microstructural transformations. It can be used as a tool for estimating the lifetime of blade components. Fig 2 is a schematic diagram of the model. Experimental profiles (Experimental and characterisation work by J. R. 0 10 20 30 40 0 50 100 150 200 250 300 Depth below coating surface [ μm ] Co Ni Weight % of e β Oxide Scale γ′ σ / μ 0 10 20 30 40 50 60 0 50 100 150 200 250 300 Distance (μm) Weight % of phase γ γ′ β σ μ β depletion Nicholls et al, Cranfield University is acknowledged) Figure 4 10μm 2μm σ / μ (light phase) β depletion σ / μ γ+γ′ Acknowledgements: • We would like to acknowledge the support of EPSRC through the Supergen 2 programme (GR/S86334/01 and EP/F029748) d th f ll i i Al t P Figure 2 The simulation code was written in the C language using MPI for parallelisation and run at the High Performance Computer Facility at Loughborough University typically Figure 6 Simulated profiles EP/F029748) and the following companies; Alstom Power Ltd., E.ON Engineering Ltd., Doosan Babcock Energy Ltd., National Physical Laboratory, QinetiQ, Rolls-Royce plc, RWE npower, Sermatech Ltd., Siemens Industrial Turbomachinery Ltd. and TATA Steel for their valuable contributions to the project. • Micrographs by Sarah Ogden * A multicomponent diffusion model for the prediction of microstructural evolution in coated Ni-based superalloy systems. M. S. A. Karunaratne, S. L. Ogden, S. D. Kenny and R. C. Thomson; Materials Science & Technology 25(2): p 287-299, 2009 using 16 processors.
Transcript of Modelling of Microstructural EvolutionModelling of ... · Modelling of Microstructural...
Modelling of Microstructural EvolutionModelling of Microstructural Evolution in Coated Superalloy Systems
M. Karunaratne and R. C. Thomson
The model can be used to design coatings with specific features such as high β phase fraction for long term oxidation resistance. Fig 5 shows
New Coatings DesignFig 3 shows how the model can accurately predict the experimentally determined concentration profiles in an Amdry997 coated
Concentration PredictionsHigh temperature components used in gas-turbine engines are commonly made from nickel-based superalloys with MCrAlY (M=Ni, Co)
Introduction
g gmodel predictions for the retained β wt.% as a function of Cr and Co in hypothetical coatings containing 12.5 wt.% Al which have been deposited on IN738 substrate and after service at 900oC for 1000 h.
p yCMSX4 superalloy sample. surface coatings. Shown in Fig 1 are some of the
changes found in a typical coated superalloy substrate during service.
Figure 5
Figure 3
The capability of the model to simulate microstructure evolution precisely is demonstrated in Fig 4 where model predicted
Microstructure PredictionFigure 1
This model can also be used to simulate modern concepts such as multi-layer coatings. Such systems consist of different layers performing specific functions and are predicted to outperform conventional coatings. Comparison in Fig 6 shows that the concentration profiles from an experimental
Future Workphase profiles are compared to experimentally observed features in an Amdry997 coated CMSX-4 superalloy sample aged at 950oC for 190h. These features include β phase recession near oxidation and interdiffusion zone boundaries, the presence of γ′ rich bands near oxidation and coating/substrate interfaces and the occurrence of TCP/carbide phases at various
The 1-D diffusion model described here* is based on a finite-difference diffusion calculation which also combines aspects of equilibrium thermodynamics and oxidation modelling. The simulation model is capable of predicting evolution of the chemistry of the
The Model
Al-rich zone
For enhanced oxidation &
type I protection
Cr enriched zone
For enhanced type II hot corrosion protection
MCrAlY coatingStandard oxidation and hot
corrosion protectionAlloy substrate
506070
AlCrCole
men
t
concentration profiles from an experimental multilayer coating system can be predicted accurately by the simulation model.
β depleted zone70
80Coating Substrate
γ′ layer
Coating-Substrate interface region
Surface region
Oxide scale
γβ
γ′
γ′
γ′
γ+γ′
γ′ rich layer
locations.p g ycoating-substrate system and the associated microstructural transformations. It can be used as a tool for estimating the lifetime of blade components. Fig 2 is a schematic diagram of the model.
Experimental profiles(Experimental and characterisation work by J. R.
010203040
0 50 100 150 200 250 300
Depth below coating surface [ μm ]
CoNi
Wei
ght %
of e
γ′
βOxideScale
γ
γ′
γ+γ′γ′
σ / μ
10μm 2μm
TCP
0
10
20
30
40
50
60
0 50 100 150 200 250 300Distance (μm)
Wei
ght %
of p
hase
γ γ′ β σ μ
β depletionNicholls et al, Cranfield University is acknowledged)
Figure 4
10μm 2μm
σ / μ(light phase)
β depletion
σ / μγ+γ′
Acknowledgements: • We would like to acknowledge the support of EPSRC
through the Supergen 2 programme (GR/S86334/01 and EP/F029748) d th f ll i i Al t P
Figure 2
The simulation code was written in the C language using MPI for parallelisation and run at the High Performance Computer Facility at Loughborough University typically
Figure 6Simulated profiles
EP/F029748) and the following companies; Alstom Power Ltd., E.ON Engineering Ltd., Doosan Babcock Energy Ltd., National Physical Laboratory, QinetiQ, Rolls-Royce plc, RWE npower, Sermatech Ltd., Siemens Industrial Turbomachinery Ltd. and TATA Steel for their valuable contributions to the project.
• Micrographs by Sarah Ogden
* A multicomponent diffusion model for the prediction of microstructural evolution in coated Ni-based superalloy systems. M. S. A. Karunaratne, S. L. Ogden, S. D. Kenny and R. C. Thomson; Materials Science & Technology 25(2): p 287-299, 2009
using 16 processors.
