Interdiffusion analysis for NiAl versus superalloys diffusion couples

Perez, E.; Patterson, Travis; Sohn, Yong Ho

doi:10.1007/bf02736569

“…The simulation also predicts the formation of σ-phase close to the original interface as shown in Figure 16. The formation of many small precipitates rich in refractory elements was reported in Perez et al [29]. The peak in the experimentally determined W concentration profile (see Figure 15) further supports the precipitation of TCP phases such as σ-phase close to the initial interface.…”

Section: Examples Of Calculation and Simulationsupporting

confidence: 78%

“…Table 1 gives the initial concentration (at. %) for the NiAl-coating and GTD111 superalloy reported in Perez et al [29]. To simplify the calculation some elements with low concentrations reported in the experimental study are ignored in the present simulation, namely C (0.48), Mo (0.97) and Ta (0.89), while Ni is the balance.…”

Section: Examples Of Calculation and Simulationmentioning

confidence: 99%

“…Bypassing the limitation of the disperse diffusion model which only considers diffusion in a single continuous matrix phase, the more recently developed, so-called homogenization model, by Larsson and Engström [28] takes into account diffusion in all the stable solution phases, including the γ-, β-and γ´-phases. Using electron probe microanalysis (EPMA) Perez et al [29] measured the concentration profiles resulting from interdiffusions in solidto-solid diffusion couples between single phase β-NiAl and various multiphase (γ + γ´) commercial Ni-base superalloys that were annealed at 1050°C for 96h. In the present paper a simulation is presented comparing with one of their experimental diffusion couples formed by joining a single phase β-NiAl with the GTD111 superalloy.…”

Section: Examples Of Calculation and Simulationmentioning

confidence: 99%

See 1 more Smart Citation

The Development and Validation of a New Thermodynamic Database for Ni‐Based Alloys

Bratberg¹,

Mao

²

,

Kjellqvist³

et al. 2012

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Thermodynamic databases developed using the CALPHAD method has been successfully applied to the modeling and simulation of Ni based superalloys for more than fifteen years. Such databases when combined with suitable software, such as Thermo-Calc, can be used for accelerating alloy design as well as improving understanding of existing alloys in terms of their processing and in-service behavior. Additionally, such databases are also essential to the modeling of microstructural evolution using methods such as phase field or mean field approaches.A new thermodynamic database, TCNI6, has been developed for Ni-based superalloys based on the critical evaluation, using the CALPHAD method, of all the constituent binary systems across their full range of composition and many of the ternary systems containing Ni, as well as a number of other key ternary systems. The database has also been validated where possible against higher order systems as well.Together with the new mobility database, MOBNI3, which contains descriptions for the atomic mobility for respectively the γ (A1), γ' (L1 2 ), α (A2), β (B2) and liquid phases, TCNI6 can be used with software such as DICTRA to predict different kinetic aspects taking all relevant phases into account, e.g. the simulation of interdiffusion across Ni-based coatings.A new user friendly computational tool, TC-PRISMA, which simulates the kinetics of precipitation processes, is demonstrated utilizing these new databases and combined with interface property data. Engineering applications of precipitation modelling are validated against experimental data.

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“…Published literature shows clearly shows that the solubility of Cr is higher in Ni-rich NiAl [70e72] and that Cr, when incorporated into beNiAl coatings in the correct amounts, decreases the interdiffusion coefficients of Al and Co [73e75]. Perez et al [76], who investigated interdiffusion behavior in NiAl/superalloy diffusion couples, observed that superalloys containing higher concentrations of Cr, Mo, and Ti had higher effective Al diffusivity into the superalloy while superalloys containing Ta, W and Al showed lower effective Al diffusivity. Furthermore, numerous computational and experimental studies have also detailed the influences of NiAl composition and stoichiometry on Ni and Al diffusion coefficients [77,78].…”

Section: Coating/substrate Interdiffusionmentioning

confidence: 98%

Influences of annealing and hafnium concentration on the microstructures of sputter deposited β-NiAl coatings on superalloy substrates

Bestor

¹

,

Martens

²

,

Holler

³

et al. 2010

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“…Using electron probe microanalysis (EPMA) Perez et al [29] measured the concentration profiles resulting from interdiffusions in solidto-solid diffusion couples between single phase β-NiAl and various multiphase (γ + γ´) commercial Ni-base superalloys that were annealed at 1050°C for 96h. In the present paper a simulation is presented comparing with one of their experimental diffusion couples formed by joining a single phase β-NiAl with the GTD111 superalloy.…”

Section: Kmentioning

confidence: 99%

The Development and Validation of a New Thermodynamic Database for Ni-based Alloys ................................... 803

Bratberg¹,

Mao²,

Kjellqvist³

et al. 2012

Superalloys 2012 (Twelfth International Symposium)

5

0

View full text Add to dashboard Cite

Thermodynamic databases developed using the CALPHAD method has been successfully applied to the modeling and simulation of Ni based superalloys for more than fifteen years. Such databases when combined with suitable software, such as Thermo-Calc, can be used for accelerating alloy design as well as improving understanding of existing alloys in terms of their processing and in-service behavior. Additionally, such databases are also essential to the modeling of microstructural evolution using methods such as phase field or mean field approaches.A new thermodynamic database, TCNI6, has been developed for Ni-based superalloys based on the critical evaluation, using the CALPHAD method, of all the constituent binary systems across their full range of composition and many of the ternary systems containing Ni, as well as a number of other key ternary systems. The database has also been validated where possible against higher order systems as well.Together with the new mobility database, MOBNI3, which contains descriptions for the atomic mobility for respectively the γ (A1), γ' (L1 2 ), α (A2), β (B2) and liquid phases, TCNI6 can be used with software such as DICTRA to predict different kinetic aspects taking all relevant phases into account, e.g. the simulation of interdiffusion across Ni-based coatings.A new user friendly computational tool, TC-PRISMA, which simulates the kinetics of precipitation processes, is demonstrated utilizing these new databases and combined with interface property data. Engineering applications of precipitation modelling are validated against experimental data.

show abstract

Interdiffusion analysis for NiAl versus superalloys diffusion couples

Cited by 27 publications

References 19 publications

The Development and Validation of a New Thermodynamic Database for Ni‐Based Alloys

The Development and Validation of a New Thermodynamic Database for Ni‐Based Alloys

Influences of annealing and hafnium concentration on the microstructures of sputter deposited β-NiAl coatings on superalloy substrates

The Development and Validation of a New Thermodynamic Database for Ni-based Alloys ................................... 803

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