Abstract
Average ternary interdiffusion coefficients in Ni3Al with Ir additions have been determined using solid-to-solid diffusion couples annealed at 1200°C for 5 hours. Disc shaped alloy specimens were prepared by the vacuum arc melting at compositions of Ni-24Al, Ni-25Al, Ni-26Al, Ni-23.5Al-1Ir, Ni-24.5Al-1Ir, Ni-23Al-2Ir, Ni-23Al-2Ir, Ni-24Al-2Ir, Ni-23Al-3Ir (at.%). Surfaces of alloys were polished down to 1200 grit and diffusion couples were assembled in Si3N4 jig for initial bonding heat treatment at 1200°C for 0.5 hours. Additional diffusion anneal was carried out at 1200°C for 4.5 hours outside of Si3N4 jig so that diffusion couples can be water quenched. Concentration profiles of individual components were measured by electron probe microanalysis using pure standard of Ni, Al and Ir. Interdiffusion flux of individual component was determined directly from the experimental concentration profiles, and the moments of interdiffusion flux were examined to calculate the average ternary interdiffusion coefficients, D̃̄ij k either with Al or Ni as dependent component. Calculated interdiffusion coefficients suggest that Ir-alloyed Al2O3-forming oxidation resistant coatings would be beneficial to reduce the interdiffusion flux of Ni from superalloy substrates to the coating, and reduce the interdiffusion flux of Al from the coating to the superalloy substrate.
| Original language | English |
|---|---|
| Pages (from-to) | 637-642 |
| Number of pages | 6 |
| Journal | Defect and Diffusion Forum |
| Volume | 273-276 |
| Publication status | Published - 2008 Jan 1 |
| Externally published | Yes |
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Keywords
- High temperature alloys
- Intermetallics
- Ir
- L1
- NiAl
- Ternary interdiffusion
ASJC Scopus subject areas
- Radiation
- Materials Science(all)
- Condensed Matter Physics
Cite this
Ternary interdiffusion in L12-Ni3Al with Ir alloying addition. / Ode, M.; Garimella, N.; Ikeda, M.; Murakami, Hideyuki; Sohn, Y. H.
In: Defect and Diffusion Forum, Vol. 273-276, 01.01.2008, p. 637-642.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Ternary interdiffusion in L12-Ni3Al with Ir alloying addition
AU - Ode, M.
AU - Garimella, N.
AU - Ikeda, M.
AU - Murakami, Hideyuki
AU - Sohn, Y. H.
PY - 2008/1/1
Y1 - 2008/1/1
N2 - Average ternary interdiffusion coefficients in Ni3Al with Ir additions have been determined using solid-to-solid diffusion couples annealed at 1200°C for 5 hours. Disc shaped alloy specimens were prepared by the vacuum arc melting at compositions of Ni-24Al, Ni-25Al, Ni-26Al, Ni-23.5Al-1Ir, Ni-24.5Al-1Ir, Ni-23Al-2Ir, Ni-23Al-2Ir, Ni-24Al-2Ir, Ni-23Al-3Ir (at.%). Surfaces of alloys were polished down to 1200 grit and diffusion couples were assembled in Si3N4 jig for initial bonding heat treatment at 1200°C for 0.5 hours. Additional diffusion anneal was carried out at 1200°C for 4.5 hours outside of Si3N4 jig so that diffusion couples can be water quenched. Concentration profiles of individual components were measured by electron probe microanalysis using pure standard of Ni, Al and Ir. Interdiffusion flux of individual component was determined directly from the experimental concentration profiles, and the moments of interdiffusion flux were examined to calculate the average ternary interdiffusion coefficients, D̃̄ij k either with Al or Ni as dependent component. Calculated interdiffusion coefficients suggest that Ir-alloyed Al2O3-forming oxidation resistant coatings would be beneficial to reduce the interdiffusion flux of Ni from superalloy substrates to the coating, and reduce the interdiffusion flux of Al from the coating to the superalloy substrate.
AB - Average ternary interdiffusion coefficients in Ni3Al with Ir additions have been determined using solid-to-solid diffusion couples annealed at 1200°C for 5 hours. Disc shaped alloy specimens were prepared by the vacuum arc melting at compositions of Ni-24Al, Ni-25Al, Ni-26Al, Ni-23.5Al-1Ir, Ni-24.5Al-1Ir, Ni-23Al-2Ir, Ni-23Al-2Ir, Ni-24Al-2Ir, Ni-23Al-3Ir (at.%). Surfaces of alloys were polished down to 1200 grit and diffusion couples were assembled in Si3N4 jig for initial bonding heat treatment at 1200°C for 0.5 hours. Additional diffusion anneal was carried out at 1200°C for 4.5 hours outside of Si3N4 jig so that diffusion couples can be water quenched. Concentration profiles of individual components were measured by electron probe microanalysis using pure standard of Ni, Al and Ir. Interdiffusion flux of individual component was determined directly from the experimental concentration profiles, and the moments of interdiffusion flux were examined to calculate the average ternary interdiffusion coefficients, D̃̄ij k either with Al or Ni as dependent component. Calculated interdiffusion coefficients suggest that Ir-alloyed Al2O3-forming oxidation resistant coatings would be beneficial to reduce the interdiffusion flux of Ni from superalloy substrates to the coating, and reduce the interdiffusion flux of Al from the coating to the superalloy substrate.
KW - High temperature alloys
KW - Intermetallics
KW - Ir
KW - L1
KW - NiAl
KW - Ternary interdiffusion
UR - http://www.scopus.com/inward/record.url?scp=40949140656&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=40949140656&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:40949140656
VL - 273-276
SP - 637
EP - 642
JO - Diffusion and Defect Data. Pt A Defect and Diffusion Forum
JF - Diffusion and Defect Data. Pt A Defect and Diffusion Forum
SN - 1012-0386
ER -