Abstract
Boron additions to Ni-based superalloys are considered to be beneficial to the creep properties of the alloy, as boron has often been reported to increase grain boundary cohesion, increase ductility, and promote the formation of stable boride phases. Despite the importance, it is not well understood whether these improvements are associated with the presence of elemental boron or stable borides along the grain boundaries. In this investigation, two experimental powder-processed Ni-based superalloys containing elevated levels of Nb were found to exhibit increased solubility for B in the γ matrix when compared to similar commercial Ni-based superalloys. This resulted in an overall lower B concentration at grain boundaries that suppressed boride formation. As the predictive capability of CALPHAD database models for Ni-based superalloys have improved over the years, some discrepancies may still persist around compositionally heterogeneous features such as grain boundaries. Improved quantification of the characteristic partitioning of B as a function of the bulk alloy composition is required for understanding and predicting the stability of borides.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 729-739 |
| Number of pages | 11 |
| Journal | Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science |
| Volume | 49 |
| Issue number | 3 |
| DOIs | |
| State | Published - Mar 1 2018 |
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ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanics of Materials
- Metals and Alloys
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Comparison of Thermodynamic Predictions and Experimental Observations on B Additions in Powder-Processed Ni-Based Superalloys Containing Elevated Concentrations of Nb. / Antonov, Stoichko; Huo, Jiajie; Feng, Qiang; Isheim, Dieter; Seidman, David N; Sun, Eugene; Tin, Sammy.
In: Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science, Vol. 49, No. 3, 01.03.2018, p. 729-739.Research output: Contribution to journal › Article
TY - JOUR
T1 - Comparison of Thermodynamic Predictions and Experimental Observations on B Additions in Powder-Processed Ni-Based Superalloys Containing Elevated Concentrations of Nb
AU - Antonov, Stoichko
AU - Huo, Jiajie
AU - Feng, Qiang
AU - Isheim, Dieter
AU - Seidman, David N
AU - Sun, Eugene
AU - Tin, Sammy
PY - 2018/3/1
Y1 - 2018/3/1
N2 - Boron additions to Ni-based superalloys are considered to be beneficial to the creep properties of the alloy, as boron has often been reported to increase grain boundary cohesion, increase ductility, and promote the formation of stable boride phases. Despite the importance, it is not well understood whether these improvements are associated with the presence of elemental boron or stable borides along the grain boundaries. In this investigation, two experimental powder-processed Ni-based superalloys containing elevated levels of Nb were found to exhibit increased solubility for B in the γ matrix when compared to similar commercial Ni-based superalloys. This resulted in an overall lower B concentration at grain boundaries that suppressed boride formation. As the predictive capability of CALPHAD database models for Ni-based superalloys have improved over the years, some discrepancies may still persist around compositionally heterogeneous features such as grain boundaries. Improved quantification of the characteristic partitioning of B as a function of the bulk alloy composition is required for understanding and predicting the stability of borides.
AB - Boron additions to Ni-based superalloys are considered to be beneficial to the creep properties of the alloy, as boron has often been reported to increase grain boundary cohesion, increase ductility, and promote the formation of stable boride phases. Despite the importance, it is not well understood whether these improvements are associated with the presence of elemental boron or stable borides along the grain boundaries. In this investigation, two experimental powder-processed Ni-based superalloys containing elevated levels of Nb were found to exhibit increased solubility for B in the γ matrix when compared to similar commercial Ni-based superalloys. This resulted in an overall lower B concentration at grain boundaries that suppressed boride formation. As the predictive capability of CALPHAD database models for Ni-based superalloys have improved over the years, some discrepancies may still persist around compositionally heterogeneous features such as grain boundaries. Improved quantification of the characteristic partitioning of B as a function of the bulk alloy composition is required for understanding and predicting the stability of borides.
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U2 - 10.1007/s11661-017-4380-7
DO - 10.1007/s11661-017-4380-7
M3 - Article
VL - 49
SP - 729
EP - 739
JO - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
JF - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
SN - 1073-5623
IS - 3
ER -