TY - JOUR
T1 - Partition behavior of alloying elements and phase transformation temperatures in Co-Al-W-base quaternary systems
AU - Omori, Toshihiro
AU - Oikawa, Katsunari
AU - Sato, Jun
AU - Ohnuma, Ikuo
AU - Kattner, Ursula R.
AU - Kainuma, Ryosuke
AU - Ishida, Kiyohito
N1 - Funding Information:
The authors wish to thank Dr. Shinagawa for his experimental supports. This work was supported by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science and by the Global COE Program “Materials Integration (International Center of Education and Research), Tohoku University”, MEXT, Japan. Support from New Energy and Industrial Technology Development Organization (NEDO) is also acknowledged.
PY - 2013/1
Y1 - 2013/1
N2 - The phase equilibria among γ (A1), γ′ (L1 2), χ (D0 19), β (B2) and μ (D8 5) phases and the γ′ solvus and γ solidus temperatures were investigated in the Co-Al-W-based quaternary systems with alloying elements of Ti, V, Nb, Ta, Cr, Mo, Mn, Fe, Ni, Si, Zr, Hf, Ru and Ir by electron probe microanalysis (EPMA) using multiphase alloys and by differential scanning calorimetry (DSC). It was found that Ta, Nb, Ti, V, Mo and W are partitioned to the γ′ or χ phase rather than to the γ phase, while Cr, Mn and Fe tend to be distributed to the γ phase. The correlation between the partition coefficient of alloying elements between γ/γ′, γ/χ and γ/β phases and ab initio formation energy of Co 3X (L1 2), Co 3X (D0 19) and CoX (B2) was respectively obtained. It was also found that the γ′ solvus temperature increases by the addition of the γ′ former elements such as Ta, Nb and Ti, which decreases the γ solidus temperature.
AB - The phase equilibria among γ (A1), γ′ (L1 2), χ (D0 19), β (B2) and μ (D8 5) phases and the γ′ solvus and γ solidus temperatures were investigated in the Co-Al-W-based quaternary systems with alloying elements of Ti, V, Nb, Ta, Cr, Mo, Mn, Fe, Ni, Si, Zr, Hf, Ru and Ir by electron probe microanalysis (EPMA) using multiphase alloys and by differential scanning calorimetry (DSC). It was found that Ta, Nb, Ti, V, Mo and W are partitioned to the γ′ or χ phase rather than to the γ phase, while Cr, Mn and Fe tend to be distributed to the γ phase. The correlation between the partition coefficient of alloying elements between γ/γ′, γ/χ and γ/β phases and ab initio formation energy of Co 3X (L1 2), Co 3X (D0 19) and CoX (B2) was respectively obtained. It was also found that the γ′ solvus temperature increases by the addition of the γ′ former elements such as Ta, Nb and Ti, which decreases the γ solidus temperature.
KW - A. Intermetallics, miscellaneous
KW - B. Alloy design
KW - B. Phase diagrams
KW - E. Phase stability, prediction
KW - E. ab initio calculations
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U2 - 10.1016/j.intermet.2012.07.033
DO - 10.1016/j.intermet.2012.07.033
M3 - Article
AN - SCOPUS:84867042559
SN - 0966-9795
VL - 32
SP - 274
EP - 283
JO - Intermetallics
JF - Intermetallics
ER -