Partition behavior of alloying elements and phase transformation temperatures in Co-Al-W-base quaternary systems

作者：Omori Toshihiro^*; Oikawa Katsunari; Sato Jun; Ohnuma Ikuo; Kattner Ursula R; Kainuma Ryosuke; Ishida Kiyohito

来源：Intermetallics, 2013, 32: 274-283.

DOI：10.1016/j.intermet.2012.07.033

• Intermetallics
• miscellaneous
• Phase diagrams
• Alloy design
• Phase stability
• prediction
• ab initio calculations

The phase equilibria among gamma (Al), gamma' (L1(2)), chi (D0(19)), beta (B2) and mu (D8(5)) phases and the gamma' solvus and gamma 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 gamma' or chi phase rather than to the gamma phase, while Cr, Mn and Fe tend to be distributed to the gamma phase. The correlation between the partition coefficient of alloying elements between gamma/gamma', gamma/chi and gamma/beta phases and ab initio formation energy of Co3X (L1(2)), Co3X (D0(19)) and CoX (B2) was respectively obtained. It was also found that the gamma' solvus temperature increases by the addition of the gamma' former elements such as Ta, Nb and Ti, which decreases the gamma solidus temperature.

• 出版日期2013-1