|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Gamma (FCC)/Gamma-Prime (L12) Co-Based Superalloys II
||Phase Stability, Element Partitioning and Atomic Site Location in Co-9Al-9W-2X Alloys
||Li Wang, Michael Oehring, Uwe Lorenz, Andreas Stark, Florian Pyczak
|On-Site Speaker (Planned)
In the Co–Al–W system the γ’–L1<SUB>2</SUB> phase can be stabilized by the addition of W and other alloying elements. In this study alloy samples with nominal compositions Co-9Al-9W-2X (X=Ti, Nb, V, Ta, Cr, Ni and Mo, at. %) were produced by arc-melting. The partitioning behavior of the alloying elements in γ and γ’ phases were investigated in dependence on temperature by energy-dispersive X-ray spectroscopy in the transmission electron microscopy in quenched specimens. In order to analyze the element occupation at atomic sites, atom location by channeling enhanced microanalysis technique was applied. The results from annealing experiments show that after 5000 hours at 900 °C, B<SUB>2</SUB>–CoAl and D0<SUB>19</SUB>–Co<SUB>3</SUB>W phases form in all alloys except Co-9Al-9W-2V. The amount, shape and type of these phases depend on the alloying element addition. Details about the partitioning behavior and the atomic site occupation of alloying elements in these alloys will be discussed in the presentation.