PT Journal
AU Amouyal, Y
   Mao, Z
   Seidman, DN
TI Phase partitioning and site-preference of hafnium in the gamma[sup [prime]](L1[sub 2])/ gamma(fcc) system in Ni-based superalloys: An atom-probe tomographic and first-principles study
SO Applied Physics Letters
PY 2009
BP 161909
VL 95
IS 16
DI 10.1063/1.3248146
DE ab initio calculations; aluminium alloys; atom probe field ion microscopy; binding energy; hafnium alloys; nickel alloys; phase diagrams; superalloys; tomography
AB Atom-probe tomography (APT) and first-principles calculations are employed to investigate the partitioning of Hf in the gamma[prime](L12)/gamma(fcc) phases in two multicomponent Ni-based superalloys. APT results indicate strong partitioning of Hf atoms to the gamma(fcc)-phase. We perform first-principles calculations of the substitutional formation energy of Hf for a model gamma(Ni)/gamma[prime](Ni3Al) system indicating Hf partitioning to the gamma[prime]-phase. Additional calculations of the Hf–Cr binding energy suggest, however, that Cr atoms, which partition to the gamma-phase, have a strong attractive binding energy with Hf atoms, thus predicting a reversal of the Hf partitioning in favor of the gamma-phase due to alloying with Cr.
ER