William J. Boettinger, Dale E. Newbury, Nicholas W. Ritchie, Maureen E. Williams, Ursula R. Kattner, Eric Lass, Kil-Won Moon, Michael B. Katz
Differential thermal analysis (DTA) and microstructural and microprobe measurements of DTA and as-cast Ni-Re alloys with compositions between 0.20 and 0.44 mass fraction Re provide information to resolve differences in previously published Ni-Re phase diagrams. This investigation determines that the peritectic invariant, L + HCP FCC, occurs at 1561.1 C ± 3.4 C (1) with compositions of liquid, FCC and HCP phases of 0.283 ± 0.036, 0.436 ± 0.026 and 0.828 ± 0.037 mass fraction Re, respectively. Analysis of the microsegregation in FCC alloys yields a partition coefficient for solidification, k=1.54 ± 0.09 (mass frac. / mass frac.). Small deviation from Scheil behavior due to dendrite tip kinetics is documented.
Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science