The local atomic order of a Ni–12.7 at.% Al alloy quenched from 1323 K

Role of intermetallic nanoparticles in radiation damage of austenitic Fe–Ni-based alloys studied by positron annihilation

“…Thicker samples (by thickness %0.25 mm) were used in this treatment series than in other series (%0.15 mm). As is shown in [31,32], because of low thermal conductivity and a finite thickness of the sample, the homogeneous nucleation of ordered Ni 3 Al phase of high density (%10 26 m À3 ) during a quenching was possible. Thus, there are Ni 3 Al precipitate particles in the quenched alloy.…”

Effects of intermetallic nanoparticles on the evolution of vacancy defects in electron-irradiated Fe–Ni–Al material

“…This feature points to the initial stage of the alloy decomposition. It is known [36,37] that nuclei of a high-density (∼10 20 cm −3 ) ordered Ni 3 Al phase may be formed owing to a low thermal conductivity and a finite thickness of samples during quenching from the homogenization temperature. Indeed, thicker (∼0.25 mm) samples were used in this treatment series.…”

Influence of relaxation of the atomic order in f.c.c.‐Ni–Al alloys on X‐ray diffuse scattering

“…Certainly, this phenomenon is conditioned by the considerable interactions of Ni and Al atoms, and, as a consequence, by specific spatial distribution of alloy constituents (i.e., formation of the superstructure). Therefore, for instance, in the Ni‐enhanced region (with Al content of c Al ≅ 25 at.%) based on the disordered f.c.c.‐Ni–Al solution, the L 1 2 ‐type ordered substitutional superstructure (“cubic Ni 3 Al”) is formed 1–13. With Al content of c Al ≅ 50 at.%, the B 2‐ or L 1 0 ‐type superstructures (“layered NiAl”) are formed 1.…”

“…At the same time, the quantitative method of studying interatomic correlation effects in alloys is only X‐ray (or thermal neutron) diffuse scattering. Formerly, this method was used for investigation of the equilibrium short‐range order (SRO) states of Ni–Al solid solutions of several compositions quenched from different temperatures, T q : Ni–7.3 and 10.5 at.% Al ( T q = 673 and 823 K) 8, Ni–8.9 at.% Al ( T q = 775 K) 9, 10, Ni–9.5 and 9.8 at.% Al ( T q = 973 K) 7, Ni–12.7 at.% Al ( T q = 1323 K) 6 as well as Ni–46.2, 50.04, 58.2 at.% Al ( T q = 1473 K) 5. In those studies, the Warren–Cowley SRO parameters, Fourier components (and originals) of static and dynamic displacements of atoms at the lattice sites 10–12, and the total “mixing” energies of Ni and Al atoms have been estimated.…”