Neutron diffraction study of the structure and low-temperature phase transformation in ternary NiAl+M (M=Ni,Fe,Co) alloys

Site-preferences and local spin-polarization of transition metal solute atoms in B2 type Ni–Al alloys

“…All the transition metal substitutions but Co prefer to replace Ni on the Al sublattice rather than on the Ni one. However, the energy difference for Co is so small that this in fact would lead to an almost random distribution of Co atoms on the B2 lattice, which is in full agreement with recent experiments, which indicates only ''slight'' [10] site preference for Co atoms [3,10]. It is also interesting to note that this weak Co site preference found in Ref.…”

“…[3] and Ref. [10] is different indicating, in particular, that relevant energy differences are indeed very small. These results for Cr, Mn, Fe and Co substitutions are also in agreement with the 32 atom super-cell calculations in Ref.…”

“…It was found that Co atoms prefer the Ni lattice sites and are non-magnetic so that their substitution has no effect on the lattice parameters and hardening behavior [7] (see also review [8]). Very recently the magnetism in these ternary alloys has been studied using Mö ssbauer spectroscopy [9] and neutron diffraction [10] techniques where it has been found that Co occupies almost equally the Ni and Al sites. Although the proposed scenario [7,8] explains the hardening behavior in case of Fe and Co substitutions the situation concerning Cr and Mn substitutions, which are magnetic, prefer Al sites, but lead to the less pronounce or even vanishing softening, remains unclear.…”

Sintering behaviour of NiAl–xTiC nanostructured composite powders (x = 0, 1, 3, 6 and 10 vf%) during hot pressing

“…Thus, the grain size is closely related to the sintering time and temperature. For instance, Guo et al 38 reported that the grain size of NiAl could grow from 8 to 100 nm after sintering at 1000°C for 2 h, while Yang et al 39 reported a grain growth from 15 to 200–500 nm after sintering at 1150°C for 2 h. However, in our work, the mean grain size of NiAl, resulting from SEM observation (Fig. 7 a 2), was ∼415 nm after sintering at 1180°C for 1 h under 48 MPa pressure that is almost similar with the mean grain size obtained by Xu et al (∼400 nm) at 1300°C for 1 h under 60 MPa pressure.…”

Thermal and physical properties of Al–Ni–Ru–M alloys

“…For completeness, these results, from Refs. [28][29][30][31][32][33][34][35][36][37][38][39][40][41][42], are provided in Table 3, although some of the experimental studies cited correspond only to equiatomic alloys. The last two columns show the results of BANN and MCAS simulations after annealing at room temperature.…”