Untitled

Abstract

In this paper, thermal expansion studies of the fcc binary alloys Ni 1−x M x (M = Cr, Mo, Re) for x 0.25 from ambient temperature to 900 K are reported. The results of the changes in the lattice constant a 0 and the coefficient of thermal expansion α with x are compared with the recent molecular dynamics (MD) simulations of Mei, Cooper and co-workers providing the first detailed comparison of this type between experiment and theory over an extended temperature and composition range. For NiMo, good agreement is obtained between experiment and theory for the increase in a 0 with x, the decrease of α with x, and the temperature variation of α. For NiCr, the agreement is considered to be fair for the increase of a 0 with x, the decrease of α with x, and the α versus temperature data. For the NiRe alloys, the observed decrease of α with x (say near 900 K) is the opposite to the MD simulation prediction of an increase of α with x in this system, although the theoretical predictions at higher temperatures (say 1500 K) tend to be in line with the experimental observations at 900 K. It is argued that effects of magnetic ordering are not responsible for the observed departure from the MD simulation prediction in the NiRe system. A rule-of-mixtures equation gives a linear decrease of α with x for the alloys, in qualitative agreement with the experimental results.

Thermal Expansion of Ni–W, Ni–Cr, and Ni–Cr–W Alloys Between Room Temperature and 800 °C

“…3. The weak dependence on chromium content observed for Ni-Cr TECs is in accordance with data reported in the literature [10]. Judging by the atomic concentration, tungsten produces a much stronger effect on the TEC than chromium.…”

Lattice Parameters and Local Lattice Distortions in fcc-Ni Solutions

“…In the cases in which the data for pure Ni were not available, the linearly extrapolated value for pure Ni is used. The experimental data for binary Ni solid solutions containing Al, [13][14][15][16] Co, [12,[17][18][19] Cr, [11,12,[20][21][22][23] Hf, [23] Mo, [23][24][25][26][27][28] Nb, [23,[29][30][31][32][33] Re, [28,34] Ru, [35][36][37] Ta, [23,38] Ti, [11,23,[39][40][41][42] and W [23,43] are used for comparison.…”

“…Experimental data: ,, [23] ·, [24] 4, [25] h, [26] e, [27] and +. [28] Fig. 9-Lattice parameter changes in Ni (c) solid solutions with additions of Ru (S N = 0.0055 Å for Ru).…”

Effective interactions and atomic ordering in Ni-rich Ni-Re alloys

“…The theoretical concentration dependence of the lattice parameters at 0 K in Ni-Re alloys is slightly steeper than the experimental one at room temperature (RT) [11,51,53]. The latter is most probably related to the fact that GGA noticeably overestimates the equilibrium volume of 5 d metals [57][58][59].…”

“…The lattice parameters of Ni-Re alloys have been previously obtained experimentally and theoretically in a number of investigations [11,[51][52][53][54]. In Fig.…”