Thermophysical properties of Ni-containing single-phase concentrated solid solution alloys

Abstract

Temperature dependent thermophysical properties, including specific heat capacity, lattice thermal expansion, thermal diffusivity and conductivity, have been systematically studied in Ni and eight Ni-containing single-phase face-centered-cubic concentrated solid solution alloys, at elevated temperatures up to 1273 K. The alloys have similar specific heat values of 0.4 -0.5Jg -1 K -1 at room temperature, but their temperature dependence varies greatly due to Curie and K-state transitions. The lattice, electronic, and magnetic contributions to the specific heat have been separated based on first-principles methods in NiCo, NiFe, Ni-20Cr and NiCoFeCr. The alloys have similar thermal expansion behavior, with the exception that NiFe and NiCoFe have much lower thermal expansion coefficient in their ferromagnetic state due to magnetostriction effects. Calculations based on the quasi-harmonic approximation accurately predict the temperature dependent lattice parameter of NiCo and NiFe with less than 0.2% error, but underestimated that of Ni-20Cr by 1%, compared to the values determined from neutron diffraction. All the alloys containing Cr have very similar thermal conductivity, which is much lower than that of Ni and the alloys without Cr, due to the large magnetic disorder.

Single-Phase Concentrated Solid-Solution Alloys: Bridging Intrinsic Transport Properties and Irradiation Resistance

“…The fraction of lattice contribution to the total thermal conductivity is shown in Figure 3, for a series of Ni-containing SP-CSAs. The lattice and electronic contributions are comparable for most NiCr-alloys (Chou et al, 2009;Jin et al, 2016dJin et al, , 2017. Again, Ni-20Cr binary alloy has basically the same behavior, compared with the other quinary alloys.…”

Effects of chemical alternation on damage accumulation in concentrated solid-solution alloys

“…Moreover, recent neutron diffraction studies 48 have revealed only fcc peaks for the Ni 80 Cr 20 alloys at room temperature without superlattice peaks (e.g. Ni 2 Cr), confirming a single-phase solid solution.…”

Origin of high strength in the CoCrFeNiPd high-entropy alloy

“…These results are driving investigation of a wide range of new alloys, including 'doping' with low concentrations of additional elements and non-dilute additions to widen alloy families. For instance, the Co-Cr-Fe-Mn-Ni family of fcc Cantor alloys has been studied over wider ranges of compositions [5] and extended with the addition of dilute Al [6][7][8], non-dilute V [9,10], and replacement of Mn with Pd to create CoCrFeNiPd [11][12][13][14].…”