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

Determination of the transition to the high entropy regime for alloys of refractory elements

“…These calculations involve the determination of the zero temperature equation of state of the pure solids (for the single element parameters) and the calculation of the energy of formation of the metastable B2 structures between the different binary combinations of all elements, from which the perturbative parameters, D AB and D BA , for every A-B pair can be obtained [5,6]. A preliminary modeling study of W-Nb-Mo-Ta and W-Nb-Mo-Ta-V alloys [45] reproduces the basic experimental findings in terms of phase structure and, consequently, validates the parameterization of the method as used in this work.…”

“…For brevity, we direct the reader to Refs. [1][2][3] for the necessary details of the method, the parameterization needed to perform the simulations, and operational equations as well as previous BFS applications to multicomponent systems [3][4][5][6][7]. The traditional Monte Carlo algorithm considers all possible swaps between atomic positions, accepted or rejected depending on a probabilistic factor e À DE kT , where DE is the change in energy upon the atomic pair exchange.…”

“…This effort is thus aimed at answering the question of what is the amount of each constituent needed to ensure HEA behavior, streamlining the trial and error approach characteristic of complex alloy development. The approach is based on the application of the Bozzolo-Ferrante-Smith (BFS) method for alloys [1,2] which is ideally suited for the atomistic study of multicomponent systems, as shown in previous applications to rather complex systems [3][4][5][6][7]. Therefore, based on experimental results and a straightforward modeling effort, it is the purpose of this work to introduce simple concepts that could allow for the determination of markers for such transition.…”

Thermal and physical properties of B2 Al–Ir–X (X=Ni, Ru, Pd, Co, Fe) alloys

“…These studies have been recently extended to consider quaternary Al-Ni-Ru-M systems (with M ¼ Ir, among others) [13][14][15]. In line with all the aforementioned studies, some work has been done on the Al-Ir-Pd and Al-Ir-Os ternary systems to investigate alternative options for improving the melting point of Ir-based materials, as well as a more complete understanding of ternary additions of the platinum metals group [16,17].…”

Study on Ru2Al5 prepared by mechanical alloying and subsequent heat treatment

“…After Fleisher [8] identified the potential of the RuAl phase for high temperature applications, the Al-Ru system has been studied extensively [9][10][11][12][13][14][15][16][17][18][19][20]. According to the latest experimental research, there are six stable intermetallic phases in the Al-Ru system, namely RuAl 6 , Ru 4 Al 13 , Ru 2 Al 5 , RuAl 2 , Ru 2 Al 3 and RuAl [14].…”