Investigation of phases in Al23Co15Cr23Cu8Fe15Ni16 and Al8Co17Cr17Cu8Fe17Ni33 high entropy alloys and comparison with equilibrium phases predicted by Thermo-Calc

On the Path to Optimizing the Al-Co-Cr-Cu-Fe-Ni-Ti High Entropy Alloy Family for High Temperature Applications

“…Figure 4c shows a STEM image of Alloy 3. This microstructure is close to the one in Alloy 1: an Al-Ni rich matrix of B2 structure (A) with 10-200 nm Cu rich precipitates (C) and cuboidal Cr-Fe rich platelets of a disordered bcc structure (B) can be observed [17]. As has been predicted by ThermoCalc in Figure 2, these three alloys are characterized by a global bcc structure.…”

“…Specimens for 3D-AP observations were first cut from a foil into rods of 0.25ˆ0.25ˆ10 mm 3 and then thinned down to a tip diameter of about 50 nm in two steps, using a final polishing solution of 98% butoxyethanol and 2% perchloric acid and a final voltage of 3 V. More detailed information can be found in [15,17]. The 3D-AP used in this study is a TAP (tomographic atom probe) by CAMECA (Genevilliers, France).…”

High-Temperature Tensile Strength of Al10Co25Cr8Fe15Ni36Ti6 Compositionally Complex Alloy (High-Entropy Alloy)

“…1a and b, respectively. The alloy of composition Al 8 Co 17 Cr 17 Cu 8 Fe 17 Ni 33 has been widely investigated 3 and it has been used as a basis for a further optimization. According to the phase diagrams displayed in Fig.…”

“…1,2 However, after one decade of investigation of these alloys, only few of them have been found consisting of a single solid solution. [3][4][5][6][7][8][9] The compositionally complex alloys (high-entropy alloys) can be classified mainly into two groups according to whether the main phase is either face-centered cubic (fcc) 3,7 or body-centered cubic (bcc). 8,9 The first can be tested under a tensile load, but their strength values are small.…”

TCHEA1: A Thermodynamic Database Not Limited for “High Entropy” Alloys

“…To meet the challenges, computational methods are indispensable. Different computational approaches, ranging from empirical rules [6,7] to semi-empirical CAL-PHAD method, [8][9][10][11][12] and to theoretical first principles method, [13,14] have been applied for screening of HEAs. For example, many empirical rules in terms of mixing enthalpy, configurational entropy, atomic size mismatch, valence electron concentration and their various combinations, have been proposed and tested to explore potential HEAs of simple solid solutions.…”