Design and High-Throughput Screening of High Entropy Alloys

Abstract

A balanced parameter was proposed to design the high entropy alloys (HEAs), which defined by average melting temperature Tm times entropy of mixing ΔSm over enthalpy of mixing ΔHm, Ω=TmΔSm/ΔHm, if Ω is larger than 1.1, we can predict that the entropy is high enough to overcome the enthalpy, and solid solution is likely to form rather than the intermetallic ordered phases. The composition can be further refined by using high-throughput screening by preparing the compositional gradient films. Multiple targets co-sputtering is usually used to prepare the films, and physical masking can separate the samples independently, chemical masking can also applied if possible. One example is the self-sharpening screening by using nanoindentations, the serration behaviors may related to the self-sharpening compositions.

Phase Prediction, Microstructure and Mechanical Properties of Fe–Mn–Ni–Cr–Al–Si High Entropy Alloys

“…Empirically, VEC can provide an idea about the formed phases. For example, single FCC and BCC solid solution phases form when VEC ≥ 8 and VEC < 6.87, respectively, while a mixture of FCC and BCC solid solution phases are expected if 6.87 ≤ VEC < 8, as reported in [47]. However, in this work, we aim to connect the equilibrium phase formation in this type of lowcost Fe-Cr-Mn-Ni-Al-Si high-entropy alloy system, predicted by Thermo-Calc TCHEA software, with the formed equilibrium/nonequilibrium phases during real solidification process without further treatment process.…”