FeCoNiCr0.5Alx High-Entropy Alloys with Dual-Phase Solidification Microstructure and High Compressive Properties

FeCoNiCr0.5Alx high-entropy alloys (HEAs) have been prepared via the self-propagating high-temperature casting method and the phase formation mechanism and related compressive properties systematically investigated. The FeCoNiCr0.5Alx HEAs showed dual-phase nature but complex as-cast microstructure depending on the Al content. The as-cast microstructure of the FeCoNiCr0.5Al0.8 and FeCoNiCr0.5Al1.0 HEAs was composed of ordered/nonordered body-centered cubic (BCC) nanocomposite dendrites, network-like interdendritic face-centered cubic (FCC)/BCC eutectics, and plate-like FCC/BCC eutectics. The high compressive properties can be attributed to the eutectics formed both interdendritically and at grain boundaries, which considerably reduce the embrittlement of the interfaces.