Design and preparation of Al-based compositionally complex alloys containing Bi and Gd potentially used for shielding both γ-ray and thermal neutron

The casting Al–Bi–Mg-Gd-X (X is Si, Cu or Zn) compositionally complex alloys (CCAs) possessed complex multiphase microstructure, where Mg₃Bi₂ and ternary Al-Gd-X phases were formed. Such microstructure endowed the CCAs with a controllable combination of strength/ductility. Al–Bi–Mg-Gd-Zn CCA had the highest ultimate compressive strength (612.5 MPa), while Al–Bi–Mg-Gd-Si CCA exhibited the best ductility (14.7%). This work provides new insights for developing one lightweight and high-specific-strength material potentially used for γ-ray and thermal neutron co-shielding.