| Abstract Scope |
This study aimed to produce novel FeNiCrCoAlNb HEAs possessing excellent strength-ductility trade-off. The samples were produced by vacuum arc melting and annealing at 1000 ˚C for 48 h. Optical Microscopy, Scanning Electron Microscope equipped with EDS, Transmission Electron Microscope, and X-ray diffraction were employed for material characterization. Tensile tests were carried out for mechanical characterization. Two different grain microstructures were obtained, including elongated grains with preferred orientation and equiaxed grains. Laminated morphology and stacking fault showing needle-like shape morphology were also observed. A remarkable hardness of 6.4 GPa, outstanding yield strength of 987 MPa, UTS of 1569 MPa, and excellent ductility of 43 % were achieved. The fracture analyses and TEM observations indicated that the enhanced strength of the HEA was attributed to grain refinement and strain hardening. The excellent ductility, on the other hand, was attributed to dislocation slipping, the formation of stacking faults, and twinning. |