Effects of isothermal annealing on the microstructures and mechanical properties of a FeCuSiBAl amorphous alloy

► Annealing results in the formation of Fe(Si) nanocrystals in amorphous matrix. ► Increasing the annealing time increases the grain sizes of the α-Fe(Si) phase. ► Increasing the annealing time increases lattice parameter of the α-Fe(Si) phase. ► Annealing effectively increases the hardness and Young's modulus of the alloy.