Mechanical properties of a FeCuSiB alloy with amorphous and/or crystalline structures

Fe76.5Cu1Si13.5B9 alloy rods with a diameter of 3 mm were fabricated using the copper mold suction casting method. Structural characterization revealed that different parts of the rods have different microstructures that comprise a complete amorphous structure, an amorphous-crystalline composite structure and a complete crystalline structure. Compression and nanoindentation testing showed that the hardness, strength and elastic modulus of the alloy increase with the crystalline component. High crack propagation rate and narrow shear bands contribute to the local melting and softening for the complete amorphous structure although it exhibits the lowest calculated value of the static elastic energy density.

► The fabricated Fe76.5Cu1Si13.5B9 alloys have complicated microstructures.
► Mechanical testing showed that the mechanical properties increase with crystalline degree.
► High crack propagation rate contributes to the local melting and softening.