Thermal, magnetic and mechanical properties of (Fe1 − xCox)68Dy6B22Nb4 bulk metallic glasses

(Fe1 − xCox)68Dy6B22Nb4 (x = 0-0.5) bulk metallic glasses (BMGs) were prepared by copper mold casting. Effects of substituting Fe with Co on the thermal, magnetic and mechanical properties of the BMGs were investigated. Addition of Co is effective in improving the glass forming ability (GFA) of the alloy and BMG rods with diameters up to 4 mm can be obtained by industry-grade raw materials. The substitution of Co for Fe leads to high saturation magnetic flux density (0.7515 T) as a result of optimized number of spin-up and spin-down electrons in the d-band. The amorphous nature of the alloy gives rise to low crystalline anisotropy and coercivity (< 10 A/m). High fracture strength (3213-3738 MPa) is also obtained for the FeCo-based BMGs.