Effect of (Mo, W) substitution for Nb on glass forming ability and magnetic properties of Fe-Co-based bulk amorphous alloys fabricated by centrifugal casting

In this study, effects of simultaneous Mo and W substitution for Nb additions on the stability and magnetic properties of Fe-Co-based bulk metallic glass (BMG) alloys fabricated by centrifugal casting are investigated. The saturation magnetization (J(s)) and coercivity (H(c)) for the as-cast Fe(36)CO(36)B(19.2)Si(4.8)X(4) (X = Nb or Mo(0.5)W(0.5)) BMG alloys and melt-spun Fe(36)Co(36)B(19.2)Si(4.8)Mo(2)W(2) were in the range of 1.02-1.57T and 11.13-1685 A/m, respectively. The Fe(36)Co(36)B(19.2)Si(4.8)X(4) (X = Nb or Mo(0.5)W(0.5)) BMG alloys in the shape of wedge with the maximum thickness of 1.5-2 mm were obtained successfully by means of conventional centrifugal casting. Replacing Nb with Mo(0.5)W(0.5) deteriorates magnetic properties in bulk form and reduces the GFA of the alloy due to promoting the precipitation of non-magnetic compounds, while it results in good soft magnetic properties in melt-spun ribbon form. (C) 2010 Elsevier B.V. All rights reserved.