Abstract
A series of [(Fe1-xCox)(72)Mo4B24](94)Dy-6 (x = 0.1, 0.2, 0.3, 0.4 and 0.5 at.%) bulk metallic glasses (BMGs) in rod geometries with critical diameter up to 3 mm were fabricated by copper mold casting method. This alloy system exhibited good thermal stability with high glass transition temperature (T-g) 860 K and crystallization temperature (T-x) 945 K. The addition of Co was found to be effective in adjusting the alloy composition deeper to eutectic, leading to lower liquidus temperature (T-l). The [(Fe0.8Co0.2)(72)Mo4B24](94)Dy-6 alloy showed the largest supercooled liquid region (Delta T-x = T-x - T-g = 92 K), reduced glass transition temperature (T-rg = T-g/T-l = 0.622) and gamma parameter (gamma = T-x/(T-g + T-l) = 0.424) among the present system. Maximum compressive fracture strength of 3540 MPa and micro-Vickers hardness of 1185 kg/mm(2) was achieved, resulting from the strong bonding structure among the alloy constituents. The alloy system possessed soft magnetic properties with high saturation magnetization of 56.61-61.78 Am-2/kg and coercivity in the range of 222-264.2 A/m, which might be suitable for application in power electronics devices. (C) 2010 Elsevier B.V. All rights reserved.