The bulk glass forming abilities and mechanical and magnetic properties of Fe–Co–Zr–Mo–W–B alloys

An investigation of bulk glass forming Fe61−xCo7+xZr10Mo5W2B15 (where x=0, 2, 4) alloys has been undertaken, using melt spun ribbon samples of various thicknesses up to ∼510 μm and suction cast rod and tube samples of various diameters (up to 4 mm). X-ray diffraction (XRD) and DSC and DTA analyses, revealed very good glass forming abilities, with glass transition temperatures Tg of ∼900 K, crystallisation temperatures Tx∼950 K and maximum diameters of amorphous rods up to 3 mm. Very large mechanical hardness values up to Hv=1200, were demonstrated. On the other hand, the large fraction of non-magnetic refractory metal and metalloid elements (32 at.% total) (and particularly the former), results in marked attenuation of the saturation magnetisation Js (down to ∼0.3 T) and of the Curie temperature.