Glass forming ability, thermal stability and elastic properties of Zr-Ti-Cu-Be-(Fe) bulk metallic glasses

A series of Zr35-xTi30Cu7.5Be27.5Fex (x = 0-10) bulk metallic glasses are cast using water-cooled copper mold casting technique. The glass forming ability (GFA) and thermal stability of Zr35-xTi30Cu7.5Be27.5Fex alloys were studied by means of X-ray diffraction and differential scanning calorimetry. It was found that the Zr35-xTi30Cu7.5Be27.5Fex (x = 2, 3, 5 and 7, respectively) alloys could be cast into glassy cylindrical rods with a diameters up to 20 mm. However, higher Fe content (x = 10) deteriorates the GFA remarkably. The supercooled liquid region (Delta T-x), gamma parameter (defined as T-x/(T-g + T-l)) and the reduced glass transition temperature T-rg (defined as T-g/T-l) are employed to evaluate the GFA in Zr35-xTi30Cu7.5Be27.5Fex (x = 0-10) alloys. The results showed that Trg was more effective in gauging the GFA of the Zr35-xTi30Cu7.5Be27.5Fex alloy systems than Delta T-x and gamma parameter. In addition, elastic constant (Poisson's ratio) was also employed as a gauge to evaluate the glass forming ability in Zr35-xTi30Cu7.5Be27.5Fex alloys. (C) 2016 The Authors. Published by Elsevier B.V.