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

摘要

A series of Zr 35?x Ti 30 Cu 7.5 Be 27.5 Fe x (x = 0–10) bulk metallic glasses are cast using water-cooled copper mold casting technique. The glass forming ability (GFA) and thermal stability of Zr 35?x Ti 30 Cu 7.5 Be 27.5 Fe x alloys were studied by means of X-ray diffraction and differential scanning calorimetry. It was found that the Zr 35?x Ti 30 Cu 7.5 Be 27.5 Fe x (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 (ΔT x ), γ 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 Zr 35?x Ti 30 Cu 7.5 Be 27.5 Fe x (x = 0–10) alloys. The results showed that T rg was more effective in gauging the GFA of the Zr 35?x Ti 30 Cu 7.5 Be 27.5 Fe x alloy systems than ΔT x and γ parameter. In addition, elastic constant (Poisson’s ratio) was also employed as a gauge to evaluate the glass forming ability in Zr 35?x Ti 30 Cu 7.5 Be 27.5 Fe x alloys.