Effect of Ti addition on the glass-forming ability of (Zr0.59Cu0.18Ni0.13Al0.10)100-xTix alloys

The effect of Ti on glass-forming ability of bulk (Zr(0.69)Cu(0.18)Ni(0.13)AI(0.10))(100-x) Ti-x (x=0, 1, 2........ 6) alloys has been investigated by differential scanning calorimetry (DSC), differential thermal analysis (DTA), and X-ray diffraction (XRD). It is shown that the liquidus temperature T-1 decreases obviously when Ti content (x) increases from 0 to 4, meanwhile the reduced glass temperature (T-rg) increases from 0.62 to 0.65. When x exceeds 4, however, T-1 increases and T-rg decreases respectively with increasing T-i content. The wedge-shaped sample with x=4 has the largest amorphous region, i.e., has the highest relative glass-forming ability, and the relevant supercooled liquid region DeltaTx is 77.6 degreesC. The alloy with this composition can be cast into cylinder-like amorphous alloy with 10 mm in diameter and 70 mm in length or sheet-like with 3 mm thickness by arc melting and copper mold casting. More intermetallics phases exist in the amorphous-crystallization zone of the wedge-shape sample with x=4 than those of alloys with x=0 and x=2 as indicated by XRD results. It is suggested that the crystallization would be retarded by the interaction and competition of various phases, thus enabling a higher glass-forming ability.