The glass forming ability and crystallization behaviour of melt spun Ti50-xCu25 Ni15Sn3Be7Zrx (x = 0, 3 and 5) amorphous alloys were investigated using differential scanning calorimetry (DSC), X-ray diffractometry and transmission electron microscopy. With increasing Zr contents, x from 0 to 5, ? Tx (= Tx - Tg) and Trg(= Tg/Tl), where Tg=glass transition temperature, Tx=crystallization temperature and Tl=liquidus temperature, gradually increase from 45 K to 56 K and from 0.57 to 0.60, respectively. The Ti50Cu25Ni15Sn3Be7 alloy shows three exothermic events in the DSC curve; initially the alloy crystallizes by forming a few nanometer scale crystalline phase, followed by decomposition into a mixture of Ti(Ni,Cu), TiCu, Ti3Sn, and TiBe12 phases at high temperature. Furthermore, the alloys containing Zr exhibit the formation of nanocrystalline phases of ∼10 nm size even after the second exothermic event due to their increased atomic packing density. For the Ti45Cu25 Ni15Sn3Be7Zr5 alloy, fully amorphous rods up to 5 mm in diameter were successfully fabricated by injection casting.
All Science Journal Classification (ASJC) codes
- Materials Chemistry