Effect of Y addition on thermal stability and the glass forming ability in Fe–Nb–B–Si bulk glassy alloy

The effect of Y addition on the thermal stability and glass forming ability (GFA) has been investigated in (Fe72Nb4B20Si4)100−xYx (x = 0–5) alloys. Addition of 3–5 at.% Y improves the GFA. With increasing the Y content, glass transition temperature (Tg) and crystallization temperature (Tx) shifted to the higher temperature region. The (Fe72Nb4B20Si4)97Y3 alloy shows a high thermal stability, with Tg of 859 K and the supercooled liquid regions reached maximum value of 56 K. The (Fe72Nb4B20Si4)97Y3 alloy exhibits the largest γ (=0.402) value among the alloy investigated, enabling fabrication of bulk metallic glass (BMG) sample with the diameter of 4 mm.