Phase formation, glass forming ability, mechanical and thermal properties of Cu50Zr50,Al (0≤x≤11.0) glass forming alloys

Phase formation, glass forming ability, mechanical and thermal properties of Cu(50)Zr(50-x)AL(x) (O <= x <= 11.0) glass forming alloys were systematically investigated. The results show that Cu50Zr47Al3 alloy has the best glass forming ability (GFA), lowest fragility index (m) and highest fracture strength. There are B-2 CuZr and B19' CuZr phases for Cu5OZr50-AL (0<x<5.0) alloys. B-2 CuZr phase disappears and two new phases (Cuu,Zr, and CuZr2) appear when 5.0<Al<8.0. Another new A1Cu2Zr phase can be clearly observed when Al > 8.0. The glass transition temperature (L), the sensitivity of the L to the heating rate (B), the activation energy for T-g (E-g) and the m value all increase with increasing Al content. The supercooled liquid region (AT) is larger for Cu(3)OZrso (x<5.0) than for CuR(2)r30 (x>5.0). Cus,,Zrso,Al (0<x<4.0) alloys are off-eutectic compositions while near-eutectic compositions for CusoZr(50)-A1, (5.0Gx<11.0) alloys. The E Ex, and E, decrease with increasing sensitive factor (fi) for the studied Cu-based alloys characterized in the room-temperature brittleness. The dependence of the phase formation and GFA on the Al content is discussed.