Improving glass forming ability of Zr50.5Cu36.5Ni4Al9 alloy by suppressing CuZr phase precipitation

CuZr phase is precipitated easily in the process of fabricating Zr50.5Cu34.5Ni4Al11 BMG. The critical diameter of amorphous rod is improved from 8 mm of Zr50.5Cu34.5Ni4Al11 to at least 20 mm of Zr53.5Cu26.5Ni5Al12Ag3 by restraining the precipitation of CuZr phase. The great improvement of GFA is attributed to the declination of Cu content and the weakening of the drastic interaction between Cu and Zr atoms by Ag addition since Ag has similarly physical and chemical properties with Cu. Therefore, suppressing the precipitation of crystalline phase should be an effective method to enhance GFA.