Design and synthesis of Cu-based metallic glass alloys with high glass forming ability

Abstract

The thermal stability, glass forming ability and viscosity of Cu-Zr-Al-M (M = Ag, Be) bulk metallic glass alloys have been investigated. Be and Ag elements were chosen because of their negative heat of mixing with Zr and their atomic size. Partial replacements of Cu with Ag or Be in Cu50Zr 43Al7 alloy enlarged the supercooled liquid region and enhanced significantly the glass forming ability. Particularly for the Cu 43Zr43Al7Be7 alloy, the supercooled liquid region reached 103 K, and fully amorphous rods up to 10 mm in diameter were successfully fabricated by copper mold casting. The decrease of the viscosity upon Be addition indicated that the large glass forming ability resulted from a high resistance to crystallization.