The effect of Ni substitution on the glass-forming ability and mechanical properties of Mg–Cu–Gd metallic glass alloys

Abstract

The effect of substitution of Ni for Cu on the glass forming ability and mechanical properties was studied in Mg 65Cu 25− x Ni x Gd 10 ( x = 0, 5, 10, 15, 20, 25) alloys by thermal analysis and X-ray diffractometry (XRD). With increasing x from 0 to 25 at.%, the glass transition temperature, T g, of Mg 65Cu 25− x Ni x Gd 10 alloys increases from 417 to 450 K, and the onset temperature of crystallization, T x , decreases slightly, resulting in a decrease in the supercooled liquid region. However, an appropriate substition of Cu by Ni (5 at.%) in Mg 65Cu 25Gd 10 significantly improves mechanical properties, especially improves the ductility of Mg-based bulk metallic glass (BMG) while keeping good glass forming ability (GFA). The Mg 65Cu 20Ni 5Gd 10 BMG sample of 5 mm in diameter is fabricated by the conventional Cu-mold casting method in an argon atomsphere.