Excellent glass-forming ability in simple Cu50Zr50-based alloys

On the basis of the novel binary CuZr bulk metallic glass (BMG), we report the excellent glass-forming ability (GFA) in the simple Cu50Zr50-based BMG-forming alloys with minor Al addition. When Al addition changes from 4 to 8 at.%, Cu50Zr50-based BMGs can be produced to cylindrical rods with a diameter of at least 5 mm. The alloys have a broad glass-forming composition range with the excellent GFA. The elastic moduli were derived from the ultrasonic and density measurements. The physical origin of this unique GFA in the alloys is investigated. Our results might provide an effective route for exploring new BMGs.