Formation of ternary Mg-Cu-Dy bulk metallic glasses

Abstract

The glass-forming ability (GFA) of ternary Mg-Cu-Dy alloys was systematically investigated by using differential scanning calorimetry (DSC) and X-ray diffractometry (XRD) techniques. The results showed that a series of ternary Mg-Cu-Dy bulk metallic glasses (BGMs) with a diameter of 4–8 mm were successfully fabricated in the system with conventional Cu-mold casting method. Mg55Cu32Dy13, Mg60Cu27Dy13, Mg65Cu25Dy10 and Mg70Cu17Dy13 BMGs exhibit a clear glass transition, a broad supercooled liquid region and different crystallization and melting behaviours. They have supercooled liquid region (ΔT x) from 41 K to 65 K, reduced glass transition temperature (T rg) from 0·5363 to 0·5974 and γ parameter from 0·4038 to 0·4136. The γ shows a relatively good agreement with the GFA of the BGMs. On the other hand, a high fracture compressive strength of 624 MPa was obtained for Mg60Cu27Dy13 BMG.