The effect of Ag addition on the glass-forming ability of Mg–Cu–Y metallic glass alloys

Abstract

The effect of Ag substitution for Cu on the glass forming ability was studied in Mg 65Cu 25− x Ag x Y 10 ( x=0,5,10,15,20,25) alloys by using thermal analysis and X-ray diffractometry (XRD). With increasing x from 0–25, the glass transition temperature, T g, of melt spun Mg 65Cu 25− x Ag x Y 10 alloys increases slightly from 426 to 436 K, and the crystallization temperature, T x , decreases from 494 to 459 K, resulting in a decrease in the supercooled liquid region. However, a partial substitution of Cu by Ag in Mg 65Cu 25Y 10 promotes the glass formation. The maximum diameter for amorphous phase formation by injection casting increases from 4 mm in Mg 65Cu 25Y 10 to 6 mm in Mg 65Cu 15Ag 10Y 10 alloy. Both amorphous Mg 65Cu 15Ag 10Y 10 alloys prepared by melt spinning and injection casting showed similar crystallization process during continuous heating in differential scanning calorimetry (DSC). The relationship between the critical diameter for the formation of an amorphous phase in injection casting and the parameters reflecting glass-forming ability was examined.