Fabrication of Mg–Y–Cu bulk metallic glass by mechanical alloying and hot consolidation

Mg45Y15Cu40 (numbers indicate at.%) metallic glass powders were prepared by the mechanical alloying of pure Mg, Y, and Cu after 10 h of milling. The thermal stability of these Mg45Y15Cu40 amorphous powders was investigated using the differential scanning calorimeter (DSC). Tg, Tx, and ΔTx are 456, 491, and 35 K, respectively. The as-milled Mg45Y15Cu40 powders were then consolidated by vacuum hot pressing into disk compacts with a diameter and thickness of 10 and 1 mm, respectively. This yielded bulk Mg45Y15Cu40 metallic glass with nanocrystalline precipitates homogeneously embedded in a highly dense glassy matrix. The pressure applied during consolidation can enhance thermal stability and prolong the existence of amorphous phase within Mg45Y15Cu40 powders.