Numerical analysis of micro-formability of Mg-based bulk metallic glass in supercooled liquid region

Mg–Cu–Y bulk metallic glass (BMG) exhibits obvious glass transition behavior and develops a supercooled liquid state in a wide temperature range. In the present paper, the plastic micro-formability of an Mg60Cu30Y10 BMG in the temperature range near the glass transition temperature (Tg) is investigated by finite element analysis (FEA). The material model includes both Newtonian and non-Newtonian flow behaviors. Two kinds of micro-dies, square and V-shaped dies are modeled to analyze the effects of forming temperature, lubrication condition and surface feature scale. Geometrical transferability is used to represent the formed surface topology that includes maximum distance and area of material flow into a die groove. The results reveal that the micro-formability depends strongly on temperatures, but slightly on lubrication condition. Furthermore, they show different curves between square and V-shaped grooves when the micro-formability is investigated with variation of the width of groove. This indicates micro-formability of the material is due to its isotropy and homogeneity on the microscale and is not very sensitive to the feature size.