Serration Behavior in Zr-Cu-Al Glass-forming Systems

The metallic glass matrix composites (MGMCs)and bulk metallic glasses (BMGs)were studied by statis-tical analysis during plastic deformation at the strain rates of 2×10 -2 ,2×10 -3 ,and 2×10 -4 s-1 ,respectively.No serration events occur in both MGMCs and BMGs during compression tests at the strain rate of 2×10 -2 s-1 .When deformed at the strain rate of 2×10 -3 s-1 ,the BMG displays a larger plasticity,which is due to the larger serration events followed by a series of small serrations caused by the continuous movement of free volume.The amplitudes and elastic-energy densities increase with increasing the strain rates owing to many serrations in MGMCs.It is deduced that the Young′s modulus decreases from the normalized stress drop and fluctuations are observed on stress-strain curves,which is attributed to a lower coefficient according to the stick-slip model.