Effects of strain rate on properties of Zr–Cu–Al–Fe bulk metallic glasses with Nb addition

Abstract

The glass-forming ability (GFA), stress-strain relationships, and fracture characteristics of Zr60-xCu27Al8Fe5Nbx (x = 0, 1, 3 and 5 at%) bulk metallic glasses (BMGs) are investigated over a wide compressive strain rate range of 10−3 to 4 × 103 s−1 using a material testing system (MTS) and split-Hopkinson pressure bar (SHPB). The addition of Nb is found to increase the supercooled liquid region (ΔTx) and parameter γ (γ = Tx/(Tg + Tl)) of the BMGs. For all of the tested alloys, the fracture stress increases with increasing strain rate. By contrast, the fracture strain decreases as the strain rate increases. The addition of 3 at% Nb results in the highest fracture stress and fracture strain. The fracture surface observations show that the fracture behavior of the BMGs is strongly related to the strain rate but is insensitive to the Nb content.