Effect of shape memory alloys on the mechanical properties of metallic glasses: A molecular dynamics study

The strength-plasticity trade-off of metallic glass (MG) has not still been effectively overcome. The introduction of shape memory alloy (SMA) is an effective way to improve the mechanical properties of MG. Here, the deformation behavior of amorphous/SMA Cu64Zr36/B-2-CuZr nanomultilayers (ASNMs) under tension loading is investigated by molecular dynamics (MD) simulation method. The results show that the peak stresses and flow stress of the ASNMs are greater than those of the monolithic MG regardless of SMA volume fraction. The martensitic transformation (MT) in the SMA phase limits the propagation of shear bands (SBs), avoids a runaway instability, and simultaneously induces plastic strain strengthening. The results also indicate that the plastic deformation mode of ASNMs changes from the interaction of multiple SBs dominated to finally brittle fracture caused by nano-pores aggregation with the increase of SMA volume fraction. This means that the plasticity and strength of ASNMs can be significantly improved by adjusting the volume fraction of SMA. The fruits stem from this paper may provide a valuable guidance and theory route for the design of high-performance MGs.

Automated summary

The study shows that introducing shape memory alloy (SMA) can improve the mechanical properties of metallic glass (MG). The martensitic transformation in the SMA phase limits shear bands propagation, avoids instability, and induces plastic strain strengthening. Adjusting the volume fraction of SMA can significantly improve the plasticity and strength of the nanomultilayers.