A Study Of Shear Band Propagation Through Metallic Glasses Interface By MD Simulations

Metallic glasses are new kind of materials that display very high strength, low internal friction and good corrosion resistance. Nevertheless, they show weaknesses in their plastic deformation as they fail dramatically after they reach their yield point, because of highly localized plastic deformation in the form of shear bands. Many studies have been conducted on means to overcome this disadvantage, for example by using nanoglasses in order to create glass/glass interfaces.Shear banding phenomenon is studied in a single phase Cu₆₄Zr₃₆ metallic glass and two biglasses Cu₆₄Zr₃₆/Al₆₄Zr₃₆ by MD simulations run on LAMMPS. Several visualization tools (Atomeye, Ovito) are used in order to observe the nucleation and propagation of the shear band. Shear bands can be spotted through Von Mises local shear invariant fields, but also by observing atomic trajectories. They display complex atomic motions that highlight the intense energy outbursts taking place there.A shear band initiated in a strong glass can freely cross over a softer glass. Nevertheless, if initiated inside a glass itself embedded in a stronger glass, it can be confined within it. This opens up new ways to design metallic glasses, and more particularly nanoglasses, as plastic deformation in the material could localized in these softer glasses, and therefore, by controlling their amount and localization, one could finally homogenize the overall plastic deformation.