Design induced plastic deformation in Zr-based bulk metallic glass

In this study, effect of sample geometry on the mechanical properties of a Zr-based bulk metallic glass was investigated. For this purpose truncated conical samples with different semi-vertex angles (α) were prepared for quasistatic compression test. It was noticed that as the geometry of the sample was slightly deviated from a cylindrical shape (for which α = 0°) to a conical shape (for which α > 0°), stress gradients were induced in the conical samples which were estimated using finite element analysis. This led to the formation of a large amount of intersecting multiple shear bands. As a result, as-cast BMG sample with negligible plasticity tends to deform in a ductile manner.

Research highlightsIn the present work it is shown that the specimen geometry strongly influences the deformation behavior of Zr57.5Cu11.2Ni13.8Al17.5 BMG. As the geometry of the sample was changed from cylindrical shape (for which α = 0°) to conical shape (for which α > 0°) gradually, the as-cast Zr57.5Cu11.2Ni13.8Al17.5 BMG sample having negligibly small plasticity tends to deform in a ductile manner due to the geometrical constraint induced complex stress distribution in the sample. This was also estimated by finite element analysis. The change in geometry led to the evolution of complex intersecting multiple shear bands helpful for avoiding the catastrophic failure.