Effect of sample geometry on the deformation behavior of Zr-based bulk metallic glass

In this study, effect of geometrical confinement on the deformation behavior of Zr(57.5)Cu(11.2)Ni(13.8)Al(17.5) bulk metallic glass (BMG) was investigated. For this purpose flat top conical samples with different semi-vertex angles (alpha) were prepared for quasi-static compression tests. It was observed that as the geometry of the sample is slightly changed from cylindrical shape (for which alpha = 0A degrees) to conical shape (for which alpha > 0A degrees), a brittle BMG sample tends to deform in a ductile manner due to the geometrical constraint-induced complex multi-axial stress distribution in the sample. In brittle Zr(57.5)Cu(11.2)Ni(13.8)Al(17.5) specimen with alpha = 5A degrees, plastic deformation of about 4% was observed due to the formation of extensive intersecting shear bands.