Time: 5:00 p.m.
Place: TU Chemnitz, Chemnitz, Germany
For crystalline materials it is a well-established concept to tune the material's properties by varying the grain size. While in case of crystalline materials the concept of grain boundary is well-defined, for the case of glasses, in contrast, there is no established concept of grain boundaries due to the lack of translational symmetry and long-range order. Nevertheless in bulk metallic glasses it has been proven that planar defects do exist, namely in the form of shear bands induced by plastic deformation. These planar defect exhibit an enhanced free volume and a modified local order and affect the properties of bulk metallic glasses. An alternative route for controlling in a systematic way the fraction of planar defects, and therefore, the properties of glassy materials, is by compacting glassy nanopowder. The resulting structure consists of glassy grains separated by glass-glass interfaces and is called a nanoglass.
This talk will illustrate a complete description of the structure of planar glass-glass interfaces and present how mechanical and vibrational properties of nanoglasses change when compared to those of a homogeneous bulk metallic glass.