Structural investigation and macroscopic properties of amorphous metals

Abstract

The structural investigation at the nano- and micro- level is the main tool to understand the behaviour of matter and to prepare new materials with even more superior properties. A novel in-situ synchrotron X-ray nano-diffraction approach for characterization and visualization of strain fields induced by nano-indentation applied to amorphous materials is introduced. The combination of those complementary methods offers the opportunity to obtain a quite complete picture about the atomic structure of investigated systems and the distribution of the strain fields. This method combines controlled deformation of a sample during constant observation of its structure (by X-ray). This offers us a direct way to correlate mechanical and structural properties of materials. This will patch a hole in the field of brittleness research of BMGs and so contributes to a better understanding of deformation processes. Several experiments on different experimental stations were performed. • Ex-situ nano-indentation experiments have shown that spatially resolved X-ray matrix scans with a nano-meter sized beam can identify the positions of the indents and quantitatively describe the strain state after nano-indentation. • In-situ nano-indentation experiments were performed using a monochromatic highly focused sub-micron X-ray beam on bulk metallic glass during nano-indentation. Performing fine grid scans on the BMG sample beneath the indenter revealed the elastic strain field in the deformation zone. It represents, to the best of our knowledge, the first experimentally observed map of elastic strains in a bulk metallic glass sample during nanoindentation obtained using real in-situ load-conditions.