BULK METALLIC GLASS COMPOSITES: MICROSTRUCTURAL INFLUENCES ON MECHANICAL PROPERTIES

摘要

Bulk metallic glasses (BMGs) have been strongly investigated as they show on the one hand interesting mechanical properties as high strength and good wear resistance but on the other hand limited ductile deformability. Bulk metallic glass composites (BMGCs) are very promising to overcome and improve the properties by clever combination of different phases. However, a major drawback is the limited choices of phase combinations in common fabrication routes and lack of major microstructure adjustability. A promising technique to overcome these drawbacks is severe plastic deformation process, e.g. high pressure torsion (HPT), where the production can be started with metallic glass powders. For this route, the powder is consolidated and deformed by applying a high shear deformation to bulk samples. Therefore, it is possible to produce fully amorphous specimens [1], but also composites containing two different amorphous phases or an amorphous and a crystalline one [2].