Nanoglasses - A way to enhanced mechanical properties of amorphous materials

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Plastic deformation of conventional metallic glasses, which are characterized by a homogeneous atomic structure and chemistry, leads to the formation of few shear bands with the consequence of inhomogeneous deformation and brittle fracture. The disturbance of the homogeneous structure due to interglass interfaces on the nanometer-scale, as possible in nanoglasses prepared by consolidation of amorphous nanoparticles, can lead to improved plasticity, higher strength and ductility, completely different from the conventional rapidly quenched amorphous alloys. The aim of the project is to identify the topological properties of interglass interfaces and to understand their influence on the mechanical properties of nanoglasses. Initially, metallic glass systems, such as FeSc- and PdSi-based alloys, are considered in order to establish the atomic structure of the interglass interfaces and their role for plastic deformation. All experimental work on the structure and mechanical properties will be complemented by computer simulations, initially on the CuZr system and at a later stage on the PdSi system. For the PdSi-system an appropriate potential will be developed. The concept of nanoglasses can be systematically extended to ionic materials and to synthesis methods which allow faster and less expensive production on a larger scale. Besides the measurements of the elastic and plastic deformation using a variety of techniques, the details of the structure of the nanoglasses will be determined by using XRD, EXAFS, SEM, TEM, etc.