Bulk Nanocrystalline Metals and Alloys

The nanostructuring of bulk metallic materials is obtained by top-down structuring using extremly large strains achieved by plastic deformation under enhanced hydrostatic pressure ("Severe Plastic Deformation, SPD").

Therfore "High Pressure Torsion, HPT" is  primarily used as hydrostatic pressure can be varied and strain can be applied continuously and unlimited.

Subsequently the measurement & understanding of the increased mechanical properties (strength, ductility, fatigue strength, fracture thoughness) as a function of grain size and annealing treatment is of main interest.

Functional properties of nanostructured materials

The improvement of following functional properties of materials by applying by severe plastic deformation is investigated:

  • Hydrogenated nanomaterials: processing by SPD; hydrogen storage, ab- and desorption, stabilization of lattice defects by hydrogen
  • Thermoelectric nanomaterials: chemical synthesis, processing by ball-milling and SPD, structural analysis and characterization, thermoelectric properties
  • Magnetic nanomaterials: processing by ball-milling and SPD, structural characterization, soft and hard magnetic properties

Modelling of mechanical properties

The mechanical properties i.e. the flow curve of micro- and nanostructured materials is modelled by

Plasticity in Polymers

The microstructural features and mechanisms of plastic deformation in polymers with semi/nanocrystalline and amorphous structure are investigated with respect to dislocation dominated plasticity in the crystalline phase.