| Abstract Scope |
A popular method nowadays to produce nanostructured bulk materials is provided through methods of severe plastic deformation (SPD). Such methods such as equal channel angular pressing and high pressure torsion are capable of imposing extraordinarily high deformation strains onto mostly coarse-grained pre-materials and induce in this way substantial grain refinement. The achievable grain size, varying strongly on deformation temperature and purity of the metal can be well below 100 nm. The grain refinement and the connected beneficial effects on the mechanical properties, such as high strength, have been in focus for several years. Nevertheless, fracture related properties have been often neglected. In this contribution the fracture behavior of SPD-processed niobium and tantalum will be compared and discussed. It will be shown that the specimen orientation can have a tremendous influence on the fracture behavior and fracture toughness. |