Repeated cold rolling with intermediate folding (RCR) represents a technique to obtain
severe plastic deformation that avoids excessive heating at the internal interfaces and that proceeds
without the simultaneous action of a high pressure in the range of several GPa. Aside from the
opportunity to obtain amorphous bulk samples, the processing pathway also allows for synthesizing
dense, bulk nanocrystalline materials. The sequential combination of different processing routes that
drive a material to a different extent -, with different rates - and by different means from
thermodynamic equilibrium present new and attractive processing opportunities to obtain bulk
nanocrystalline or massive ultrafine grained materials that are widely unexplored. Here, an overview
is presented concerning the sequential application of different deformation methods with largely
different strain and pressure levels. The basic underlying mechanisms that can lead to ultrafine
grained or nanocrystalline microstructures for pure metals or to two-phase nanocomposites or bulk
metallic glasses for alloys are discussed and the current state of nanostructure control is highlighted
by selected examples.
Depth-sensing indentation tests in studying plastic instabilities
