Speaker
Description
The Accumulative Roll Bonding (ARB) process is well known for producing ultrafine-grained structures with remarkable material properties compared to conventionally produced sheet material [Saito1998]. Additionally, manifold tailoring possibilities by combining different metallic materials into so-called laminated metallic composites (LMCs) open a broad potential to produce new advanced sheet materials [Hausöl2010]. For a successful use of this new technology in technical applications, a fundamental understanding of microstructural processes and relevant strengthening mechanisms is essential. The mechanical properties of different LMCs consisting of copper (Cu) and niobium (Nb) have been investigated concerning microstructural length scales to get insights into changing deformation mechanisms. Usually, grain sizes respectively layer thicknesses of several tens of microns to around 100 microns are referred to a dislocation pile-up deformation mechanism, which seems to break down reaching below 70 nm [Misra2005]. The predominant deformation at smaller layer thicknesses, the so-called confined layer slip (CLS), is attributed to single dislocations slip within the individual layers. Nevertheless, recent studies on Cu/Nb-LMCs show an intermediate strengthening contribution within 1 µm and 100 nm that has not been observed in previous investigations at all. We suggest a further specification of dominant deformation mechanisms depending on microstructural length scales of chemically inhomogeneous LMCs between the well-known dislocation pile-up and single dislocation slip regimes. The investigations were mainly based on hardness and tensile tests data and microstructural analysis of highly cycled ARB processed LMC sheets.
[Saito1998] Saito, Scripta Materialia, 1998
[Hausöl2010] Hausöl, Journal of Materials Science, 2010
[Misra2005] Misra, Acta Materialia, 2005
| Speaker Country | Germany |
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