Metallic Materials

news

research

publications

equipment

nano characterization

TEM

solidification/melting

alloy development

characterization of nanostructures

Nanostructuring offers the potential to drastically change both structural and functional properties of a material. Thus, new applications and application fields become accessible that cannot be covered by conventional materials.

One of the reasons for the unique properties of nanomaterials is that they contain a high volume fraction of grain boundaries or interfaces. For understanding the structure-property relationships of nanomaterials in detail, it is first necessary to characterize the properties of the internal interfaces. Until present there remain ample open questions concerning interfaces and grain boundaries in nanocrystalline materials.

Our research work aims at a better understanding of both internal interfaces and thermodynamically metastable structures.
Emphasis is laid on mechanisms of effects that stabilize the nanostructures and slow down or prevent coarsening, i.e. that suppress grain boundary migration.

In a cooperation with the research group of Prof. Xiaoyan Song at Beijing University of Technology (BJUT), nanostructured metals and alloys are characterized with respect to grain size distribution and further characteristic features. The nanomaterials are produced at BJUT by a special procedure involving Spark Plasma Sintering of a nanoscale powder. The condensed materials have a mean grain size that is smaller than the size of the initial powder particles. It is worth noting that conventional TEM techniques are at their limit when characterizing ultra fine grained materials. It is necessary to further develop advanced TEM techniques to gain the required information.

grain size distribution of a nanomaterial

$nano beam diffraction on two nanocrystals$

Impressum