Deformation of metals on the nanometer scale: a TEM study

During the last few years experimental evidence was found that in the micrometer regime material properties are no longer size independent, but dominated by the smallest microstructural component or a local strain gradient. Recent experiments on miniaturized single crystal specimens depicted the occurrence of a size effect even in the absence of microstructural features under uniaxial loading. Currently, there is no uniform interpretation of this effect. Moreover, different interpretations based on the assumption of different governing mechanisms are discussed. It is the aim of the proposed project to identify the deformation mechanisms governing the mechanical behaviour in these small dimensions by well designed quantitative in-situ TEM tensile tests. Primary output of these results will be a deeper understanding of mechanics in these small dimensions. With the ongoing trend in miniaturization of material components (information technology, medical technique, ) these results are also of high commercial relevance. The insights gained in this project should allow an improvement of existing laws for material behaviour required for the design of miniaturized products. This will finally lead to commercial products with enhanced quality and reliability.