What are the properties of dimensions

Mechanical properties in small dimensions

Mechanical properties in small dimensions (lecturer: G. Dehm, language: German, semester: SS, time: block course, note notices): Miniaturized materials with dimensions ranging from a few atoms to a few micrometers are used in sensor technology, in electronic components, for solder connections or as layers (e.g. wear protection, magnetic memories, optical systems). Although the miniaturized materials are mostly functional tasks optimized, the mechanical material behavior is of fundamental importance for the reliability of the application. It turns out that miniaturized materials have a mechanical behavior that differs significantly from that of the corresponding solid material; therefore it is necessary to understand mechanical material properties in small dimensions. The same applies to nanocrystalline materials. Due to the extremely small grain size, these can show different deformation mechanisms and thus lead to unexpected mechanical properties. Both miniaturized and nanocrystalline materials are discussed in this lecture, the corresponding basics of mechanical size effects are conveyed and miniaturized or local measurement methods and the challenges associated with them are explained. In addition to an introduction to the manufacturing processes for solid nanocrystalline materials and thin layers, the content also includes selected methods of microstructure analysis. The dislocation plasticity of materials is expanded in the course of the lecture to include dislocation effects in thin layers and multilayer systems. The causes of stresses in thin layers are explained and methods of stress measurement are presented. Another focus is on the explanation of plasticity, creep, fatigue and breakage in nanocrystalline materials and the consequences for applications of these material systems in practice.
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