Mechanische Charakterisierung und Untersuchung des Verformungsverhaltens hochfester Strukturen mit 3D Mikroarchitektur

A. Albiez


The combination of low density and superior mechanical properties is requi- red for lightweight applications. Foam materials achieve low density values due to their high porosity, however, only low strength values are reached as a consequence of their stochastic architecture. A specific architecture with respect to the mechanical load shows a superior behavior, as shown in bio- logical materials, for example in bone. In this respect, cellular solids with a specific, periodic three-dimensional architecture which also exploit the so-called mechanical size effect have attracted a lot of attention recently. Within this thesis, a mechanical characterization of high-strength, low- weight microlattices with a specific 3D microarchitecture was performed. The analysis was focused on the interplay between the mechanical pro- perties of different constituent materials and the behavior of different 3D microarchitectures. Moreover, the energy absorption capability of the mir- colattices as well as their deformation and failure behavior was analyzed by in situ compression tests in a scanning electron microscope. It was shown that a further processing of the polymeric constituent material influences the mechanical behavior of both, the constituent material and the microlat- tice. Here, the further processing steps included an annealing treatment, a pyrolysis, and a coating. Energy dissipation under cyclic compression was mainly attributed to irreversible processes, whereas polymeric microlattices also achieved a high recoverability.