[en] In this work, new experimental methods and techniques for the analysis of the microscopic and the micromechanical material behavior of nickel- and iron-based superalloys are developed with the emphasis on the material characteristics and processes at smallest length scales. Superalloys are high performance structural materials which are for instance used in the turbine sections of aircraft engines and thus, exposed to very harsh environments. The research in this work will help to design new further advanced alloys for future applications in even extremer environments. Previous works have shown that the nickel-based superalloys Haynes 282 and Inconel 718 display a different micromechanical material behavior despite exhibiting a similar microstructure. To explain this phenomenon physically, neutron diffraction experiments have been performed at the FRM II research reactor in Garching to analyze the formation of residual stresses during uniaxial tensile deformation of the specimens. For interpretation of the experiments, the measurement results are compared to crystal plasticity based finite element simulations. Another essential part of this thesis are experiments to investigate the alloys' microstructure by highest resolution microscopy techniques and a correlation of the results with accompanied neutron diffraction experiments. The focus of this study is the characterization of nanosized intermetallic phases which are responsible for the outstanding creep performance of superalloys. To analyze the chemical composition, the morphology and the amount of these phases, a complementary study by scanning and transmission electron microscopy (at the Uni Stuttgart and at the KIT), by atom probe tomography (at the Uni Stuttgart) and by small angle neutron scattering (at the FRM II in Garching) is performed. Hereby, techniques for data evaluation are refined with the aim to develop a new method to differentiate and quantify different intermetallic phases by small angle neutron scattering. In the second part of this thesis, the experience and techniques to investigate the microstructure of nickel-based superalloys are transferred to study a fundamentally different alloy. For this purpose, the ferritic alloy FBB-8 was chosen, which is a recently suggested iron-based superalloy with a remarkable high temperature performance; but at the expense of the alloys’ ductility at room temperature. Principally different is the alloys crystal structure; while nickel-based superalloys exhibit a face-centered cubic crystal structure, alloy FBB-8 exhibits a body-centered cubic structure. The alloy is commercially not yet available and therefore fabricated within this study and pre-characterized. After subsequent heat treatments, two new methods for the study of smallest precipitates that form during cooling and which are responsible for the poor alloy ductility at room temperature are developed. This is achieved by a complementary study applying transmission electron microscopy, atom probe tomography and assisting numerical simulations. The proposed methods are not only suited to study ferritic alloys but can also be applied to study smallest precipitates in any other system.