Correlative Tomography – Comparing X-ray Nanotomography and Focused Ion Beam Serial Sectioning
achievable even on a laboratory scale. In the field of serial sectioning techniques using focused ion beam
(FIB), the development of new ion beam sources, for example Xe-Plasma, has significantly increased the
analyzable volume into the 200µm edge length range. Thus, the resolution and volume ranges of both
techniques overlap and correlative investigation of the very same sample volume becomes possible.
In this work, both x-ray nanotomography and serial sectioning techniques using Ga-FIB and Xe-Plasma-FIB were used to image the microstructure of an AlSi13 cast alloy. Aluminum alloys with silicon as the
main alloying element are a widely used group of materials for machine or vehicle parts. The
microstructure of hypereutectic Al-Si alloys (>12% Si) consists of primary silicon particles and a complex
shaped Al-Si eutectic. Elements such as Cu, Mg, and Ni are added to form intermetallic hard phases that
improve mechanical properties at elevated temperatures. The size, shape and connectivity of these
complex shaped intermetallic phases play a crucial role for the material’s properties and are therefore
of great interest. Since classical 2D techniques cannot capture the connectivity, 3D analysis of the
microstructure is required. Due to the size of the particles in the µm range, only high-resolution 3D
imaging techniques are suitable. The 3D images were partially acquired in the same sample volume in
order to compare the information from the different techniques. Based on the results, the advantages
and disadvantages of the corresponding techniques are discussed.