Ultramicroscopy
February 2024
Three-dimensional elemental mapping in atom probe microscopy provides invaluable insights into the structure and composition of interfaces in materials. Quasi-atomic resolution facilitates access to the solute decoration of grain boundaries, advancing the knowledge on local segregation and depletion phenomena. More recent developments unlocked three-dimensional mapping of the interfacial excess across grain boundaries.
View Article and Find Full Text PDFPlasma focused ion beam microscopy (PFIB) is a recent nanofabrication technique that is suitable for site-specific atom probe sample preparation. Higher milling rates and fewer artifacts make it superior to Ga+ FIBs for the preparation of samples where large volumes of material must be removed, for example, when trying to avoid lift-out techniques. Transmission Kikuchi diffraction (TKD) is a method that has facilitated phase identification and crystallographic measurements in such electron transparent samples.
View Article and Find Full Text PDFRecent advancements in data mining methods in atom probe microscopy have enabled new quantitative chemical and microstructural characterization beyond the standard three-dimensional reconstruction. For example, spatial distribution maps have been developed to enable visualisation of the local lattice occupation of a selected region of interest. However, the precision of such studies yet remains unknown as correlation with complementary methods would be required.
View Article and Find Full Text PDFPolycrystalline Ni-based superalloys for aerospace and power generation applications are often precipitation hardened to achieve strengthening at elevated temperatures. Here, atom probe microscopy has become an essential tool to study the complex morphology of nanoscale precipitates. This study focuses on Alloy 718, which is hardened by semi-coherent, ordered γ' (Ni3(Al, Ti)) and γ″ (Ni3(Nb)) particles.
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