EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

In-situ material testing in SEM is already an established technique. It can deliver unique information about the dynamic response of material under mechanical load and reveal the relationship between its macroscopic mechanical properties and microstructure. Especially when combined with further techniques such as EDS and EBSD, the response of material microstructure under load can be related to its chemical composition and crystallographic orientations. Such understanding is essential for developing novel materials. However, performing an in-situ experiment in the SEM is nowadays still a demanding task, especially for new users. The complete in-situ system is usually composed of parts and their corresponding control software from different vendors. Doing experiments here usually involves operating different software modules and multiple computers. Such intensive manual operation limits typical in-situ experimentation to only highly experience user, and only a few deformation steps.
In this contribution, a fully integrated in situ lab will be presented together with its application examples. It combines a mechanical tensile-compression sub-stage, a heating unit, dedicated high temperature SE/BSE detectors and EDS/EBSD analytics into a FE-SEM system. A unified software environment controls all components of the system from a single PC. Furthermore, the system enables unattended automatic in situ experiments whereby the user can define multiple region of interests (ROIs), which will be investigated during the automatic workflow. A robust feature tracking and autofocus method is presented to center and focus ROI automatically at each deformation step. Different imaging condition such as scan methods, dwell time and image resolution can be chosen individually for each ROI. EDS/EBSD maps can also be triggered for selected ROIs. The features on the sample surface can then be used for digital image correlation (DIC) to analyze the local strain field during sample deformation.