Novel automated approaches for extended in situ mechanical tests on metals and materials in the scanning electron microscope

Analytical microscopy, in particular Energy Dispersive X-ray Spectroscopy (EDS) and Electron Backscatter Diffraction (EBSD) have become ubiquitous techniques in the characterization of metals and materials in the scanning electron microscope. Extending these techniques to a third dimension, not in space but in time, with in situ mechanical and thermal testing, allows the researcher to observe and characterize the transformation of a material at the nano scale and in real time with forces that model real world service conditions.

Such transformations during long experiments present their own challenges, in that over time, the consistent imaging, focusing and tracking of features can prevent adequate interpretation of time-resolved in situ images and analytics.

This work describes the evolution of strain and crystal structure in metallic and non-metallic samples under mechanical and thermal testing and how the combination of a heated tensile or compression stage, dedicated high-temperature SE and BSE detectors with EDS and EBSD analytics can provide a comprehensive picture of the microstructural behavior of samples under stress.

Novel approaches in digital image correlation and automatic feature tracking provide the possibility of long unattended automated time-resolved EDS or EBSD mapping, even with multiple regions of interest.