Periodic Reporting for period 1 - FracTAlS (High Cycle Fatigue Cracking of Meso- and Micromechanical Testpieces of Aluminide Intermetallics, with in situ Nanoscale Strain Mapping)
Periodo di rendicontazione: 2020-09-01 al 2022-08-31
Following n3D-XRD-CT acquisitions at the ESRF, the microcompression testpieces were analysed using the FIB-3D-HR-EBSD method by S. Kalácska with similar spatial resolution, to compare the lattice rotations (and hence GND arrays) and residual stress states per layer measured by this destructive alternative method. Where this process was not carried out, transmission electron imaging of FIB-thinned lamellae enabled dislocation structure identification for correlation with the residual stress states observed.
In parallel, the capability for in situ meso-scale mechanical testing in an SEM with concurrent measurement of local stress states applied to specific slip systems and the resulting local plastic strain, all at a sample surface (2D approach), was developed. It was applied in a first instance to 50 – 100 µm thick foils of 316L stainless steel as a proof of concept.
Publications on the results from these studies are currently in progress.