First stages of fatigue damage

First stages of fatigue damage

The local accumulation of fatigue damage is not understood for micron sized materials possessing grain and phase boundaries. This is primarily due to the lack of a characterization technique measuring the decisive material parameters (e.g. local strains, dislocation densities, grain boundary character, etc.) non-destructively with high spatial resolution (<1μm).

Within this project, a new microscope, the so-called ‘Differential Aperture X-ray Microscopy’ (DAXM), combined with a Straining Device is developed. The project is funded by a joint ANR-DFG (French and German science foundation) call.

This combination allows to deform micron sized pure copper bicrystal and measure locally their microstructure evolution in 3D simultaneously. Figure 1 shows a scanning electron microscope (SEM) image together with a 3D reconstruction of the grain orientation. The voxel size of this reconstruction is 1µm³.

The instrument is shown in Fig. 2.

Figure 1: SEM image and 3D reconstruction of an undeformed copper bicrystal cantilever (5x5x25µm³).

Figure 2: Numerical model of the DAX/Straining device developed at BM32.

Go to Editor View