How do metals work harden and fail?

The proposers, who pioneered DFXM, have recently visualized the formation and subsequent division of 40,000 dislocation cells during plastic deformation – revealing the underlying physical mechanisms and showing these to exhibit scaling. In this LTP we generalize the methods to visualize the structural evolution at higher degrees of plastic deformation - all the way to materials failure. Specifically, we will address the fundamental questions of: How does the organization of dislocations lead a sample to become stronger? How does a sample break? When and where does the failure nucleate (in terms of voids forming)? How does the local structure and stress control the void coalescence and thereby crack formation? To facilitate this, we will provide an MLL objective to improve the spatial resolution from 150 nm to 30 nm and we will improve visibility of dislocations by 2 orders of magnitude by use of Fourier optics. We will also implement HR-3DXRD, based on a unique 150 Mpixel camera.