Periodic Reporting for period 1 - MicroFrac (Visualization and modelling of fracture at the microscale)
Reporting period: 2015-07-01 to 2016-06-30
The investigations carried out under the MicroFrac project (a research project funded by the European Union under the Marie Skłodowska-Curie actions) aimed at providing a contribution towards our understanding of fracture at the microscale through a combination of state-of-the-art experiments and models.
These results allowed us to better understand the early stages of fracture in metals, when voids are still very small. The preliminary simulations results are very promising for the development of advanced simulation tools to more accurately predict when materials will break and to design fracture resistant materials.
A 2-dimensional configuration was first created using the Focused Ion Beam, a technique which allows for the machinig of a void within a single grain. The sample was then deformed inside a Scanning Electron Microscope where the growth of the voids can be observed in details. 3-dimensional samples were also created by drilling voids in metallic sheets and bonding them at high temperature. The growth of the voids was visualized using x-ray tomography as shown in the figure.
Experimental void growth results were then compared to advanced simulations, where the effect of the underlying grain orientation was accounted for.
These results allowed us to better understand the early stages of fracture in metals, when voids are still very small.
The preliminary simulations results, some of them already published, are very promising for the development of advanced simulation tools and to design fracture resistant materials.