In recent years, large spills from oil pipelines and tankers, leaks from nuclear reactors and the constant need for lighter, stronger, and safer materials in the transportation industry illustrate how breaks or cracks (fracture) can have detrimental effects in terms of health and safety, the environment, and the economy. Recent reports also suggest that the costs of fracture in Europe reach 4% of Europe’s gross domestic product which means about 500 billion euros. There is therefore a growing need for materials with improved fracture resistance. When materials are deforming during in-service use, there is a point at which very small voids start appearing inside the material, whose diameters are less than a hundreds of the width of a human hair. These tiny voids grow, and when they are large enough, they link with each other resulting in material failure. Knowing how fast these voids grow is therefore a key aspect to understand when materials will fail. Most work to date has been focused on rather large voids and there is very little experimental information on the mechanisms of void growth at lower scales (i.e. the microscale). This lack of information on fracture at the microscale is one of the key factors that prevent better fracture predictions and the design of damage resistant materials.
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.
