Seeing how grain boundaries transform in a metal
Grain boundaries are one of the most prominent defects in engineering materials separating different crystallites, which determine their strength, corrosion resistance and failure. Typically, these interfaces are regarded as quasi two-dimensional defects and controlling their properties remains one of the most challenging tasks in materials engineering. However, more than 50 years ago the concept that grain boundaries can undergo phase transformations was established by thermodynamic concepts, but they have not been considered, since they could not be observed. Dr. Christian Liebscher, head of the group "Advanced Transmission Electron Microscopy" and his team members at the Max-Planck-Institut für Eisenforschung (MPIE), now found a way to directly observe grain boundary transitions experimentally. With colleagues from the Lawrence Livermore National Laboratory (LLNL), U.S., who modeled the grain boundary transformations, the researchers published their recent findings in Nature.