The evolution in microstructure and local crystallography is described, with emphasis on the behaviour of medium to high stacking fault energy FCC metals deformed at low temperature. This evolution is analysed within a common framework of grain subdivision on different size scales. The largest scale is the macroscopic subdivision of crystals or grains, which will be presented using the behaviour of single crystals as an example. Subdivision on smaller scales is demonstrated for polycrystals, with emphasis on the effects of strain and grain orientation on the evolution in microstructure and local crystallography. This leads to an introduction of structural parameters and their analysis using a scaling hypothesis. A key finding is the correlation between structure and crystallographic orientation, which allows a slip pattern description by standard crystal plasticity models leading to an analysis of the relationship between slip pattern and microstructure. These findings are briefly related to the macroscopic properties of deformed metals.

We observed the in situ growth of a grain during recrystallization in the bulk of a deformed sample. We used the three-dimensional x-ray diffraction microscope located at the European Synchrotron Radiation Facility in Grenoble, France. The results showed a very heterogeneous growth pattern, contradicting the classical assumption of smooth and spherical growth of new grains during recrystallization. This type of in situ bulk measurement opens up the possibility of obtaining experimental data on scientific topics that before could only be analyzed theoretically on the basis of the statistical characterization of microstructures. For recrystallization, the in situ method includes direct measurements of nucleation and boundary migration through a deformed matrix.