The relation between microstructure and crystallographic orientation in rolled copper and brass

The relation between microstructure and crystallographic orientation is investigated in rolled copper and brass. For the two main types of microstructure in copper (the high wall density and the low wall density structure) there is a certain relation: the orientations corresponding to a specific type tend to cluster in certain regions of orientation space.

However, the clustering is not very pronounced (there is a lot of overlap), and it cannot be related to any model. There is also a certain grain-size effect: the average grain with high wall density structure is larger than the average grain with low wall density structure. For a third type of microstructure (to be described) there is a very clear relation to the crystallographic orientation.

For brass the distinction is between grains with and grains without deformation twins. There is a clear trend for the grains with twins to cluster in certain regions of orientation space - regions with relatively high resolved shear stress on a twin system. But also in brass there is a significant overlap - between the orientations of grains with and grains without twins.

We ascribe the ambiguities in the relation between microstructure and orientation to grain-to-grain interaction: because of the variations in the orientations of the neighbouring grains, different grains with a specific crystallographic orientation do not necessarily behave in the same way.