Distribution of Grain Boundaries in Aluminum as a Function of Five Macroscopic Parameters

The grain boundary character distribution in commercially pure Al has been measured as a function of lattice misorientation and boundary plane orientation. The results demonstrate a tendency to terminate grain boundaries on low index planes with relatively low surface energies and large interplanar spacings. The most frequently observed grain boundary plane orientation is (111). However, there are also instances where boundaries terminated by higher index planes have significant populations. For example, certain twist configurations on {11w} planes, which correspond to symmetric [110] tilt boundaries, also have relatively high populations. The population of symmetric [110] tilt boundaries exhibits an inverse relationship with previously measured energies.