Hybrid Additive Manufacturing of Island Grain Bicrystals...

We demonstrate cylindrical island grain bicrystals grown via a hybrid additive manufacturing/directional solidification technique. The island grain bicrystal is formed using a specialized mold in which one grain (the island) is enveloped by another larger grain (the surrounding matrix). The grain boundary plane orientation varies continuously around the circumference of the island grain, making these specimens ideal for probing grain boundary structure–property relations. We report thermal groove angle measurements along the grain boundary in a tin island grain bicrystal which show the grain boundary energy as a function of a single degree of freedom in the five-dimensional grain boundary parameter space.