The Role of I£9 Boundaries in Grain Boundary Engineering

In a grain-boundary-engineered (GBE) microstructure, I 9 pound boundaries are the second most abundant boundary type. This article presents data showing that, in GBE copper, most I 9s pound were special. I 9 pound boundaries are also a geometrically necessary component of a GBE microstructure. It is suggested that there are competing requirements for I 9s; pound during iterative GBE processing, they are required to be mobile, whereas afterward, it is desirable that they are special boundaries.