A more holistic characterisation of internal interfaces in a variety of materials via complementary use of transmission Kikuchi diffraction and Atom probe tomography

Changes in the chemistry of internal interfaces, particularly grain boundaries, are known to affect the macroscopic properties of a wide range of material systems. Solute segregation to grain boundaries is dependent on, amongst other factors, the physical structure of the grain boundary. We demonstrate how complementary use of transmission Kikuchi diffraction (TKD) and atom probe tomography (APT) can provide a more holistic characterisation of grain boundaries in a variety of materials. Structural information is reported from TKD data for a model steel, a titanium alloy, and a multicrystalline silicon sample. Complementary APT analyses are used to determine the segregation behaviour to these interfaces. A novel specimen preparation protocol allows for the grain boundary to be positioned more reliably within the apex of an APT specimen. Meanwhile, a method that allows a grain boundary's five macroscopic degrees of freedom to be determined from TKD data alone is also proposed.