3D characterization of abnormal grain growth in nanocrystalline nickel

Abstract

Abstract Abnormal grain growth, a pervasive phenomenon witnessed during the annealing of nanocrystalline metals, precipitates a swift diminution of the distinctive properties inherent to such materials. Historically, conventional transmission electron microscopy has struggled to efficiently procure comprehensive five‐parameter crystallographic information from a substantial number of grain boundaries in nanocrystalline metals, thus inhibiting a deeper understanding of abnormal grain growth behavior within nanocrystalline materials. In this study, we utilize a high‐throughput characterization method—three‐dimensional orientation mapping in the TEM (3D‐OMiTEM) to characterize the crystallographic five‐parameter character of grain boundaries with an area of over 3.4 × 106 nm2 in an abnormally grown nanocrystalline nickel sample. When coupled with existing theoretical simulation results, it is discerned that the grain boundary population shows a relatively large scatter when it is correlated to the calculated grain boundary energy; the grain boundaries of abnormally grown grains exhibit lower grain boundary energy compared to those that have not undergone abnormal growth. Merging high‐throughput grain boundary information obtained from three‐dimensional orientation mapping data with grain boundary properties derived from high‐throughput theoretical calculations following the concept of materials genome engineering will undoubtedly facilitate further advancements in comprehending and discerning the interfacial behaviors of crystalline materials.

Keywords

• 3D reconstruction
• 3D‐OMiTEM
• grain boundaries
• grain growth
• nanocrystalline metals