Karina Hemmendinger¹, Joel Bahena¹, Andrea Hodge¹; ¹University of Southern California

5xxx series aluminum alloys are susceptible to sensitization, where magnesium beta-phase precipitates at the grain boundaries increase the likelihood of intergranular corrosion. One method that could improve the corrosion resistance of these materials is to increase the proportion of special grain boundaries (Sigma ≤ 29) through grain boundary engineering. Thus, films of 5xxx series aluminum were synthesized via magnetron sputtering to study the effect of sputtering rate on the proportion of special grain boundaries.Electron backscatter diffraction (EBSD) was used to determine the grain structure, grain orientations, and distribution of special grain boundaries through the material. Standard EBSD and transmission EBSD (t-EBSD) were performed. Analysis of EBSD measurements and TEM images showed a correlation between sputtering rates and the fractions of special grain boundaries, as well as between sputtering rates and grain diameter.