Characterization of Grain Boundary‐Engineered Aluminum–Magnesium Alloys

Abstract

Herein, the effect of sputtering rate on the fraction of special grain boundaries in 5xxx series Al–Mg alloys is explored. Samples are synthesized via interrupted direct current (DC) magnetron sputtering with varying deposition rates, and the grain size and grain boundary character are evaluated with electron backscatter diffraction (EBSD). The highest sputtering rate (7 nm s−1) leads to an increase in the total number of special grain boundaries, ≈1.5× greater than that of the lower rates. Increased thermal energy and enhanced stress relaxation during film growth promote the formation of Σ3 and Σ7 boundaries.