Structure-based phase identification in aluminum alloys using Kikuchi band and Hough-based EBSD

Accurate phase identification in aluminum alloys is critical for optimizing material properties and performance, yet remains challenging due to the low volume fraction, compositional overlap, and morphological similarity of intermetallic phases. This study presents a comprehensive methodology for phase discrimination in a case study of AA5182, integrating optimized sample preparation—including ion milling—with high-resolution electron backscatter diffraction (EBSD) and complementary energy-dispersive X-ray spectroscopy (EDS). Kikuchi band width analysis within a conventional Hough-based indexing framework enables differentiation of structurally similar phases, including those sharing crystallographic symmetries with the aluminum matrix. The approach is validated through correlative EBSD-EDS mapping and demonstrates improved indexing reliability without reliance on computationally intensive pattern-matching algorithms. Compared to advanced techniques such as dictionary and spherical indexing, the proposed method offers a scalable, accessible solution for accurate phase identification and microstructural interpretation in complex alloy systems. These findings support both research and industrial applications, bridging the gap between advanced algorithms and routine characterization workflows. • Optimized sample prep improves EBSD pattern quality in aluminum alloys. • Kikuchi band analysis enables phase ID in structurally similar intermetallics. • EBSD-EDS mapping enhances phase discrimination and cross-validation. • Hough-based indexing offers scalable phase analysis without heavy computing. • Structure-based EBSD resolves limits of composition-only phase identification.