Resolving bimodal grain distribution in Zr-Al alloy with high efficiency and accuracy

Instruments used

EDAX^® Velocity™ Ultra EBSD camera, OIM Analysis™, and OIM Matrix™

Background

Zirconium alloys are highly valued in industries requiring materials with exceptional corrosion resistance, robust mechanical properties, and stability under extreme conditions. The addition of aluminum to zirconium not only significantly enhances the alloy’s strength but also improves its high-temperature stability and oxidation resistance. This makes Zr-Al alloys suitable for demanding applications in extreme environments, such as aerospace and high-performance industrial settings. However, hot-rolled Zr-Al samples typically exhibit considerable strain and a complex microstructure characterized by small spheroidized and larger primary grains. This bimodal grain distribution, combined with mixed phases of Zr HCP and Zr-Al FCC, poses significant challenges for efficient and accurate electron backscatter diffraction (EBSD) characterization. To address these challenges, we developed a high-speed EBSD system paired with a robust spherical indexing algorithm, enabling precise analysis of these intricate microstructures.