Abstract: Magnesium alloys are the lightest metal structural materials owing to their excellent physical and chemical properties. Microstructural evolution in magnesium alloys under the conditions of casting, thermal-mechanical processing, and in-service environment, play an important role in governing their mechanical properties and reliability/sustainability. A synchrotron light source produces high flux, tunable X-ray energy, high resolution, and high coherence X-ray beams, which can realize in-situ dynamic observation of microstructural evolution in a wide range of alloys during the entire processing chain and in simulated service environments. This article reviews the fundamentals of synchrotron radiation characterization techniques (imaging, diffraction, scattering, and fluorescence holography) and state-of-the-art advanced synchrotron characterization techniques on the microstructure evolution mechanism of magnesium alloys. Case studies span a broad range of solidification, deformation, precipitation, fracture and damage, corrosion, and energy storage. Research opportunities and challenges of physical metallurgy studies of magnesium alloys are highlighted for future studies.

Key words: Synchrotron radiation, Magnesium alloy, Solidification, Deformation, Microstructure evolution