Spatiotemporal mapping of alloy mesostructure dynamics via multimodal coherent X-ray diffraction imaging

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Optimizing mechanical properties of precipitation-strengthened alloys requires understanding their mesoscale structural dynamics.
• Current methods lack the spatiotemporal resolution to capture these dynamic processes in real-time.

Purpose of the Study:

• To establish a multimodal coherent X-ray diffraction imaging framework for mapping mesoscale structural dynamics.
• To visualize and quantify the real-time evolution of microstructures in precipitation-strengthened alloys.

Main Methods:

• Utilized ptychographic reconstruction for wide-field (~100 μm²) imaging over hours.
• Combined dynamic coherent diffraction imaging with X-ray photon correlation spectroscopy for high-resolution (~10 μm², tens of seconds) local dynamics.
• Applied optical flow analysis for quantitative kinetic analysis.

Main Results:

• Visualized real-time nucleation, growth, and coarsening in Mg₉₇Zn₁Gd₂ during isothermal annealing.
• Observed decomposition of (Mg, Zn)₃Gd and precipitation/coarsening of long-period stacking ordered phases.
• Revealed rapid nanoscale precipitate formation (<10 s) and subsequent coarsening.

Conclusions:

• Demonstrated the capability of in situ coherent X-ray techniques for real-time mesoscale structural evolution.
• The developed methodology provides a robust framework for studying dynamic phenomena in diverse materials.
• This approach is applicable to metals, polymers, and nanomaterials under various conditions.