High-throughput betatron X-ray tomography of pore evolution in additively manufactured alloys*

We apply betatron x-ray sources for high-resolution, high-throughput imaging of porosity evolution in additively manufactured (AM) AlSi10Mg alloys. Using the Advanced Laser Light Source in Varennes, Canada, betatron source was optimized for high-throughput imaging at 2.5 Hz. The x-ray spectrum, flux, stability, spatial resolution, and emission length from gases (He, N₂, He+N₂) was evaluated to obtain image quality and minimized acquisition time. Using He+N₂ gas at 2.5 Hz, tomographic scans of AlSi10Mg samples over 180° at 3° increments were obtained in about one hour. This rate of tomography enabled high-throughput imaging of AlSi10Mg samples under different tensile loads, providing visualization of micrometer pore evolution and coalescence prior to material fracture. These measurements will support development of porosity evolution curves that are pivotal to validate material degradation models and explain fracture mechanisms in AM alloys. High-throughput imaging using betatron sources has the potential to accelerate characterization of complex mechanical processes in novel materials.