Abstract Scope |
The laser-based powder-blown directed energy deposition (L-DED) additive manufacturing process is promising for its fabrication of complex, multi-material metallic parts with superior mechanical parts for a wide range of applications. However, porosity in L-DED parts is common due to rapid solidification and can pose obstacles in qualification and certification. This talk will discuss the fundamental interactions between in-flight powder particles and the underlying melt pool that lead to porosity in the process. High-speed synchrotron X-ray imaging (up to 80,000 fps) experiments at the 32-ID beamline at the Advanced Photon Source in Argonne National Laboratory show porosity mechanisms that originate from feedstock powders, laser attenuation during deposition, the interplay between the kinetic and surface energies during deposition, as well as particle characteristics of shape, size, and chemical composition. In addition, work with external magnetic fields and mixing dissimilar materials for both porosity control and alloy development will be discussed. |