- Cang Zhao, Argonne National Laboratory, Lemont, Illinois
Metal additive manufacturing is about 30 years old. Compared with conventional manufacturing, it provides superior capacity to fabricate parts of geometrically complex shapes. However, it is still far away from being a breakthrough because of the structural defects (e.g., porosity, cracks) and the unfavorable grain and phase structures. In 2016, a state-of-the-art in situ and in-real-time synchrotron-x-ray-based full-field imaging technique and the laser processing system were integrated and combined at the Advanced Photon Source. Many significant phenomena in metal additive manufacturing, such as melt pool dynamics, powder ejection, rapid solidification, and phase transformation, can be examined with unprecedented spatial and temporal resolution with those combined capabilities. In this talk, we will introduce the research progress. The speaker will use laser spattering behavior of Ti-6Al-4V as an example. The discovery opens a door to manufacturing spatter- and defect-free metal parts via precise control of the keyhole dynamics.