| Abstract Scope |
Additive friction stir deposition is a newly-developed solid-state additive process that enables freeform metal fabrication by integrating the friction stir principle with material feeding. While it holds the promise of achieving refined, equiaxed microstructures and excellent mechanical properties in the as-printed state, the process fundamentals have remained elusive. In this talk, I will give an overview of the in situ monitoring strategies for additive friction stir deposition, with the aim to better understand the temperature evolution, force/torque evolution, interface contact, and the material flow behavior. From these studies, empirical relationships are established between the peak temperature and processing parameters, while various force and torque regimes are determined for the plunge and deposition phases. Moreover, a comparative study of printing Al and Cu provides new insights into the role of intrinsic material properties, such as forgeability and friction coefficient, in heat generation and plastic deformation during the process. |