| Abstract Scope |
The current state of the art in the Wire Arc Additive Manufacturing industry involves adjusting a robot’s kinematic programming to deflect from the centerline of the direction of travel, creating certain weaving patterns. This approach, however, can lead to shutdown conditions in certain circumstances when the direction of travel changes, stemming from errors in the robot’s kinematic system which currently cannot be predicted nor recovered from. Moving this weaving profile external to the motion kinematics of the system by deflecting the welding arc through the influence of external magnetic fields would resolve this issue, as well as provide the ability to better tailor the process to the desired final product. While the utilization of external magnetic fields within various welding processes is not a contemporary concept, very seldom is it seen integrated into the wire arc additive manufacturing architecture. Additionally, it is also rarely used in Gas Metal Arc Welding applications outside of narrow-groove welding processes in which current commercially available solutions are analog devices that have limited application due to a lack of programmability and control. Historically used as a process aid in long-run industrial welding applications, such as power piping, or to tailor grain structure in research applications, Magnetic Arc Oscillation involves the use of electromagnets to influence the position of an electric welding arc by varying the external field strength input axially to create a desired amount of deflection. By utilizing this process within the additive manufacturing space, robotic kinematic input required could be dramatically reduced, allowing for a combination of decreased overall build times, comparable quality and increased equipment maintenance windows, all while resolving the aforementioned kinematic programming errors seen in current systems. Hardware and control system development will be discussed, as well as a demonstration and comparison between simulated weave profiles with actual produced welds. |