Thermal process monitoring and control for a near-net-shape Wire and Arc Additive Manufacturing
Daniel Baier, Franz Wolf, Tobias Weckenmann, Maja Lehmann, Michael F. Zaeh
Abstract
Abstract Wire and Arc Additive Manufacturing (WAAM) is a promising technology for the fabrication of large metal parts. During the process, the wire electrode is melted continuously or in a pulsating mode and deposited layer-by-layer onto a substrate. Due to the recurring energy input into the part during WAAM, adequate thermal management is crucial. The temperature distribution, especially the interlayer temperature in the part, is determined by the parameter settings as well as by the dwell times and can be monitored. This paper presents the cause-effect relationships between the interlayer temperature and the dwell times to enable a suitable temperature management. Thermal imaging was implemented during the manufacturing process, allowing the analysis of different interlayer dwell times and their effect on the interlayer temperatures. In addition, the influence of the temperature management on the geometric quality characteristics of the part was investigated. It was observed that a constant interlayer dwell time led to geometric irregularities in the part height and width. Monitoring the interlayer temperature is crucial in WAAM in order to maintain a constant temperature level along multiple layers for meeting the requirements for the geometry of the part and enabling near-net-shape manufacturing.