A knowledge mapping of the state-of-the-art on DED-WAAM deposition trajectory evaluation

This article aims at mapping the current knowledge related to DED-WAAM in order to assess and control the deposition trajectory and associated manufacturing strategy, especially the toolpath, for building weld beads with DED-WAAM technology. To do so, a thorough state of knowledge study from a group of experts and a targeted list of scientific articles points out several issues identified as critical parameters or handles due to their influence onto the deposition trajectory throughout the WAAM manufacturing process, and therefore onto the final part quality. For instance, the studied elements in this work are namely the trajectory generation variables (e.g. deposition rate, fixtures or substrate geometry), the heating parameters (e.g. arc power or heating devices), the manufacturing time management, the weld bead shape defects, the workpiece geometry, or the final part quality indicators. Thanks to a global research methodology, the resulting maps represent the interrelations between the WAAM parameters as well as the multi-physical phenomena at stake before, during and after building a weld beadand encompasses various scientific challenges, whether geometrical, mechanical or thermal. Therefore, they contribute to understanding the main performance criteria for assessing a deposition trajectory, guiding WAAM practitioners' decisions before building a complete part with this additive technology.