Effect of stepover and torch tilting angle on a repair process using WAAM

To sustain the transition to a greener economy and greener manufacturing, it is necessary to develop new approaches and technologies to repair metal components; this will result in a drastic reduction in energy and material usage. In this study, wire arc additive manufacturing (WAAM) was used to deposit a layer of new material on an existing surface, with the objective of finding the optimal configuration that maximized the layer quality and material efficiency. The parameters considered are the stepover among the deposited beads and the inclination of the torch with respect to the repaired surfaces. The inclination angle is crucial when repairing complex surfaces, like those of a mold, owing to accessibility issues, the torch cannot be maintained orthogonal to the surfaces along the entire toolpath. Different configurations were tested in order to assess the quality of the materials in terms of the presence of material voids, depth of penetration, and the heat affected zone (HAZ) and to understand the effects of these variables on the material efficiency and thickness of the repairing layer. It should be noted that by adopting deposition parameters set to have a low heat input, the use of a tilting angle has beneficial effects on the quality of the deposited layer and the process efficiency. Metallurgical and geometrical measurements were carried out to assess the effect of these two variables depositing a layer of plain carbon steel.