Defining and Modeling of Height-Related Geometrical Parameters for Thin Wall Structures Manufactured by Metal Additive Manufacturing

Cold metal transfer wire and arc additive manufacturing (CMT-WAAM) is a type of metal additive manufacturing technology that has attracted attention in recent years due to its ability to print walls with less dimensional inaccuracies than regular WAAM. To print near net shape parts by CMT-WAAM, there is a need to define a set of height-related geometrical parameters (HGPs) that can capture, quantify, and compare the quality of the height of the produced parts. In this study, a set of HGPs, namely, the average height error (AHE), maximum height variation (MHV), and average absolute slope (AAS) are defined and assessed. Fifteen single-track multi-layer walls are printed to check the effect of process parameters on the defined HGPs. It is found that the stability of the print cannot be guaranteed by checking the visual appearance of the single beads and at least five-to-ten-layer walls should be printed to check the quality and stability of the print. It is also found that the travel speed (TS) and wire feed speed (WFS) have positive monotonic relationships with AAS and MHV, respectively. Correlations between process parameters and HGPs are modeled and validation tests are performed to check the validity of the developed models. The defined three HGPs are shown to be able to quantify, capture, and compare the quality of a height of a wall and can be used for other similar applications.