Effects of Process Parameters on Thin-Wall Substrate WAAM Deposition

Abstract

Wire arc additive manufacturing can produce thin-walled components at much faster rates than conventional subtractive manufacturing processes. The as-built components have a poor surface finish, which requires post-processing via machining. However, tool reach limitations of cutting tools means that the desired component must be produced in sections, where the hybrid manufacturing process is conducted iteratively. A key aspect of this hybrid manufacturing process is the deposition of the first bead onto the previously machined component section, a thin-walled substrate. Since the deposition traverse speed and wire feed rate heavily impact geometry, and therefore the subsequent machining process, this work seeks to analyze the thin-wall substrate deposition geometry resulting from different deposition process parameters. Additionally, this work assesses the impact of the deposition geometry on subsequent machining by assessing the area of excess material which must be removed to achieve net shape geometry. Traverse speed was found to have the largest impact on bead morphology, with wire feed speed having an increased impact at higher traverse speeds. The penetration and remelting geometry of the samples was investigated and found to contribute to the relatively uniform bead height seen in the different samples.