Abstract
Directed energy deposition-arc (DED-Arc) is a promising additive manufacturing technique for efficiently and cost-effectively producing large-scale, complex aluminum exterior members. However, achieving uniform thickness in structures fabricated by DED-Arc remains challenging due to heat accumulation and other process-related factors. This study aimed to suppress thickness variation in aluminum components fabricated by DED-Arc by using a deposition strategy incorporating interpass temperature control, and further evaluated their structural performance. Interpass temperature control regulates the temperature between deposition layers to reduce heat buildup, leading to a more consistent material deposition and reduced variation in thickness. In addition, the geometric accuracy, tensile strength, and compressive strength of aluminum stub column specimens produced using this approach were evaluated. Compression tests were conducted on specimens with and without thickness variation to assess the impact of thickness variation on buckling performance. This approach helps predict the design strength based on the width-to-thickness ratio, regardless of the variation in thickness. Furthermore, a buckling mode transition, indicating a shift in the deformation pattern under compressive loads, was observed at a width-to-thickness ratio of approximately 12.5, offering insights into the structural stability of these components. This study demonstrates that combining a DED-Arc process incorporating interpass temperature control with a width-to-thickness ratio-based evaluation enables the fabrication of structurally reliable aluminum components, even in the presence of thickness variation.
