Experiments on Aluminum Alloy Additive Layer WAAM Lamination Using the Arc Current Reduction Technique

Abstract

Recent advancements in additive manufacturing have been propelled by innovations in processes, materials, and fabrication techniques. This study focuses specifically on optimizing Wire and Arc Additive Manufacturing (WAAM) within the Gas Metal Arc Welding (GMAW) process. The goal is to build laminated layers using aluminum alloys from the five-thousand series. A novel technique is introduced in this research that employs reduced arc-current during the additive layer progress for aluminum alloys, along with a double pulse current in the GMAW process to enhance weldability. The material used for layer addition is ER5356 aluminum wire, which is applied to an Al-5083 substrate. This study successfully optimized a close-path structure comprising up to 20 layers. These layers serve as the basis for evaluating laminate formation, effective dimension, and imperfection occurrence to achieve a near-net shape with low additive defects. A thorough evaluation was conducted to identify the suitable conditions for successful laminate build-up. Additionally, a metallography analysis was performed to examine the chemical distribution and microstructure grain size. The results revealed insignificant chemical distribution and composition along the additive layer cross section under suitable conditions. Furthermore, the grain size measurements indicate that lower reduced arc current conditions led to the formation of finer grains, implying superior mechanical properties. This research provides significant insights into GMAW enhancement for aluminum additive manufacturing, underscoring the importance of process parameters, material choice, and fabrication techniques in obtaining improved laminate formation, microstructure, and mechanical performance results. The developed WAAM laminated layers are particularly suitable for fabricating or repairing large-scale components such as ship propellers, hull sections, and offshore platform structures. Additionally, the corrosion-resistant properties of aluminum alloys make them suitable for applications in marine and offshore environments.