| Abstract Scope |
This study presents a novel approach to thermal monitoring and modeling of Wire Arc Additive Manufacturing (WAAM) by fabricating an 1100 aluminum tube on a 6061 substrate. Unlike conventional methods using thermocouples or fixed pyrometers, temperature is dynamically monitored adjacent to the weld pool using an infrared Mikron pyrometer to emulate the thermal behavior of the weld pool during the process. Data is captured via Infrawin software, enabling real-time tracking of thermal fluctuations following the moving heat source. A finite element model (FEM) with element activation is tuned to accurately replicate these dynamic temperature profiles, including phase change effects. The thermal model advances the Goldak double ellipsoidal heat source by introducing a new term to the standard equations, enhancing its adaptability to complex thermal gradients. Previously validated on stainless steel and 5356 aluminum using fixed thermocouples, this updated model now integrates data from the moving pyrometer on a WAAM 1100 aluminum tube. Semi-ellipsoidal Goldak parameters are derived from post-solidification weld pool dimensions and cross-sectional geometry, ensuring physical consistency. Results demonstrate strong agreement between the model and experimental data, with a double validation of the modified Goldak heat source achieved through fixed and dynamic measurements, yielding a small relative error. Notably, the weld pool expands along the circular path compared to its initial state after idle-time cooling, reflecting the influence of thermal history. The methodology has potential applications in optimizing WAAM processes for aluminum alloys, improving predictive accuracy for weld pool evolution, and enhancing component performance. Scanning electron microscopy (SEM) is being conducted on the sample to analyze grain size, porosity, and microcracks, providing insights into microstructural integrity. |