| Abstract Scope |
Copper-based feedstocks are of interest to the marine, chemical, and aerospace industries for their combination of corrosion resistance and electrical and thermal properties. Furthermore, gas metal arc directed energy deposition (GMA-DED) is an ideal method to produce large scale structural components for these industries. However, more work needs to be done to understand the relationships between processing conditions, microstructure, and weldability of copper-based feedstocks. In this study, a wide range of copper based feedstocks including a nominally pure copper, silicon bronze, aluminum bronze, and nickel aluminum bronze alloy wires were printed using GMA-DED and the solidification structure and weldability were evaluated. A robotic Fronius gas metal arc heat source was used to deposit the copper-based feedstocks using different transfer modes and heat inputs. The builds were sectioned, and solidification structure was characterized using optical microscopy, scanning electron microscopy (SEM), and electron backscattered diffraction (EBSD). Experimental measurements of the solidification structure were compared to model predictions. Measurements of solidification cracking from SigmaJig testing is compared to model predictions of crack susceptibility index. The results of this work are expected to provide a deeper understanding of welding metallurgy of copper-based feedstocks to enable a broader application of these materials for structural applications. LA-UR-24-24142. Keywords: WAAM, copper, weldability, solidification cracking, solidification |