Low cost platform for hybrid manufacturing of light metals

Wire arc additive manufacturing (WAAM) uses an electric arc to locally melt and fuse wire to build parts layer by layer. The benefits are a high deposition rate, dense final structures, compatibility with light metals such as aluminum and magnesium, and low cost. In gas metal arc welding (GMAW), wire is fed continuously into the arc where it is melted to form a bead. WAAM parts typically need to be finish machined to achieve the desired final part geometry and surface finish on functional surfaces. This creates a challenge when moving from an additive machine to a traditional machining center, as it is difficult to align machine axes without reference features. One potential solution is hybrid manufacturing, where the additive process and machining center are coupled. The work coordinate systems for the additive deposition and subtractive machining spindle are set from the same reference, enabling the part to be built and machined in the same setup. This reduces the required overbuild to ensure the part is encompassed by the printed structure and decreases setup time. In this work, a commercial gas metal arc welder was mounted adjacent to a machine spindle and is triggered using the machine controller. A fixture plate was designed to isolate the machine from the thermal and current input. To develop an understanding of the process, a 5356 aluminum wire alloy was chosen as a less expensive and better understood alternative to more costly light metals, such as magnesium.