BeschreibungThe development of novel metallic alloys tailored for additive manufacturing has been in research focus of recent years. While substantial progress was achieved using powder-based processes, fewer efforts have been reported using wire feedstock and most literature in this field is based on commercial welding wires. In wire-arc additive manufacturing (WAAM), a metallic wire is fed into an energy source, such as an electric arc, whereby the wire is melted and deposited according to a predefined path. In this work, we make use of an alloy concept established for high pressure die casting (Al-7Mg-3Si-Mn). This alloy exhibits a large fraction of eutectic and, thus, reduced hot cracking susceptibility. As cooling rates of high pressure die casting and WAAM are similar, comparable microstructure formation upon solidification is expected. The alloy was modified by addition of 1.5 wt.% Zn, promoting further solid solution strengthening and the formation of additional phases with the aim of improving mechanical properties in the as-built and aged material conditions. The alloy was cast using vacuum induction melting and directly extruded to wires with 1.6 mm diameter a rapid procedure for testing novel alloy concepts. Single track walls were then fabricated by Cold Metal Transfer. We present a comprehensive analysis of microstructure formation in correlation with mechanical properties of an Al-7Mg-3Si-1.5Zn-Mn alloy. Microstructure characterization was conducted by scanning electron microscopy (SEM). Phase evolution was substantiated by thermodynamic calculations (MatCalc) and differential scanning calorimetry (DSC). Corresponding mechanical properties were analyzed using microhardness measurements and tensile testing in horizontal and vertical directions. The results provide a sound basis for development of novel aluminum alloys tailored for WAAM processing.
|12 Sept. 2022 → 14 Sept. 2022
|Alloys for Additive Manufacturing Symposium 2022
- Wire-Based Additive Manufacturing