Microstructural and Mechanical Behavior of Inoculated Aluminum 7075 Alloy Fabricated through Wire Arc Additive Manufacturing

Wire arc additive manufacturing (WAAM) is an attractive technique to achieve high deposition rates and large volume builds. Aluminum alloy 7075 is used widely for its lightweight properties but is susceptible to solidification cracking during printing, which can be exacerbated by columnar grains formed during build. Grain refinement by addition of inoculants is one solution to mitigating solidification cracking. This presentation explores the role of inoculants in nucleation and microstructural evolution as well as elevated temperature tensile and room temperature fatigue behavior in 7075-RAM2 builds produced with WAAM. Understanding the process-structure-property relationships for inoculated aluminum alloys can enable rapid production of near net shape, high strength aluminum alloy parts with higher buy-to-fly ratios than conventionally manufactured materials.

Sandia National Laboratories is a multimission Laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.