WAAM of Al–Cu Alloy: Effect of Cooling and Remelting on Grain Size and Mechanical Properties

Abstract

Wire arc additive manufacturing (WAAM) can create massive metallic components with high deposition rate. The high deposition rate is coupled with heat accumulation in the deposit caused due to repeated heating. Further, the heat accumulation promotes grain growth and deteriorates the mechanical properties of the deposit. Therefore, the objective of the research is to minimize the heat accumulation in the deposit. In this study, the gas tungsten arc welding-based WAAM technique is used to create 40-layered deposit of 2319 aluminum alloy in air- and water-cooled condition. The effect of cooling and remelting is investigated. Under similar processing conditions, the water-cooled deposit is comprised of finer grains compared to the air-cooled deposit. Remelting favors grain refinement of the top region of the deposit. Under tensile loading conditions, the water-cooled deposit performs better with an ultimate tensile strength of 268 ± 5 MPa.