Microstructures and mechanical properties of wire arc additive manufactured 5183-Al: Influences of deposition dimensions

Abstract

Wire arc additive manufacturing (WAAM) is a promising technology to fabricate near-net large-scale structures with reduced cost and improved flexibility. Due to the cathode cleaning phenomenon of electric arc and relatively slow solidification rates, WAAM is suitable for depositing various series of aluminum alloys. The WAAM of complex aluminum parts usually requires deposition layers with diverse dimensions. Understanding the relationship between microstructures, mechanical properties, and deposition dimensions is thus necessary. In this work, WAAM based on gas tungsten arc welding is used to produce 5183-Al components. Three single path multi-layered parts with different layer widths were deposited using ER5183 wires. The influences of layer widths on grain morphology, defects, and mechanical properties were investigated experimentally. And the intrinsic influencing mechanism is analyzed with results from the numerical simulation on the thermal process. Results show that different layer widths lead to changes in solidification rates and temperature gradients, significantly influencing grain morphologies. However, the mechanical properties are found insensitive to the layer width, especially for the microhardness and strength. Larger layer width results in better ductility due to pores reduction. This research provides new findings on the relationship between microstructures, mechanical properties, and deposition dimensions, which is helpful for layer and path geometric optimization in WAAM of complex structures.