Design and prototyping wire arc additively manufactured aluminum alloy lattice structures

Aluminum alloy lattice structures have important application prospects in modern engineering, construction, and lightweight manufacturing of key industrial components. The current "dot-by-dot" manufacturing method, using Wire Arc Additive Manufacturing (WAAM) with Cold Metal Transfer (CMT) as the heat source is an important way to achieve integrated manufacturing of large-sized and complex aluminum alloy lattice structure. In this paper, a detailed study is conducted on the design and prototype manufacturing of aluminum alloy dot-by-dot deposition process. Single strut design, "X lattice unit" design and geometric parameter design are explored through characterization of both microstructural and mechanical properties. The porosity, microstructure, and mechanical properties of the lattice strut in different areas were studied. The majority of pores were present between each layer deposition and accumulated in the line bridge area. A detailed discussion was then conducted on the formation mechanism of pores in aluminum alloy struts and the deposition strategy of the so-called X lattice unit. Finally, the manufacturing of a circular lattice structure composed of X lattice unit was achieved through deposition strategies control.