Research on transition layer microstructure and properties of Al–Cu/Al–Si gradient materials fabricated by cold metal transfer

Abstract

As an important part of the additive manufacturing technology, wire arc additive manufacture (WAAM) is outstanding with high deposition efficiency, large size of deposited parts, short periodic time, and low costs. WAAM also shows potential in in-situ composite manufacturing and gradient material preparation. Given the potential in wire arc manufacturing of double-alloy gradient structured materials, the walls were deposited using alternating feeds (depositing a layer of A wire and then depositing a layer of B wire) of high-strength-low-plasticity ZL205 and low-strength-high-plasticity 4043 welding wire. In this process, the liquid phases of the two types of wire were efficiently mixed, which showed a regular distribution of molten pool track and avoided evident defects. Generally, through such gradient structure design, high-strength low-toughness materials and high-toughness low-strength materials can be effectively combined, which achieves the regulation of mechanical properties. Specifically, the overall structural and mechanical properties can be improved by adjusting the proportion of a certain component. As an extension from the wire arc printing technology, WAAM shows extremely high application potential and industrial values. Moreover, the addition of a dissimilar alloy can decrease the formation of columnar grains during additive manufacturing. Such compositional gradient can destroy the columnar extensive growth during the deposition in WAAM.