Microstructure evolution and mechanical properties of wire-arc-additively manufactured Al–Cu–Mg–Ag alloy

Abstract

In this article, Al–Cu–Mg–Ag specimens were successfully wire-arc-additive-manufactured based on by gas metal arc process to investigate the evolution of microstructure and mechanical properties. The results showed that the grain morphology and pore size in the printed specimens varied in height direction. Under the influence of repeated thermal cycling, which affected the solid-state diffusion of the deviated elements at the grain boundaries, the distribution of the nanoscale second phase appeared significantly different in the height direction. The precipitation phase changes caused the microhardness of the printed specimens to decrease gradually from a peak of 125 HV and stabilise at around 100 HV. The changes in the printed specimens’ horizontal mechanical properties were insignificant mainly due to interlayer porosity.