Wire-arc directed energy deposited high-performance AZ31 magnesium alloy via a novel interlayer hammering treatment

The inferior performance of additive manufactured magnesium (Mg) alloys has become an obstacle to their wider application in the aerospace and automotive industries. In this study, hybrid additive manufacturing and interlayer hammering techniques was employed to fabricate AZ31 Mg-alloy components. The defects characteristic, grain structure, dislocations, crystallographic texture, and electrochemical corrosion performance of the additively manufactured and interlayer hammered samples with different deformation levels were analyzed systematically. Compared with the virgin wire-arc directed energy deposited (DED) sample, the yield strength (YS) and ultimate tensile strength (UTS) of the interlayer hammered samples increased from 102.6 to 239.8 MPa–140.6 MPa and 259.2 MPa, respectively, which exceed those of their wrought counterparts. The improved YS of interlayer hammered AZ31 are mainly ascribed to the grain refinement and increased dislocation density. In addition, the electromechanical corrosion performance was superior to that of the additively manufactured sample as well. This study thus sheds new insights into defect alleviation, microstructure modification and performance enhancement of additive manufactured Mg-alloys via a novel interlayer hammering treatment.