Improving mechanical properties of additive manufactured AZ31 by mechanical rolling

The mechanical performance of AZ31, a popular aerospace structural material, manufactured using CMT-WAAM was studied in this paper. A wall of 70 × 200 × 4 mm was built by layer-by-layer deposition of 4 mm thick beads. The influence of rolling along the direction of welding on hardness, tensile strength and residual stress was investigated and compared with the control build fabricated using “synergic” parameters recommended by Fronius, Austria. The specimens extracted from the AM (Additive Manufacturing) built walls were subjected to cross-section reduction up to 22.5% compared to control specimens. The rolled specimens displayed up to 10% increase in the tensile strength values compared to control specimens and a generally lower elongation value. A similar trend was observed in the hardness examination as well. A peak hardness of 77 HV0.5 was observed in the specimen subjected to 22.17% reduction. The rolled samples exhibit a 14.32% reduction in residual stresses.