CMT Assisted Wire Arc Additive Manufacturing of SS 316L: Fabrication, Characterization, and Fractography

CMT-WAAM, an advanced manufacturing technology, garners significant attention due to its ability to fabricate intricate components efficiently. In this investigation, a 40-layered structure was manufactured from SS 316L using the CMT-WAAM process, with the utilization of optimized process parameters. This research involved the analysis of microstructure and mechanical properties, including microhardness, tensile testing, and fractography, for both WAAM and wrought SS 316L. The UTS of WAAM reached 592.31 MPa and YS of 276.46 MPa, outperforming the UTS of wrought 316L, which was 557.62 MPa, and YS of 284.35 MPa. The PE of WAAM was 59.85%, while for wrought 316L, it was 53.20%, indicating that wrought 316L demonstrated a higher ductility than the WAAM part. The microhardness profile of WAAM showed an average value of 238.14 HV, indicating a 28% increase compared to the MH of wrought 316L, which was measured at 192.37 HV. The microstructure of CMT-WAAM displays δ-ferrite and γ-austenite, along with skeletal and lathy ferrites, similar in wrought 316L. The fractography analysis of tensile specimens exhibited numerous dimples, indicating favorable ductility in the fabricated structure. Therefore, the findings indicate that the CMT-WAAM process meets industrial requirements.