Analysis of AISI 316L-Ti Graded Deposition Fabricated by Wire and Arc Additive Manufacturing

Abstract

Manufacturing of steel and titanium-based bimetallic material using cold metal transfer-based wire arc additive manufacturing (CMT-WAAM) is a novel exploration. It can be helpful in on-line repairing of dissolver tank piping in nuclear reactor power plants. In the present work, owing to the unique characteristic of lower heat input, CMT-WAAM was used for fabrication of AISI 316L-Ti graded structure on the AISI 316L substrate. The deposition shows apparent cracks and delamination at the bimetallic interface. The interface microstructure mainly consists of Fe–Ti intermetallic compounds (IMCs) of cellular and dendritic shapes and their boundaries were wetted by Cr–Ti IMCs. However, the cellular grains were fine and equiaxed and there was no evidence of presence of large columnar grains. EDS results show that the total graded region was of approx. 6 mm and Fe shows deeper penetration into Ti due to lesser requirement of activation energy. The presence of brittle IMC phases was also confirmed by the XRD analysis. Graphical Abstract: [Figure not available: see fulltext.] © 2023, The Indian Institute of Metals - IIM.