Investigation of effects of repair sequence on residual stress distribution and post-deformation to repair metallic parts using a directed energy deposition process
摘要
Directed energy deposition (DED) processes have been widely used to repair metalllic parts in industrial areas. The rapid heating and cooling phenomenon during the repair causes excessive residual stress in the vicinity of the repaired region and post deformation of the repaired part. The repair strategy, including the repair sequence, greatly affects the residual stress and the post-deformation characteristics of parts repaired by the DED process. The goal of this study is to investigate the effects of the repair sequence on the residual stress distribution and the post-deformation of metallic parts with multiple repaired regions using thermo-mechanical analyses. Three continuous sequences and two discountinuous sequences are designed. From the results of thermo-mechanical analyses, the influence of the repair sequence on residual stress characteristics in the vicinity of repaired regions and the post-deformation pattern of repaired parts is quantitatively examined. Finally, an appropriate repair sequence to simultaneously reduce the residual stress and the post-deformation of a metallic part with multiple repaired regions is proposed.