Influence of build up height on residual stresses in additive repair and modification using DED Arc

  • Directed Energy Deposition (DED)-Arc is suitable for the hybrid additive manufacturing, modification and repair of large metal components with high deposition rates. Residual stresses and distortion are of central importance when characterizing the manufactured components and the sensitive transition area between AM component and semi-finished product. Residual stresses caused by the thermal cycles during the manufacturing process can impair the mechanical properties of the manufactured parts and can lead component failure. Therefore, understanding and controlling residual stresses, especially when combining different base and filler materials, is critical to improving the quality and efficiency of the hybrid DED-Arc process. This article deals with the influence of the build-up height on the residual stress distribution of additively manufactured components with a selected base and filler material combination. Using a robot-assisted DEDsystem and a controlled short arc, systematicDirected Energy Deposition (DED)-Arc is suitable for the hybrid additive manufacturing, modification and repair of large metal components with high deposition rates. Residual stresses and distortion are of central importance when characterizing the manufactured components and the sensitive transition area between AM component and semi-finished product. Residual stresses caused by the thermal cycles during the manufacturing process can impair the mechanical properties of the manufactured parts and can lead component failure. Therefore, understanding and controlling residual stresses, especially when combining different base and filler materials, is critical to improving the quality and efficiency of the hybrid DED-Arc process. This article deals with the influence of the build-up height on the residual stress distribution of additively manufactured components with a selected base and filler material combination. Using a robot-assisted DEDsystem and a controlled short arc, systematic step cancellation tests were carried out at a selected working temperature (200 C°) and heat input (600 kJ/m). In a 5-stage termination experiment, straight walls were produced using a one bead per layer strategy and selected increasing component heights between 15 mm and 300 mm. The influence of the build height on the longitudinal residual stress in the process direction was analyzed and discussed. All experiments showed a comparable stress distribution in the area of the substrate plate up to the heat-affected zone (HAZ) and the transition zone, regardless of the buliding height. However, the height showed a significant influence on the of residual stress distribution of the deposited AM-component. High positive stress gradients with a maximum range between 300 MPa to 400 MPa were always found in the last approx. 18 component layers (upper 40 mm), which can be explained by the shrinkage of the nonheat- treated top layer. Underlying layers, where present, showed a homogeneous residual stress distribution characterized by low compressive stresses. This can be explained by the process related tempering during the deposition of the upper layers. A constant boundary layer number was determined for all specimens. Once this number was exceeded, the distribution of residual stresses no longer changed, but merely shifted with the increasing height of the component in the direction of build-up. These correlations contribute to the understanding of residual stress development with increasing structure height. This study is part of a running research project on the properties of hybrid additive components and processes. It aims the stress optimized hybrid additive manufacturing of high-strength components and the necessary recommendations for application.zeige mehrzeige weniger

Volltext Dateien herunterladen

  • 2025-06-19_Slides_IIW_2025_scharf-wildenhain_lite.pdf
    eng

Metadaten exportieren

Weitere Dienste

Suche bei Google Scholar Anzahl der Zugriffe auf dieses Dokument
Metadaten
Autor*innen:R. Scharf-Wildenhain
Koautor*innen:Lorenz Engelking, A. Hälsig, Dirk Schröpfer, J. Hensel, Thomas Kannengießer
Dokumenttyp:Vortrag
Veröffentlichungsform:Präsentation
Sprache:Englisch
Jahr der Erstveröffentlichung:2025
Organisationseinheit der BAM:9 Komponentensicherheit
9 Komponentensicherheit / 9.2 Versuchsanlagen und Prüftechnik
9 Komponentensicherheit / 9.4 Integrität von Schweißverbindungen
DDC-Klassifikation:Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Ingenieurwissenschaften und zugeordnete Tätigkeiten
Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Angewandte Physik
Freie Schlagwörter:Additive manufacturing; DED-Arc; Residual stress
Themenfelder/Aktivitätsfelder der BAM:Energie
Energie / Windenergie
Material
Material / Additive Fertigung
Veranstaltung:78th IIW Annual Assembly and International Conference on Welding and Joining
Veranstaltungsort:Genoa, Italy
Beginndatum der Veranstaltung:22.06.2025
Enddatum der Veranstaltung:27.06.2025
Verfügbarkeit des Dokuments:Datei im Netzwerk der BAM verfügbar ("Closed Access")
Datum der Freischaltung:18.12.2025
Referierte Publikation:Nein
Eingeladener Vortrag (wissenschaftliche Konferenzen):Nein
Einverstanden
Diese Webseite verwendet technisch erforderliche Session-Cookies. Durch die weitere Nutzung der Webseite stimmen Sie diesem zu. Unsere Datenschutzerklärung finden Sie hier.