Zitieren Sie bitte immer diesen URN: urn:nbn:de:kobv:b43-629289
Laser powder bed fusion: Defect type influences critical porosity re-growth during reheating after hot isostatic pressing
- Despite the remarkable product design flexibility offered by additive manufacturing (AM) techniques, such as laser powder bed fusion, AM processes are susceptible to the formation of defects. In this context, the control of process parameters and the application of post-processing treatments, such as hot isostatic pressing (HIP), are of paramount importance to achieve the desired mechanical properties. The present study investigates the effectiveness of HIP as a function of process parameters in laser powder bed fused Ti-6V-4Al (PBF-LB/Ti64) using X-ray computed tomography. The process parameters are modified to obtain reference samples with low porosity, lack of fusion defects, or keyhole porosity. In all instances, subsurface keyhole porosity was observed in the as-built parts. Moreover, it was found that the efficacy of pore closure is dependent on the specific defect type. In the case of low porosity and keyhole pores, HIP resulted in effective closure. Conversely, larger lack ofDespite the remarkable product design flexibility offered by additive manufacturing (AM) techniques, such as laser powder bed fusion, AM processes are susceptible to the formation of defects. In this context, the control of process parameters and the application of post-processing treatments, such as hot isostatic pressing (HIP), are of paramount importance to achieve the desired mechanical properties. The present study investigates the effectiveness of HIP as a function of process parameters in laser powder bed fused Ti-6V-4Al (PBF-LB/Ti64) using X-ray computed tomography. The process parameters are modified to obtain reference samples with low porosity, lack of fusion defects, or keyhole porosity. In all instances, subsurface keyhole porosity was observed in the as-built parts. Moreover, it was found that the efficacy of pore closure is dependent on the specific defect type. In the case of low porosity and keyhole pores, HIP resulted in effective closure. Conversely, larger lack of fusion defects were not closed due to their interconnectivity and the entrapment of argon gas. Subsequent heat treatments above the β-transus temperature allowed the investigation of the impact of defect type on porosity re-growth. For the first time, we reveal that lack of fusion defects are affected by considerable pore re-growth during post-HIP heat treatments of PBF-LB/Ti64. Such phenomenon is driven by the increasing internal pore pressure and local creep deformation at high temperatures. In contrast, re-growth is limited in samples with low porosity or keyhole pores.…


| Autor*innen: | Jakob SchröderORCiD, Tobias FritschORCiD, Bruno FerrariORCiD, Mika León Altmann, Giovanni BrunoORCiD, Anastasiya ToenjesORCiD |
|---|---|
| Dokumenttyp: | Zeitschriftenartikel |
| Veröffentlichungsform: | Verlagsliteratur |
| Sprache: | Englisch |
| Titel des übergeordneten Werkes (Englisch): | Journal of Materials Processing Technology |
| Jahr der Erstveröffentlichung: | 2025 |
| Organisationseinheit der BAM: | 5 Werkstofftechnik |
| 5 Werkstofftechnik / 5.1 Mikrostruktur Design und Degradation | |
| 8 Zerstörungsfreie Prüfung | |
| 8 Zerstörungsfreie Prüfung / 8.5 Röntgenbildgebung | |
| Veröffentlichende Institution: | Bundesanstalt für Materialforschung und -prüfung (BAM) |
| Verlag: | Elsevier B.V. |
| Jahrgang/Band: | 340 |
| Aufsatznummer: | 118839 |
| Erste Seite: | 1 |
| Letzte Seite: | 9 |
| DDC-Klassifikation: | Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Ingenieurwissenschaften und zugeordnete Tätigkeiten |
| Freie Schlagwörter: | Additive Manufacturing; Heat Treatment; Hot Isostatic Pressing; Laser Powder Bed Fusion; Porosity; Titanium; X-ray Computed Tomography |
| Themenfelder/Aktivitätsfelder der BAM: | Material |
| Material / Additive Fertigung | |
| DOI: | 10.1016/j.jmatprotec.2025.118839 |
| URN: | urn:nbn:de:kobv:b43-629289 |
| Verfügbarkeit des Dokuments: | Datei für die Öffentlichkeit verfügbar ("Open Access") |
| Lizenz (Deutsch): | Creative Commons - CC BY - Namensnennung 4.0 International |
| Datum der Freischaltung: | 10.04.2025 |
| Referierte Publikation: | Ja |
| Datum der Eintragung als referierte Publikation: | 05.05.2025 |
| Schriftenreihen ohne Nummerierung: | Wissenschaftliche Artikel der BAM |


