Understanding the behavior of laser surface remelting after directed energy deposition additive manufacturing through comparing the use of iron and Inconel powdersShow others and affiliations
2021 (English)In: Journal of Manufacturing Processes, ISSN 1526-6125, Vol. 70, p. 494-507Article in journal (Refereed) Published
Abstract [en]
Laser directed energy deposition with powder (pDED-L) is one of the most popular techniques for additive manufacturing. However, for some applications, the resulting surface finish requires post-processing machining. Laser remelting processing has been cited as a means of decreasing machining needs in other applications. The objective of this study was to assess the performance and gain a better physical understanding of the laser remelting process as an alternative to the conventional post-processing techniques applied after pDED-L. pDED-L and remelting were performed using a 10 kW fiber laser source and iron and Inconel 625 powders as feedstock to compare the surface roughness and waviness under different processing conditions (three heat input levels). Through 2D and 3D surface measurements, as well as scanning electron microscopy (SEM), surface features were qualified and quantified. SEM and optical microscopy (OM) were also employed for metallurgical characterization of the roughness. The surface micro-notch effect was assessed through the stress concentration factor (kt). The results indicated attenuation of the average roughness (Ra) by around 30% for iron and 70% for Inconel when laser remelting was employed. In addition, kt presented a 31% reduction for iron and 29% reduction for Inconel. The performance varied according to the type of material used and was mainly related to differences in thermal diffusivity and electrical resistivity. It was concluded that laser remelting is a promising technology for coupling with pDED-L aimed at producing 3D metal components with superior quality while allowing a faster production rate in comparison to current practices.
Place, publisher, year, edition, pages
2021. Vol. 70, p. 494-507
Keywords [en]
3D printers; Additives; Deposition; Fiber lasers; Iron; Laser heating; Scanning electron microscopy; Stress concentration, % reductions; Directed energy; Energy depositions; Inconel; Laser metal deposition; Laser re-melting; Laser surface remelting; Performance; Surface finishes, Surface roughness
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
URN: urn:nbn:se:hv:diva-17468DOI: 10.1016/j.jmapro.2021.08.061ISI: 000696728400003Scopus ID: 2-s2.0-85114661594OAI: oai:DiVA.org:hv-17468DiVA, id: diva2:1595639
2021-09-202021-09-202022-03-31Bibliographically approved