Effect of post-processes on the microstructure and mechanical properties of laser powder bed fused IN718 superalloy
2021 (English)In: Additive Manufacturing, ISSN 2214-8604, E-ISSN 2214-7810, Vol. 48, article id 102416Article in journal (Refereed) Published
Abstract [en]
The post-processing on the additively manufactured component is of huge interest as the key to tailor the microstructure to obtain certain mechanical properties. In this present study, the effects of hot isostatic pressing, as well as heat treatment on the microstructure, phase configuration and mechanical properties of laser powder bed fused (LPBF) IN718 superalloy were systematically investigated. Three different post-processes were studied such as hot isostatic pressing (HIP), heat treatment (HT), and HIP followed by HT (HIP+HT). The HIP process effectively eliminated the Laves phase remained in the as-built microstructure and brought uniformly distributed super fine γ″ precipitates in nano-meter size. In the heat-treated microstructure, larger γ″ precipitates were promoted directly from the as-built material. In comparison the HIP+HT process caused a moderate growth of γ″. In the latter two cases, the developed γ″ significantly strengthened the material. Yield strength of IN718 was increased from 738 MPa in as-built condition to 1015 MPa and 1184 MPa after HT and HIP+HT, respectively. On the contrary the ductility in the as-built IN718 condition was reduced by more than 40% after HT and HIP+HT. This can be compared to an increase in the ductility by almost 30% when subjected the as-built specimens to only HIPping. Finally, the correlation between microstructure evolution and mechanical properties is discussed in detail. © 2021 The Authors
Place, publisher, year, edition, pages
Elsevier B.V. , 2021. Vol. 48, article id 102416
Keywords [en]
Heat treatments, Hot isostatic pressing (HIP), IN718 superalloy, Laser powder bed fusion (LPBF), Mechanical properties, TEM characterization, Ductility, Microstructure, Sintering, Superalloys, Condition, Hot isostatic pressing, Hot-isostatic pressings, Laser powder bed fusion, Laser powders, Post process, Powder bed, γ' precipitates
National Category
Manufacturing, Surface and Joining Technology
Identifiers
URN: urn:nbn:se:ri:diva-56910DOI: 10.1016/j.addma.2021.102416Scopus ID: 2-s2.0-85117883933OAI: oai:DiVA.org:ri-56910DiVA, id: diva2:1613623
Note
Funding details: 2017-05200; Funding text 1: RISE IVF AB is acknowledged for the research funding as well as the Additive Manufacturing Research Laboratory at RISE IVF, who provided support regarding printing of the laser powder bed fusion specimens. Lighter Academy (Vinnova 2017-05200) is acknowledged for financial support during this project. The authors would like to thank H?gan?s AB for providing the powder material for this study. Sigurd Berg at H?gan?s AB is acknowledged for the valuable discussions. The authors are grateful to Bj?rn Bergwall for the experimental assistance.; Funding text 2: RISE IVF AB is acknowledged for the research funding as well as the Additive Manufacturing Research Laboratory at RISE IVF , who provided support regarding printing of the laser powder bed fusion specimens. Lighter Academy ( Vinnova 2017-05200 ) is acknowledged for financial support during this project. The authors would like to thank Höganäs AB for providing the powder material for this study. Sigurd Berg at Höganäs AB is acknowledged for the valuable discussions. The authors are grateful to Björn Bergwall for the experimental assistance.
2021-11-232021-11-232023-06-08Bibliographically approved