Can Appropriate Thermal Post-Treatment Make Defect Content in as-Built Electron Beam Additively Manufactured Alloy 718 Irrelevant?
Journal article, 2020

Electron beam melting (EBM) is gaining rapid popularity for production of complex customized parts. For strategic applications involving materials like superalloys (e.g., Alloy 718), post-treatments including hot isostatic pressing (HIPing) to eliminate defects, and solutionizing and aging to achieve the desired phase constitution are often practiced. The present study specifically explores the ability of the combination of the above post-treatments to render the as-built defect content in EBM Alloy 718 irrelevant. Results show that HIPing can reduce defect content from as high as 17% in as-built samples (intentionally generated employing increased processing speeds in this illustrative proof-of-concept study) to <0.3%, with the small amount of remnant defects being mainly associated with oxide inclusions. The subsequent solution and aging treatments are also found to yield virtually identical phase distribution and hardness values in samples with vastly varying as-built defect contents. This can have considerable implications in contributing to minimizing elaborate process optimization efforts as well as slightly enhancing production speeds to promote industrialization of EBM for applications that demand the above post-treatments.

alloy 718

post-treatment

hardness

microstructure

defects

additive manufacturing

electron beam melting

hot isostatic pressing

Author

Sneha Goel

University West

Kévin Bourreau

University of Limoges

Jonas Olsson

University West

Uta Klement

Chalmers, Industrial and Materials Science, Materials and manufacture

Shrikant Joshi

University West

Materials

19961944 (eISSN)

Vol. 13 3 536

Areas of Advance

Production

Materials Science

Subject Categories

Manufacturing, Surface and Joining Technology

Other Materials Engineering

Metallurgy and Metallic Materials

DOI

10.3390/ma13030536

PubMed

31979203

More information

Latest update

6/16/2020