Negative Additive Manufacturing of Complex Shaped Boron Carbides

Journal Article · Tue Sep 18 04:00:00 EDT 2018 · Journal of Visualized Experiments

DOI:https://doi.org/10.3791/58438· OSTI ID:1491640

Lu, Ryan ^[1]; Miller, Dorothy J. ^[1]; Du Frane, Wyatt L. ^[1]; Chandrasekaran, Swetha ^[1]; Landingham, Richard L. ^[1]; Worsley, Marcus A. ^[1]; Kuntz, Joshua D. ^[1]

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1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Boron carbide (B₄C) is one of the hardest materials in existence. However, this attractive property also limits its machineability into complex shapes for high wear, high hardness, and lightweight material applications such as armors. To overcome this challenge, negative additive manufacturing (AM) is employed to produce complex geometries of boron carbides at various length scales. Negative AM first involves gelcasting a suspension into a 3D-printed plastic mold. The mold is then dissolved away, leaving behind a green body as a negative copy. Resorcinol-formaldehyde (RF) is used as a novel gelling agent because unlike traditional hydrogels, there is little to no shrinkage, which allows for extremely complex molds to be used. Furthermore, this gelling agent can be pyrolyzed to leave behind ~50 wt% carbon, which is a highly effective sintering aid for B₄C. Due to this highly homogenous distribution of in situ carbon within the B₄C matrix, less than 2% porosity can be achieved after sintering. This protocol highlights in detail the methodology for creating near fully dense boron carbide parts with highly complex geometries.

• Research Organization: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: AC52-07NA27344
• OSTI ID: 1491640
• Report Number(s): LLNL-JRNL--750634; 935230
• Journal Information: Journal of Visualized Experiments, Journal Name: Journal of Visualized Experiments Vol. 139; ISSN 1940-087X; ISSN JVEOA4
• Publisher: MyJoVE Corp.
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE