Negative Additive Manufacturing of Complex Shaped Boron Carbides.
J Vis Exp
; (139)2018 09 18.
Article
em En
| MEDLINE
| ID: mdl-30295663
ABSTRACT
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.
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1
Base de dados:
MEDLINE
Assunto principal:
Compostos de Boro
Idioma:
En
Revista:
J Vis Exp
Ano de publicação:
2018
Tipo de documento:
Article