Freeform Fabrication of Non-Metallic Objects by Selective Laser Sintering and Infiltration
Silicon infiltrated silicon carbide parts have been manufactured using selective laser sintering (SLS). The processing route has been defined, including post-processing steps: formation of a green part from silicon carbide powder using a phenolic binder, infiltration with a transient epoxy binder, dissociation of the binders thermally to create a brown part, heating the brown part to the infiltration temperature and infiltrating with molten silicon. A dimensional analysis study was performed. Cubes 25.4 mm on each side were selective laser sintered and measured after each processing step. The largest dilatation (volume strain), 7.3%, was associated with creation of the green part relative to the computer solid model. The smallest dilatation, -6%, was associated with binder dissociation shrinkage. These volume strains nominally offset, resulting in creation of nonmetallic parts with small dimensional errors relative to the computer solid model. This research was funded by the National Science Foundation under grant award DMI-0522176.
Young Won Chang, Nack J. Kim and Chong Soo Lee
B.Y. Stevinson et al., "Freeform Fabrication of Non-Metallic Objects by Selective Laser Sintering and Infiltration", Materials Science Forum, Vols. 561-565, pp. 817-820, 2007