Nanophase materials in solid freeform fabrication

Solid freeform fabrication (SFF) is a manufacturing technology that produces parts directly from computer-aided design databases. Examples of the SFF approach are selective laser sintering (SLS) and selective laser reactive sintering (SLRS), both of which have the potential to directly produce structurally sound metallic or ceramic parts. The development of suitable materials systems that can optimize the SLS or SLRS processes are critical to this technology. For instance, nanocomposites, in which the constituents are mixed on a nanometer scale, have the potential to provide important advantages in the SLS and SLRS processes. One strategy is to design and develop nanocomposites in which one nanosize component has a lower melting point than the other nanosize component, either of which can serve as the matrix phase. The nanoscale dispersion of the low-melting component can aid the sintering process during SLS or SLRS. In this article, the philosophical basis for SLS and SLRS of nanocomposites is discussed. Conceptual design of nanocomposite systems and the SLS/SLRS results of a few exploratory systems are presented.