This report is a review of materials used in additive manufacturing technique otherwise known as Solid Freeform Fabrication (SFF), this approach has resided largely in the prototyping realm, where the methods of producing complex freeform solid objects directly from a computer model without part- specific tooling or knowledge started. But these technologies are evolving steadily and are beginning now to encompass related systems of material addition, assembly, and insertion of components made by other processes. Furthermore, these various additive processes are starting to evolve into rapid manufacturing techniques for mass-customized products, away from narrowly defined rapid prototyping. Specific examples include: laser sintering of powders, direct metal deposition(See Fig 1) and laser fusion of powders, and ink jet printing techniques. Truly integrated layer- by-layer additive processes under development are limited. Materials requirements for SFF include the ability to produce the feedstock in a form amenable to the specific SFF process, suitable processing of the material by SFF, capability to be acceptably post- processed to enhance geometry and properties, and manifestation of necessary performance characteristics in service. As SFF has matured, septic classes of material have become associated with septic SFF processes and applications.

Keywords : Prototyping, Free Form Fabrication, Materials.