DESIGN, ASSEMBLY AND CHARACTERIZATION OF COMPOSITE ...

1.1. Motivation
CHAPTER 1 INTRODUCTION
Solid freeform fabrication (SFF) refers to the collection of techniques that build
solid objects directly from computer aided designs to near net shape through "stacking"
of build materials layer-by-layer on the micrometer to millimeter scale. SFF is most often
used either for rapid production of prototypes or for low throughput, small volume, but
high value-added parts that are either uneconomical or impossible to fabricate by other
methods. The insight gained by holding a three-dimensional prototype produced by SFF
is often enough to justify the relatively high production cost. Recent trends in direct SFF
production of high value, functional devices can also drive the use of SFF methods. A
broad spectrum of build materials are available in SFF, including high strength alloys, 1-3
performance plastics, 4 and functional ceramics. 5, 6 These materials combined with the
SFF approach also promise novel structures and functions in the form of composites.
To date, functionally graded or composite parts are rare. Fabrication of functional
composites, especially ceramic-metal composites face several technical hurdles to
become feasible, however, progress has been made toward composites in several of the
SFF areas. Techniques such as Selective Laser Sintering (SLS) 2 and Electron Beam
Melting (EBM) 1 may directly fuse ceramic and metal particles, but have lacked the
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