TABLE OF CONTENTS Solid freeform fabrication (SFF) refers to a category of manufacturing processes in which parts are built by depositing one cross-sectional layer of material on top of the next. It is very much like "printing" a succession of slice images one on top of the next so that thickness is gradually built up (Fig. 10.1). Owing to the fact that material is deposited in thin cross-sectional layers, there are typically no concerns about tool collisions, parting lines, undercuts, etc. It is a toolless and fixtureless approach to making parts. Fabricating highly complex geometric shapes via layered manufacturing processes therefore is no more difficult than fabricating simple geometric shapes such as cubes or cylinders. This is evident in Fig. 10.2, which shows a very impressive geometric sculpture designed by artist Bathsheba Grossman (www.bathsheba.com). The sculpture was fabricated using ProMeta's Direct Metal Printing process.
Rapid prototyping (RP) and rapid manufacturing (RM) are terms that typically are associated with SFF. In both cases, the parts being fabricated are built layer by layer. The distinction lies simply with the end use of the part being produced. RP produces parts that will be used as part of the iterative design process. RM produces a functional end item to be delivered and used by the customer. Note that the end item can be a steel mold or die if the customer is a molding, casting,...
