SFF - Solid Freeform Fabrication

The objective of this project is the development of a generalized solid modeling method for SFF that permits the use of functionally gradient materials (FGM). This capability does not exist in today’s CAD systems. One of the prominent potential benefits offered by SFF technology is the ability to create parts with compositional variation. Such local composition control (LCC) has the potential to create new classes of components, such as monolithic components that integrate the functions of multiple discrete components. Among the SFF processes, three-dimensional printing (3DP), developed by Professors Sachs and Cima, is particularly well suited to the fabrication of parts with LCC. Three-dimensional printing creates parts by spreading powder and then ink-jet printing a “binder” material into the powder bed to define the component. This process can be extended to the fabrication of LCC components by printing different materials in different locations, each through its own ink-jet nozzle or nozzles. This is analogous to color ink-jet printing except that instead of controlling color on a two-dimensional sheet, control over physical composition is effected in three dimensions. Such local composition “construction” has been demonstrated with the “printing” of ceramic parts possessing local toughness. The current thrusts for this work are to identify globally useful design methods, develop an appropriate representation and apply these methods to particular examples.