Desk-Top Selected Laser Sintering of Stereometric Shapes

Abstract

Solid Freeform Fabrication (SFF) in manufacturing is a rapidly developing technology. The University of Connecticut has a special research position in the development of both CO2 and diode laser based technologies for SFF. Usually, the SFF technologies refer to the fabrication of physical parts directly from computer based solid models described by STL (STereo Lithography) or VRML (Virtual Reality Modeling Language) files generated by Computer-Aided Design (CAD) systems. Most SFF processes produce parts by building each consecutive layer using a row by row pattern, though it is possible to build the part using other patterns. The SFF technology represents a larger than average challenge to designers who, besides making decisions concerning optimum shape and functionality of the entire part, have to take into consideration several other manufacturing factors. These factors can be divided into two groups. The first group depends on design for manufacturing, Computer-Aided Design model generation, and part description files, as well as model slicing, precision of part design, and shape of the part. The second group is made up of factors that depend on fabrication technology i.e. laser path files, and the orientation of residual stress phenomena.