| In 1993, the University of Louisville installed a DTM Sinterstation rapid prototyping (RP) system at its Rapid Prototyping Facility (RPF). The system was to provide local and regional industries with a solution to their prototyping needs, and its students with a competitive edge in design for product development. This system is based on an RP technology called the Selective Laser Sintering (SLS) process, and presented designers and manufacturers with expanded possibilities and ease in their model-making capabilities.; However, several problems were noted in parts made with the Sinterstation. The most important problem that SLS users have encountered is manifested in the form of inaccuracy and low quality caused by material distortion. The early batches of parts produced using the SLS system exhibited shrinkage, dimensional growth and curl.; This study found that the depth at which a part is built inside the part cylinder, the radial distances from the centerline of the part cylinder, and the angular orientations of the part with respect to the laser travel are factors that have significant effects on the dimensional accuracy of SLS parts. More important, the data helped determine that the location effects are only by-products of thermal imbalances existing in the part cylinder at various stages of an SLS production cycle. (Abstract shortened by UMI.)... |
