Optimization of SLS Process Parameters Using D-Optimality

Solid Freeform Fabrication (SFF) refers to a group of processes that manufacture parts of arbitrarily complex geometry without tooling. Currently, the operation of most SFF machines requires skilled operators with expertise in choosing process parameters in ordered to achieve the desired part quality. Thus, the “push-button 3D hardcopy” promise of SFF has yet to be realized. This paper presents a framework for selecting optimal process parameter values automatically for the selective laser sintering (SLS) process. The research described considered five process parameters that are important for the SLS process. To achieve quality measures from the five process parameters, optimization is inevitable. The method optimizes these process parameters of SLS with respect to a set of desired quality measures, based on user input of the relative importance of each of the quality measures. The basis for the framework is the so-called Doptimality criterion applied to a series of factorial experiments that capture empirically the relationships between the process parameters and part quality measures. The framework is implemented in MINITAB™ and a macro is used to perform the optimization.