A Parametric Optimization of Selective Laser Sintering Process to Increase Process Efficiency

Abstract

Selective laser sintering (SLS) is a powder-based layer-additive manufacturing process generally meant for rapid prototyping and rapid tooling. Laser beams either in continuous or pulse mode are used as a heat source for scanning and joining powders in predetermined sizes and shapes of layers. The geometry of the scanned layers corresponds to the various cross sections of the computer-aided design (CAD) models or stereo lithography (STL) files of the object. Selective laser sintering has been used to make models for design testing, patterns for investment casting, and small lots of functional parts. But with SLS, it is sometimes difficult to achieve the best quality in appearance with the best mechanical properties and it is time consuming and inefficient too. So, it is important to obtain a better understanding of the relationship between powder properties, fabrication parameters in the SLS process, and the parts produced using this process. So, this thesis aims to find the optimum quality and better efficiency by setting these parameters differently according to powder properties and requirements of application. It is therefore required to optimize the relationship between the fabrication parameters and powder properties. This thesis aims to relate fabrication parameters with powder properties and they are: laser power ratio, layer thickness, grain size etc. In this thesis, optimization tool has been used to obtain suitable fabrication parameters to satisfy the demands of specific applications. Finally, the research direction is therefore a means of balancing in-process parameters with post-process parameters in order to meet the requirements for good overall quality components and better efficiency with minimum time and effort.