Experimental analysis of the effectiveness of current modelling methods for SLS parameter determination

Selective Laser Sintering (SLS) is a powder-bed Additive Manufacturing process that has a large amount of potential for future growth. Historically SLS has been limited to a narrow selection of polymers, although there have been recent advances in working with composite powders, such as Alumide. One of the biggest limitations to developing new materials for sintering is the elevated risk involved in testing to determine their suitability. In recent years, models of powder behaviour have largely focused on thermal characteristics. Models such as the Sintering Window and Energy Melt Ratio demonstrate how methodologies such as Differential Scanning Calorimetry can be used to determine suitability of materials. Testing of two Nylon powders with similar physical and thermal properties reveals limitations in the models when accounting for the colour of material and therefore the absorption of laser energy. Thus, it was identified that existing models require further investigation of laser energy inputs. This paper contributes a framework upon which new models can be tested in order to characterize their effectiveness.