The microstructural characterization of PA6/PA12 blend specimens fabricated by selective laser sintering

This study investigates the processing of blends of polyamide 6 (PA6) and polyamide 12 (PA12) by selective laser sintering (SLS) using a CO2 laser. Powder properties of undiluted polymers, mixture composition, and processing parameters, as well as their influence on the microstructure of the specimens manufactured, were evaluated. Polyamides showed higher absorption of laser energy during the sintering of blend specimens, with subsequent thermal energy transfer to the melting of the polymeric phases. The structure of parts obtained by SLS is dependent on the process parameters and the characteristics of the powder material to be processed. The microstructures of PA6/PA12 blend specimens were heterogeneous, with co-continuous and disperse phases depending on the quantity of PA12. The porosity and crystallinity also changed as a function of the component proportions. The use of polymeric blends can increase the range of structures and properties of SLS parts. (C) 2009 Published by Elsevier Ltd.