Material properties: Selective laser sintering of PA12/HDPE blends: Effect of components on elastic/plastic behavior

The use of polymeric blends can increase the range of structures and properties of selective laser sintering (SLS) parts. This study investigates the processing of blends of polyamide 12 (PA12) and high-density polyethylene (HDPE) by SLS using a CO2 laser. Mixture composition, processing conditions and their influence on the dynamic-mechanical properties of the specimens manufactured were evaluated. As expected, the average value for the elastic modulus of PA12 was higher than that for the HDPE specimens. The low values of ultimate strength obtained for PA12/HDPE 80/20 and 50/50 specimens indicate the low chemical affinity between the PA12 and the HDPE domains. The microstructures of the PA12/HDPE blend specimens were heterogeneous with co-continuous and disperse phases depending on the quantity of HDPE. The higher ultimate strength of PA12/HDPE 20/80 is due to the greater HDPE content in the blend, which provides higher toughness. The creep and fatigue behavior also changed as a function of the component quantities.