Analysis on the Effect of Energy Density on Mechanical Properties of Selective Laser Sintering Processed Polyamide-12

Additive manufacturing (AM) is now considered a reasonable alternative for fabricating polymer parts with sufficient strength, dimensional accuracy and surface quality, able to be used in demanding engineering applications. Selective Laser Sintering (SLS) is one of the most popular AM techniques for polymers able to produce complex geometries with acceptable quality. However, in order to meet the necessary requirements, process parameters need to be controlled. Thus, in the present study the effect of Volumetric Energy Density (VED) on mechanical properties of Polyamide-12 (PA12) specimens is investigated with a view to determine the necessary conditions for improved strength of produced parts. After comprehensive analysis of the results via statistical methods was carried out, it was found that increased VED leads generally to improved mechanical properties and that in most cases regarding Young’s Modulus and Ultimate Tensile Strength (UTS) laser power causes even higher mechanical properties, suggesting that concerning the mechanical properties the most preferable combination of process parameters is the 26 W laser power and 0.9 J/mm3 VED. On the other hand, the in-between VEDs of 0.5 and 0.7 J/mm3 tend to have lower Coefficient of Variation implying a higher degree of repeatability for the process.